c/EPA
United States
Environmental Protection
Agency
National Training
and Opera'tional
Technology Center
Cincinnati OH 45268
EPA-430/1-80-005
May 1980
Water
Plankton and
Periphyton Analyses
Training Manual
-------
EPA-430/ 1-80-005
May 1980
Plankton and Periphyton Analyses
This course is offered for personnel concerned with
the evaluation of surface water by means of direct
observation and chemical and instrumental
measurements of microorganisms.
After successfully completing the course, the
student will be able to carry out basic laboratory
procedures in identification and counting; recognize
common types of organisms; calibrate a microscope;
carry counting and group identification to the point
of obtaining results which are qualitatively and
quantitatively accurate.
The training activities consists of laboratory and
classroom sessions.
U. S. ENVIRONMENTAL PROTECTION AGENCY
Office of Water Program Operations
National Training and Operational Technology Center
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DISCLAIMER
Reference to commercial products, trade names, or
manufacturers is for purposes of example and illustration.
Such references do not constitute endorsement by the
Office of Water Program Operations, U. S. Environmental
Protection Agency.
-------
CONTENTS
Title or Description
The Aquatic Environment
Classification of Communities, Ecosystems, and Trophic Levels
Limnology and Ecology of Plankton
Biology of Zooplankton Communities
Optics and the Microscope
Structure and Function of Cells
Types of Algae
Blue-Green Algae
Green and Other Pigmented Flagellates
Filamentous Green Algae
Coccoid Green Algae
Diatoms
Filamentous Bacteria
Fungi and the "Sewage Fungus" Community
Protozoa, Nematodes, and Rotifers
Activated Sludge Protozoa
Free-Living Amoebae and Nematodes
Animal Plankton
Techniques of Plankton Sampling Programs
Preparation and Enumeration of Plankton in the Laboratory
Attached Growths (Periphyton or Aufwuchs)
Determination of Plankton Productivity
Algal Growth Potential Test
Algae and Actinomycetes in Water Supplies
Algae as Indicators of Pollution
Outline Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
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Title or Description Outline Number
Odor Production by Algae and Other Organisms 26
Plankton in Oligotrophic Lakes 27
Using Benthic Biota in Water Quality Evaluation 28
Ecology Primer 29
Global Environmental Quality 30
The Effects of Pollution on Lakes 31
Application of Biological Data 32
Significance of "Limiting Factors" to Population Variation 33
Algae and Cultural Eutrophication 34
Control of Plankton in Surface Waters 35
Control of Interference Organisms in Water Supplies 36
The Biology of Pipes, Conduits, and Canals 37
San Francisco Experience with Nuisance Organisms 38
Laboratory: Identification of Diatoms 39
Preparation of Permanent Diatom Mounts 40
Laboratory: Identification of Animal Plankton 41
Laboratory: Proportional Counting of Plankton 42
Calibration and Use of Plankton Counting Equipment 43
Laboratory: Fundamentals of Quantitative Counting 44
Key to Selected Groups of Freshwater Animals 45
Key to Freshwater Algae Common in Water Supplies and 46
in Pollutated Water
A Key for the Initial Separation of Some Common Plankton Organisms 47
Classification - Finder for Names of Aquatic Organisms in 48
Water Supplies and Polluted Waters
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THE AQUATIC ENVIRONMENT
Part 1: The Nature and Behavior of Water
I INTRODUCTION
The earth is physically divisible into the
lithosphere or land masses, and the
hydrosphere which includes the oceans,
lakes, streams, and subterranean waters;
and the atmosphere.
A Upon the hydrospere are based a number
of sciences which represent different
approaches. Hydrology is the general
science of water itself with its various
special fields such as hydrography,
hydraulics, etc. These in turn merge
into physical chemistry and chemistry.
B Limnology and oceanography combine
aspects of all of these, and deal not only
with the physical liquid water and its
various naturally occurring solutions and
forms, but also with living organisms
and the infinite interactions that occur
between them and their environment.
C Water quality management, including
pollution control, thus looks to all
branches of aquatic science in efforts
to coordinate and improve man's
relationship with his aquatic environment.
II SOME FACTS ABOUT WATER
A Water is the only abundant liquid on our
planet. It has many properties most
unusual for liquids, upon which depend
most of the familiar aspects of the world
about us as we know it. (See Table 1)
TABLE 1
UNIQUE PROPERTIES OF WATER
Property
Highest heat capacity (specific heat) of any
solid or liquid (except NH^)
Significance
Stabilizes temperatures of organisms and
geographical regions
Highest latent heat of fusion (except NH )
o
Thermostatic effect at freezing point
Highest heat of evaporation of any substance
Important In heat and water transfer of
atmosphere
The only substance that has its maximum
density as a liquid (4°C)
Fresh and brackish waters have maximum
density above freezing point. This is
important in vertical circulation pattern
in lakes.
Highest surface tension of any liquid
Controls surface and drop phenomena,
important in cellular physiology
Dissolves more substances in greater
quantity than any other liquid
Makes complex biological system possible.
Important for transportation of materials
in solution.
Pure water has the highest di-electric
constant of any liquid
Leads to high dissociation of inorganic
substances In solution
Very little electrolytic dissociation
Neutral, yet contains both H+ and OH ions
Relatively transparent
Absorbs much energy in infra red and ultra
violet ranges, but little in visible range.
Hence "colorless"
BI.21g. 3.80
1-1
-------
The Aquatic Environment
B Physical Factors of Significance
1 Water substance
Water is not simply "H,,C)" but in
reality is a mixture of some 33
different substances involving three
isotopes each of hydrogen and oxygen
(ordinary hydrogen H1, deuterium H2,
and tritium H^; ordinary oxygen O ,
oxygen 17, and oxygen 18) plus 15
known types of ions. The molecules
of a water mass tend to associate
themselves as polymers rather than
to remain as discrete units.
(See Figure 1)
SUBSTANCE OF PURE WATER
TABLE 2
EFFECTS OF TEMPERATURE ON DENSITY
OF PURE WATER AND ICE*
'•) (o18 7o">1 o") (o
Temperature (°C) Density
Water Ice**
-10
- 8
- 6
- 4
- 2
0
2
4
6
8
10
20
40
60
80
100
.99815
.99869
.99912
.99945
.99970
.99987
.99997
1.00000
.99997
.99988
.99973
.99823
.99225
.98324
.97183
.95838
.9397
.9360
.9020
.9277
.9229
.9168
Figure 1
Tabular values for density, etc., represent
estimates by various workers rather than
absolute values, due to the variability of
water.
Regular ice is known as "ice I". Four or
more other "forms" of ice are known to
exist (ice II, ice III, etc.), having densities
at 1 atm. pressure ranging from 1. 1595
to 1.67. These are of extremely restricted
occurrence and may be ignored in most
routine operations.
2 Density
a Temperature and density: Ice.
Water is the only known substance
in which the solid state will float
on the liquid state. (See Table 2)
This ensures that ice usually
forms on top of a body of water
and tends to insulate the remain-
ing water mass from further loss
of heat. Did ice sink, there
could be little or no carryover of
aquatic life from season to season
in the higher latitudes. Frazil or
needle ice forms colloidally at a
few thousandths of a degree
below 0° c. It is adhesive and
may build up on submerged objects
as "anchor ice", but it is still
typical ice (ice I).
1-2
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The Aquatic Environment
1) Seasonal increase in solar
radiation annually warms
surface waters in summer
while other factors result in
winter cooling. The density
differences resulting establish
two classic layers: the epilimnion
or surface layer, and the
hypolimnion or lower layer, and
in between is the thermocline
or shear-plane.
2) While for certain theoretical
purposes a "thermocline" is
defined as a zone in which the
temperature changes one
degree centigrade for each
meter of depth, in practice,
any transitional layer between
two relatively stable masses
of water of different temper-
atures may be regarded as a
thermocline.
3) Obviously the greater the
temperature differences
between epilimnion and
hypolimnion and the sharper
the gradient in the thermocline,
the more stable will the
situation be.
4) From information given above,
it should be evident that while
the temperature of the
hypolimnion rarely drops
much below 4° C, the
epilimnion may range from
0° C upward.
5) When epilimnion and hypolimnion
achieve the same temperature,
stratification no longer exists.
The entire body of water behaves
hydrologically as a unit, and
tends to assume uniform chemical
and physical characteristics.
Even a light breeze may then
cause the entire body of water
to circulate. Such events are called
overturns, and usually result in
water quality changes of consider-
able physical, chemical, and
biological significance.
Mineral-rich water from the
hypolimnion, for example,
is mixed with oxygenated
water from the epilimnion.
This usually triggers a
sudden growth or "bloom"
of plankton organisms.
6) When stratification is present,
however, each layer behaves
relatively independently, and
significant quality differences
may develop.
7) Thermal stratification as
described above has no
reference to the size of the
water mass; it is found in
oceans and puddles.
b The relative densities of the
various isotopes of water
influence its molecular com-
position. For example, the
lighter O16 tends to go off
first in the process of evaporation,
leading to the relative enrichment
of air by O16 and the enrichment
of water by O17 and Olg. This
can lead to a measurably higher
OIQ content in warmer climates.
Also, the temperature of water
in past geologic ages can be
closely estimated from the ratio
of O^g in the carbonate of mollusc
shells.
c Dissolved and/or suspended solids
may also affect the density of
natural water masses (see Table 3)
TABLE 3
EFFECTS OF DISSOLVED SOLIDS
ON DENSITY
Dissolved Solids
(Grams per liter)
0
1
2
3
10
Density
(at 40 C)
1.00000
1.00085
1.00169
1.00251
1.00818
35 (mean for sea water)
1.02822
1-3
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The Aquatic Environment
d Types of density stratification
1) Density differences produce
stratification which may be
permanent, transient, or
seasonal.
2) Permanent stratification
exists for example where
there is a heavy mass of
brine in the deeper areas of
a basin which does not respond
to seasonal or other changing
conditions.
3) Transient stratification may
occur with the recurrent
influx of tidal water in an
estuary for example, or the
occasional influx of cold
muddy water into a deep lake
or reservoir.
4) Seasonal stratification is
typically thermal in nature,
and involves the annual
establishment of the epilimnion,
hypolimnion, and thermocline
as described above.
5) Density stratification is not
limited to two-layered systems;
three, four, or even more
layers may be encountered in
larger bodies of water.
e A "plunge line" (sometimes called
"thermal line") may develop at
the mouth of a stream. Heavier
water flowing into a lake or
reservoir plunges below the
lighter water mass of the epiliminium
to flow along at a lower level. Such
a line is usually marked by an
accumulation of floating debris.
f Stratification may be modified
or entirely suppressed in some
cases when deemed expedient, by
means of a simple air lift.
The viscosity of water is greater at
lower temperatures (see Table 4).
This is important not only in situations
involving the control of flowing water
as in a sand filter, but also since
overcoming resistance to flow gen-
erates heat, it is significant in the
heating of water by internal friction
from wave and current action.
Living organisms more easily support
themselves in the more viscous
(and also denser) cold waters of the
arctic than in the less viscous warm
waters of the tropics. (See Table 4).
TABLE 4
VISCOSITY OF WATER (In miUipoises at 1 atm)
Temp, o c
-10
- 5
0
5
10
30
100
Dissolved solids in g/L
0
26.0
21.4
17.94
15.19
13.10
8.00
2.84
5
18.1
15.3
13.2
8.1
10
18.24
15.5
13.4
8.2
30
18.7
16.0
13.8
8.6
4 Surface tension has biological as well
as physical significance. Organisms
whose body surfaces cannot be wet by
water can either ride on the surface
film or in some instances may be
"trapped" on the surface film and be
unable to re-enter the water.
5 Heat or energy
Incident solar radiation is the prime
source of energy for virtually all
organic and most inorganic processes
on earth. For the earth as a whole,
the total amount (of energy) received
annually must exactly balance that
lost by reflection and radiation into
space if climatic and related con-
ditions are to remain relatively
constant over geologic time.
1-4
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The Aquatic Environment
a For a given body of water,
immediate sources of energy
include in addition to solar
irradiation: terrestrial heat,
transformation of kinetic energy
(wave and current action) to heat,
chemical and biochemical
reactions, convection from the
atmosphere, and condensation of
water vapor.
b The proportion of light reflected
depends on the angle of incidence,
the temperature, color, and other
qualities of the water; and the
presence or absence of films
of lighter liquids such as oil.
In general, as the depth increases
arithmetically, the light tends to
decrease geometrically. Blues,
greens, and yellows tend to
penetrate most deeply while ultra
violet, violets, and orange-reds
are most quickly absorbed. On
the order of 90% of the total
illumination which penetrates the
surface film is absorbed in the
first 10 meters of even the clearest
water, thus tending to warm the
upper layers.
6 Water movements
a Waves or rhythmic movement
1) The best known are traveling
waves caused by wind. These are
effective only against objects near
the surface. They have little
effect on the movement of large
masses of water.
2) Seiches
Standing waves or seiches occur
in lakes, estuaries, and other
enclosed bodies of water, but are
seldom large enough to be
observed. An "internal wave or
seich" is an oscillation in a
submersed mass of water such
as a hypolimnion, accompanied
by compensating oscillation in the
overlying water so that no
significant change in surface
level is detected. Shifts in
submerged water masses of
this type can have severe effects
on the biota and also on human
water uses where withdrawals
are confined to a given depth.
Descriptions and analyses of
many other types and sub-types
of waves and wave-like movements
may be found in the literature.
b Tides
1) Tides are the longest waves
known, and are responsible for
the once or twice a day rythmic
rise and fall of the ocean level
on most shores around the world.
2) While part and parcel of the
same phenomenon, it is often
convenient to refer to the rise
and fall of the water level as
"tide, " and to the resulting
currents as "tidal currents. "
3) Tides are basically caused by the
attraction of the sun and moon on
water masses, large and small;
however, it is only in the oceans
and possibly certain of the larger
lakes that true tidal action has
been demonstrated. The patterns
of tidal action are enormously
complicated by local topography,
interaction with seiches, and other
factors. The literature on tides
is very large.
c Currents (except tidal currents)
are steady arythmic water movements
which have had major study only in
oceanography although they are
most often observed in rivers and
streams. They are primarily
concerned with the translocation of
water masses. They may be generated
internally by virtue of density changes,
or externally by wind or terrestrial
topography. Turbulence phenomena
or eddy currents are largely respon-
sible for lateral mixing in a current.
These are of far more importance
in the economy of a body of water than
mere laminar flow.
1-5
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The Aquatic Environment
d Coriolis force is a result of inter-
action between the rotation of the
earth, .and the movement of masses
or bodies on the earth. The net
result is a slight tendency for moving
objects to veer to the right in the
northern hemisphere, and to the
left in the southern hemisphere.
While the result in fresh waters is
usually negligible, it may be con-
siderable in marine waters. For
example, other factors permitting,
there is a tendency in estuaries for
fresh waters to move toward the
ocean faster along the right bank,
while salt tidal waters tend to
intrude farther inland along the.
left bank. Effects are even more
dramatic in the open oceans.
e Langmuire spirals (or Langmuire
circulation) are a relatively
massive cylindrical motion imparted
to surface waters under the influence
of wind. The axes of the cylinders
are parallel to the direction of the
wind, and their depth and velocity
depend on the depth of the water,
the velocity and duration of the
wind, and other factors. The net
result is that adjacent cylinders
tend to rotate in opposite directions
like meshing cog wheels. Thus
the water between two given spirals
may be meeting and sinking, while
that between spirals on either side
will be meeting and rising. Water
over the sinking, while that between
spirals on either side will be meet-
ing and rising. Water over the
sinking areas tends to accumulate
flotsam and jetsam on the surface
in long conspicuous lines.
a This phenomenon is of consider-
able importance to those sampling
for plankton (or even chemicals)
near the surface when the wind
is blowing. Grab samples from
either dance might obviously
differ considerably, and if
a plankton tow is contemplated
it should be made across the
wind in order that the net
may pass through a succession
of both dances.
WATER
RISING
WATER
SURFACE
WATER
SINKING
Figure 2. Langmuire Spirals
b. Blue dance, water rising, r. Red
dance, water sinking, floating or
swimming ofojects concentrated.
1-6
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The Aquatic Environment
b Langmuire spirals are not
usually established until the
wind has either been blowing
for an extended period, or
else is blowing rather hard.
Their presence can be detected
by the lines of foam and
other floating material which
coincide with the direction
of the wind.
6 The pH of pure water has been deter-
mined between 5. 7 and 7. 01 by various
workers. The latter value is most
widely accepted at the present time.
Natural waters of course vary widely
according to circumstances.
The elements of hydrology mentioned
above represent a selection of some of
the more conspicuous physical factors
involved in working with water quality.
Other items not specifically mentioned
include: molecular structure of waters,
interaction of water and radiation,
internal pressure, acoustical charac-
teristics, pressure-volume -temperature
relationships, refractivity, luminescence,
color, dielectrical characteristics and
phenomena, solubility, action and inter-
actions of gases, liquids and solids,
water vapor, phenomena of hydrostatics
arid hydrodynamics in general.
REFERENCES
1 Buswell, A. M. and Rodebush, W. H.
Water. Sci. Am. April 1956.
2 Dorsey, N. Ernest. Properties of
Ordinary Water - Substance.
Reinhold Publ. Corp. New York.
pp. 1-673. 1940.
3 Fowle, Frederick E. Smithsonian
Physical Tables. Smithsonian
Miscellaneous Collection, 71(1),
7th revised ed., 1929.
4 Hutcheson, George E. A Treatise on
Limnology. John Wiley Company.
1957.
1-7
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Part 2: The Aquatic Environment as an Ecosystem
I INTRODUCTION
Part 1 introduced the lithosphere and the
hydrosphere. Part 2 will deal with certain
general aspects of the biosphere, or the
sphere of life on this earth, which photo-
graphs from space have shown is a finite
globe in infinite space.
This is the habitat of man and the other
organisms. His relationships with the
aquatic biosphere are our common concern.
II THE BIOLOGICAL NATURE OF THE
WORLD WE LIVE IN
A We can only imagine what this world
must have been like before there was life.
B The world as we know it is largely shaped
by the forces of life.
1 Primitive forms of life created organic
matter and established soil.
2 Plants cover the lands and enormously
influence the forces of erosion.
3 The nature and rate of erosion affect
the redistribution of materials
(and mass) on the surface of the
earth (topographic changes).
4 Organisms tie up vast quantities of
certain chemicals, such as carbon
and oxygen.
5 Respiration of plants and animals
releases carbon dioxide to the
atmosphere in influential quantities.
6 CO affects the heat transmission of
the atmosphere.
C Organisms respond to and in turn affect
their environment. Man is one of the
most influential.
Ill ECOLOGY IS THE STUDY OF THE
INTERRELATIONSHIPS BETWEEN
ORGANISMS, AND BETWEEN ORGA-
NISMS AND THEIR ENVIRONMENT.
A The ecosystem is the basic functional
unit of ecology. Any area of nature that
includes living organisms and nonliving
substances interacting to produce an
exchange of materials between the living
and nonliving parts constitutes an
ecosystem. (Odum, 1959)
1 From a structural standpoint, it is
convenient to recognize four
constituents as composing an
ecosystem (Figure 1).
a Abiotic NUTRIENT MINERALS
which are the physical stuff of
which living protoplasm will be
synthesized.
b Autotrophic (self-nourishing) or
PRODUCER organisms. These
are largely the green plants
(holophytes), but other minor
groups must also be included
(See Figure 2). They assimilate
the nutrient minerals, by the use
of considerable energy, and combine
them into living organic substance.
c Heterotrophic (other-nourishing)
CONSUMERS (holozoic), are chiefly
the animals. They ingest (or eat)
and digest organic matter, releasing
considerable energy in the process.
d Heterotrophic REDUCERS are chiefly
bacteria and fungi that return
complex organic compounds back to
the original abiotic mineral condition,
thereby releasing the remaining
chemical energy.
2 From a functional standpoint, an
ecosystem has two parts (Figure 2)
1-9
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The Aquatic Environment
CO NSUMERS
PRO DUCERS
REDUCERS
NUTRIENT
MINERALS
FIGURE 1
B
a The autotrophic or producter
organisms, which utilize light
energy or the oxidation of in-
organic compounds as their
sole energy source.
b The heterotropic or consumer
and reducer organisms which
utilizes organic compounds for
its energy and carbon requirements.
3 Unless the autotrophic and hetero-
trophic phases of the cycle approximate
a dynamic equilibrium, the ecosystem
and the environment will change.
Each of these groups includes simple,
single-celled representatives, persisting
at lower levels on the evolutionary stems
of the higher organisms. (Figure 2)
1 These groups span the gaps between the
higher kingdoms with a multitude of
transitional forms. They are collectively
called the PROTISTA and MONERA.
These two groups can be defined on
the basis of relative complexity of
structure.
a The bacteria and blue-green algae,
lacking a nuclear membrane are
the Monera.
b The single-celled algae and
protozoa are Protista.
C Distributed throughout these groups will
be found most of the traditional "phyla"
of classic biology.
IV FUNCTIONING OF THE ECOSYSTEM
A A food chain is the transfer of food energy
from plants through a series of organisms
with repeated eating and being eaten.
Food chains are not isolated sequences but
are interconnected.
1-10
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The Aquatic Environment
RELATIONSHIPS BETWEEN FREE LIVING AQUATIC ORGANISMS
Energy Flows from Left to Right, General Evolutionary Sequence is Upward
PRODUCERS |
Organic Material Produced,
Usually by Photosynthesis I
CONSUMERS
Organic Material Ingested or
Consumed
Digested Internally
REDUCERS
Organic Material Reduced
by Extracellular Digestion
and Intracellular Metabolism
to Mineral Condition
ENERGY STORED
ENERGY RELEASED
ENERGY RELEASED
Flowering Plants and
Gymnosperms
Club Mosses, Ferns
Liverworts, Mosses
Multicellular Green
Algae
Red Algae
Brown Algae
Arachnids
Insects
Crustaceans
Segmented Worms
Molluscs
Bryozoa
Rotifers
Roundworms
Flatworms
Mammals
Birds
Reptiles
Amphibians
Fishes
Primitive
Chordates
Echinoderms
Coelenterates
Sponges
Basidiomycetes
Fungi Imperfect!
Ascomycetes
Higher Phycomycetes
DEVELOPMENT OF MULTICELLULAR OR COENOCYTIC STRUCTURE
PROTISTA
Protozoa
Unicellular Green Algae
Diatoms
Pigmented Flagellates
Amoeboid
Flagellated,
(non-pigmented)
Cilliated
Suctoria
Lower
Phycomycetes
(Chytridiales, et. al. )
DEVELOPMENT OF A NUCLEAR MEMBRANE
J
MONERA
Blue Green Algae
Phototropic Bacteria
Cheiriotropic Bacteria
Actinomycetes
Spirociiaotes
Saprophyt :c
Bacterial
Types
I I
BI. ECO. pi. 2a. 1. 69
FIGURE 2
1-11
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The Aquatic Environment
B A food web is the interlocking pattern of
food chains in an ecosystem. (Figures 3, 4)
In complex natural communities, organisms
whose food is obtained by the same number
of steps are said to belong to the same
trophic (feeding) level.
C Trophic Levels
1 First - Green plants (producers)
(Figure 5) fix biochemical energy and
synthesize basic organic substances.
This is "primary production '.
2 Second - Plant eating animals (herbivores)
depend on the producer organisms for
food.
3 Third - Primary carnivores, animals
which feed on herbivores.
4 Fourth - Secondary carnivores feed on
primary carnivores.
5 Last - Ultimate carnivores are the last
or ultimate level of consumers.
D Total Assimilation
The amount of energy which flows through
a trophic level is distributed between the
production of biomass (living substance),
and the demands of respiration (internal
energy use by living organisms) in a ratio
of approximately 1:10.
E Trophic Structure of the Ecosystem
The interaction of the food chain
phenomena (with energy loss at each
transfer) results in various communities
having definite trophic structure or energy
levels. Trophic structure may be
measured and described either in terms
of the standing crop per unit area or in
terms of energy fixed per unit area per
unit time at successive trophic levels.
Trophic structure and function can be
shown graphically by means of ecological
pyramids (Figure 5).
Figure 3 . Diagram cf the pond ecosystem. Basic units are as follows: I, abiotic substances—basic inorganic and
organic compounds; IIA, producers—rooted vegetation; IIB, producers-phytoplankton; III-1A, primary consumers
(herbivores)-bottom forms; Ill-IB, primary consumers (herbivores)— zooplankton; III-2, secondary consumers (car-
nivores); III-3, tertiary consumers (secondary carnivores); IV, decomposers-bacteria and fungi of decay.
1-12
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The Aquatic Environment
Figure 4. A MARINE ECOSYSTEM (After Clark, 1954 and Patten, 1966)
13
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The Aquatic Environment
(a)
Decomposers fl Carnivores (Secondar
M Carnivores (Primary
| | Herbivores
| Producers |
(b)
1
1 1
(c)
Pn
("UvA/// / 1
?{]// /////////
[///>/ / 1 1 1 1 1 I 1 1 1 1 1 1
///I
Figure 5. HYPOTHETICAL PYRAMIDS of
(a) Numbers of individuals, (b) Biomass, and
(c) Energy (Shading Indicates Energy Loss).
V BIOTIC COMMUNITIES
A Plankton are the macroscopic and
microscopic animals, plants, bacteria,
etc., floating free in the open water.
Many clog filters, cause tastes, odors,
and other troubles in water supplies.
Eggs and larvae of larger forms are
often present.
1 Phytoplankton are plant-like. These
are the dominant producers of the
waters, fresh and salt, "the grass
of the seas".
2 Zooplankton are animal-like.
Includes many different animal types,
range in size from minute protozoa
to gigantic marine jellyfishes.
B Periphyton (or Aufwuchs) - The communities
of microscopic organisms associated with
submerged surfaces of any type or depth.
Includes bacteria, algae, protozoa, and
other microscopic animals, and often the
young or embryonic stages of algae and
other organisms that normally grow up
to become a part of the benthos (see below).
Many planktonic types will also adhere
to surfaces as periphyton, and some
typical periphyton may break off and
be collected as plankters.
C Benthos are the plants and animals living
on, in, or closely associated with the
bottom. They include plants and
invertebrates.
D Nekton are the community of strong
aggressive swimmers of the open waters,
often called pellagic. Certain fishes,
whales, and invertebrates such as
shrimps and squids are included here.
E The marsh community is based on larger
"higher" plants, floating and emergent.
Both marine and freshwater marshes are
areas of enormous biological production.
Collectively known as "wetlands", they
bridge the gap between the waters and the
dry lands.
VI PRODUCTIVITY
A The biological resultant of all physical
and chemical factors in the quantity of
life that may actually be present. The
ability to produce this "biomass" is
often referred to as the "productivity"
of a body of water. This is neither good
nor bad per se. A water of low pro-
ductivity is a "poor" water biologically,
and also a relatively "pure" or "clean"
water; hence desirable as a water supply
or a bathing beach. A productive water
on the other hand may be a nuisance to
man or highly desirable. It is a nuisance
if foul odors and/or weed-chocked
waterways result, it is desirable if
bumper crops of bass, catfish, or
oysters are produced. Open oceans have
a low level of productivity in general.
1-14
-------
The Aquatic Environment
I PERSISTENT CHEMICALS IN THE
ENVIRONMENT
Increasingly complex manufacturing processes,
coupled with rising industrialization, create
health hazards for humans and aquatic life.
Compounds besides being toxic (acutely or
chronic) may produce mutagenic effects
including cancer, tumors, and teratogenicity
(embryo defects). Fortunately there are tests,
such as the Amis test, to screen chemical
compounds for these effects.
A Metals - current levels of cadmium, lead
and other substances constitute a mount-
ing concern. Mercury pollution, as at
Minimata, Japan has been fully documented.
B Pesticides
1 A pesticide and its metabolites may
move through an ecosystem in many
ways. Hard (pesticides which are
persistent, having a long half-life in
the environment includes the organo-
chlorines, ex., DDT) pesticides
ingested or otherwise borne by the
target species will stay in the
environment, possibly to be recycled
or concentrated further through the
natural action of food chains if the
species is eaten. Most of the volume
of pesticides do not reach their target
at all.
2 Biological magnification
Initially, low levels of persistent
pesticides in air, soil, and water may
be concentrated at every step up the
food chain. Minute aquatic organisms
and scavengers, which screen water and
bottom mud having pesticide levels of a
few parts per billion, can accumulate
levels measured in parts per million—a
thousandfold increase. The sediments
including fecal deposits are continuously
recycled by the bottom animals.
D
a Oysters, for instance, will con-
centrate DDT 70, 000 times higher
in their tissues than it's concentration
in surrounding water. They can
also partially cleanse themselves
in water free of DDT.
b Fish feeding on lower organisms
build up concentrations in their
visceral fat which may reach several
thousand parts per million and levels
in their edible flesh of hundreds of
parts per million.
c Larger animals, such as fish-eating
gulls and other birds, can further
concentrate the chemicals. A survey
on organochlorine residues in aquatic
birds in the Canadian prairie provinces
showed that California and ring-billed
gulls were among the most contaminated.
Since gulls breed in colonies, breeding
population changes can be detected and
related to levels of chemical con-
tamination. Ecological research on
colonial birds to monitor the effects
of chemical pollution on the environ-
ment is useful.
"Polychlorinated biphenyls'1 (PCB's).
PCB's were used in plasticizers, asphalt,
ink, paper, and a host of other products.
Action was taken to curtail their release
to the environment, since their effects
are similar to hard pesticides. However
this doesn't solve the problems of con-
taminated sediments and ecosystems and
final fate of the PCB's still circulating.
There are numerous other compounds
which are toxic and accumulated in the
ecosystem.
1-15
-------
The Aquatic Environment
REFERENCES 5 Odum, E.P. Fundamentals of Ecology.
W. B. Saunders Company,
1 Clarke, G. L. Elements of Ecology. Philadelphia and London. 1959.
John Wiley & Sons, New York. 1954.
6 Patten, B.C. Systems Ecology.
2 Cooke W.B. Trickling Filter Ecology. Bio-Science. 16(9). 1966.
Ecology 4
-------
Part 3. The Freshwater Environment
I INTRODUCTION
The freshwater environment as considered
herein refers to those inland waters not
detectably diluted by ocean waters, although
the lower portions of rivers are subject to
certain tidal flow effects.
Certain atypical inland waters such as saline
or alkaline lakes, springs, etc., are not
treated, as the main objective here is typical
inland water.
All waters have certain basic biological cycles
and types of interactions most of which have
already been presented, hence this outline
will concentrate on aspects essentially
peculiar to fresh inland waters.
II PRESENT WATER QUALITY AS A
FUNCTION OF THE EVOLUTION OF
FRESH WATERS
A The history of a body of water determines
its present condition. Natural waters have
evolved in the course of geologic time
into what we know today.
B Streams
In the course of their evolution, streams
in general pass through four stages of
development which may be called: birth,
youth, maturity, and old age.
These terms or conditions may be
employed or considered in two contexts:
temporal, or spatial. In terms of geologic
time, a given point in a stream may pass
through each of the stages described below
or: at any given time, these various stages
of development can be loosely identified
in successive reaches of a stream traveling
from its headwaters to base level in ocean
or major lake.
1 Establishment or birth. This
might be a "dry run" or headwater
stream-bed, before it had eroded
down to the level of ground water.
During periods of run-off after a
rain or snow-melt, such a gulley
would have a flow of water which
might range from torrential to a
mere trickle. Erosion may proceed
rapidly as there is no permanent
aquatic flora or fauna to stabilize
streambed materials. On the other
hand, terrestrial grass or forest
growth may retard erosion. When
the run-off has passed, however,
the "streambed" is dry.
2 Youthful streams. When the
streambed is eroded below the
ground water level, spring or
seepage water enters, and the
stream becomes permanent. An
aquatic flora and fauna develops
and water flows the year round.
Yout hful streams typically have a
relatively steep gradient, rocky beds,
with rapids, falls, and small pools.
3 Mature streams. Mature streams
have wide valleys, a developed
flood plain, are deeper, more
turbid, and usually have warmer
water, sand, mud, silt, or clay
bottom materials which shift with
increase in flow. In their more
favorable reaches, streams in this
condition are at a peak of biological
productivity. Gradients are moderate,
riffles or rapids are often separated
by long pools.
4 In old age, streams have approached
geologic base level, usually the
ocean. During flood stage they scour
their beds and deposit materials on
the flood plain which may be very
broad and flat. During normal flow
the channel is refilled and many
shifting bars are developed. Meanders
and ox-bow lakes are often formed.
1-17
-------
The Aquatic Environment
(Under the influence of man this
pattern may be broken up, or
temporarily interrupted. Thus an
essentially "youthful" stream might
take on some of the characteristics
of a "mature" stream following soil
erosion, organic enrichment, and
increased surface runoff. Correction
of these conditions might likewise be
followed by at least a partial reversion
to the "original" condition).
C Lakes and Reservoirs
Geological factors which significantly
affect the nature of either a stream or
lake include the following:
1 The geographical location of the
drainage basin or watershed.
2 The size and shape of the drainage
basin.
3 The general topography, i.e.,
mountainous or plains.
4 The character of the bedrocks and
soils.
5 The character, amount, annual
distribution, and rate of precipitation.
6 The natural vegetative cover of the
land is, of course, responsive to and
responsible for many of the above
factors and is also severely subject
to the whims of civilization. This
is one of the major factors determining
run-off versus soil absorption, etc.
D Lakes have a developmental history which
somewhat parallels that of streams. This
process is often referred to as natural
eutrophication.
1 The methods of formation vary greatly,
but all influence the character and
subsequent history of the lake.
In glaciated areas, for example, a
huge block of ice may have been covered
with till. The glacier retreated, the
ice melted, and the resulting hole
1-18
became a lake. Or, the glacier may
actually scoop out a hole. Landslides
may dam valleys, extinct volcanoes may
collapse, etc., etc.
2 Maturing or natural eutrophication of
lake s.
a If not already present shoal areas
are developed through erosion
and deposition of the shore material
by wave action and undertow.
b Currents produce bars across bays
and thus cut off irregular areas.
c Silt brought in by tributary streams
settles out in the quiet lake water
d Algae grow attached to surfaces,
and floating free as plankton. Dead
organic matter begins to accumulate
on the bottom.
e Rooted aquatic plants grow on
shoals and bars, and in doing so
cut off bays and contribute to the
filling of the lake.
f Dissolved carbonates and other
materials are precipitated in the
deeper portions of the lake in part
through the action of plants.
g When filling is well advanced,
mats of sphagnum moss may extend
outward from the shore. These
mats are followed by sedges and
grasses which finally convert the
lake into a marsh.
3 Extinction of lakes. After lakes reach
maturity, their progress toward
filling up is accelerated. They become
extinct through:
a The downcutting of the outlet.
b Filling with detritus eroded from
the shores or brought in by
tributary streams.
c Filling by the accumulation of the
remains of vegetable materials
growing in the lake itself.
(Often two or three processes may
act concurrently)
-------
The Aquatic Environment
III PRODUCTIVITY IN FRESH WATERS
A Fresh waters in general and under
natural conditions by definition have a
lesser supply of dissolved substances
than marine waters, and thus a lesser
basic potential for the growth of aquatic
organisms. By the same token, they
may be said to be more sensitive to the
addition of extraneous materials
(pollutants, nutrients, etc.) The
following notes are directed toward
natural geological and other environ-
mental factors as they affect the
productivity of fresh waters.
B Factors Affecting Stream Productivity
(See Table 1)
TABLE 1
EFFECT OF SUBSTRATE ON STREAM
PRODUCTIVITY*
(The productivity of sand bottoms is
taken as 1)
Bottom Material
Sand
Marl
Fine Gravel
Gravel and silt
Coarse gravel
Moss on fine gravel
Fissidens (moss) on coarse
gravel
Ranunculus (water buttercup)
Watercress
Elodea (waterweed)
Relative
Productivity
1
6
9
14
32
89
111
194
301
452
-Selected from Tarzwell 1937
To be productive of aquatic life, a
stream must provide adequate nutrients,
light, a suitable temperature, and time
for growth to take place.
1 Youthful streams, especially on rock
or sand substrates are low in essential
nutrients. Temperatures in moun-
tainous regions are usually low, and
due to the steep gradient, time for
growth is short. Although ample
light is available, growth of true
plankton is thus greatly limited.
2 As the stream flows toward a more
"mature" condition, nutrients tend to
accumulate, and gradient diminishes
and so time of flow increases, tem-
perature tends to increase, and
plankton flourish.
Should a heavy load of inert silt
develop on the other hand, the
turbidity would reduce the light
penetration and consequently the
general plankton production would
diminish.
3 As the stream approaches base level
(old age) and the time available for
plankton growth increases, the
balance between turbidity, nutrient
levels, and temperature and other
seasonal conditions, determines the
overall productivity.
C Factors Affecting the Productivity of
lakes (See Table 2)
1 The size, shape, and depth of the
lake basin. Shallow water is more
productive than deeper water since
more light will reach the bottom to
stimulate rooted plant growth. As
a corollary, lakes with more shore-
line, having more shallow water,
are in general more productive.
Broad shallow lakes and reservoirs
have the greatest production potential
(and hence should be avoided for
water supplies).
TABLE 2
EFFECT OF SUBSTRATE
ON LAKE PRODUCTIVITY *
(The productivity of sand bottoms is taken as 1)
Bottom Material
Sand
Pebbles
Clay
Flat rubble
Block rubble
Shelving rock
Relative Productivity
1
4
8
9
11
77
Selected from Tarzwell 1937
1-19
-------
The Aquatic Environment
2 Hard waters are generally more
productive than soft waters as there
are more plant nutrient minerals
available. This is often greatly in-
fluenced by the character of the soil
and rocks in the watershed and the
quality and quantity of ground water
entering the lake. In general, pH
ranges of 6. 8 to 8.2 appear to be
most productive.
3 Turbidity reduces productivity as
light penetration is reduced.
4 The presence or absence of thermal
stratification with its semi-annual
turnovers affects productivity by
distributing nutrients throughout the
water mass.
5 Climate, temperature, prevalence of
ice and snow, are also of course
important.
D Factors Affecting the Productivity of
Reservoirs
1 The productivity of reservoirs is
governed by much the same principles
as that of lakes, with the difference
that the water level is much more
under the control of man. Fluctuations
in water level can be used to de-
liberately increase or decrease
productivity. This can be demonstrated
by a comparison of the TVA reservoirs
which practice a summer drawdown
with some of those in the west where
a winter drawdown is the rule.
2 The level at which water is removed
from a reservoir is important to the
productivity of the stream below.
The hypolimnion may be anaerobic
while the epilimnion is aerobic, for
example, or the epilimnion is poor in
nutrients while the hypolimnion is
relatively rich.
3 Reservoir discharges also profoundly
affect the DO, temperature, and
turbidity in the stream below a dam.
Too much fluctuation in flow may
permit sections of the stream to dry,
or provide inadequate dilution for
toxic waste.
IV CULTURAL EUTROPHICATION
A The general processes of natural
eutrophication, or natural enrichment
and productivity have been briefly out-
lined above.
B When the activities of man speed up
these enrichment processes by intro-
ducing unnatural quantities of nutrients
(sewage, etc.) the result is often called
cultural eutrophication. This term is
often extended beyond its original usage
to include the enrichment (pollution) of
streams, estuaries, and even oceans, as
well as lakes.
V CLASSIFICATION OF LAKES AND
RESERVOIRS
A The productivity of lakes and impound-
ments is such a conspicuous feature that
it is often used as a convenient means of
classification.
\
1 Oligotrophic lakes are the younger,
less productive lakes, which are deep,
have clear water, and usually support
Salmonoid fishes in their deeper waters.
2 Eutrophic lakes are more mature,
more turbid, and richer. They are
usually shallower. They are richer
in dissolved solids; N, P, and Ca are
abundant. Plankton is abundant and
there is often a rich bottom fauna.
3 Dystrophic lakes, such as bog lakes,
are low in Ph, water yellow to brown,
dissolved solids, N, P, and Ca scanty
but humic materials abundant, bottom
fauna and plankton poor, and fish
species are limited.
B Reservoirs may also be classified as
storage, and run of the river.
1 Storage reservoirs have a large
volume in relation to their inflow.
2 Run of the river reservoirs have a
large flow-through in relation to their
storage value.
1-20
-------
The Aquatic Environment
C According to location, lakes and
reservoirs may be classified as polar,
temperate, or tropical. Differences in
climatic and geographic conditions
result in differences in their biology.
VI SUMMARY
A A body of water such as a lake, stream,
or estuary represents an intricately
balanced system in a state of dynamic
equilibrium. Modification imposed at
one point in the system automatically
results in compensatory adjustments at
associated points.
B
The more thorough our knowledge of the
entire system, the better we can judge
where to impose control measures to
achieve a desired result.
REFERENCES
1 Chamberlin, Thomas C. and Salisburg,
Rollin P. Geological Processes and
Their Results. Geology 1; pp i-xix,
and 1-654. Henry Holt and Company.
New York. 1904.
2 Hutcheson, George E. A Treatise on
Limnology Vol. I Geography, Physics
and Chemistry. 1957. Vol. II.
Introduction to Lake Biology and the
Limnoplankton. 1115 pp. 1967.
John Wiley Co.
3 Hynes, H.B.N. The Ecology of Running
Waters. Univ. Toronto Press.
555 pp. 1970.
De Santo, Robert S.
Applied Ecology.
Verlag. 1978.
Concepts of
Springer-
1-21
-------
Part 4. The Marine Environment and its Role in the Total Aquatic Environment
I INTRODUCTION
A The marine environment is arbitrarily
defined as the water mass extending
beyond the continental land masses,
including the plants and animals harbored
therein. This water mass is large and
deep, covering about 70 percent of the
earth's surface and being as deep as
7 miles. The salt content averages
about 35 parts per thousand. Life extends
to all depths.
B The general nature of the water cycle on
earth is well known. Because the largest
portion of the surface area of the earth
is covered with water, roughly 70 percent
of the earth's rainfall is on the seas.
(Figure 1)
1. THE WATER CYCLE
Since roughly one third of the
rain which falls on the land is again
recycled through the atmosphere
(see Figure 1 again), the total amount
of water washing over the earth's surface
is significantly greater than one third of
the total world rainfall. It is thus not
surprising to note that the rivers which
finally empty into the sea carry a
disproportionate burden of dissolved and
suspended solids picked up from the land.
The chemical composition of this burden
depends on the composition of the rocks
and soils through which the river flows,
the proximity of an ocean, the direction
of prevailing winds, and other factors.
This is the substance of geological erosion.
(Table 1)
TABLE 1
PERCENTAGE COMPOSITION OF THE MAJOR IONS
OF TWO STREAMS AND SEA WATER
(Data from Clark, F.W., 1924, "The Composition of River
and Lake Waters of the United States", U.S. Geol. Surv.,
Prof. Paper No. 135; Harvey, H.W., 1957, "The Chemistry
and Fertility of Sea Waters", Cambridge University Press,
Cambridge)
Ion
Na
K
Ca
Mg
Cl
S°4
C03
Delaware River
at
Lambertville, N.J.
6.70
1.46
17.49
4.81
4.23
17.49
32.95
Rio Grande
at
Laredo, Texas
14.78
.85
13.73
3.03
21.65
30. 10
11.55
Sea Water
30.4
1. 1
1. 16
3.7
55.2
7.7
<-HCO, 0.35
0
C For this presentation, the marine
environment will be (1) described using
an ecological approach, (2) characterized
ecologically by comparing it with fresh-
water and estuarine environments, and
(3) considered as a functional ecological
system (ecosystem).
E FRESHWATER, ESTUARINE,
MARINE ENVIRONMENTS
AND
Distinct differences are found in physical,
chemical, and biotic factors in going from
a freshwater to an oceanic environment.
In general, environmental factors are more
constant in freshwater (rivers) and oceanic
environments than in the highly variable
and harsh environments of estuarine and
coastal waters. (Figure 2)
A Physical and Chemical Factors
Rivers, estuaries, and oceans are
compared in Figure 2 with reference to
the relative instability (or variation) of
several important parameters. In the
oceans, it will be noted, very little change
occurs in any parameter. In rivers, while
"salinity" (usually referred to as "dissolved
solids") and temperature (accepting normal
seasonal variations) change little, the other
four parameters vary considerably. In
estuaries, they all change.
23
-------
The Aquatic Environment
Type of environment
and general direction
of water movement
Degree of instability
Salinity
Temperature
Water
elevation
Vertical
strati-
fication
Avail-
ability
of
nutrients
(degree)
Turbidity
Riverine
Oceanic
Figure 2 . RELATIVE VALUES OF VARIOUS PHYSICAL AND CHEMICAL FACTORS
FOR RIVER, ESTUARINE, AND OCEANIC ENVIRONMENTS
B Biotic Factors
1 A complex of physical and chemical
factors determine the biotic composi-
tion of an environment. In general,
the number of species in a rigorous,
highly variable environment tends to be
less than the number in a more stable
environment (Hedgpeth, 1966).
2 The dominant animal species (in
terms of total biomass) which occur
in estuaries are often transient,
spending only a part of their lives in
the estuaries. This results in better
utilization of a rich environment.
C Zones of the Sea
The nearshore environment is often
classified in relation to tide level and
water depth. The nearshore and offshore
oceanic regions together, are often
classified with reference to light penetra-
tion and water depth. (Figure 3)
1 Neritic - Relatively shallow-water
zone which extends from the high-
tide mark to the edge of the
continental shelf.
1-24
-------
The Aquatic Environment
MARINE ECOLOGY
PEL A G I C-
-OCEANIC—
€ f i f » I at I e
ApC'Ot
dOIN
Jl
////S/J'S/J'SS/J'J'SSSSm
PCLMIC
Nirilie
Octonic
Cpiptlaga
Uetopetigie
BENTHIC (BoMom)
Supro-liMorol
Litlorol (IMtrliJol)
Sublilloral
OuKi
Bolhyol
Abyliol
Hotel
U i i a p a lag it
*bSSJ'SJSSSJSSS
BENTHIC
FIGURE 3—ClassifittitioH of marine environments
a Stability of physical factors is
intermediate between estuarine
and oceanic environments.
b Phytoplankters are the dominant
producers but in some locations
attached algae are also important
as producers.
c The animal consumers are
zooplankton, nekton, and benthic
forms.
2 Oceanic - The region of the ocean
beyond the continental shelf. Divided
into three parts, all relatively
poorly populated compared to the
neritic zone.
a Euphotic zone - Waters into which
sunlight penetrates (often to the
bottom in the nsritic zone). The
zone of primary productivity often
extends to 600 feet below the surface.
1) Physical factors fluctuate
less than in the neritic zone.
2) Producers are the phyto-
plankton and consumers are
the zooplankton and nekton.
k Bathyal zone - From the bottom
of the euphotic zone to about
2000 meters.
1) Physical factors relatively
constant but light is absent.
2) Producers are absent and
consumers are scarce.
c Abyssal zone - All the sea below
the bathyal zone.
1) Physical factors more con-
stant than in bathyal zone.
2) Producers absent and consumers
even less abundant than in the
bathyal zone.
1-25
-------
The Aquatic Environment
III SEA WATER AND THE BODY FLUIDS
A Sea water is a remarkably suitable
environment for living cells, as it
contains all of the chemical elements
essential to the growth and maintenance
of plants and animals. The ratio and
often the concentration of the major
salts of sea water are strikingly similar
in the cytoplasm and body fluids of
marine organisms. This similarity is
also evident, although modified somewhat
in the body fluids of fresh water and
terrestrial animals. For example,
sterile sea water may be used in
emergencies as a substitute for blood
plasma in man.
B Since marine organisms have an internal
salt content similar to that of their
surrounding medium (isotonic condition)
osmoregulation poses no problem. On the
other hand, fresh water organisms are
hypertonic (osmotic pressure of body
fluids is higher than that of the surround-
ing water). Hence, fresh water animals
must constantly expend more energy to
keep water out (i. e., high osmotic
pressure fluids contain more salts, the
action being then to dilute this concen-
tration with more water).
1 Generally, marine invertebrates are
narrowly poikilosmotic, i.e., the salt
concentration of the body fluids changes
with that of the external medium. This
has special significance in estuarine
situations where salt concentrations
of the water often vary considerably
in short periods of time.
2 Marine bony fish (teleosts) have lower
salt content internally than the external
environment (hypotonic). In order to
prevent dehydration, water is ingested
and salts are excreted through special
cells in the gills.
IV FACTORS AFFECTING THE DISTRI-
BUTION OF MARINE AND ESTUARINE
ORGANISMS
A Salinity. Salinity is the single most
constant and controlling factor in the
marine environment, probably followed
by temperature. It ranges around
35, 000 mg. per liter, or "35 parts per
thousand" (symbol: 35%o) in the language
of the oceanographer. While variations
in the open ocean are relatively small,
salinity decreases rapidly as one
approaches shore and proceeds through
the estuary and up into fresh water with
a salinity of "0 %a (see Figure 2)
B Salinity and temperature as limiting
factors in ecological distribution.
1 Organisms differ in the salinities
and temperatures in which they
prefer to live, and in the variabilities
of these parameters which they can
tolerate. These preferences and
tolerances often change with successive
life history stages, and in turn often
dictate where the organisms live:
their "distribution."
2 These requirements or preferences
often lead to extensive migrations
of various species for breeding,
feeding, and growing stages. One
very important result of this is that
an estuarine environment is an
absolute necessity for over half of
all coastal commercial and sport
related species of fishes and invertebrates,
for either all or certain portions of their
life histories. (Part V, figure 8)
3 The Greek word roots "eury"
(meaning wide) and "steno" (meaning
narrow) are customarily combined
with such words as "haline" for salt,
and "thermal" for temperature, to
give us "euryhaline" as an adjective
to characterize an organism able to
tolerate a wide range of salinity, for
example; or "stenothermal" meaning
one which cannot stand much change
in temperature. "Meso-" is a prefix
indicating an intermediate capacity.
1-26
-------
The Aquatic Environment
C Marine, estuarine, and fresh water
organisms. (See Figure 4)
Fresh Water
Stenohal ine
Marine
Stenohaline
Salinity_
ca.35
Figure 4. Salinity Tolerance of Organisms
1 Offshore marine organisms are, in
general, both stenohaline and
stenothermal unless, as noted above,
they have certain life history require-
ments for estuarine conditions.
2 Fresh water organisms are also
stenohaline, and (except for seasonal
adaptation) meso- or stenothermal.
(Figure 2)
3 Indigenous or native estuarine species
that normally spend their entire lives
in the estuary are relatively few in
number. (See Figure 5). They are
generally meso- or euryhaline and
meso- or eurythermal.
10
15 20
Sa
25 30 35
Salinity
Figures. DISTRIBUTION OF
ORGANISMS IN AN ESTUARY
a Euryhaline, freshwater
b Indigenous, estuarine, (mesohaline)
c Euryhaline, marine
4 Some will known and interesting
examples of migratory species which
change their environmental preferences
with the life history stage include the
shrimp (mentioned above), striped bass,
many herrings and relatives, the
salmons, and many others. None are
more dramatic than the salmon hordes
which hatch in headwater streams,
migrate far out to feed and grow,
then return to the mountain stream
where they hatched to lay their own
eggs before dying.
5 Among euryhaline animals landlocked
(trapped), populations living in lowered
salinities often have a smaller maximum
size than individuals of the same species
living in more saline waters. For
example, the lamprey (Petromyzon
marinus) attains a length of 30 - 36"
in the sea, while in the Great Lakes
the length is 18 - 24".
Usually the larvae of aquatic organisms
are more sensitive to changes in
salinity than are the adults. This
characteristic both limits and dictates
the distribution and size of populations.
D The effects of tides on organisms.
1 Tidal fluctuations probably subject
the benthic or intertidal populations
to the most extreme and rapid variations
of environmental stress encountered
in any aquatic habitat. Highly specialized
communities have developed in this
zone, some adapted to the rocky surf
zones of the open coast, others to the
muddy inlets of protected estuaries.
Tidal reaches of fresh water rivers,
sandy beaches, coral reefs and
mangrove swamps in the tropics; all
have their own floras and faunas. All
must emerge and flourish when whatever
water there is rises and covers or
tears at them, all must collapse or
retract to endure drying, blazing
tropical sun, or freezing arctic ice
during the low tide interval. Such a
community is depicted in Figure 6.
1-27
-------
The Aquatic Environment
dfr
A'"' '
SNAILS
a Littorina neritoides
C> L. rudis
0 L. obtusata
Q L. littorea
RAitNACLES
* Chthamalus stellatus
® Balanus balanoides
(fy B. perforatus
, ''^Sfer -'*»
/^,V>>*
'.'.:.••;.:••••••,.•.• •-•i.»,^a fl o
'l-;''^ '•^.'•.•'.•••••"^-.•':-'--.:f'"f
M^^'a'^-'g-t&Z
^fPSS^% -
•'
Figure 6
Zonation of plants, snails, and barnacles on a rocky shore. While
this diagram is based on the situation on the southwest coast of
England, the general idea of zonation may be applied to any temper-
ate rocky ocean shore, though the species will differ. The gray
zone consists largely of lichens. At the left is the zonation of rocks
with exposure too extreme to support algae; at the right, on a less
exposed situation, the animals are mostly obscured by the algae.
Figures at the right hand margin refer to the percent of time that
the zone is exposed to the air, i. e., the time that the tide is out.
Three major zones can be recognized: the Littorina zone (above the
gray zone); the Balanoid zone (between the gray zone and the
laminarias); and the Laminaria zone. a. Pelvetia canaliculata;
b. Fucus spiralis; c. Ascophyllum nodosum; d. Fucus serratus;
e. Laminaria digitata. (Based on Stephenson)
28
-------
The Aquatic Environment
V FACTORS AFFECTING THE REFERENCES
PRODUCTIVITY OF THE MARINE
ENVIRONMENT 1 Harvey, H. W. The Chemistry and
Fertility of Sea Water (2nd Ed.).
A The sea is in continuous circulation. With- Cambridge Univ. Press, New York.
out circulation, nutrients of the ocean would 234 pp. 1957.
eventually become a part of the bottom and
biological production would cease. Generally, 2 Wickstead, John H. Marine Zooplankton
in all oceans there exists a warm surface Studies in Biology no. 62. The Institute
layer which overlies the colder water and of Biology. 1976.
forms a two-layer system of persistent
stability. Nutrient concentration is usually
greatest in the lower zone. Wherever a
mixing or disturbance of these two layers
occurs biological production is greatest.
B The estuaries are also a mixing zone of
enormous importance. Here the fertility
washed off the land is mingled with the
nutrient capacity of seawater, and many
of the would's most productive waters
result.
C When man adds his cultural contributions
of sewage, fertilizer, silt or toxic waste,
it is no wonder that the dynamic equilibrium
of the ages is rudely upset, and the
environmentalist cries, "See what man
hath wrought"!
A CKNOWLEDGEMENT:
This outline contains selected material
from other outlines prepared by C. M.
Tarzwell, Charles L. Brown, Jr.,
C. G. Gunnerson, W. Lee Trent, W. B.
Cooke, B. H. Ketchum, J. K. McNulty,
J. L. Taylor, R. M. Sinclair, and others.
1-29
-------
Part 5: Wetlands
I INTRODUCTION
A Broadly defined, wetlands are areas
which are "to wet to plough but too
thick to flow. " The soil tends to be
saturated with water, salt or fresh,
and numerous channels or ponds of
shallow or open water are common.
Due to ecological features too numerous
and variable to list here, they comprise
in general a rigorous (highly stressed)
habitat, occupied by a small relatively
specialized indigenous (native) flora
and fauna.
B
They are prodigiously productive
however, and many constitute an
absjolutely essential habitat for some
portion of the life history of animal
forms generally recognized as residents
of other habitats (Figure 8). This is
particularly true of tidal marshes as
mentioned below.
C Wetlands in toto comprise a remarkably
large proportion of the earth's surface,
and the total organic carbon bound in
their mass constitutes an enormous
sink of energy.
D Since our main concern here is with
the "aquatic" environment, primary
emphasis will be directed toward a
description of wetlands as the transitional
zone between the waters and the land, and
how their desecration by human culture
spreads degradation in both directions.
II TIDAL MARSHES AND THE ESTUARY L-rr -.^H--r=lI^Er-^=
B Estuarine pollution studies are usually
devoted to the dynamics of the circulating
water, its chemical, physical, and
biological parameters, bottom deposits, etc.
C It is easy to overlook the intimate relation-
ships which exist between the bordering
marshland, the moving waters, the tidal
flats, subtidal deposition, and seston
whether of local, oceanic, or riverine
origin.
D The tidal marsh (some inland areas also
have salt marshes) is generally considered
to be the marginal areas of estuaries and
coasts in the intertidal zone, which are
dominated by emergent vegetation. They
generally extend inland to the farthest
point reached by the spring tides, where
they merge into freshwater swamps and
marshes (Figure 1). They may range in
width from nonexistent on rocky coasts to
many kilometers.
"There is no other case in nature, save
in the coral reefs, where the adjustment
of organic relations to physical condition
is seen in such a beautiful way as the
balance between the growing marshes
and the tidal streams by which they are
at once nourished and worn away. "
(Shaler, 1886)
Figure 1. Zonatlon in a positive Now England estuary. 1. Spring tide level. 2. Mean Ugh tide,
3. Mean low tide, 4. Bog hole. 5. Ico cleavage pool, 6. Chunk of Spartina turf deposited by ice.
T, Organic ooze with associated community, 6. eolgrass (Zoatera), 9. Ribbed mussels (modiolus)-
clom (mm) - mud snail (Nassa) community. 10. Sea lettuce (Ulva)
1-31
-------
The Aquatic Environment
III MARSH ORIGINS AND STRUCTURES
A In general, marsh substrates are high in
organic content, relatively low in minerals
and trace elements. The upper layers
bound together with living roots called
turf, underlaid by more compacted peat
type material.
1 Rising or eroding coastlines may
expose peat from ancient marsh
growth to wave action which cuts
into the soft peat rapidly (Figure 2).
Such banks are likely to be cliff-like,
and are often undercut. Chunks of
peat are often found lying about on
harder substrate below high tide line.
If face of cliff is well above high water,
overlying vegetation is likely to be
typically terrestrial of the area.
Marsh type vegetation is probably
absent.
Low lying deltaic, or sinking coast-
lines, or those with low energy wave
action are likely to have active marsh
formation in progress. Sand dunes
are also common in such areas
(Figure 3). General coastal
configuration is a factor.
Figure 2. Diagrammatic section of eroding peat cliff
MHW-IB iioo >ec
0
MHW 0' 1930 ! AO
Figure 3
Development of a Massachusetts Marsh since 1300 BC, involving an
18 foot rise in water level. Shaded area indicates sand dunes. Note
meandering marsh tidal drainage. A: 1300 BC, B: 1950 AD.
1-32
-------
The Aquatic Environment
Rugged or precipitous coasts or
slowly rising coasts, typically
exhibit narrow shelves, sea cliffs,
fjords, massive beaches, and
relatively less marsh area (Figure 4).
An Alaskan fjord subject to recent
catastrophic subsidence and rapid
deposition of glacial flour shows
evidence of the recent encroachment
of saline waters in the presence of
recently buried trees and other
terrestrial vegetation, exposure
of layers of salt marsh peat along
the edges of channels, and a poorly
compacted young marsh turf developing
at the new high water level (Figure 5).
Figure 4 A River Mouth on a Slowly Rising Coast. Note absence
of deltaic development and relatively little marshland,
although mud flats stippled are extensive.
Shifting flats
o I Terrestria
Figure 5 Some general relationships in a northern fjord with a rising water level. 1. mean low
water, 2. maximum high tide, 3. Bedrock, 4. Glacial flour to depths in excess of
400 meters, 5. Shifting flats and channels, 6. Channel against bedrock, 7. Buried
terrestrial vegetation, 8. Outcroppings of salt marsh peat.
Low lying coastal plains tend to be
fringed by barrier islands, broad
estuaries and deltas, and broad
associated marshlands (Figure 3).
Deep tidal channels fan out through
innumerable branching and often
interconnecting rivulets. The
intervening grassy plains are
essentially at mean high tide level.
1-33
-------
The Aquatic Environment
Tropical and subtropical regions
such as Florida, the Gulf Coast,
and Central America, are frequented
by mangrove swamps. This unique
type of growth is able to establish
itself in shallow water and move out
into progressively deeper areas
(Figure 6). The strong deeply
embedded roots enable the mangrove
to resist considerable wave action
at times, and the tangle of roots
quickly accumulates a deep layer of
organic sediment. Mangroves
in the south may be considered to
be roughly the equivalent of the
Spartina marsh grass in the north
as a land builder. When fully
developed, a mangrove swamp is an
impenetrable thicket of roots over
the tidal flat affording shelter to an
assortment of semi-aquatic organisms
such as various molluscs and
crustaceans, and providing access
from the nearby land to predaceous
birds, reptiles, and mammals.
Mangroves are not restricted to
estuaries, but may develop out into
shallow oceanic lagoons, or upstream
into relatively fresh waters.
TROPICU. CONOCAHPUS . AWCENMA
fOBlST TRANSITION ASSOCICS SALT-MARSH ASSOOCS
RHIZOPMORA
CONiOCIES
MOOUM not
Figure 6 Diagrammatic transect of a mangrove swamp
showing transition from marine to terrestrial
habitat.
tidal marsh is the marsh grass, but very
little of it is used by man as grass.
(Table 1)
The nutritional analysis of several
marsh grasses as compared to dry land
hay is shown in Table 2.
'TABLE 1. General Orders of Magnitude of Gross Primary Productivity In Terms
of Dry Weight of Organic Matter Fixed Annually
Ecosystem
gms/M /year
((trams/ square meters/year)
Ibs/acre/year
Land deserts, deep oceans Tens
Grasslands, forests, cutrophlc Hundreds
lakes, ordinary agriculture
Estuaries, deltas, coral reefs. Thousands
Intensive agriculture (sugar
cane, rice)
Hundreds
Thousands
Ten-thousands
TABLE 2. Analyses of Some Tidal Marsh Grasses
T/A Percentage Composition
Dry Wt. Protein Fat Fiber Water
Ash
N-free Extract
Dis'ichiis spicara (pure stand, dry)
2.8 5.3 1.7 32.4 8.2 6.7 45.5
Short Spartina altcrnillora and Saficornia curopaea (in standing water)
1.2 7.7 2.5 31.1 8.8 12.0 37.7
Spartina alternillora (tall, pure stand in standing water)
3.5 7.f> 2.0 29.0 8.3 15.5 37.3
Sparfina pa":m 'pur': Mand, dry)
3.2 Ci.0 2.2 30.0 8.1 9.0 44.5
Spwiina altcrnillura and Spjrt'nu porens (mixed stand, wet)
3.4 6.8 1.9 29.11 8.1 10.4 42.8
SfMrtinj altcrniflura (short, wrt)
2.2 0.0 2.4 30.4 8.7 13.3 36.3
Comparable Analyses lor Hay
Isi r in fi.O 2.0 36.2 6.7 4.2 44.9
2nd < ill 11.0 3.7 2U.5 10.4 5.9 30.5
Analyses performed by Roland W. Gilbert, Department
of Agricultural Chemistry, U.R.I.
IV PRODUCTIVITY OF WETLANDS
A Measuring the productivity of grasslands
is not easy, because today grass is seldom
used directly as such by man. It is thus
usually expressed as production of meat,
milk, or in the case of salt marshes, the
total crop of animals that obtain food per
unit of area. The primary producer in a
1-34
-------
The Aquatic Environment
B The actual utilization of marsh grass is
accomplished primarily by its decom-
position and ingestion by micro organisms.
(Figure 7) A small quantity of seeds and
solids is consumed directly by birds.
Figure 7 The nutritive composition of
successive stages of decomposition of
Spartina marsh grass, showing increase
in protein and decrease in carbohydrate
with increasing age and decreasing size
of detritus particles.
The quantity of micro invertebrates
which thrive on this wealth of decaying
marsh has not been estimated, nor has
the actual production of small indigenous
fishes and invertebrates such as the
top minnows (Fundulus), or the mud
snails (Nassa), and others.
Many forms of oceanic life migrate
into the estuaries, especially the
marsh areas, for important portions
of their life histories as is mentioned
elsewhere (Figure 8). It has been
estimated that in excess of 60% of the
marine commercial and sport fisheries
are estuarine or marsh dependent in
some way.
EGGS
Figure 8 Diagram of the life cycle
of white shrimp (after Anderson and
Lunz 1965).
3 An effort to make an indirect
estimate of productivity in a Rhode
Island marsh was made on a single
August day by recording the numbers
and kinds of birds that fed on a
relatively small area (Figure 9).
Between 700 and 1000 wild birds of
12 species, ranging from 100 least
sandpipers to uncountable numbers
of seagulls were counted. One food
requirement estimate for three-
pound poultry in the confined inactivity
of a poultry yard is approximately one
ounce per pound of bird per day.
Greater yellow legs (left)
and black duck
Great blue heron <"
Figure Q Some Common Marsh Birds
1-35
-------
The Aquatic Environment
One-hundred black bellied plovers
at approximately ten ounces each
would weigh on the order of sixty
pounds. At the same rate of food
consumption, this would indicate
nearly four pounds of food required
for this species alone. The much
greater activity of the wild birds
would obviously greatly increase their
food requirements, as would their
relatively smaller size.
Considering the range of foods con-
sumed, the sizes of the birds, and the
fact that at certain seasons, thousands
of migrating ducks and others pause
to feed here, the enormous productivity
of such a marsh can be better under-
stood.
V INLAND BOGS AND MARSHES
A Much of what has been said of tidal
marshes also applies to inland wetlands.
As was mentioned earlier, not all inland
swamps are salt-free, any more than all
marshes affected by tidal rythms are
saline.
B The specificity of specialized floras to
particular types of wetlands is perhaps
more spectacular in freshwater wetlands
than in the marine, where Juncus,
Spartina, and Mangroves tend to dominate.
1 Sphagnum, or peat moss, is
probably one of the most widespead
and abundant wetland plants on earth.
Deevey (1958) quotes an estimate that
there is probably upwards of 223
billions (dry weight) of tons of peat
in the world 'today, derived during
recent geologic time from Sphagnum
bogs. Particularly in the northern
regions, peat moss tends to overgrow
ponds and shallow depressions, eventually
forming the vast tundra plains and
moores of the north.
2 Long lists of other bog and marsh plants
might be cited, each with its own
special requirements, topographical,
and geographic distribution, etc.
Included would be the familiar cattails,
spike rushes, cotton grasses, sedges,
trefoils, alders, and many, many
others.
C Types of inland wetlands.
1 As noted above (Cf: Figure 1)
tidal marshes often merge into
freshwater marshes and bayous.
Deltaic tidal swamps and marshes
are often saline in the seaward
portion, and fresh in the landward
areas.
2 River bottom wetlands differ from
those formed from lakes, since wide
flood plains subject to periodic
inundation are the final stages of
the erosion of river valleys, whereas
lakes in general tend to be eliminated
by the geologic processes of natural
eutrophi cation often involving
Sphagnum and peat formation.
Riverbottom marshes in the southern
United States, with favorable climates,
have luxurient growths such as the
canebrake of the lower Mississippi,
or a characteristic timber growth
such as cypress.
3 Although bird life is the most
conspicuous animal element in the
fauna (Cf: Figure 9), many mammals,
such as muskrats, beavers, otters,
and others are also marsh-oriented.
(Figure 12)
Figure 12
1-36
-------
The Aquatic Environment
VI POLLUTION
A No single statement can summarize the
effects of pollution on marshlands as
distinct from effects noted elsewhere on
other habitats.
B Reduction of Primary Productivity
The primary producers in most wetlands
are the grasses and peat mosses.
Production may be reduced or eliminated
by:
1 Changes in the water level brought
about by flooding or drainage.
a Marshland areas are sometimes
diked and flooded to produce fresh-
water ponds. This may be for
aesthetic reasons, to suppress the
growth of noxious marsh inhabitating
insects such as mosquitoes or biting
midges, to construct an industrial
waste holding pond, a thermal or a
sewage stabilization pond, a
"convenient" result of highway
causeway construction, or other
reason. The result is the elim-
ination of an area of marsh. A
small compensating border of
marsh may or may not develop.
b High tidal marshes were often
ditched and drained in former days
to stabilize the sod for salt hay or
"thatch" harvesting which was highly
sought after in colonial days. This
inevitably changed the character
of the marsh, but it remained as
essentially marshland. Conversion
to outright agricultural land has
been less widespread because of the
necessity of diking to exclude the
periodic floods or tidal incursions,
and carefully timed drainage to
eliminate excess precipitation.
Mechanical pumping of tidal marshes
has not been economical in this
country, although the success of
the Dutch and others in this regard
is well known.
2 Marsh grasses may also be eliminated
by smothering as, for example, by
deposition of dredge spoils, or the
spill or discharge of sewage sludge.
3 Considerable marsh area has been
eliminated by industrial construction
activity such as wharf and dock con-
struction, oil well construction and
operation, and the discharge of toxic
brines and other chemicals.
Consumer production (animal life) has
been drastically reduced by the deliberate
distribution of pesticides. In some cases,
this has been aimed at nearby agricultural
lands for economic crop pest control, in
other cases the marshes have been sprayed
or dusted directly to control noxious
insects.
1 The results have been universally
disastrous for the marshes, and the
benefits to the human community often
questionable.
2 Pesticides designed to kill nuisance
insects, are also toxic to other
arthropods so that in addition to the
target species, such forage staples as
the various scuds (amphipods), fiddler
crabs, and other macroinvertebrates
have either been drastically reduced
or entirely eliminated in many places.
For example, one familiar with fiddler
crabs can traverse miles of marsh
margins, still riddled with their burrows,
without seeing a single live crab.
3 DDT and related compounds have been
"eaten up the food chain" (biological
magnification effect) until fish eating
and other predatory birds such as herons
and egrets (Figure 9), have been virtually
eliminated from vast areas, and the
accumulation of DDT in man himself
is only too well known.
1-37
-------
The Aquatic Environment
D Most serious of the marsh enemies is
man himself. In his quest for "lebensraum"
near the water, he has all but killed the
water he strives to approach. Thus up to
twenty percent of the marsh--estuarine
area in various parts of the country has
already been utterly destroyed by cut and
fill real estate developments (Figures
10, 11).
E Swimming birds such as ducks, loons,
cormorants, pelicans, and many others
are severely jeopardized by floating
pollutants such as oil.
Figure 10. Diagrammatic representation of cut-and-fill for
real estate development, mlw = mean low water
Figure 11. Tracing of portion of map of a southern
city showing extent of cut-and-fill real
estate development.
1-38
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The Aquatic Environment
VII SUMMARY
A Wetlands comprise the marshes, swamps,
bogs, and tundra areas of the world.
They are essential to the well-being of
our surface waters and ground waters.
They are essential to aquatic life of
all types living in the open waters. They
are essential as habitat for all forms of
wildlife.
B The tidal marsh is the area of emergent
vegetation bordering the ocean or an
estuary.
C Marshes are highly productive areas,
essential to the maintenance of a well
rounded community of aquatic life.
D Wetlands may be destroyed by:
1 Degradation of the life forms of
which it is composed in the name of
nuisance control.
2 Physical destruction by cut-and-fill
to create more land area.
5 Morgan, J.P. Ephemeral Estuaries of
the Deltaic Environment in: Estuaries,
pp. 115-120. Publ. No. 83, Am.
Assoc. Adv. Sci. Washington, DC. 1967.
6 Odum, E.P. and Dela Crug, A. A.
Particulate Organic Detritus in a
Georgia Salt Marsh - Estuarine
Ecosystem, in: Estuaries, pp. 383-
388, Publ. No. 83, Am. Assoc. Adv.
Sci. Washington, DC. 19S7.
7 Redfield, A. C. The Ontogeny of a Salt
Marsh Estuary, in: Estuaries, pp.
108-114. Publ. No. 83, Am. Assoc.
Adv. Sci. Washington, DC. 1967.
8 Stuckey, O. H. Measuring the Productivity
of Salt Marshes. Maritimes (Grad
School of Ocean., U.R.I.) Vol. 14(1):
9-11. February 1970.
9 Williams, R.B. Compartmental
Analysis of Production and Decay
of Juncus reomerianus. Prog.
Report, Radiobiol. Lab., Beaufort, NC,
Fiscal Year 1968, USDI, BCF, pp. 10-
12.
REFERENCES
1 Anderson, W.W. The Shrimp and the
Shrimp Fishery of the Southern
United States. USDI, FWS, BCF.
Fishery Leaflet 589. 1966.
Deevey, E.S., Jr.
199(4):115-122.
Bogs. Sci. Am. Vol.
October 1958.
This outline was prepared by H. W. Jackson,
former Chief Biologist, National Training
Center, and revised by R. M. Sinclair, Aquatic
Biologist, National Training Center, MOTD,
OWPO, EPA, Cincinnati, OH 45268.
3 Emery, K. O. and Stevenson. Estuaries
and Lagoons. Part n, Biological
Aspects by J.W. Hedgepsth, pp. 693-
728. in: Treatise on Marine Ecology
and Paleoecology. Geol. Soc. Am.
Mem. 67. Washington, DC. 1957.
4 Hesse, R., W. C. Allee, and K. P.
Schmidt. Ecological Animal
Geography. John Wiley & Sons. 1937.
Descriptors: Aquatic Environment, Biological
Estuarine Environment, Lentic Environment,
Lotic Environment, Currents, Marshes,
Limnology, Magnification, Water Properties
1-39
-------
CLASSIFICATION OF COMMUNITIES, ECOSYSTEMS, AND TROPHIC LEVELS
I A COMMUNITY is an assemblage of
populations of plants, animals, bacteria,
arid fungi that live in an environmental and
interact with one another, forming together
a destinctive living system with its own
composition, structure, environmental
relations, development, and function.
II An ECOSYSTEM is a community and its
environment treated together as a functional
system of complementary relationships,
and transfer and circulation of energy and
matter. (A delightful litte essay on the
odyssey of atoms X and Y through an
ecosystem is in Leopold's, A Sand County
Almanac.)
III TROPHIC levels are a convenient means
of classify ing organisms according to
nutrition, or food and feeding. (See
Figure 1. )
A PRODUCER, the photo synthetic plant or
first organism on the food chain sequence.
Fossil fuels were produced photosynthe-
ticallyl
B Herbivore or primary CONSUMER, the
first animal which feeds on plant food.
C First carnivore or secondary CONSUMER,
an animal feeding on a plant-eating animal.
D Second carnivore or tertiary CONSUMER
feeding on the preceding.
E Tertiary carnivore.
F Quaternary carnivore.
G DECOMPOSERS OR REDUCERS, bacteria
which break down the above organisms.
Often called the middlemen or stokers of
the furnace of photosynthesis.
H Saprovores or DETRITIVORES which feed
on bacteria and/or fungi.
I Macroinvertebrates have been subdivided
into trophic levels according to feeding
habits (See Figure 1 from Cummin's).
1 Collectors strain, filter, or otherwise
collect fine particulate organic matter
from the passing current.
2 Shredders feed on leaves, detritus,
and coarse particulate organic matter.
3 Grazers feed on attached growths.
4 Predators feed on other organisms.
IV Taxonomic Groupings
A TAXOCENES, a specific group of organisms.
Ex. midges. For obvious reasons most
systematists (taxonomists) can specialize
in only one group of organisms. This fact
is difficult for the non-biologist to graspl
B Size, which is often dictated by the inves-
tigator's sampling equipment and specific
interests.
V Arbitrary due to organism habitat prefer-
ences, available sampling devices,
personal preference of the investigator,
and mesh sizes of nets and sieves.
A PLANKTON, organisms suspended in a
body of water and at the mercy of currents.
This group has been subject to numerous
divisional schemes. Plants are PHYTO-
PLANKTON, and animals, ZOOPLANKTON.
Those retained by nets are obviously, MET
PLANKTON. Those passing thru even the
finest meshed nets are NANNOPLANKTON.
B PERIPHYTON, the community of micro-
organisms which grow on submerged
objects (substrates). Literal meaning
"to grow around plants", however
standard glass microslides are sub-
mersed in the aquatic habitat to
standardize results.
C BENTHOS, is often used to mean
MACROINVERTEBRATES, although there
are benthic organisms in other plant,
animal, and protist groups. Benthic
refers strictly to the bottom substrates of
lakes, streams, and other water bodies.
BI. ECO. 25a. 3. 80
2-1
-------
Classification of Communities. Ecosystems and Trophic Levels
PRODUCERS
(PHYTOPLANKTON)
OLLECTORS
(ZOOPLANKTON)
EDATORS
•QMS
FIGURE 1
2-2
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Classification of Communities. Ecosystems and Trophic Levels
D MACROINVERTEBRATES, are animals
retained on a No. 30 mesh screen (approx-
imately 0. 5 mm) and thus visible to the
naked eye.
E MACROPHYTES, the larger aquatic plants
which are divided into emersed, floating,
and submersed communities. Usually
vascular plants but may include the larger
algae and "primitive" plants. These have
posed tremendous economic problems in
the large man-made lakes, especially
in tropical areas.
F NEKTON, in freshwater, essentially fish,
salamanders, and the larger Crustacea.
In contrast to PLANKTON, these organisms
are not at the mercy of the current.
G NEUSTON, or PLEUSTON, are inhabitants
of the surface film (meniscus organisms),
either supported by it, hanging from, or
breaking through it. Other organisms
are trapped by this neat little barrier of
nature. The micro members of this are
easily sampled by placing a clean cover
slip on top of the surface film then either
leaving it a specified time or examining
it immediately under the microscope.
H DRIFT, macroinvertebrates which drift
with the streams current either periodically
(diel or 24 hour), behaviorally, catastro-
phically or incidentally.
I BIOLOCIAL FLOGS, are suspended
microorganisms that are formed by
various means. In wastewater treatment
plants they are encouraged in concrete aer
aeration basins using diffused air or
oxygen (the heart of the activated sludge
process).
J MANIPULATED SUBSTRATE COMMUNI-
TIES. Like the preceding community,
theses are manipulated by man. Placing
artificial or natural substrates in a body
of water will cause these communities
to appear thereon.
K We will again emphasize ARBITRARY,
because organisms confound our neat
little schemes to classify them. Many
move from one community to another
for various reasons. However, all
these basic scheme do have intrinsic
value, provided they are used with
reasonl
REFERENCES
1 Cummins, Kenneth W. The Ecology
of Running Waters, Theory and
Practice in Proc. Sandusky River
Symposium. International Joint
Commission. 1975.
2 Leopold, Aldo. A Sand County Almanac.
Oxford University Press. 1966.
3 Peters, Robert Henry. The Unpredictable
Problems of Tropho-dynamics.
Env. Biol. Fish 2:97-101. 1977.
This outline was prepared by R. M. Sinclair,
Aquatic Biologist, National Training and
Operational Technology Center, MOTD,
OWPO, USEPA, Cincinnati, Ohio 45268.
Descriptors: Biological Communities
2-3
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LIMNOLOGY AND ECOLOGY OF PLANKTON
INTRODUCTION
A Most Interference Organisms are
Small.
B Small Organisms generally have
Short Life Histories.
C Populations of Organisms with
Short Life Histories may Fluctuate
Rapidly in Response to Key Environ-
mental Changes.
D Small Organisms are Relatively
at the Mercy of the Elements
E The Following Discussion will
Analyze the Nature of These Ele-
ments with Reference to the Res-
ponse of Important Organisms.
PHYSICAL FACTORS OF THE ENVIRON-
MENT
A Light is a Fundamental Source of
Energy for Life and Heat.
1 Insolation is affected by geo-
graphical location and mete-
orological factors.
2 Light penetration in water is
affected by angle of incidence
(geographical), turbidity, and
color. The proportion of light
reflected depends on the angle
of incidence, the temperature,
color, and other qualities of
the water. In general, as the
depth increases arithmetically,
the light tends to decrease geo-
metrically. Blues, greens, and
yellows tend to penetrate most
deeply while ultra violet, vio-
lets, and orange-reds are most
quickly absorbed. On the order
of 90% of the total illumination
which penetrates the surface
film is absorbed in the first
10 meters of even the clearest
water.
3 Turbidity may originate within
or outside of a lake.
a That which comes in from
outside (allochthonous) is
predominately inert solids
(tripton).
b That of internal origin (auto-
chthonous) tends to be bio-
logical in nature.
B Heat and Temperature Phenomena
are Important in Aquatic Ecology.
1 The total quantity of heat avail-
able to a body of water per year
can be calculated and is known
as the heat budget.
2 Heat is derived directly from in-
solation; also by transfer from
air, internal friction, and other
sources.
C Density Phenomena
1 Density and viscosity affect the
floatation and locomotion of
microorganisms.
a Pure fresh water achieves
its maximum density at 4 C
and its maximum viscosity
at 0°C.
b The rate of change of density
increases with the temperature.
2 Density stratification affects
aquatic life and water uses.
a In summer, a mass of warm
surface water, the epilimnion,
is usually present and separated
from a cool deeper mass, the
hypolimnion, by a relatively
thin layer known as the
thermocline.
b Ice cover and annual spring
and fall overturns are due to
successive seasonal changes
in the relative densities of
the epilimnion and the hypo-
BI. MIC. eco. 4e.3.80
3-1
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Limnology and Ecology of Plankton
limnion, profoundly influ-
enced by prevailing meteoro-
logical conditions.
The sudden exchange of
water masses having differ-
ent chemical characteris-
tics may have catastrophic
effects on certain biota, may
cause others to bloom.
D Shore development, depth, inflow -
outflow pattern, and topographic
features affect the behavior of the water.
E Water movements that may affect organ-
isms include such phenomena as waves,
currents, tides, seiches, floods, and
others.
d Silt laden waters may seek
certain levels, depending
on their own specific gravity
in relation to existing layers
already present.
e Saline waters will also
stratify according to the
relative densities of the
various layers.
3 The viscosity of water is greater
at lower temperatures.
a This is important not only
in situations involving the
control of flowing water as in
a sand filter, but also since
overcoming resistance to
flow generates heat, it is
significant in the heating
of water by internal friction
from wave and current ac-
tion and many delay the
establishment of anchor
ice under critical conditions.
Waves or rhythmic movement
a The best known are traveling
waves. These are effective
only against objects near
the surface. They have little
effect on the movement of
large masses of water.
b Standing waves or seiches
occur in all lakes but are
seldom large enough to be
observed. An "internal seich"
is an oscillation in a density
mass within a lake with no
surface manifestation may
cause considerable water
movement.
It is easier for plankton
to remain suspended in cold
viscous (and also dense)
water than in less viscous
warm water. This is re-
flected in differences in the
appearance of winter vs
summer forms of life (also
arctic vs tropical).
3-2
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Limnology and Ecology of Plankton
Currents
a Currents are arhythmic
water movements which have
had major study only in ocean-
ography. They primarily
are concerned with the trans-
location of water masses.
They may be generated inter-
nally by virtue of density
changes, or externally by
wind or runoff.
b Turbulence phenomena or
eddy currents are largely re-
sponsible for lateral mixing
in a current. These are of
far more importance in the
economy of a body of water
than mere laminar flow.
c Tides, or rather tidal
currents, are reversible
(or oscillatory) on a relative-
ly long and predictable period.
They are closely allied to
seiches. For all practical
purposes, they are restricted
to oceanic (especially coastal)
waters.
If there is no freshwater
inflow involved, tidal currents
are basically "in and out;"
if a significant amount of
freshwater is added to the
system at a constant rate, the
outflowing current will in general
exceed the inflow by the amount
of freshwater input.
There are typically two tidal
cycles per lunar day (approx-
imately 25 hours), but there is
continuous gradation from this
to only one cycle per (lunar) day
in some places.
Estuarine plankton populations
are extremely influenced by local
tidal patterns.
d Flood waters range from torren-
tial velocities which tear away
and transport vast masses of
substrate to quiet backwaters
which may inundate normally dry
land areas for extended periods
of time. In the former case,
planktonic life is flushed away
completely; in the latter, a local
plankton bloom may develop which
may be of immediate significance,
or which may serve as an inoculum
for receding waters.
F Surface Tension and the Surface Film
1 The surface film is the habitat of
the "neuston", a group of special
significance.
2 Surface tension lowered by surfactants
may eliminate the neuston. This can
be a significant biological observation.
Ill DISSOLVED SUBSTANCES
A Carbon dioxide is released by plants and
animals in respiration, but taken in by
plants in photosynthesis.
B Oxygen is the biological complement of
carbon dioxide, and necessary for all
animal life.
C Nitrogen and phosphorus are fundamental
nutrients for plant life.
1 Occur in great dilution, concentrated
by plants.
3-3
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Limnology and Ecology of Plankton
The distribution.of nitrogen
compounds is generally correlat-
ed with the oxygen curve, espe-
cially in oceans.
D Iron, manganese, sulphur, and silicon
are other minerals important to aquatic
life which exhibit biological stratification.
E Many other minerals are present but their
biological distribution in waters is less
well known, fluorine, tin, and vanadium
have recently been added to the "essential"
list, and more may well follow.
F Dissolved organic matter is present in
even the purest of lakes.
IV BIOLOGICAL FACTORS
A Nutritional Classification of Organisms
1 Holophyt ic or independent or-
ganisms, like green plants, pro-
duce their own basic food elements
from the physical environment.
2 Holozoic or dependent organisms,
like animals, ingest and digest
solid food particles of organic
origin.
3 Saprophytic or carrion eating
organisms, like many fungi and
bacteria, digest and assimilate
the dead bodies of other organ-
isms or their products.
B The Prey-Predator Relationship is
Simply one Organism Eating Another.
C Toxic and Hormonic Relationships
1 Some organisms such as certain
blue green algae and some ar-
mored flagellages produce sub-
stances poisonous to others.
2 Antibiotic action in nature is
not well understood but has been
shown to play a very influential
role in the economy of nature.
V BIOTIC COMMUNITIES (OR ECOSYSTEMS)
A A biotic community will be defined here
as an assemblage of organisms living in
a given ecological niche (as defined
below). Producer (plant-like), consumer
(animal-like) and reducer (bacteria and
fungi) organisms are usually included.
A source of energy (nutrient, food) must
also be present. The essential concept
in that each so-called community is a
relatively independent entity. Actually
this position is only tenable at any given
instant, as individuals are constantly
shifting from one community to another in
response to stages in their life cycles,
physical conditions, etc. The only one
to be considered in detail here is the
plankton.
B Plankton are the macroscopic and
microscopic animals, plants, bacteria,
etc. floating free in the open water.
Many clog filters, cause tastes, odors,
and other troubles in water supplies.
1 Those that pass through a plankton
net (No. 25 silk bolting cloth or
equivalent) or sand filter are often
known as nannoplankton (they
usually greatly exceed the "net"
plankton in actual quantity).
2 Those less than four microns in
length are sometimes called
ultraplankton.
3 There are many ways in which
plankton may be classified: taxo-
nomic, ecological, industrial.
4 The concentration of plankton varies
markedly in space and time.
a Depth, light, currents, and
water quality profoundly affect
plankton distribution.
b The relative abundance of
plankton in the various sea-
sons is generally:
1 spring,
4 winter
2 fall, 3 summer,
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Limnology and Ecology of Plankton
5 Marine plankton include many
larger animal forms than are
found in fresh waters.
C The benthic community is generally
considered to be the macroscopic life
living in or on the bottom.
D The jDeripJivton community might be
defined as the microscopic benthos,
except that they are by no means confined
to the bottom. Any surface, floating, or
not, is usually covered by film of living
organisms. There is frequent exchange
between the periphyton and plankton
communities.
E The_ngktqn is the community of larger,
free-swimming animals (fishes, shrimps,
etc.), and so is dependent on the other
communities for basic plant foods.
F Neuston or Pleuston
This community inhabits the air/water
interface, and may be suspended above
or below it or break it. Naturally this
interface is a very critical one, it being
micro molecular and allowing interchange
between atmospheric contaminants and
the water medium. Rich in bacteria,
metals, protozoa, pesticides etc.
VI THE EVOLUTION OF WATERS
A The history of a body of water determines
its present condition. Natural waters have
evolved in the course of geologic time
to what we know today.
B In the course of their evolution, streams
in general pass through four general
stages of development which may be called:
birth, youth, maturity, and old age.
1 Establishment of birth. In an
extant stream, this might be
a "dry run" or headwater
streambed, before it had eroded
down to the level of ground water.
2 Youthful streams; when *he
stream bed is eroded below the
ground water level, spring water
enters and the stream becomes
permanent.
3 Mature streams; have wide
valleys, a developed flood plain.
deeper, more turbid, and usually
warmer water, sand, mud, silt,
or clay bottom materials which
shift with increase in flow.
4 In old age, streams have approa-
ched base level. During flood
stage they scour their bed and de-
posit materials on the flood plain
which may be very broad and flat.
During normal flow the channel is
refilled and many shifting bars are
developed.
(Under the influence of man this
pattern may be broken up, or tem-
porarily interrupted. Thus as essen-
tially "youthful" stream might take
on some of the characteristics of a
"mature" stream following soil
erosion, organic enrichment, and
increased surface runoff. Correction
of these conditions might likewise be
followed by at least a partial rever-
sion to the "original" condition.)
C Lakes have a developmental history
which somewhat parallels that of streams.
1 The method of formation greatly
influences the character and sub-
sequent history of lakes.
2 Maturing or natural eutrophication
of lakes
a If not already present, shoal
areas are developed through
erosion of the shore by wave
action and undertow.
b Currents produce bars across
bays and thus cut off irregulars
areas.
c Silt brought in by tributary
streams settles out in the quiet
lake water.
d Rooted aquatics grow on shoals
and bars, and in doing so cut
off bays and contribute to the
filling of the lake.
e Dissolved carbonates and other
materials are precipitated in the
deeper portions of the lake in
part through the action of plants.
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Limnology and Ecology of Plankton
f When filling is well advanced
sphagnum mats extend out-
ward from the shore. These
mats are followed by sedges
and grasses which finally
convert the lake into a
marsh.
3 Extinction of lakes. After lakes
reach maturity their progress
toward filling up is accelerated.
They become extinct through:
a The downcutting of the out-
let.
b Filling with detritus eroded
from the shores or brought
in by tributary streams.
c Filling by the accumulation of
the remains of vegetable
materials growing in the
lake itself.
(Often two or three pro-
cesses may act concurrently)
When man hastens the above
process, it is often called
"cultural eutrophication. "
VII PRODUCTIVITY
A The biological resultant of all physical
and chemical factors is the quantity of
life that may actually be present. The
ability to produce this "biomass" is
often referred to as the "productivity"
of a body of water. This is neither good
nor bad per se. A water of low producti-
vity is a "poor" water biologically, and
also a relatively "pure" or "clean" water;
hence desirable as a water supply. A
productive water on the other hand may
be a nuisance to man or highly desirable.
Some 01 the factors which influence the
productivity of waters are as follows:
i
B Factors affecting stream productivity.
To be productive of plankton, a stream
must provide adequate nutrients, light,
a suitable temperature, and time for
growth to take place.
1 Youthful streams, especially on
rock or sand substrates are low
in essential nutrients. Tempera-
tures in mountainous regions are
usually low, and due to the steep
gradient, time for growth is short.
Although ample light is available,
growth of true plankton is thus
greatly limited.
2 As the stream flows toward a
more "mature" condition nutrients
tend to accumulate, and gradient
diminishes and so time of flow
increases, temperature tends to
increase, and plankton flourish.
Should a heavy load of inert silt
develop on the other hand, the
turbidity would reduce the light
penetration and consequently the
general plankton production would
diminish.
3 As the stream approaches base
level (old age) and the time avail-
able for plankton growth increases,
the balance between turbidity,
nutrient levels, and temperature
and other seasonal conditions,
determines the overall produc-
tivity.
Factors Affecting the Productivity
of Lakes
1 The size, shape, and depth
of the lake basin. Shallow water
is more productive than deeper
water since more light will reach
the bottom to stimulate rooted
plant growth. As a corollary,
lakes with more shoreline, having
more shallow water, are in general
more productive. Broad shallow
lakes and reservoirs have the
greatest production potential (and
hence should be avoided for water
supplies).
2 Hard waters are generally more
productive than soft waters as
there are more plant nutrient
minerals available. This is often
3-6
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FACTORS AFFECTING PRODUCTIVITY
Geographic Location
Human
Influence
Latitude
Longitude
Altitude
Geological
Formation
Topography
Composition
of Substrate
Shape of Basin
Area Bottom \ Precipitation // \ Insolation
Conformation \ ^, / / \
Drainage
Area
Sewage
Agriculture
Mining
Primary
Nutritive
Materials
Nature oŁ Inflow of —^- Trans-—^^-Lighft Heaf Penetration ^D? Penetra Develop of^*> Seasonal Cycle
Bottom ^Allochthonous parency Penetration and Stratification ^ and Littoral Circulat. Stagnation
Deposit* Materials , . / / _j^ Utilization Region Growing Season
-T?
Trophic Nature of a Lake
o
I—'
o
a
H
o
o
-------
Limnology and Ecology of Plankton
greatly influenced by the
character of the soil and rocks
in the watershed, and the quality
and quantity of ground water
entering the lake. In general,
pH ranges of 6. 8 to 8.2 appear
to be most productive.
3 Turbidity reduces productivity
as light penetration is reduced.
4 The presence or absence of
thermal stratification with its
semi-annual turnovers affect
productivity by distributing
nutrients throughout the water
mass.
5 Climate, temperature, pre-
valance of ice and snow, are
also important.
D Factors Affecting the Productivity of
Reservoirs
1 The productivity of reservoirs
is governed by much the same
principles as that of lakes, with
the difference that the water
level is much more under the
control of man. Fluctuations
in water level can be used to
deliberately increase of decrease
productivity. This can be dem-
onstrated by a comparison of
the TVA reservoirs which practice
a summer drawdown with some of
those in the west where a winter
drawdown is the rule.
2 The level at which water is re-
moved from the reservoir is also
important. The upper epilimnion
may have a high plankton turbi-
dity while lower down the plankton
count may be less, but a taste
and odor causer (such as Mallpj-
monas) may be present. There
may be two thermoclines, with
a mass of muddy water flowing
between a clear upper epilimnion
and a clear hypolimnion. Other
combinations ad infinitum may
occur.
3 Reservoir discharges also pro-
foundly affect the DO, temperature,
and turbidity in the stream below
a dam. Too much fluctuation in
flow may permit sections of the
stream to dry periodically.
VIII CLASSIFICATION OF LAKES AND
RESERVOIRS
A The productivity of lakes and impound-
ments is such a conspicuous feature
that it is often used as a means of
classification.
1
Oligotrophic lakes are the
geologically younger, less produc-
tive lakes, which are deep, have
clear water, and usually support
Salmonoid fishes.
2 Mesotropic lakes are generally
intermediate between oligotrophlc
and eutrophic lakes. They are
moderately productive, yet
pleasant to be around.
3 Jlu^oghic_lakes are more mature,
more turbid, and richer. They
are usually shallower. They are
richer in dissolved solids; N, P,
and Ca are abundant. Plankton is
abundant and there is often a
rich bottom fauna. Nuisance
conditions often appear.
4 Dystrophic lakes - bog lakes -
low in pH, water yellow to brown,
dissolved solids; N, P, and Ca
scanty but humic materials abun-
dant; bottom fauna and plankton
poor, and fish species are limited.
B Reservoirs may be classified as storage,
or run of the river.
1 Storage reservoirs have a large
volume in relation to their inflow.
2 Run of the river reservoirs have
a large flow through in relation
to their storage value.
3-8
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Limnology and Ecology of Plankton
C According to location, lakes and
reservoirs may be classified as polar,
temperate, or tropical. Differences
in climatic and geographic conditions
result in differences in their biology.
DC THE MANAGEMENT OR CONTROL OF
ENVIRONMENTAL FACTORS
A Liebig's Law of the Minimum states
that productivity is limited by the
nutrient present in the least amoung
at any given time relative to the
assimilative capacity of the organism.
B Shelford's Law of Toleration:
Minimum Limit
of toleration
Absent
Decreasing
Abundance
Range of Optimum
of factor
Greatest abundance
Maximum limit of
toleration
Decreasing
Abundance
Absent
The artificial introduction of nutrients
(sewage pollution or fertilizer) thus
tends to eliminate existing limiting
minimums for some species and create
intolerable maximums for other species.
1
Known limiting minimums may
sometimes be deliberately
maintained.
As the total available energy
supply is increased, productivity
tends to increase.
As productivity increases, the
whole character of the water
may be changed from a meagerly
productive clear water lake
(oligotrophic) to a highly pro-
ductive and usually turbid lake
(eutrophic).
Eutrophication leads to treatment
troubles.
D Control of e utrophication may be accom-
plished by various means
1 Watershed management, ade-
quate preparation of reservoir
sites, and pollution control tend
to maintain minimum limiting nu-
tritional factors.
2 Shading out the energy of insola-
tion by roofing or inert turbidity;
suppresses photosynthesis.
3 Introduction of substances toxic
to some fundamental part of the
food chain (such as copper sul-
phate) tends to temporarily inhibit
productivity.
X SUMMARY
A A body of water such as a lake rep-
resents an intricately balanced system
in a state of dynamic equilibrium.
Modification imposed at one point in
the system automatically results in
compensatory adjustments at associated
points.
B The more thorough our knowledge of
the entire system, the better we can
judge where to impose control measures
to achieve a desired result.
REFERENCES
1 Chamberlin, Thomas C., and Salisburg,
RollinP., Geology Vol. 1, "Geolo-
gical Processes and Their Results",
pp i-xix, and 1-654, Henry Holt and
Company, New York, 1904.
2 Dorsey, N. Ernest. Properties of
Ordinary Water - Substance.
Reinhold Publ. Corp., New York.
pp. 1-673. 1940.
3 Hutcheson, George E. A Treatise on
Limnology. John Wiley Company.
1957.
4 Ruttner, Franz. Fundamentals of
Limnology. University of Toronto
Press, pp. 1-242. 1953.
5 Tarzwell, Clarence M. Experimental
Evidence on the Value of Trout 1937
Stream Improvement in Michigan.
American Fisheries Society Trans.
66:177-187. 1936.
3-9
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Limnology and Ecology of Plankton
6 US DHEW. PHS. Algae and Metropolitan
Wastes, transactions of a seminar
held April 27-29, 1960 at the
Robert A. Taft Sanitary Engineer-
ing Center, Cincinnati, Ohio.
No. SEC TR W61-3.
7 Ward and Whipple. Freshwater Biology
(Introduction). John Wiley
Company. 1918.
8 Whittaker, R. H. Communities and
Ecosystems. Macmillan,
New York. 162 pp. 1970.
9 Zhadin, V. I. and Gerd, Sr. Fauna
and Flora of the lakes and
Reservoirs of the USSR. Avail-
able from the Office of Technical
Services, U. S. Dept. Commerce,
Washington, DC.
10 Josephs, Melvin and Sanders, Howard J.
Chemistry and the Environment
ACS Publications, Washington, DC.
1967.
This outline was prepared by H. W. Jackson,
former Chief Biologist, National Training
Center, and revised by R. M. Sinclair,
Aquatic Biologist, National Training Center,
MOTD, OWPO. USEPA, Cincinnati, Ohio
45268.
Descriptors: Plankton, Ecology, Limnology
3-10
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BIOLOGY OF ZOOPLANKTON COMMUNITIES
I CLASSIFICATION
A The planktonic community is composed of
organisms that are relatively independent
of the bottom to complete their life history.
They inhabit the open water of lakes
(pelagic zone). Some species have inactive
or resting stages that lie on the bottom
and carry the species through periods of
stress; e. g. , winter. A few burrow in
the mud and enter the pelagic zone at night,
but most live in the open water all the
time that the species is present in an active
form.
B Compared to the bottom fauna and flora,
the plankton consists of relatively few
kinds of organisms that are consistently
and abundantly present. Two major cat-
egories are often called phytoplankton
(plants) and zooplankton (animals), but
this is based on an outmoded classification
of living things. The modern tendency is
to identify groupings according to their
function in the ecosystem: Primary pro-
ducers (photosynthetic organisms), consumers
(zooplankton), and decomposers (hetero-
trophic bacteria and fungi).
C The primary difference then is nutritional;
phytoplankton use inorganic nutrient
elements and solar radiation. Zooplankton
feed on particles, much of which can be
phytoplankton cells, but can be bacteria or
particles of dead organisms (detritus)
originating in the plankton, the shore
region, or the land surrounding the lake.
D The swimming powers of planktonic
organisms is so limited that their hori-
zontal distribution is determined mostly
by movements of water. Some of the
animals are able to swim fast enough that
they can migrate vertically tens of meters
each day, but they are capable of little
horizontal navigation. At most, some
species of crustaceans show a general
avoidance of the shore areas during calm
weather when the water is moving more
slowly than the animals can swim. By
definition, animals that are able to control
their horizontal location are nekton, not
plankton.
E In this presentation, a .minimum of clas-
sification and taxonomy is used, but it
should be realized that each group is
typified by adaptations of structure on
physiology that are related to the plank-
tonic mode of existence. These adapta-
tions are reflected in the classification.
II FRESHWATER ZOOPLANKTON
A The freshwater zooplankton is dominated
by representatives of three groups of
animals, two of them crustaceans:
Copepoda, Cladocera, Rotifera. All have
feeding mechanisms that permit a high
degree of selectivity of food, and two can
produce resting eggs that can withstand
severe environmental conditions. In
general the food of usual zooplankton pop-
ulations ranges from bacteria and small
algae to small animals.
B The Copepoda reproduce by a normal
biparental process, and the females lay
fertilized eggs in groups which are carried
around in sacs until they hatch. The
immature animals go through an elaborate
development with many stages. The later
stages have mouthparts that permit them
to collect particles. In many cases, these
are in the form of combs which remove
small particles by a sort of filtration
process. In others, they are modified to
form grasping organs by which small
animals or large algae are captured
individually.
C The Cladocera (represented by Daphnia)
reproduce much of the time by partheno-
genesis, so that only females are present.
Eggs are held by the mother in a brood
chamber until the young are developed far
enough to fend for themselves. The newborn
animals look like miniature adults, and do
not go through an elaborate series of
developmental stages in the water as do
the copepods. Daphnia has comb-formed
filtering structures on some of its legs
that act as filters.
BI.AQ. 29. 6. 76
4-1
-------
Biology of Zooplankton Communities
Under some environmental conditions the
development of eggs is affected and males
are produced. Fertilized eggs are produced
that can resist freezing and drying, and
these carry the population through
unsatisfactory conditions.
The Rotifera are small animals with a
ciliated area on the head which creates
currents used both for locomotion and for
bringing food particles to the mouth. They
too reproduce by parthenogenesis during
much of the year, but production of males
results in fertilized, resistant resting eggs.
Most rotifers lay eggs one at a time and
carry them until they hatch.
Ill ZOOPLANKTON POPULATION DYNAMICS
A In general, zooplankton populations are at
a minimum in the cold seasons, although
some species flourish in cold water. Species
with similar food requirements seem to
reproduce at different times of the year or
are segregated in different layers of lakes.
B There is no single, simple measurement
of activity for the zooplankton as a whole
that can be used as an index of production
as can the uptake of radioactive carbon for
the phytoplankton. However, it is possible
to find the rate of reproduction of the species
that carry their eggs. The basis of the
method is that the number of eggs in a
sample taken at a given time represents
the number of animals that will be added
to the population during an interval that
is equal to the length of time it takes the
eggs to develop. Thus the potential growth
rate of the populations can be determined.
The actual growth rate, determined by
successive samplings and counting, is less
than the potential, and the difference is a
measure of the death rate.
C Such measurements of birth and death rates
permits a more penetrating analysis to be
made of the causes of population change
than if data were available for population
size alone.
D Following is an indication of the major
environmental factors in the control of
zooplankton.
1 Temperature has an obvious effect in
its general control of rates. In addition,
the production and hatching of resting
eggs may be affected.
2 Inorganic materials
Freshwater lakes vary in the content
of dissolved solids according to the
geological situation. The total salinity
and proportion of different dissolved
materials in water can affect the pop-
ulation. Some species are limited to
soft water, others to saline waters, as
the brine shrimp. The maximum pop-
ulation size developed maybe related
to salinity, but this is probably an
indirect effect working through the
abundance of nutrients and production
of food.
3 Food supply
Very strong correlations have been
found between reproduction and food
supply as measured by abundance of
phytoplankton. The rate of food supply
can affect almost all aspects of pop-
ulation biology including rate of indi-
vidual growth, time of maturity, rate
of reproduction and length of life.
4 Apparently in freshwater, dissolved
organic materials are of little nutri-
tional significance, although some
species can be kept if the concentration
of dissolved material is high enough.
Some species require definite vitamins
in the food.
5 Effect of predation on populations
The kind, quantity and relative pro-
portions of species strongly affected
by grazing by vertebrate and. inverte-
brate predators. The death rate of
Daphnia is correlated with the abun-
dance of a predator. Planktivorous
fish (alewives) selectively feed on
larger species, so a lake with alewives
is dominated by the smaller species of
crustaceans and large ones are scarce
or absent.
6 Other aspects of zooplankton
Many species migrate vertically con-
siderable distances each day. Typically,
migrating species spend the daylight
hours deep in the lake and rise toward
the surface in late afternoon and early
evening.
Some species go through a seasonal
change of form (cyclomorphosis) which
is not fully understood. It may have an
effect in reducing predation.
4-2
-------
Biology of Zooplankton Communities
REFERENCES
1 Baker, A. L. An Inexpensive Micro-
sampler. Limnol. and Oceanogr.
15(5): 158-160. 1970.
2 Brooks, J. L. and Dodson, S. I.
Predation, Body, Size, and Com-
position of Plankton. Science 150:
28-35. 1965.
3 Dodson, Stanley I. Complementary
Feeding Niches Sustained by Size-
Selective Predation, Limnology
and Oceanography 15(1): 131-137.
4 Hutchinson, G. E. 1967. A Treatise
on Limnology. Vol. II. Introduction
to Lake Biology and the Limnoplankton.
xi+ 1115. John Wiley & Sons, Inc.,
New York.
5 Jossi, JackW. Annotated Bibliography
of Zooplankton Sampling Devices.
USFWS. Spec. Sci. : Rep. -Fisheries.
609. 90 pp. 1970.
6 Likens, Gene E. and Gilbert, John J.
Notes on Quantitative Sampling of
Natural Populations of Planktonic
Rotifers. Limnol. and Oceanogr.
15(5): 816-820.
7 Lund, J. W. G. 1965. The Ecology of
the Freshwater Plankton. Biological
Reviews, 40:231-293.
8 UNESCO. Zoolplankton Sampling.
UNESCO Monogr. Oceanogr. Methodol.
2. 174 pp. 1968. (UNESCO. Place
de Fortenoy, 75, Paris 7e France).
This outline was prepared by W. T. Edmondson,
Professor of Zoology, University of
Washington, Seattle, Washington.
Descriptor: Zooplankton
4-3
-------
Biology of Zooplankton Communities
FIGURE 1 SEASONAL CHANGES OF ZOOPLANKTON IN LAKE ERKEN, SWEDEN
Diaptomus gracixoides
Ceriodaphnia quadraneula
Each panel shows the abundance of a species of animal. Each
mark on the vertical axis represents 10 individuals/liter.
Nauwerck, A. 1963. Die Beziehungen zwlschen Zooplankton und
Phytoplankton im See Erken. Symbolae Botanicae Upsaliensis, 17:1-163.
-------
FIGURE 2 REPRODUCTIVE RATE OF ZOOPLANKTON ASA FUNCTION OF ABUNDANCE OF FOOD
Young per -
Brood _
20 -
10
Cells/ml
of food
100,000
Days
\
4O
Total young
223
177
132
-76
200
400
600
Number of young produced in each brood by Daphnia living in
four different concentrations of food organisms, renewed
daily. The total number produced during the life of a
mother is shown by the numbers at the right. The Daphnia
at the two lowest concentrations produced their first batch
of eggs on the same day as the others, but the eggs degen-
erated, and the first viable eggs were released two days
later. Richman, S. 1958. The transformation of energy by
Daphnia pulex. Ecol. Monogr. 28: 273-291.
Abundance of food organisms ygm/1, dry weight
Mean rate of laying eggs by the planktonic
rotifer Keratella cochlearis in natural
populations as a function of abundance of
food organisms and temperature. W. T.
Edmonson. 1965. Reproductive rate of
planktonic rotifers as related to food
and temperature in nature. Ecol. Mmogr.
35: 61-111.
IN
O
n
O
3
3
0>
en
-------
Biology of Zooplankton Communities
PROTOZOA
Difflugia
Amoebae
Codonella
Stentor
Epistylis
Ciliates
-------
Biology of Zooplankton Communities
ROTIFERA
Synchaeta
Polygarthra
Brachionus
Cladocera
ARTHROPODA
Crustacea
Copepoda
Nauplius larva of copepod
Insecta - Chaoborus
-------
Biology of Zooplankton Communities
PLANKTON1C BIVALVE LARVAE
380M,
377|i
spined (fin attached)
simple (gill attached)
Glochidia (Unionidae) Fish Parasites
(1-3)
veliger
pediveliger
Veliger Larvae (Corbiculidae) Free Living Planktonic
(4-5)
Pediveliger attaches byssus lines)
-------
OPTICS AND THE MICROSCOPE
I OPTICS
An understanding of elementary optics is
essential to the proper use of the microscope.
The microscopist will find that unusual pro-
blems in illumination and photomicrography
can be handled much more effectively once
the underlying ideas in physical optics are
understood.
A Reflection
A good place to begin is with reflection at
a surface or interface. Specular (or
regular) reflection results when a beam
of light leaves a surface at the same angle
at which it reached it. This type of
reflection occurs with highly polished
smooth surfaces. It is stated more pre-
cisely as Snell's Law, i. e., the angle of
incidence, i, is equal to the angle of
reflection, r (Figure l). Diffuse (or
scattered) reflection results when a beam
of light strikes a rough or irregular sur-
face and different portions of the incident
light are reflected from the surface at
different angles. The light reflected from
a piece of white paper or a ground glass is
an example of diffuse reflection.
Figure 1
SPECULAR REFLECTION - SNELL'S
LAW
BI. MIC. 18. 2. 79
Strictly speaking, of course, all reflected
light, even diffuse, obeys Snell's Law.
Diffuse reflected light is made up of many
specularly reflected rays, each from a
a tiny element of surface, and appears
diffuse when the reflecting elements are
very numerous and very small. The terms
diffuse and .specular, referring to reflection,
describe not so much a difference in the
nature of the reflection but rather a differ-
ence in the type of surface. A polished sur-
face gives specular reflection; a rough
surface gives diffuse reflection.
It is also important to note and remember
that specularly reflected light tends to be
strongly polarized in the plane of the reflect-
ing surface. This is due to the fact that
those rays whose vibration directions lie
closest to the plane of the reflection surface
are most strongly reflected. This effect is
strongest when the angle of incidence is
such that the tangent of the angle is equal
to the refractive index of the reflecting sur-
face. This particular angle of incidence is
called the Brewster angle.
B Image Formation on Reflection
Considering reflection by mirrors, we find
(Figure 2) that a plane mirror forms a
virtual image behind the mirror, reversed
right to left but of the same size as the
object. The word virtual means that the
image appears to be in a given plane but
that a ground glass screen or a photographic
film placed in that plane would show no
image. The converse of a virtual image is
a real image.
Spherical mirrors are either convex or con-
cave with the surface of the mirror repre-
senting a portion of the surface of a sphere.
The center of curvature is the center of the
sphere, part of whose surface forms the
mirror. The focus lies halfway between the
center of curvature and the mirror surface.
5-1
-------
Optics and the Microscope
Object
1
Virtual
Image
Mirror
Figure 2
IMAGE FORMATION BY PLANE MIRROR
Construction of an image by a concave
mirror follows from the two premises
given below (Figure 3):
Figure 3
IMAGE FORMATION BY CONCAVE MIRROR
1 A ray of light parallel to the axis of
the mirror must pass through the
focus after reflection.
2 A ray of light which passes through the
center of curvature must return along
the same path.
A corollary of the first premise is:
3 A ray of light which passes through the
focus is reflected parallel to the axis
of the mirror.
The image from an object can be located
using the familiar lens formula:
_t
P
I
q
where p = distance from the object to
the mirror
q = distance from the image to
the mirror
f = focal length
C Spherical Aberration
No spherical surface can be perfect in its
image-forming ability. The most serious
of the imperfections, spherical aberration,
occurs in spherical mirrors of large
aperture (Figure 4). The rays of light
making up an image point from the outer
zone of a spherical mirror do not pass
through the same point as the more central
rays. This type of aberration is reduced by
blocking the outer zone rays from the image
area or by using aspheric surfaces.
Figure 4
SPHERICAL ABERRATION BY
SPHERICAL MIRROR
5-2
-------
Optics and the Microscope
D Refraction of Light
Turning now to lenses rather than mirrors
we find that the most important charade r-
istic is refraction. Refraction ivIVrs to
the change of direction and/or velocity of
light as it passes from one m.-dium to
another. The ratio of the velocity in air
(or more correctly in a vacuum) to tin-
velocity in the medium is called the
refractive index. Some typical values of
refractive index measured with mono-
chromatic light (sodium D line) are listed
in Table 1.
Refraction causes an object immersed in
a medium of higher refractive index than
air to appear closer to the surface than it
actually is (Figure 5). This effect may
into focus and the now micrometer reading
is taken. KinaUy, the microscope is re-
focused until the surface of the liquid appears
in sharp focus. The micrometer reading
is taken again and, with this information,
the refractive index miy be calculated from
the simplified equation:
.. ,. . . actual depth
rclruclive index = f-—77-
apparent depth
Table 1. RKKRACTIVK INDICES OF COMMON
MATERIALS MKASURED WITH SODIUM LIGHT
Vacuum
Air
CO.;
Water
1 . 0000000
1. 0002918
1. 0004498
1. 3330
Crown glass
Rock salt
Diamond
Lead sulfide
1.48 to
1.5443
2.417
3.912
1.61
Actual
depth
Apparent I
depth |
Air
Medium
Image
Object
When the situation is reversed, and a ray
of light from a medium of high refractive
index passes through the interface of a
medium of lower index, the ray is refracted
until a critical angle is reached beyond which
all of the light is reflected from the interface
(Figure 6). This critical angle, C, has the
following relationship to the refractive indices
of the two media: {
sin C = — 2
where
-------
Optics and the Microscope
E Dispersion
Dispersion is another important property
of transparent materials. This is the
variation of refractive index with color
(or wavelength) of light. When white light
passes through a glass prism, the light
rays are refracted by different amounts
and separated into the colors of the
spectrum. This spreading of light into
its component colors is due to dispersion
which, in turn, is due to the fact that the
refractive index of transparent substances,
liquids and solids, is lower for long wave-
lengths than for short wavelengths.
Because of dispersion, determination of
the refractive index of a substance re-
quires designation of the particular wave-
length used. Light from a sodium lamp
has a strong, closely spaced doublet with
an average wavelength of 5893A, called
the D line, which is commonly used as a
reference wavelength. Table 2 illustrates
the change of refractive index with wave-
length for a few common substances.
F Lenses
There are two classes of lenses, con-
verging and diverging, called also convex
and concave, respectively. The focal
point of a converging lens is defined as
the point at which a bundle of light rays
parallel to the axis of the lens appears to
converge after passing through the lens.
The focal length of the lens is the distance
from the lens to the focal point (Figure 7).
Table 2. DISPERSION OF REFRACTIVE
INDICES OF SEVERAL COMMON MATERIALS
Refractive index
F line D line C line
blue (yellow) (red)
4861A 5893A 6563A
Carbon disulfide
Crown glass
Flint glass
Water
1. 6523
1.5240
1. 6391
1.3372
1.6276
1.5172
1.6270
1.3330
1.6182
1. 5145
1. 6221
1. 3312
The dispersion of a material can be defined
quantitatively as:
_,. .
v = dispersion =
n (593mn) - 1
n (yellow) - 1
=
_
. n (red)
n (486m|i) - n(656mn)
where n is the refractive index of the
material at the particular wavelength
noted in the parentheses.
Figure 7
CONVERGENCE OF LIGHT AT FOCAL POINT
G Image Formation by Refraction
Image formation by lenses (Figure 8)
follows rules analogous to those already
given above for mirrors:
1 Light traveling parallel to the axis of
the lens will be refracted so as to pass
through the focus of the lens.
2 Light traveling through the geometrical
center of the lens will be unrefracted.
The position of the image can be determined
by remembering that a light ray passing
through the focus. F, will be parallel to
the axis of the lens on the opposite side of
the lens and that a ray passing through the
geometrical center of the lens will be
unrefracted.
5-4
-------
Optics and the Microscope
Figure? 8
IMAGE FORMATION BY A CONVEX LENS
The magnification, M, of an image of an
object produced by a lens is given by the
relationship:
image size _ image distance _ q
object size object distance p
where q = distance from image to lens
and p = distance from object to lens.
H Aberrations of Lenses
Lenses have aberrations of several types
which, unless corrected, cause loss of
detail in the image. Spherical aberration
appears in lenses with spherical surfaces.
Reduction of spherical aberration can be
accomplished by diaphragming the outer
zones of the lens or by designing special
aspherical surfaces in the lens system.
Chromatic aberration is a phenomenon
caused by the variation of refractive index
with wavelength (dispersion). Thus a lens
receiving white light from an object will
form a violet image closer to the lens and
a red one farther away. Achromatic
lenses are employed to minimize this
effect. The lenses are combinations of
two or more lens elements made up of
materials having different dispersive
powers. The use of monochromatic light
is another obvious way of eliminating
chromatic aberration.
Astigmatism is a third aberration of
spherical lens systems. It occurs when
object points are not located on the optical
axis of the lens and results in the formation
of an indistim.-t image. The simplest
remedy for astigmatism is to place the
object dose to the axis of the lens system.
Interference Phenomena
Interference and diffraction are two phe-
nomena which are due to the wave character-
istics of light. The superposition of two
light rays arriving simultaneously at a given
point will give rise to interference effects,
whereby the intensity at that point will vary
from dark to bright depending on the phase
differences between the two light rays.
The first requirement for interference is
that the light must come from a single
source. The light may be split into any
number of paths but must originate from
the same point (or coherent source). Two
light waves from a coherent source arriv-
ing at a point in phase agreement will
reinforce each other (Figure 9a). Two
light waves from a coherent source arriv-
ing at a point in opposite phase will cancel
each other (Figure 9b).
Figure 9a. Two light rays, 1 and 2, of
the same frequency but dif-
ferent amplitudes, are in phase
in the upper diagram. In the
lower diagram, rays 1 and 2
interfere constructively to give
a single wave of the same fre-
quency and with an amplitude
equal to the summation of the
two former waves.
5-5
-------
Optics and the Microscope
o+b
Figure .9b. Rays 1 and 2 are IKKV 180°
out of phase and interfere
destructively. The resultant,
in the bottom diagram, is of
the same frequency but is of
reduced amplitude (a is
negative and is subtracted
from b).
The reflection of a monochromatic light
beam by a thin film results in two beams,
one reflected from the top surface and one
from the bottom surface. The distance
traveled by the latter beam in excess of
the first is twice the thickness of the film
and its equivalent air path is:
2 nt
where n is the refractive index and
t is the thickness of the film.
The second beam, however, upon reflection
at the bottom surface, undergoes a half
wavelength shift and now the total retard-
ation of the second beam with respect to
the first is given as:
retardation = 2 nt + -5-
where X is the wavelength of the light
beam.
When retardation is exactly an odd number
of half wavelengths, destructive interfer-
ence takes place resulting in darkness.
When it is zero or an even number of half
wavelengths, constructive interference
results in brightness (Figure 10).
5-6
Figure 10
INTERFERENCE IN A THIN FILM
A simple interferometer can be made by
partially silvering a microscope slide and
cover slip. A preparation between the two
partially silvered surfaces will show inter-
ference fringes when viewed with mono-
chromatic light, either transmitted or by
vertical illuminator. The fringes will be
close together with a wedge-shaped prep-
aration and will reflect refractive index
differences due to temperature variations,
concentration differences, different solid
phases, etc. The method has been used to
measure quantitatively the concentration of
solute around a growing crystal^ '(Figure 11).
50% Mirror/
N
\
J- Cover slip- - f_
Specimen
W"
Figure 11
MICROSCOPICAL METHOD OF VIEWING
INTERFERENCE IMAGES
a Examination ia by transmitted light.
Light ray undergoes multiple
reflections and produces dark and
light fringes in the field. A speci-
men introduces a phase shift and
changes the fringe pattern.
b Illumination is from the top. The
principle is the same but fringes
show greater contrast.
-------
Optics and the Microscope
Each dark band represents an equivalent
air -thickness of an odd number of half
wavelengths. Conversely, each bright
band is the result of an even number of
half wavelengths.
With interference illumination, the effect
of a transparent object of different re-
fractive index than the medium in the
microscope field is:
1 a change of light intensity of the object
if the background is uniformly illumi-
nated (parallel cover slip), or
2 a shift of the interference bands within
the object if the background consists
of bands (tilted cover slip).
The relationship of refractive indices of
the surrounding medium and the object is
as follows:
. ex ,
d =
2.44 fx
m*
360t
where ns = refractive index of the
specimen
nm = refractive index of the
surrounding medium
9 = phase shift of the two
beams, degrees
X = wavelength of the light
t = thickness of the specimen.
J Diffraction
In geometrical optics, it is assumed that
light travels in straight lines. This is not
always true. We note that a beam passing
through a slit toward a screen creates a
bright band wider than the slit with alter-
nate bright and dark bands appearing on
either side of the central bright band,
decreasing in intensity as a function of
the distance from the center. Diffraction
describes this phenomenon and, as one of
its practical consequences, limits the
lens in it.= ability to reproduce an image.
For example, the image of a pin point of
light produced by a lens is not a pin point
but is revealed to be a somewhat larger
patch of light surrounded by dark and
bright rings. The diameter, d, of this
diffraction disc (to the first dark ring)
is given as:
where f is the focal length of the lens,
X the wavelength, and D the diameter
of the lens.
It is seen that in order to maintain a
small diffraction disc at a given wave-
length, the diameter of the lens should
be as large as possible with respect to
the focal length. It should be noted,
also, that a shorter wavelength produces
a smaller disc.
If two pin points of light are to be distin-
guished in an image, their diffraction discs
must not overlap more than one half their
diameters. The ability to distinguish such
image points is called resolving power and
is expressed as one half of the preceding
expression:
resolving power =
1. 22 f X
D
II THE COMPOUND MICROSCOPE
The compound microscope is an extension in
principle of the simple magnifying glass;
hence it is essential to understand fully the
properties of this simple lens system.
A Image Formation by the Simple Magnifier
The apparent size of an object is determined
by the angle that is formed at the eye by the
extreme rays of the object. By bringing the
object closer to the eye, that angle (called
the visual angle) is increased. This also
increases the apparent size. However a
limit of accommodation of the eye is reached,
at which distance the eye can no longer focus.
This limiting distance is about 10 inches or 25
centimeters. It is at this distance that the
magnification of an object observed by the
unaided eye is said to be unity. The eye can,
of course, be focused at shorter distances but
not usually in a relaxed condition.
A positive, or converging, lens can be used
to permit placing an object closer than 10
inches to the eye (Figure 12). By this means
the visual angle of the object is increased
(as is its apparent size) while the image of
5-7
-------
Optics and the Microscope
Eye
L«ns Rtllno
Ey«
VIRTUAL IMAGE FORMATION BY
CONVEX LENS
the object appears to be 10 inches from
the eye, where it is best accommodated.
B Magnification by a Single Lens System
The magnification, M, of a simple magni-
fying glass is given by:
where f = focal length of the lens in
centimeters.
Theoretically the magnification can be
increased with shorter focal length lenses.
However such lenses require placing the
eye very close to the lens surface and
have much image distortion and other
optical aberrations. The practical limit
for a simple magnifying glass is about
20X.
In order to go to magnifications higher
than 20X, the compound microscope is
required. Two lens systems are used
to form an enlarged image of an object
(Figure 13). This is accomplished in
two steps, the first by a lens called the
objective and the second by a lens known
as the eyepiece (or ocular).
C The Objective
The objective is the lens (or lens system)
closest to the object. Its function is to
reproduce an enlarged image of the object
in the body tube of the microscope.
Objectives are available in various focal
Eyepiece
Objective
V rural Imoge
Figure 13
IMAGE FORMATION IN
COMPOUND MICROSCOPE
lengths to give different magnifications
(Table 3). The magnification is calculated
from the focal length by dividing the latter
into the tube length, usually 160 mm.
The numerical aperture (N. A.) is a measure
of the ability of an objective to resolve detail.
This is more fully discussed in the next
section. The working distance is in the free
space between the objective and the cover
slip and varies slightly for objectives of the
same focal length depending upon the degree
of correction and the manufacturer.
There are three basic classifications of
objectives: achromats, fluorites and
apochromats, listed in the order of their
complexity. The achromats are good for
routine work while the fluorites and apo-
chromats offer additional optical corrections
to compensate for spherical, chromatic and
other aberrations.
5-8
-------
Optics and the Microscope
Table 3. NOMINAL CHARACTERISTICS OF USUAL
Nominal
focal length
mm
56
32
16
8
4
4
1.8
Nominal
magnif.
2. 5X
5
10
20
43
45
90
N.A.
0.08
0. 10
0.25
0.50
0. 66
0. 85
1. 30
Working
distance
mm
40
25
7
1.3
0. 7
0.5
0.2
Depth
focus
V-
50
16
8
2
1
1
0.4
Diam. of
field
mm.
8.5
5
2
1
0.5
0.4
0.2
MICROSCOPE OBJECTIVES
Resolving
power, white
light, ji
4.4
3.9
1.4
0.7
0.4
0.35
0. 21
Maximum
useful
magnif.
80X
90X
250X
500X
660X
850X
1250X
Eyepiece
for max.
useful magnif
3 OX
20X
25X
25X
15X
2 OX
12X
Another system of objectives employs •
reflecting surfaces in the shape of concave
and convex mirrors. Reflection optics,
because they have no refracting elements,
do not suffer from chromatic aberrations
as ordinary refraction objectives do. Based
entirely on reflection, reflecting objectives
are extremely useful in the infrared and
ultraviolet regions of the spectrum. They
also have a much longer working distance
than the refracting objectives.
The body tube of the microscope supports
the objective at the bottom (over the object)
and the eyepiece at the top. The tube
length is maintained at 160 mm except for
Leitz instruments, which have a 170-mm
tube length.
The objective support may be of two kinds,
an objective clutch changer or a rotating
nosepiece:
1 The objective clutch changer ("quick-
change" holder) permits the mounting ,
of only one objective at a time on the
microscope. It has a centering arrange-
ment, so that each objective need be
centered only once with respect to the
stage rotation. The changing of objec-
tives with this system is somewhat
awkward compared with the rotating
nosepiece.
2 The revolving nosepiece allows mounting
three or four objectives on the microscope
at one time (there are some nosepieces
that accept five and even six objectives).
In this system, the objectives are
usually noncenterable and the stage is
centerable. Several manufacturers pro-
vide centerable objective mounts so that
each objective on the nosepiece need be
centered only:once to the fixed rotating
stage. The insides of objectives are
better protected from dust by the rotating
nosepiece. This, as well as the incon-
venience of the so-called "quick-change"
objective holder, makes it worthwhile
to have one's microscope fitted with
rotating nosepiece.
D The Ocular
The eyepiece, or ocular, is necessary in
the second step of the magnification process.
The eyepiece functions as a simple magni-
fier viewing the image formed by the
objective.
There are three classes of eyepieces in
common use: huyghenian, compensating
and flat-field. The huyghenian (or huyghens)
eyepiece is designed to be used with
achromats while the compensating type is
used with fluorite and apochromatic
objectives. Flat-field eyepieces, as the
name implies, are employed in photo-
micrography or projection and can be used
with most objectives. It is best to follow
the recommendations of the manufacturer
as to the proper combination of objective
and eyepiece.
5-9
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Optics and the Microscope
The usual magnifications available in
oculars run from about 6X up to 25 or
SOX. The 6X is generally too low to be of
any real value while the 25 and SOX oculars
have slightly poorer imagery than medium
powers and have a very low eyepoint. The
most useful eyepieces lie in the 10 to 20X
magnification range.
E Magnification of the Microscope
The total magnification of the objective-
eyepiece combination is simply the product
of the two individual magnifications. A
convenient working rule to assist in the
proper choice of eyepieces states that the
maximum useful magnification (MUM) for
the microscope is 1, 000 times the numeri-
cal aperture (N. A.) of the objective.
The MUM is related to resolving power
in that magnification in excess of MUM
gives little or no additional resolving
power and results in what is termed empty
magnification. Table 4 shows the results
of such combinations and a comparison
with the 1000XN. A. rule. The under-
lined figure shows the magnification near-
est to the MUM and the eyepiece required
with each objective to achieve the MUM.
From this table it is apparent that only
higher power eyepieces can give full use
of the resolving power of the objectives.
It is obvious that a 10X, or even a 15X,
eyepiece gives insufficient magnification
for the eye to see detail actually resolved
by the objective.
F Focusing the Microscope
The coarse adjustment is used to roughly
position the body tube (in some newer
microscopes, the stage) to bring the image
into focus. The fine adjustment is used
after the coarse adjustment to bring the
image into perfect focus and to maintain
the focus as the slide is moved across the
stage. Most microscope objectives are
parfocal so that once they are focused any
other objective can be swung into position
without the necessity of refocusing except
with the fine adjustment.
The student of the microscope should first
learn to focus in the following fashion, to
prevent damage to a specimen or objective:
1 Raise the body tube and place the speci-
men on the stage.
2 Never focus the body tube down (or the
stage up) while observing the field
through the eyepiece.
3 Lower the body tube (or raise the stage)
with the coarse adjustment while care-
fully observing the space between the
Table 4. MICROSCOPE MAGNIFICATION CALCULATED
FOR VARIOUS OBJECTIVE-EYEPIECE COMBINATIONS
Objective
Focal Magni-
length
56mm
32
16
8
4
1.8
fication
3X
5
10
20
40
90
5X
15X
25X
SOX
100X
200X
450X
10X
SOX
SOX
100X
200X
400X
900X
Eyepiece
15X
45X
75X
150X
300X
600X
135 OX
2 OX
60X
100X
200X
40 OX
80 OX
1800X
25X
75X
125X
25 OX
500X
1000X
2250X
MUMa
(1000 NA)
80X
100X
250X
500X
660X
1250X
aMUM = maximum useful magnification
5-10
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Optics and the Microscope
objective and slide and permitting the
two to come close together without
touching.
4 Looking through the microscope and
turning the fine adjustment in such a
way as to move the objective away from
.the specimen, bring the image into
sharp focus.
The fine adjustment is usually calibrated
in one- or two-micron steps to indicate
the vertical movement of the body tube.
This feature is useful in making depth
measurements but should not be relied
upon for accuracy.
G The Substage Condenser
The substage holds the condenser and
polarizer. It can usually be focused in a
vertical direction so that the condenser can
be brought into the correct position with
respect to the specimen for proper
illumination. In some models, the conden-
ser is center-able so that it may be set
exactly in the axis of rotation of the stage;
otherwise it will have been precentered at
the factory and should be permanent.
H The Microscope Stage
The stage of the microscope supports the
specimen between the condenser and
objective, and may offer a mechanical stage
as an attachment to provide a means of
moving the slide methodically during obser-
vation. The polarizing microscope is
fitted with a circular rotating stage to
which a mechanical stage may be added.
The rotating stage, which is used for object
orientation to observe optical effects, will
have centering screws if the objectives are
not centerable, or vice versa. It is un-
desirable to have both objectives and stage
centerable as this does not provide a fixed
reference axis.
I The Polarizing Elements
A polarizer is fitted to the condenser of all
polarizing microscopes. In routine instru-
ments, the polarizer is fixed with its
vibration direction oriented north-south
(east-w°st for most European instruments)
while in research microscopes, the
polarizer can be rotated. Modern instru-
ments have polarizing filters (such as
Polaroid) replacing the older calcite
prisms. Polarizing filters are preferred
because they:
1 are low-cost;
2 require no maintenance;
3 permit use of the full condenser
aperture.
An analyzer, of the same construction as
the polarizer, is fitted in the body tube of
the microscope on a slider so that it may
be easily removed from the optical path.
It is oriented with its plane of vibration
perpendicular to the corresponding direction
of the polarizer.
J The Bertrand Len&
The Bertrand lens is usually found only on
the polarizing microscope although some
manufacturers are beginning to include it
on phase microscopes. It is located in the
body tube above the analyzer on a slider
(or pivot) to permit quick removal from
the optical path. The Bertrand lens is used
to observe the back focal plane of the objective.
It is convenient for checking quickly the type
and quality of illumination, for observing
interference figures of crystals, for adjust-
ing the phase annuli in phase microscopy
and for adjusting the annular and central
stops in dispersion staining.
K The Compensator Slot
The compensator slot receives compensators
(quarter-wave, first-order red and quartz-
wedge) for observation of the optical prop-
erties of crystalline materials. It is usually
placed at the lower end of the body tube just
above the objective mount, and is oriented
45° from the vibration directions of the
polarizer and analyzer.
L The Stereoscopic Microscope
The stereoscopic microscope, also called
the binocular, wide-fie Id, dissecting or
5-11
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Optics and the Microscope
Greenough binocular microscope, is in
reality a combination of two separate
compound microscopes. The two micro-
scopes, usually mounted in one body, have
their optical axes inclined from the vertical
by about 7° and from each other by twice
this angle. When an object is placed on the
stage of a stereoscopic microscope, the
optical systems view it from slightly
different angles, presenting a stereoscopic
pair of images to the eyes, which fuse the
two into a single three-dimensional image.
.1
The objectives are supplied in pairs, either
as separate units to be mounted on the
microscope or, as in the new instruments,
built into a rotating drum. Bausch and
Lomb was the first manufacturer to have a
zoom lens system which gives a continuous
change in magnification over the full range.
Objectives for the stereomicroscope run
from about 0. 4X to 12X, well below the
magnification range of objectives available
for single-objective microscopes.
The eyepieces supplied with stereoscopic
microscopes run from 10 to 25X and have
wider fields than their counterparts in the
single-objective microscopes.
Because of mechanical limitations, the
stereomicroscope is limited to about 200X
magnification and usually does not permit
more than about 120X. It is most useful
at relatively low powers in observing
shape and surface texture, relegating the
study of greater detail to the monocular
microscope. The stereomicroscope is
also helpful in manipulating small samples,
separating ingredients of mixtures, pre-
paring specimens for detailed study at
higher magnifications and performing
various mechanical operations under micro-
scopical observation, e. g. micromanipulation.
Ill ILLUMINATION AND RESOLVING POWER
Good resolving power and optimum specimen
contrast are prerequisites for good microscopy.
Assuming the availability of suitable optics
(ocular, objectives and substage condenser)
it is still of paramount importance to use
proper illumination. The requirement for a
good illumination system for the microscope
is to have uniform intensity of illumination
over the entire field of view with independent
control of intensity and of the angular aperture
of the illuminating cone.
A Basic Types of Illumination
There are three types of illumination
(Table 5) used generally:
1 Critical. This is used when high levels
of illumination intensity are necessary
for oil immersion, darkfield, fluores-
cence, low birefringence or photo-
micrographic studies. Since the lamp
filament is imaged in the plane of the
specimen, a ribbon filament or arc
lamp is required. The lamp must be
focusable and have an iris diaphragm;
the position of the filament must also
be adjustable in all directions.
2 Ko'hler. Also useful for intense illumi-
nation, Ko'hler illumination may be
obtained with any lamp not fitted with a
ground glass. The illuminator must,
however, be focusable, it must have an
adjustable field diaphragm (iris) and the
lamp filament position must be adjust-
able in all directions.
3 "Poor man's". So-called because a low-
priced illuminator may be used, this
method gives illumination of high quality
although of lower intensity because of the
presence of a ground glass in the system.
No adjustments are necessary on the
illuminator or lamp filament although
an adjustable diaphragm on the illuminator
is helpful.
All three types of illumination require that
the microscope substage condenser focus
the image of the illuminator aperture in the
plane of the specimen. In each case, then,
the lamp iris acts as a field diaphragm and
should be closed to just illuminate the field
of view. The differences in these three
types of illumination lie in the adjustment
of the lamp condensing lens. With poor
man's illumination there is no lamp conden-
ser, hence no adjustment. The lamp should
be placed close to the microscope so that
5-12
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Optics and the Microscope
Table 5. COMPARISON OF CRITICAL,
KOHLER AND i'OOR MAN'S ILLUMINATION
Lamp filament
Lamp condensing lens
Lamp iris
Ground glass at lamp
Image of light source
Image of field iris
Image of substage iris
Critical
ribbon filament
required
required
none
in object plane
near object
plane
back focal plane
of objective
Kohler
any type
required
required
none
at substage
iris
in object •
plane
back focal plane
of objective
Poor man's
any type
none
useful
present
none
near object
plane
back focal plane
of objective
the entire field of view is always
illuminated. If the surface structure of the
ground glass becomes apparent in the field
of view the substage condenser is very
slightly defocused.
Critical Illumination
V/ith critical illumination the lamp conden-
ser is focused to give parallel rays; focus-
ing the lamp filament on a far wall is
sufficient. Aimed, then, at the substage
mirror, the substage condenser will focus
the lamp filament in the object plane. The
substage condenser iris will now be found
imaged in the back focal plane of the ob-
jective; it serves as a control over con-
vergence of the illumination. Although the
substage iris also affects the light intensity
over the field of view it should most decid-
edly not be used for this purpose. The
intensity of illumination may be varied by
the use of neutral density filters and, unless
color photomicrography is anticipated, by
the use of variable voltage on the lamp
filament.
it
Kohler illumination (Figure 14) differs
from critical illumination in the use of the
lamp condenser. With critical illumination
the lamp condenser focuses, the lamp
filament at infinity; with Kohler illumination
the lamp filament is focused in the plane of
the substage condenser iris (also coincident
with the anterior focal plane of the substage
condenser). The functions of the lamp
condenser iris and the substage condenser
iris in controlling, respectively, the area
of the illuminated field of view and the
angular aperture of the illuminating cone
are precisely alike for all three types of
illumination.
Critical illumination is seldom used because
it requires a special lamp filament and be-
cause, when used, it shows no advantage
over well-adjusted Kohler illumination.
ii
Kohler Illumination
To arrange the microscope and illuminator
for Kohler illumination it is well to proceed
through the following steps:
a Remove the diffusers and filters
from the lamp.
b Turn the lamp on and aim at a con-
venient wall or vertical screen about
19 inches away. Open the lamp
diaphragm.
c By moving the lamp condenser, focus
a sharp image of the filament. It
should be of such a size as to fill,
not necessarily evenly, the microscope
5-13
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Optics and the Microscope
Critical
Kohler
Eye
Eyepoint
Ocular
Focal plane
Focal plane
Objective
Preparation
Substage
condenser
Substage —,
iris
Lamp iris —
Lamp
condenser
Light source
Poor man's
5-14
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Optics and the Microscope
substage condenser opening. If it
does not, move the lamp away from
the wall to enlarge the filament image;
refocus.
d Turn the lamp anil aim it at the micro-
scopc mirror so as to maintain the
same 18 inches (or adjusted lamp
distance).
e Place a specimen on Hie microscope
stage and focus sharply with a Hi-mm
(1GX) objective. Open fully the
aperture diaphragm in the substage
condenser. If the light is loo bright,
temporarily place a neutral density
filter or a diffuser in the lamp.
f Close the lamp diaphragm, or field
diaphragm, to about a 1-cm opening.
Rack the microscope substage con-
denser up and down to focus the
field diaphragm sharply in the same
plane as the specimen.
g Adjust the mirror to center the field
diaphragm in the field of view.
h Remove the 16-mm objective and
replace with a 4-mm objective. Move
the specimen so that a clear area is
under observation. Place the
Bertrand lens in the optical path, or
remove the eyepiece and insert an
auxiliary telescope (sold with phase
contrast accessories) in its place,
or remove the eyepiece and observe
the back aperture of the objective
directly. Remove any ground glass
diffusers from the lamp. Now
observe the lamp filament through
the microscope.
i If the filament does not appear to be
centered, swing the lamp housing in
a horizontal arc whose center is at
the field diaphragm. The purpose
is to maintain the field diaphragm on
the lamp in its centered position. If
a vertical movement of the filament
is required, loosen the buib base and
slide it up or down. If the base is
fixed, tilt the lamp housing in a
vertical arc with the field diaphragm
as the center of movement (again
endeavoring to keep the lamp dia-
phragm in the centered position).
If you have mastered this step, you
have accomplished the most difficult
portion. (Belter microscope lamps
have adjustments to move the bulb
independently of the lamp housing to
simplify this step. )
j Put. the specimen in place, replace
the eyepiece and the desired objec-
tive and rofocus.
k Open or close the field diaphragm
until it just disappears from the field.
1 Observe the back aperture of the
objective, preferably with the Bertrand
lens or the ..auxiliary telescope, and
close the aperture diaphragm on the
substage condenser until it is about
four-fifths the diameter of the back
aperture. This is the best position
for the aperture diaphragm, a posi-
tion which minimizes glare and maxi-
mizes the resolving power. It is
instructive to vary the aperture dia-
phragm and observe the image criti-
cally during the manipulation.
m If the illumination is too great,
insert an appropriate neutral density
filter between the illuminator and
the condenser. Do not use the con-
denser aperture diaphragm or the
lamp field diaphragm to control the
intensity of illumination.
Poor Man's Illumination
Both critical and Kohler illumination re-
quire expensive illuminators with adjust-
able focus, lamp iris and adjustable lamp
mounts. Poor man's illumination requires
a cheap illuminator although an expensive
illuminator may be used if its expensive
features are negated by inserting a ground
glass diffuser or by using a frosted bulb.
Admittedly an iris diaphragm on the lamp
would be a help though it is not necessary.
a The illuminator must have a frosted
bulb or a ground glass diffuser.
5-15
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Optics and the Microscope
It should bo possible to direct it in
the general direction of the substage
mirror, very close thereto or in
place thereof.
b Focus on any preparation after
tilting the mirror to illuminate the
field.
c Remove the top lens of the condenser
and, by racking the condenser up or,
more often, down, bring into focus
(in the same plane as the specimen)
a finger, pencil or other object placed
in the same general region as the
ground glass diffuser on the lamp.
The glass surface itself can then be
focused in the plane of the specimen.
d Ideally the ground glass surface will
just fill the field of view when centered
by the substage mirror; adjustment
may be made by moving the lamp
closer to or farther from the micro-
scope (the position might be marked
for each objective used) or by cutting
paper diaphragms of fixed aperture
(one for each objective used). In this
instance a lamp iris would be useful.
e Lower the condenser just sufficiently
to defocus the ground glass surface
and render the field of illumination
even.
f Observe the back aperture of the
objective and open the substage con-
denser iris about 75 percent of the
way. The final adjustment of the
substage iris is made while observing
the preparation; the iris should be
open as far as possible, still giving
good contrast.
g The intensity of illumination should
be adjusted only with neutral density
filters or by changing the lamp voltage.
Proper illumination is one of the most im-
portant operations in microscopy. It is
easy to.judge a microscopist's ability by
a glance at his field of view and the objec-
tive back lens.
5-16
H Ill-solving Power
The resolving power of the microscope is
its ability to distinguish separate details
of «:lo.s
-------
Optics and the Microscope
1 Maximum useful magnification
A helpful rule of thumb is that the use-
ful magnification will not exceed 1,000
times the numerical aperture of the
objective (see Tables 3 and 4). Although
somewhat higher magnification may be
used in specific cases, no additional
detail will be resolved.
It is curious, considering the figures
in the table, that most, if not all, manu-
facturers of microscopes furnish a 10X
eyepiece as the highest power. A 10X
eyepiece is useful but anyone interested
in critical work should use a 15-25X eye-
piece; the 5-10X eyepieces are best for
scanning purposes.
2 Abbe's theory of resolution
One of the most cogent theories of
resolution is due to Ernst Abbe, who
suggested that microscopic objects act
like diffraction gratings (Figure 16) and
that the angle of diffraction, therefore,
increases with the fineness of the detail.
He proposed that a given microscope
objective would resolve a particular
detail if at least two or three transmitted
rays (one direct and two diffracted rays)
entered the objective. In Figure 16 the
detail shown would be resolved in A and
C but not in B. This theory, which can
be borne out by simple experiment, is
useful in showing how to improve resolu-
tion. Since shorter wavelengths will
give a smaller diffraction angle, there
is more chance of resolving fine detail
with short wavelengths. Also, since
only two of the transmitted rays are
needed, oblique light and a high N.A.
condenser will aid in resolving fine detail.
3 Improving resolving power
The following list summarizes the
practical approaches to higher resolu-
tion with the light microscope:
a The specimen should be illuminated
by either critical or Kohler
illumination.
V
Figure 16
ABBE THEORY OF RESOLUTION
b The condenser should be well-
corrected and have a numerical
aperture as high as the objective to
be used.
c An apochrornatic oil-immersion
objective should be used with a com-
pensating eyepiece of at least 15X
magnification. The immersion oil
should have an index close to 1. 515
and have proper dispersion for the
objective being used.
d Immersion oil should be placed
between the condenser and slide and
between cover slip and objective.
The preparation itself should be
surrounded by a liquid having a
refractive index of 1. 515 or more.
e The illumination should be reasonably
monochromatic and as short in wave-
length as possible. An interference
filter transmitting a wavelength of
about 480-500 millimicrons is a
suitable answer to this problem.
Ideally, of course, ultraviolet light
should be used to decrease the wave-
length still further.
The practical effect of many of these
factors is critically discussed by
Loveland^2) in a paper on the optics of
object space.
5-17
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Optics and the Microscope
IV PHOTOMICROGRAPHY
A Introduction
Photomicrography, as distinct from micro-
photography, is the art of taking pictures
through the microscope. A microphoto-
graph is a small photograph; a photomicro-
graph is a photograph of a small object.
Photomicrography is a valuable tool in
recording the results of microscopical
study. It enables the microscopist to:
1 describe a microscopic field objectively
without resorting to written descriptions,
2 record a particular field for future
reference,
3 make particle size counts and counting
analyses easily and without tying up a
microscope,
4 enhance or exaggerate the visual micro-
scopic field to bring out or emphasize
certain details not readily apparent
visually,
5 record images in ultraviolet and infra-
red microscopy which are otherwise
invisible to the unaided eye.
There are two general approaches to photo-
micrography; one requires only a plate or
film holder supported above the eyepiece
of the microscope with a light-tight bellows;
the other utilizes any ordinary camera with
its own lens system, supported with a light-
tight adaptor above the eyepiece. It is
best, in the latter case, to use a reflex
camera so that the image can be carefully
focused on the ground glass. Photomi-
crography of this type can be regarded
simply as replacing the eye with the camera
lens system. The camera should be focused
at infinity, just as the eye is for visual
observation, and it should be positioned
close to and over the eyepiece.
The requirements for photomicrography,
however, are more rigorous than those
for visual work. The eye can normally
compensate for varying light intensities,
curvature of field and depth of field. The
photographic plate, however, lies in one
plane; hence the greatest care must be
used to focus sharply on the subject plane
of interest and to select optics to give
minimum amounts of field curvature and
chromatic aberrations.
With black and white film, color filters
may be used to enhance the contrast of
some portions of the specimen while mini-
mizing chromatic aberrations of the lenses.
In color work, however, filters cannot
usually be used for this purpose and better
optics may be required.
Photomicrographic cameras which fit
directly onto the microscope are available
in 35-mm or up to 3-1/4 X 4-1/4 inch sizes.
Others are made which accommodate larger
film sizes and which have their own support
independent of the microscope. The former,
however, are preferred for ease of handling
and lower cost. The latter system is pre-
ferred for greater flexibility and versatility
and lack of vibration. The Polaroid camera
has many applications in microscopy and
can be used on the microscope directly but,
because of its weight, only when the micro-
scope has a vertically moving stage for
focusing rather than a focusing body tube.
B Determination of Correct Exposure
Correct exposure determination can be
accomplished by trial and error, by relating
new conditions to previously used successful
conditions and by photometry.
With the trial and error method a series of
trial exposures is made, noting the type of
subject, illumination, filters, objective,
eyepiece, magnification, film and shutter
speed. The best exposure is selected. The
following parameters can be changed and
the exposure time adjusted accordingly:
1 Magnification. Exposure time varies
as the square of the magnification.
Example: Good exposure was obtained
with a I/10-second exposure
and a magnification of 100X.
If'(he magnification is now
5-18
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Optics and the Microscope
200X, the correct exposure
is calculated as follows:
new
exposure time = old exposure time
new magnification.2 _ ,/10 /200>2 _
\>ld magnification ' ' 1100;
4/10 or, say, 1/2 second.
Kodachrome II Type A
Professional is 40.
new exposure time = old exposure time
X A.S.A. of old film = 1/100(400/40) =
A. S. A. of new film
10/100 or 1/10 second.
It should be noted, however, that the
above calculation can be made only when
there has been no change in the illumi-
nation system including the condenser
or the objective. Only changes in magni-
fication due to changing eyepieces or
bellows extension distance can be hand-
led in the above manner.
Numerical aperture. Exposure time
varies inversely as the square of the
smallest working numerical aperture
of the condenser and objective.
Example: Good exposure was obtained
at 1/10 second with the 10X
objective, N.A. 0.25, at
full aperture. With a 20X
objective, N.A. 0. 25, at
full aperture and the same
final magnification, what is
the correct exposure time?
new exposure time = old exposure time
_
new N.A.
say, 1/50 second.
or,
It is seen that more light reaches the
photographic film with higher numeri-
cal apertures at the same magnification.
Film. Exposure time varies inversely
with the American Standards Association
speed index of the film.
Example: A good picture was obtained
with Eastman Tri-X film at
I/ 100 second. What is the
correct exposure for
Eastman Kodachrome II
Type A. The A. S. A. speed
for Tri-X is 400 and for
4 Other parameters may be varied but the
prediction of exposure time cannot be
made readily. Experience and photo-
electric devices are the best guides to
the proper exposure.
Photoelectric devices are excellent for
determining correct exposure. Since
ordinary photographic exposure meters
are not sensitive enough for photomi-
crography, more sensitive instruments,
having a galvanometer or electronic
amplifying circuit, are required. Some
photosensitive cells are inserted in the
body tube in place of the eyepiece for
light intensity readings. This has the
advantage of detecting the light level at a
point of high intensity but does not take
into account the eyepiece, the distance to
the film or the film speed.
The cell may be placed just above the eye-
piece so that it registers the total amount
of light leaving the eyepiece. Again, the
effects of film speed and the projection
distance are not accounted for. The prin-
cipal drawback with the total light
measuring photometer is the difficulty of
taking into account the area of field covered.
Take, for example, a bright field in which
only a few crystals appear; perhaps 1 per-
cent of the light entering the field of view is
scattered by the crystals and the photometer
shows close to a maximum reading. Now
assume that everything remains constant
except the number of crystals and, conse-
quently, the amount of light scattered.
The photometer reading could easily drop
by 50 percent, yet the proper exposure is
unchanged. The situation is similar for
photomicrography with crossed polars since
the photometer reading depends on the
intensity of illumination, on the bire-
fringence and thickness of the crystals and
5-19
-------
Optics and the Microscope
on the number and size of the crystals in
the field or, alternatively, on the art-a of
the field covered by birefringent crystals.
One of the best solutions to this problem
is to measure the photometer reading with
no preparation on the stage. A first-order
red compensator or a quartz wedge is in-
serted when crossed polars are being used
to illuminate the entire field.
An alternative is to place the cell on the
ground glass where the film will be
located. However, although all variables
except film speed are now taken into
account, measurements in the image plane
have the disadvantage of requiring a more
sensitive electronic photoelectric apparatus.
No matter what method is used for placing
the photocell, the exposure time can be
determined by the general formula:
exposure time = meter.kreading •
The constant k will depend on the physical
arrangement and film used. To determine
k for any particular system, first set up
the microscope to take a picture. Record
the meter reading and take a series of
trial exposures. Pick out the best exposure
and calculate k. Then the k which was
determined holds as long as no change is
made in the light path beyond the photocell,
e.g. changing to a faster film or changing
the projection distance. Thus the objective,
condenser position or illuminator may be
changed without affecting k if the cell is
used as described above.
Example: With one particular arrange-
ment of photocell and film.
the meter reading is found to
be 40. A series of photographs
are taken at 1/2, 1/5, 1/10,
1/25 and 1/50 seconds. The
photomicrograph taken at 1/5
second is judged to be the best;
hence k is calculated as follows:
k = meter reading X exposure
time = 40 X 1/5 = 8.
Assume now that a new picture
is to be taken at another
magnification (but with the
same film and projection
distance) and that the new
meter reading is 16; therefore:
exposure time = k/meter
reading = 8/16 = 1/2 second.
V MICROMETRY
A Particle Size Determination
Linear distances and areas can be
measured with the microscope. This
permits determination of particle size
and quantitative analysis of physical
mixtures. The usual unit of length for
microscopical measurements is the micron
(1 X 10-3mm or about 4 X lO'Sinch).
Measuring particles in electron microscopy
requires an even smaller unit, the milli-
micron (1 X 10~3 micron or 10 Angstrom
units). Table 6 shows the approximate
average' size of a few common airborne
materials.
Table 6. APPROXIMATE PARTICLE SIZE OF
SEVERAL COMMON PARTICULATES
Ragweed pollen
Fog droplets
Power plant flyash
(after precipitators)
Tobacco smoke
Foundry fumes
25 microns
20 microns
2-5 microns
0. 2 micron
(200 millimicrons)
0.1 - 1 micron
(100-1000 millimicrons)
The practical lower limit of accurate
particle size measurement with the light
microscope is about 0. 5 micron. The
measurement of a particle smaller than
this with the light microscope leads to
errors which, under the best circum-
stances, increase to about + 100 percent
(usually +).
One of the principal uses of high resolving
power is in the precise measurement of
5-20
-------
Optics and the Microscope
particle size. There are, however, a
variety of approximate and useful proce-
dures as well.
1 Methods of particle size measurement
a Knowing the magnification of the
microscope (product of the magni-
fication of objective and eyepiece),
the size of particles can be esti-
mated. For example, with a 10X
eyepiece and a 16-mm (or 10X)
objective, the total magnification
is 100X. A particle that appears to
be 10-mm at 10 inches from the eye
has an actual size of 10 mm divided
by 100 or 0. 10 mm or 100 microns.
This is in no sense an accurate
method, but it does permit quick
estimation of particle size; the error
in this estimation is usually 10-25
percent.
b Another approximate method is also
based on the use of known data. If
we know approximately the diameter
of the microscope field, we can
estimate the percentage of the
diameter occupied by the object to
be measured and calculate from
these figures the approximate size
of the object. The size of the micro-
scope field depends on both the objec-
tive and the ocular although the latter
is a minor influence. The size of
the field should be determined with
a millimeter scale for each objective
and ocular. If this is done, esti-
mation of sizes by comparison with
the entire field diameter can be quite
accurate (5-10%).
c The movement of a graduated mechan-
ical stage can also be used for rough
measurement of diameters of large
particles. Stages are usually gradu-
ated (with vernier) to read to 0. 1
millimeter, or 100 microns. In
practice, the leading edge of the
particle is brought to one of the lines
of the cross hair in the eyepiece and
a reading is taken of the stage position.
Then the particle is moved across the
field by moving the mechanical stage
in an appropriate direction until the
second trailing edge just touches the
cross-hair line. A second reading is
taken and the difference in the two
readings is the distance moved or the
size of the particle. This method is
especially useful when the particle
is larger than the field, or when the
optics give a distorted image near the
edge of the field.
d The above method can be extended to
projection or photography. The image
of the particles can be projected on a
screen with a suitable light source or
they may be photographed. The final
magnification, M, on the projection
surface (or film plane) is given approxi-
mately by
M = DXO. M. XE. M. /25
where O. M. = objective magnification
E. M. = eyepiece magnification
D = projection distance
from the eyepiece in
centimeters.
The image detail can then be measured
in centimeters and the actual size com-
puted by dividing by M. This method
is usually accurate to within 2-5 percent
depending on the size range of the detail
measured.
e The stated magnifications and/or focal
lengths of the microscope optics are
nominal and vary a bit from objective
to objective or eyepiece to eyepiece.
To obtain accurate measurements, a
stage micrometer is used to calibrate
each combination of eyepiece and
objective. The stage micrometer is
a glass microscope slide that has,
accurately engraved in the center, a
scale, usually 2 millimeters long,
divided into 200 parts, each part repre-
senting 0. 01 millimeter. Thus when
this scale is observed, projected or
photographed, the exact image magni-
fication can be determined. For
example, if 5 spaces of the stage micro-
meter measure 6 millimeters when
projected, the actual magnification is
5-21
-------
Optics and the Microscope
5(0.01)
= 120 times.
This magnification figure can be
used to improve the accuracy of
method 4 above.
f The simplest procedure and the most
accurate is based on the use of a
micrometer eyepiece. Since the
eyepiece magnifies a real image
from the objective, it is possible
to place a transparent scale in the
same plane as the image from the
objective and thus have a scale
superimposed over the image. This
is done by first placing an eyepiece
micrometer scale disc in the eyepiece.
The eyepiece micrometer has an
arbitrary scale and must be cali-
brated with each objective used. The
simplest way to do this is to place
the stage micrometer on the stage
and note a convenient whole number
of eyepiece micrometer divisions.
The value in microns for each eye-
piece micrometer division is then
easily computed. When the stage
micrometer is removed and replaced
by the specimen, the superimposed
eyepiece scale can be used for accu-
rate measurement of any feature in
the specimen by direct observation,
photography or projection.
2 Calibration of eyepiece micrometer
Each micrometer stage scale has
divisions lOOjj (0. 1 mm) apart; one
or two of these are usually subdivided
into 10\i (0. 01-mm) divisions. These
form the standard against which the
arbitrary divisions in the micrometer
eyepiece are to be calibrated. Each
objective must be calibrated separately
by noting the correspondence between
the stage scale and the eyepiece scale.
Starting witti the lowest power objective
focus on the stage scale, arrange the
two scales parallel and in good focus.
It should be possible to determine the
number of eyepiece divisions exactly
equal to some whole number of
divisions of the stage scale, a distance
readily, expressed in microns.
The calibration consists, then, of
calculating the number of microns per
eyepiece scale division. To make the
comparison as accurate as possible, a
large part of each scale must be used
(see Figure 17). Let's assume that
with the low power 16-mm objective
6 large divisions of the stage scale
(s. m. d.) are equal to 38 divisions of
the eyepiece scale. This means that
38 eyepiece micrometer divisions (e.m. d.)
are equivalent to 600 microns. Hence:
1 e. m. d. = 600/38
= 15. 8n.
Figure 17
COMPARISON OF STAGE MICROMETER
SCALE WITH EYEPIECE MICROMETER SCALE
Thus when that micrometer eyepiece
is used with that 16-mm objective each
division of the eyepiece scale is equivalent
to 15. 8u, and it can be used to make an
accurate measurement of any object on
the microscope stage. A particle, for
example, observed with the 16-mm objec-
tive and measuring 8. 5 divisions on the
eyepiece scale is 8. 5 (15. 8) or 135n in
diameter.
Each objective on your microscope must
be calibrated in this manner.
A convenient way to record the necessary
data and to calculate n/emd is by means
of a table.
5-22
-------
Optics and theJVIicroscope
Objective
32-mm
16-mm
4-mm
No.
no.
18
6
1
Table
smd =
emd
= 44
= 38
= 30
7
V-
no.
1800
600
100
emd
= 44
= 38
= 30
H =
1 emd
40.
15.
3.
9n
8n
33(1
Determination of particle size
distribution
The measurement of particle size can
vary in complexity depending on parti-
cle shape. The size of a sphere may be
denoted by its diameter. The size of a
cube may be expressed by the length of
an edge or diagonal. Beyond these two
configurations, the particle "size" must
include information about the shape of
the particle in question, and the
expression of this shape takes a more
complicated form.
Martin's diameter is the simplest means
of measuring and expressing the dia-
meters of irregular particles and is
sufficiently accurate when averaged for
a large number of particles. In this
method, the horizontal or east-west
dimension of each particle which divides
the projected area into halves is taken as
Martin's diameter (Figure 18).
P — |
I- P -j
"9
Figure 18
MARTIN'S DIAMETER
The more particles counted, the more
accurate will be the average particle
size. Platelike and needlelike particles
should have a correction factor applied
to account for the third dimension since
all such particles are restricted in their
orientation on the microscope slide.
When particle size is reported, the
general shape of the particles as well as
the method used to determine the
"diameter" should be noted.
Particle size distribution is determined
routinely by moving a preparation of
particles past an eyepiece micrometer
scale in such a way that their Martin's
diameter can be tallied. All particles
whose centers fall within two fixed
divisions on the scale are tallied. Move-
ment of the preparation is usually
accomplished by means of a mechanical
stage but may be carried out by rotation
of an off-center rotating stage. A sample
tabulation appears in Table 8. The eye-
piece and objective are chosen so that
at least six, but not more than twelve,
size classes are required and sufficient
particles are counted to give a smooth
curve. The actual number tallied (200 -
2, 000) depends on particle shape
regularity and the range of sizes. The
size tallied for each particle is that
number of eyepiece micrometer divisions
most closely approximating Martin's
diameter for that particle.
4 Calculation of size averages
The size data may be treated in a variety
of ways; one simple, straightforward
treatment is shown in Table 9. For a
more complete discussion of the treat-
ment of particle size data see Chamot
and Mason's Handbook of Chemical
Microscopy^3', page 26.
The averages^ with respect to number,
d_i; surface, d3; and weight or volume,
d,}, are calculated as follows for the
data in Table 9.
5-23
-------
Optics and the Microscope
Table 8. PARTICLE SIZE TALLY FOR A SAMPLE OF STARCH GRAINS
Size claM
(emd»)
Number of particles
Total
M-4J 1
n-wi
rt-+4 ri-w
r-*-u
rr-w «-*4 rt-w rt-u
rr-»u rv*4 111
rt-w r-t-w r*4.i rt-u r-r-w r-r-u
rt-w M-*J rt-w rt-u I-*-AJ rt-w
rt-u
16
as
no
i-t-w r*-*j
rt-w «-*j rt-w r-w-i
r-t-*a
107
rt-w.
1 1
r*-i-a rt-*~i
rn-i
rt-w
fl-*4
1 1
45
*emd • ejceniece mlcrometeE.dlKialaa«
d1 = Łnd/En = 1758/470
= 3.74 emdX 2.82*= 10. 5^
d3 = End3/ 2nd2 = 37440/7662
= 4. 89 emdX 2. 82 = 13. 8p
d4 = 2nd4/Znd3 = 199194/37440
= 5. 32 emdX 2.82 = 15. OJJL
*2. 82 microns per emd
(determined by calibration of the
eyepiece-objective combination
used for the determination).
Cumulative percents by number,
surface and weight (or volume) may be
plotted from the data in Table 9. The
calculated percentages, e. g.
d = 1
d = 15
nd4 X 100
d = 1
for the cumulative weight or volume
curve, are plotted against d. Finally,
the specific surface, Sm, in square
meters per gram, m, may be calculated
if the density, D, is known; the surface
average d3, is used.
If D = 1. 1, Sm = 6/d3D = 6/13. 8(1. 1)
= 0. 395m2/g.
5-24
-------
Optics and the Microscope
Table 9. CALCULATIONS FOR PARTICLE SIZE AVERAGE
d
(Aver. diam.
in emd)
1
2
3
4
5
6
7
8
n
16
98
110
107
71
45
21
2
nd
16
196
330
423
355
270
147
16
nd2
16
392
990
1712
1775
1620
1029
128
nd3
16
784
2970
6848
8875
9720
7203
1024
nd4
16
1568
8910
27392
44375
58320
50421
8192
470 1758 7662 37440 199194
B Counting Analysis
Mixtures of particulates can often be
quantitatively analyzed by counting the
total number of particulates from each
component in a representative sample.
The calculations are, however, compli-
cated by three factors: average particle
size, particle shape and the density
of the components. If all of the compon-
ents were equivalent in particle size,
shape and density then the weight per-
centage would be identical to the number
percentage. Usually, however, it is
necessary to determine correction factors
to account for the differences.
When properly applied, this method can
be accurate to within +_ 1 percent and,
in special cases, even better. It is often
applied to the analysis of fiber mixtures
and is then usually called a dot-count
because the tally of fibers is kept as the
preparation is moved past a point or dot
in the eyepiece.
A variety of methods can be used to
simplify recognition of the different
components. These include chemical
stains or dyes and enhancement of optical
differences such as refractive indices,
dispersion or color. Often, however, one
relies on the differences in morphology.
e. g. counting the percent of rayon fibers
in a sample of "silk".
Example 1: A dot-count of a mixture of
fiberglass and nylon shows:
nylon
fiberglass
262
168
Therefore:
% nylon = 262/(262 + 168)X 100
= 60. 9% by number.
However, although both fibers are smooth
cylinders, they do have different densities
and usually different diameters. To
correct for diameter one must measure
the average diameter of each type of fiber
and calculate the volume of a unit length
of each.
aver. diam. volume of
M. l-(i slice, n3
nylon
fiberglass
18.5
13.2
268
117
The percent by volume is, then:
262 X 268
% nylon
(262 X 268)+(168X 117)
= 78. 1% by volume.
X 100
Still we must take into account the density of
each in order to calculate the weight percent.
5-25
-------
Optics and the Microscope
If the densities are 1. 6 for nylon and 2. 2
for glass then the percent by weight is:
nylon =•
262 X 268 X 1.6
(262 X 268 X 1.6)+(168X 117X2.2)
= 72% by weight.
Example 2: A count of quartz and
gypsum shows:
quartz
gypsum
283
467
To calculate the percent by weight we must
take into account the average particle size,
the shape and the density of each.
The average particle size with respect to
weight, 64, must be measured for each
and the shape factor must be determined.
Since gypsum is more platelike than quartz
each particle of gypsum is thinner. The
shape factor can be approximated or can be
roughly calculated by measuring the actual
thickness of a number of particles. We
might find, for example, that gypsum parti-
cles average 80% of the volume of the aver-
age quartz particle; this is our shape factor.
The final equation for the weight percent is:
quartz =
283 X ird4/6X Dq
X 100
238
Dq + 467 X IT dj/ 6 X 0. 80 X Dg
X 100
where Dq and Dg are the densities of quartz
and gypsum_ respeŁtively; 0.80 is the shape
factor and d4 and d4 are the average parti-
cle sizes with respect to weight for quartz
and gypsum respectively.
ACKNOWLEDGMENT: This outline was
prepared by the U. S. Public Health Service,
Department of Health. Education and Welfare,
for use in ita Training Program.
REFERENCES
1 Bunn, C. W. Crystal Growth from
Solution. Discussions of the Faraday
Society No. 5. 132. Gunery and Jackson.
London. (1949).
2 Loveland. R. P., J. Roy. Micros. Soc.
79, ?9. (1980).
3 Chamot. Smile Monnin, and Maaon,
Clyde Walter. Handbook of Chemical
Microscopy, VoL 1. third ed.
John Wiley and Sons, New York (1959).
DESCRIPTORS:
properties
Microscope and Optical
5-26
-------
STRUCTURE AND FUNCTION OF CELLS
I INTRODUCTION
What are cells? Cells may be defined as the
basic structural units of life. The cell has
many different parts which carry on the
various functions of cell life. These are
called organelles ("little organs").
A The branch of biology which deals with the
form and structure of plants and animals
is called "Morphology. " The study of the
arrangement of their several parts is
called "anatomy", and the study of cells
is called "cytology".
B There is no "typical" cell, for cells differ
from each other in detail, and these
differences are in part responsible for the
variety of life that exists on the earth.
H FUNDAMENTALS OF CELL STRUCTURE
A How do we recognize a structure as a cell?
We must look for certain characteristics
and/or structures which have been found
to occur in cells. The cell is composed
of a variety of substances and structures,
some of which result from cellular
activities. These include both living and
non-living materials.
1 Non-living components include:
a A "cell wall" composed of cellulose
may be found as the outermost
covering of many plant cells.
b "Vacuoles" are chambers in the
protoplasm which contain fluids of
different densities (i.e., different
from the surrounding protoplasm).
2 The "living" parts of the cell are called
"protoplasm. " The following structures
are included:
a A thin "cell membrane" is located
just inside the cell wall. This
membrane may be thought of as the
outermost layer of protoplasm.
In plant cells the most conspicuous
protoplasmic structures are the
"chloroplasts", which contain
highly organized membrane systems
bearing the photosynthetic pigments
(chlorophylls, carotenoids, and
xanthophylls) and enzymes.
The "nucleus" is a spherical body
which regulates cell function by
controlling enzyme synthesis.
"Granules" are structures of small
size and may be "living" or
non-living" material.
"Flagella" are whip-like structures
found in both plant and animal cells.-
The flagella are used for locomotion,
or to circulate the surrounding
medium.
"Cilia"resemble short flagella, found
almost exclusively on animal cells.
In the lower animals, cilia are used
for locomotion and food gathering.
The "pseudopod", or false foot, is
an extension of the protoplasm of
certain protozoa, in which the
colloidal state of the protoplasm
alternates from a "sol" to a "jel"
condition from time to time to
facilitate cell movement.
"Ribosomes" are protoplasmic bodies
which are the site of protein
synthesis. They are too small
(150 A in diameter)to be seen with
a light microscope.
"Mitochondria" are small mem-
branous structures containing
enzymes that oxidize food to produce
energy transfer compounds (ATP).
BI.CEL. la. 6.76
6-1
-------
Structure and Function of Cells
B How basic structure is expressed in some
major types of organisms.
We can better visualize the variety of cell
structure by considering several specific
cells.
1 Bacteria have few organelles, and are
so minute that under the light
microscope only general morphological
types (i.e., the three basic shapes;
rods, spheres, and spirals) can be
recognized. The following structures
have been defined:
a The "capsule" is a thick protective
covering of the cell exterior, con-
sisting of polysaccharide or
polyp eptide.
b The cell wall and plasma membrane
are present.
c Although no well defined nucleus is
visible in bacterial cells, the
electron microscope has revealed
areas of deoxyribose nucleic acid
(DNA) concentration. This sub-
stance is present within the nucleus of
of higher cells, and is the genetic
or hereditary material.
d Some types of bacteria contain a
special type of chlorophyll
(bacteriochlorophyll) and carry on
photosynthesis.
2 The blue-green algae are similar to the
bacteria in structure, but contain the
photo synthetic pigment chlorophyll a.
a Like the bacteria, these forms also
lack an organized nucleus (the
nuclear region is not bounded by a
membrane).
b The chlorophyll-bearing membranes
are not localized in distinct bodies
(chloroplasts), but are dispersed
throughout the cell.
c Gas-filled structures called
"pseudovacuoles" are found in some
types of blue-greens.
The green algae as a group include a
great variety of structural types,
ranging from single-celled non-motile
forms to large motile colonies. Some
types are large enough to resemble
higher aquatic plants.
a The chloroplasts are modified into
a variety of shapes and are located
in different positions. Examples
of chloroplast shape and position are:
1) Parietal - located on the
periphery of the cell; usually
cup-shaped and may extend
completely around the inner
surface of the plasma membrane.
2) Discoid - also located on the
periphery of the cell, but are
plate-shaped; usually many per
cell.
3) Axial - lying in the central axis
of the cell; may be ribbon-like
or star-shaped.
4) Radial - have arms or processes
that extend outward from the
center of the cell (radiate),
reaching the plasma membrane.
5) Reticulate - a mesh-like network
that extends throughout volume
of the cell.
b Located in the chloroplasts may be
dense, proteinaceous, starch-
forming bodies called "pyrenoids".
The flagellated algae possess one-to-
eight flagella per cell. The chloro-
plasts may contain brown and/or red
pigments in addition to chlorophyll.
a Reserve food may be stored as
starch (Chlamydomonas) paramylon
(Euglena), or as oil.
The protozoa are single-celled
animals which exhibit a variety of
cell structure.
6-2
-------
Structure and Function of Cells
The amoebae move by means of
pseudopodia, as described
previously.
The flagellated protozoa
(Mastigophora) possess one or more
flagella.
The ciliates are the most highly
modified protozoans. The cilia may
be more or less evenly distributed
over the entire surface of the cell,
or may be localized.
IE FUNCTIONS OF CELLS
What are the functions of cells and their
structural components? Cellular function
is called "life", and life is difficult to define.
Life is characterized by processes commonly
referred to as reproduction, growth, photo-
synthesis, etc.
A Microorganisms living in surface waters
are subjected to constant fluctuations in
the physical and chemical characteristic
of the environment, and must constantly
modify their activities.
1 The cell requires a source of chemical
energy to carry on life processes and
successfully compete with other
organisms. Plant cells may obtain
this energy from light, which is
absorbed by chlorophyll and converted
into ATP or food reserves, or from
the oxidation of food stuffs. Animal
cells obtain energy only from the
oxidation of food.
2 Cells must obtain raw materials from
the environment in order to grow and
carry out other life functions. Inorganic
and organic materials may be taken up
by passive diffusion or by "active
transport". In the later process,
energy is used to build up and maintain
a higher concentration of a substance
(such as phosphate) inside the cell than
is found outside. Algae are able to
synthesis organic matter from inorganic
raw materials (carbon dioxide and
water), with the aid of energy derived
from light, whereas animal cells must
obtain their organic matter "ready-
made" by consuming other organisms,
organic debris, or dissolved organics.
IV SUMMARY
The cell is made up of many highly special-
ized substructures. The types of sub-
structures present, and their appearance
(shape, color, etc,) are very important in
understanding the role of the organism in
the aquatic community, and in classification.
REFERENCES
1 Bold, H. C. Cytology of algae. In: G.M.
Smith, (ed.), Manual of Phycology.
Ronald Press. 1951.
Bourne, GeoffryH.,
Cell Physiology.
Press. 1964.
ed. Cytology and
3rd ed. Academic
3 Brachet, Jean. The Living Cell.
Scientific American. 205(3). 1961.
4 Corliss, John O. Ciliated Protozoa.
Pegamon. 1961.
5 Fritsch, F. E. The structure and
reproduction of the algae. Cambridge
Univ. Press. 1965.
6 Frobisher, M. Fundamentals of
microbiology. 7th edition. W. B.
Saunders Co., Philadelphia. 1962.
7 Round, F.E. The biology of the algae.
St. Martin's Press. New York. 1965.
This outline originally prepared by Michael
E. Bender, Biologist, formerly with
Training Activities, FWPCA, SEC. and
revised by Cornelius I. Weber, March 1970.
Descriptor: Cytological Studies
6-3
-------
TYPES OF ALGAE
I INTRODUCTION
A Algae in general may be defined as
small pigmented plant-like organisms
of relatively simple structure. Actually
the size range is extreme: from only a
few microns to over three hundred feet
in length. Commonly observed examples
include the greenish pond scum or frog
spittle of freshwater ponds, much of the
golden brown slime covering rocks in a
trout stream, and the great marine kelps
and seaweeds. Large freshwater forms
as Nitella and Chara or stonewort are
also included.
B Algae approach ubiquity in distribution.
In addition to the commonly observed
bodies of water, certain algae also live
in such unlikely places as thermal springs,
the surface of melting snow, on the hair
of the three toed sloth in Central America,
and in conjunction with certain fungi to
form lichens.
Ill ALGAE WILL BE GROUPED FOR THE
SAKE OF CONVENIENCE INTO FOUR
GENERAL TYPES:
A Blue-greens (See plate: Blue-Green
Algae, Cyanophyceae). This is a valid
technical group. The size range is not
very great, some being so small as to
approach the size range of the bacteria.
1 These are the only algae in which
the pigments are not localized in
definite bodies but dissolved through-
out the cell. Blue, red, or other
pigments are present in addition to
chlorophyll thus giving the cells a
bluish green, yellow, or red color,
at least enmasse.
2 The nucleus lacks a nuclear membrane.
3 Tend to achieve nuisance concentrations
more frequently in the warm summer
months and in the richer waters.
4 Vegetative reproduction, in addition
to cell division, includes the forma-
tion of "hormogones, " or short specif-
ically delimited sections of trichomes
(filaments).
5 Spores of three types are encountered:
a Akinetes are usually larger, thick
walled resting spores.
b Heterocysts appear like empty
cell walls, but are actually filled
with protoplasm, have occasionally
been observed to germinate.
c Endospores, also called "gonidia"
or conidia, are formed by repeated
division of the protoplast within a
given cell wall. Present in only a
few genera.
6 Some common examples of blue-
green algae are:
Anacystis (Microcystis or
Polycystis), Anabaena, Aphani-
zomenon, and Oscillatoria
The Pigmented flagellates (in contrast
to the non-pigmented or animal-like
flagellates) are a heterogeneous
collection of motile forms from several
different algal groups (See plate:
Flagellated algae).
1 There may be one, two, four, or
more flagella per cell.
2 There is a well organized nucleus.
3 A light-sensitive red eyespot usually
present.
4 The chlorophyll is contained in one
or more distinctive bodies called
plastids.
Bl.MIC.cla. 19a. 6. 76
7-1
-------
Types of Algae
5 Two or more cells may be associated
in a colony.
6 Non-motile life history stages may
be encountered.
7 Masses of stored starch called •
pyrenoid bodies are often conspicuous.
8 Some examples of pigmented flag-
ellates are: Euglena, Phacus,
Chlamydomonas, Gonium, Volvox,
Peridinium, Ceratium Mallomonas,
Synura and Dinobryon.
The Non-motile green algae constitute
another heterogeneous assembly of un-
related forms (See plate: Non-Motile
Green Algae)
1 Like the flagellates they have well
organized nuclei and chloroplasts.
The shape of the chloroplast is often
distinctive.
2 They lack flagella or any other loco-
motor device.
3 There is extreme structural variation
among the group.
4 Some types tend to occur as a general
planktonic mass or bloom, " often in
combinations of two or more species.
Some examples are: Sphaerocystis,
Pediastrum, Scenedesmus, and the
desmid Cosmarium.
5 Threadlike (filamentous) green algae
may form masses or blankets, cutting
off light, and reducing water circula-
tion. They also add considerably to
the total mass of organic matter.
Some examples of this type are:
Spirogyra, Hydrodictyon, Cladophora,
Oedogonium, and Chara.
D The Diatoms constitute another valid
technical group (See plate: Diatoms-
Bacillariophyceae).
In appearance, they are geometrically
regular in shape. The presence of a
brownish pigment in addition to the
chlorophyll gives them a golden to
greenish color.
Motile forms have a distinctive
hesitating progression.
The most distinctive structural
feature is the two-part shell
(frustule) composed of silicon
dioxide (glass).
a One part fits inside the other as
the two halves of a pill box, or a
petri dish.
b The surface of these shells are
sculptured with minute pits and
lines arrange'd with geometrical
perfection.
c The view from the side is called
the "girdle view, " that from above
or below, the "valve view. "
There are two general shapes of
diatoms, circular (centric) and
elongate (pennate). The elongate
forms may be motile, the circular
ones are not.
Diatoms may associate in colonies
in various ways.
Examples of diatoms frequently en-
countered are: Stephanodiscus
Cyclotella, Asterionella. Fragilaria,
Tabellaria, Synedra. and Nitzschia.
This outline was prepared by H. W. JACKSON,
former Chief Biologist. National Training
Center, and revised by R. M. SINCLAIR,
Aquatic Biologist, National Training Center,
MOTD. OWPO, USEPA. Cincinnati, Ohio
45268.
Descriptor: Algae
7-2
-------
Types of Algae
KEY FOR IDENTIFICATION OF GROUPS OF FRESHWATER ALGAE
Beginning with "la" and "ib", choose one of the two contrasting
statements and follow this procedure with the "a" and "b" state-
ments of the number given at the end of the chosen statement.
Continue until the name of the algal group is given instead of
another key number.
la. Plastid (separate color body) absent; complete protoplast
pigmented; generally blue-green; iodine starch test*
negative Blue-green algae
Ib. Plastid or plastids present; parts of protoplast free of some
or all pigments; generally green, brown, red, etc., but not
blue-green; iodine starch test* positive or negative 2
2a. Cell wall permanently rigid (never showing evidence of
collapse), and with regular pattern of fine markings
(striations, etc.); plastids brown to green; iodine starch test*
negative; flagella absent; wall of two essentially similar halves,
one placed over the other as a cover Diatoms
2b. Cell wall, if present, capable of sagging, wrinkling, bulging
or rigidity, depending on existing turgor pressure of cell
protoplast; regular pattern of fine markings on wall generally
absent; plastids green, red, brown, etc.; iodine starch test*
positive or negative; flagella present or absent; cell wall
continuous and generally not of two parts 3
3a. Cell or colony motile; flagella present (often not readily visible);
anterior and posterior ends of cell different from one another in
contents and often in shape Flagellate algae
3b. Non-motile; true flagella absent; ends of cells often not
differentiated Green algae and associated forms
*Add one drop Lugol's (iodine) solution, diluted 1-1 with distilled water. In about 1 minute,
if positive, starch is stained blue and, later black. Other structures (such as nucleus,
plastids, cell wall) may also stain, but turn brown to yellow.
7-3
-------
Types of Algae
CMP
COMPARISON OF FOUR MAJOR GROUPS OF ALGAE
Color
Location
of pigment
Starch
Slimy
coating
Nucleus
Flagellum
Cell Wall
"Eye "spot
Blue-Green
Blue-Green
(Brown)
Throughout
cell
Absent
Present
Absent
Absent
Inseparable
from slimy
coating
Absent
Pigmented
flagellates
Green
Brown
In plastids
Present or
Absent
Absent
in most
Present
Present
Thin or
Absent
Present
Greens
Green
In plastids
Present
Absent
in most
Present
Absent
Semi-rigid
smooth or
with spines
Absent
Diatoms
Brown
(Light-Green)
In plastids
Absent
Absent
in most
Present
Absent
Very rigid,
with regular
markings
Absent
-------
BLUE-GREEN ALGAE
I WHAT ARE THE BLUE-GREEN ALGAE?
The blue-green algae (Myxophyceae) comprise
that large group of microscopic organisms
living in aquatic or moist habitats, carrying
on photosynthesis and having differentiation
of cells which is a little more complex than
bacteria, and simpler than all of the other
plants called algae.
II WHY ARE THEY CALLED BLUE-GREEN:
In addition to the green photosynthetic pigment
(chlorophyll-a) they always have a blue pig-
ment (phyocyanin-c) which tends to give the
cushions or mats they may form a blue-green
tinge.
Ill WHERE ARE THE BLUE-GREENS FOUND?
Some are free floating (pelagic and planktonic),
others grow from submerged or moist soil,
rocks, wood and other objects in both fresh-
wa.ter and marine habitats.
IV WHAT ARE SOME OF THEIR GENERAL
CHARACTERISTICS?
Some are gelatinous masses of various shapes
floating in water. Others, microscopic in
size, grow in great numbers so as to color
the water in which they live. Structurally
their cells are similar to bacteria. Their
protoplasts may be sheathed or imbedded in
gelatin, making them slimy. Cells of blue -
green algae are without organized nuclei,
central vacuoles, or cilia and flagella.
No sexual reproduction is known. Asexual
reproduction may be effected by fragmentation,
in which case special separation devices are
formed (dead cells, and heterocysts). Some
species are preserved over unfavorable
periods by special spores (akinetes and endo-
spores).
V OF WHAT IMPORTANCE ARE BLUE-
GREEN ALGAE?
They have both positive and negative economic
significance. Because they can convert
radient energy into chemical energy, they
are producers forming a first link at the base
of the food chain. Because many very in-
tricate nutritional relationships exist among
the myraids of organisms it is difficult to
know the value of the blue-greens. However,
people who know what the blue-greens can dp
to drinking and recreational water classify
them as of negative economic importance,
because they are often nuisances when they
impart color, bad odors, and fishy tastes,
or toxins. Some of them can foul pipes
and clog filters.
VI WHEN ARE THEY MOST COMMON?
They are widely distributed in time and space,
but tend to reach nuisance concentrations more
frequently in the late summer and in eutrophic
waters.
VII WHAT DO BLUE-GREEN ALGAE DO
FOR A LIVING?
The pioneer-forms are of great ecological
importance because they live in habitats fre-
quented by few other forms of live, synthesiz-
ing organic substances and building substrata
that can support other kinds of life.
A Some blue-greens live in association
with other organisms as symbionts.
Still others are found in polluted
waters, because they are able to
exist in habitats poor in oxygen. The
growth of these kinds of algae under
such conditions tends to make a pol-
luted condition worse.
B On the other hand some species
should be promoted because they
provide oxygen and food through photo-
synthesis. The first evident product
of photosynthesis is glycogen, and
is the cause of the brown coloration
with the iodine test. Some of the
glycogen is used to produce glycopro-
teins. The gelatinous sheath is com-
posed of pectic substances, cellulose
and related compounds.
BI.MIC.cla. 16a. 6.76
8-1
-------
Blue-Green Algae
When blue-greens mat at the surface
of the water the increased lighting
may be too strong, resulting in a
kill. At this time they may turn
from a blue-green to a yellow-green
color. Here they decompose in
mass. The resulting intermediate
products of decomposition may be
highly undesirable, because of bad
looks, four odors, bad tastes and
toxins. Under these conditions the
BOD may produce conditions not
unlike raw sewage.
VHI WHAT DO BLUE-GREEN ALGAE LOOK
LIKE UNDER THE MICROSCOPE?
A A cross section of a typical cell
would show an outside nonliving
gelatinous layer surrounding a woody
cell wall, which is bulging from
turgor pressure from the cell (plasma)
membrane, pushing the wall outward-
ly. The protoplasm, contained with-
in the plasma membrane, ie divided
into two regions. The peripheral
pigmented portion called chroma-
toplasm, and an inner centroplas'm,
the centroplasm contains chromatins,
which is also known as in incipient
nucleus or central body, containing
chromosomes and genes. Structures
(chromatophores or plastids) con-
taining pigments have not been found
in the blue-greens. The photosyn-
thetic pigments are dissolved in the
peripheral cytoplasm, which is known
as the chromatoplasm.
B A simple way to understand the cross
section would be to compare it with
a doughnut, with the hole represent-
ing the colorless central body or
incipient nucleus, which houses the
chromatoplasm, having the charac-
teristic blue-green color from its
dissolved photosynthetic pigments.
DC WHAT CAUSES THESE FOUL-TO-SMELL
UNSIGHTLY BLOOMS?
When the protoplasts become sick or old they
may develop a great number of "pseudovac-
uoles" filled with gas. These gas bubbles make
the algae buoyant in such a way that they may
"flower" or bloom by rising to the surface
(planktonic, healthy blue-greens normally
possess pseudovacuoles, which are here
excepted). Soon they begin to stink because
of the odors produced from putrefaction.
The lack of dissolved oxygen during this
period may affect other organisms.
X ARE ALL BLOOMS PUTREFACTIVE?
No. Healthy blooms are produced by myraids
of cells living near the surface of the water
at times when environmental conditions are
especially favorable for them. Putrefactive
blooms are usually from masses of algae
undergoing degradation.
XI WHAT ARE SOME OF THE MAJOR
KINDS OF BLUE-GREENS?
Most species of blue-greens may be placed
into two major groups: the nonfilamentous
(coccoid) forms, and the filamentous forms.
See the set of drawings following this treat-
ment to get a graphic concept of the two
groups.
XH WHAT ARE SOME OF THE MORE
DISTINCTIVE FEATURES OF BLUE-
GREENS?
A In comparing the blue-greens with
other algae it is easier to tell what
they do not possess than what they
do. They do not have chromatophores
or plastids, cilia, flagella, organized
nuclei, gametes, central vacuoles,
chlorophyll-b, or true starch.
B Many of the filamentous forms, es-
pecially the Oscillatoriaceae, exhibit
an unexplained movement. When the
filamentous forms are surrounded
by a gelatinous sheath the row of cells
inside is called a trichome. and the
trichome with its enclosing sheath is
called a filament. There may be more
than one trichome within a sheath.
8-2
-------
Blue-Green Algae
True branching occurs when a cell
of the series divides lengthwise and
the outer-formed cell adds cells to
form a true branch. However, two
or more trichomes within a single
sheath may be so arranged that though
they appear to be branches, their cells
actually have all divided in the same
plane, and the trichomes have pushed
out from growth to form false branch-
ing, as in Tolypothrix.
C An occasional reticulated or bubbly
appearance is referred to as pseudov-
acuolation, and en mass imparts a
pale, yellowish color to the algae.
Under low powers these vacuoles
appear dark, under higher magnifi-
cations they are reddish.
D Vegetative reproduction in addition
to cell division for the unicellular
forms, is by special kinds of frag-
mentation. This includes the for-
mation of hormogones, which are
specifically delimited sections of
trichomes, and are characteristic
of some taxonomic entities.
E Spores of three types are encountered.
1 Akinetes are usually larger, non-
motile, thick-walled resting spores.
2 Heterocysts appear like empty cell
walls, but are filled with colorless
protoplasm and have been occasion-
ally observed to germinate.
3 Endospores, also called gonidia,
are formed by a repeated division
of the protoplast within a cell wall
container.
XIII WHAT ARE SOME EXAMPLES OF BLUE-
GREEN ALGAE?
A Anacystis (Microcystis) is common
in hard waters.
1 Colonies are always free floating.
2 Their shapes may be roughly
spherical or irregular, micro-
scopic or macroscopic.
3 The gelatinous matrix may be
extremely transparent, easily
broken up on preservation.
4 They frequently contain pseudov-
acuoles.
Anabaena is an example of a fila-
mentous form.
1 Filaments may occur singly or
in irregular colonies, and free
floating or in a delicate nucous
matrix.
2 Trichomes have practically
the same diameter throughout;
may be straight, spiral, or
irregularly contorted.
3 Cells are usually spherical,
or barrel shaped, rarely cy-
lindrical and never discoid.
4 Heterocysts are usually the same
shape but are slightly larger
than the vegetative cells.
5 Akinetes are always larger than
the vegetative cells, roughly
cylindrical, and with rounded
ends.
6 It may be readily distinguished
from Nostoc by the lack of a
firm gelatinous envelope.
7 It may produce an undesirable
grassy, moldy or other odor.
Aphanizomenon is a strictly plank-
tonic filamentous form.
1 Trichomes are relatively straight,
and laterally joined into loose
macroscopic free-floating flake-
like colonies.
2 Cells are cylindrical or barrel
shaped, longer than broad.
3 Heterocysts occur within the
filament (i. e., not terminal).
4 Akinetes are cylindrical and
relatively long.
8-3
-------
Blue-Green Algae
SOME BLUE-GREEN ALGAE
Anacystis (Chroococcus) X600.
Agmenellum
(Merismopediurn.)-..X600.
Coccochloris (Gloeocapaa) X600.
(X825)
II. Filamentous blue-green algae:
Trichotnea of Spirulina. (X600).
Trichomes of Arthrospira
(X60TJT:
j^)}vegetative cell
neterocyst
akinete
I (spore)
Anabaena
(X825).
Phortnidium (with sheath)
(X825).
Oscillatoria (without sheath)
(X825)
False branching
True branching Tolypothrix (X375)
Hapatf^phon Prepared by Louis G. Williams
Aquatic : Biologist, Basic Data, SEC.
8-4
-------
Blue-Green Algae
5 Often imparts grassy or nastur-
tium-like odors to water.
D Oscillatoria is a large and ubiquitous
genus.
1 Filaments may occur singly or
interwoven to form mats of
indefinite extent.
2 Trichomes are unbranched, cy-
lindrical, and practically with-
out sheaths.
3 Species with narrow trichomes
have long cylindrical cells
while those with broader tri-
chomes have short broad cells.
4 No heterocysts or akinetes are
known in Oscillatoria. It re -
produces by fragmentation from
hormongonia only.
5 Live species exhibit "oscillatoria"
movements, which are oscillating.
6 Species of Oscillatoria may be
readily distinguished from
Lyngbya by the absence of a
sheath.
E Nodularia is an occasional producer
of blooms.
Trichomes are practically the
same diameter throughout.
Sheaths are usually distinct,
fairly firm, and with a single
trichome.
REFERENCES
1 Bartsch, A. F. (ed.) Environmental
Requirements of Blue-Green Algae.
FWPCA. Pacific Northwest Water
Laboratory, Corvallis, Oregon.
lllpp. 1967.
2 Desikachary, T. V. Cyanophyta, Indian
Council Agric. Res. New Delhi. 1959.
3 Drouet, Francis. Mxyophyceae. Chapter
5 in Edmondson. Freshwater Biology.
p. 95-114. Wiley. 1959.
4 Drouet, Francis. Revision of the Classifi-
cation of the Oscillariaceae. Monograph
15. Acad. Nat. Sci. Phil. 370 pp. 1968.
5 Jackson, Daniel F. (ed.) Algae, Man, and
the Environment. Univ. Syracuse Press.
554 pp. 1968.
This outline was prepared by L. G. Williams,
Formerly Aquatic Biologist, Aquatic Biology
Activities, Research and Development,
Cincinnati Water Research Laboratory, FWPCA.
1 Vegetative cells, heterocysts,
and even the akinetes are broader
than long.
Descriptor: Cyanophyta
8-5
-------
GREEN AND OTHER PIGMENTED FLAGELLATES
I INTRODUCTION
A A flagellate is a free swimming cell
(or colony) with one or more flagella.
B Motile flagellated cells occur in most
(not all) great groups of plants and animals.
C Out main concern will be with "mature"
flagellated algae.
E THE STRUCTURE OF A PIGMENTED OR
PLANT-LIKE FLAGELLATE
A There is a well organized nucleus.
B The flagellum is a long whip-like process
which acts as a propeller.
1 It has a distinctive structure.
2 There may be one or several per cell.
C The chlorophyll is contained in one or
more chloroplasts.
D Two or more cells may be associated in
a colony.
E Non-Motile Life history stages may be
en countered.
F Size is of little use in identification.
G Pyrenoid bodies are often conspicuous.
in The Euglenophyta or Euglena-like algae
(Figures 1-4) are almost exclusively single
celled free swimming flagellates. Nutrition
may be holophytic, holozoic, or saprophytic,
even within the same species. Referred to
by zoologists as mastigophora; many animal
like forms are parasitic or commensalistic.
Food reserves of plant-like forms are as
paramylin (an insoluble carbohydrate) and
fats (do not respond to starch test). Thick
walled resting stages (cysts) are common.
"Metabolic movement" characteristics of
some genera (Euglena).
Eyespot usually present in anterior end,
rarely more than one flagellum.
A Euglena is a large genus with pronounced
metabolic movement (Figure 1).
1 Cells spindle shaped
2 Single flagellum
3 Eyespot usually present
4 Chloroplasts numerous, discoid
to band shaped
5 E_. sanguinea has red pigment.
6 E. viridis generally favors water
rich in organic matter.
7 E_. gracilis is less tolerant of pollution.
B Phacus cells maintain a rigid shape
(Figure 2).
1 Often flattened and twisted, with
pointed tip or tail end.
2 Cell wall (periplast) often marked
with fine ridges.
3 P. pyrum favored by polluted water.
4 P. pleuronectes relatively intolerant
of pollution.
C Trachelomonas cells surrounded by a
distinct shell (lorica) with flagellum
sticking through hole or collar (Figure 4).
1 Surface may be smooth or rough
2 Usually brown in color
3 Some species such as T. cerebea
known to clog filters
BI.MIC.cla.6c. 6.76
9-1
-------
Green and Other Pigmented Flagellates
D Lepocinclis has rigid naked cells with
longitudinal or spiral ridges (Figure 3).
1 Cells uncompressed, elipsoidal to oval
(in contrast to phacus)
2 Only two species with pointed tails
3 L. texta often associated with waters
of high organic content
IV The Chlorophyta or grass green algae
(Figures 5-9) are the largest and most varied
group. Non-flagellated forms predominate but
many conspicuous flagellates are included.
Food reserves are usually stored as starch
which is readily identified with iodine.
Usually two flagella of equal length are
present. More planktonic forms are included
than in any other group, predominating in the
late spring and early autumn.
The cell is typically surrounded by a definite
wall and usually has a definite shape. Cell
pigments closely resemble those of higher
plants, but some have accessory pigments
and a few forms have little or none. The
chloroplasts always have a shape charac-
teristic of the genus.
The flagellated chlorophyta are contained in
the Order Volvocales, the Volcocine algae.
All are actively motile during vegetative
phases. May be unicellular or colonial. All
have an eyespot near the base of the flagella.
Colonies may range from a simple plate
(Gonium sociale) to a complete hollow sphere
(Volvox spp ).
A Chlamydomonas is a solitary free swimming
genus (Figure 5).
1 Species range from cylindrical to
pearshaped.
2 Some species have a gelatinous sheath.
3 There are two flagella inserted close
together.
4 Generally favored by polluted waters.
B Carteria resembles Chlamydomonas very
closely except that it has four flagella
instead of two. Generally favored by
polluted water (Figure 7).
C Phacotus usually has free swimming
biflagellate cells surrounded by biconcave
envelopes resembling two clam shells.
These are usually sculptured, dark
colored, and impregnated with calcium
carbonate.
1 The eyespot ranges from anterior
to posterior.
2 Several daughter cells may be retained
within the old envelopes of the parent
cell.
3 A clean water indicator.
D Chlorogonium is a distinctive genus in
which the cell is fusiform, the tail end
pointed, and the anterior end slightly
blunt (Figure 6).
1 The two flagella only about half as
long as the cell.
2 The cell wall is rather delicate.
3 An eyespot usually present near the
anterior end.
4 Favored by pollution.
E Gonium colonies typically have 4 to 32
cells arranged in a plate (Figure 8).
1 The cells are imbedded in a gelatinous
matrix.
2 Sixteen celled colonies move through
the water with a somersault-like
motion.
3 Four and eight celled colonies swim
flagella end first.
4 Gonium pectorale is typically a
plankton form.
F Pandorina colonies range up to 32 cells,
usually roughly spherical (Figure 9).
9-2
-------
Green and Other Pigmented Flagellates
1 Cells arranged in a hollow sphere
within a gelatinous matrix.
2 Often encountered especially in hard-
water lakes, but seldom abundant.
3 P. morurn may cause a faintly fishy
odor.
G Eudorina has up to 64 cells in roughly
spherical colonies.
1 The cells may be deeply imbedded in
a gelatinous matrix.
2 Common in the plankton of soft water
lakes.
^ !?• elegans is widely distributed.
4 May cause faintly fishy odor.
H Pleodorina has up to 128 cells located
near the surface of the gelatinous matrix.
It is widespread in the United States.
I Volvox rarely has less than 500 cells
per colony.
1 Central portion of the mature colony
may contain only water.
2 Daughter colonies form inside the
parent colony.
3 V. aureus imparts a fishy odor to the
water when present in abundance.
J Chlamydobotrys has "mulberry shaped"
colonies, with biflagellate cells alternately
arranged in tiers of four each.
(Spondylomorum has quadriflagellate cells).
1 There is no enveloping sheath.
2 C. stellata is favored by pollution.
V The Pyrrhophyta includes principally the
armored or dinoflagellates (Dinophyceae)
(Figures 14-16). This group is almost
exclusively flagellated and is characterized
by chromatophores which are yellow-brown
in color. Food reserves are stored as
starch or oil. Naked, holozoic, and
saprozoic representatives are found.
Both "unarmored", and "armored" forms
with chromatophores are found to ingest
solid food readily, and holozoic nutrition
may be as important as holophytic.
The great majority have walls of cellulose
consisting of a definite number of articulated
plates which may be very elaborate in
structure. There is always a groove
girdling the cell in which one flagellum
operates, the other extends backward from
the point of origin.
Most of the dino-flagellates are marine and
some are parasitic. There are six fresh
water genera of importance in this country.
A Gymnodinum species are generally naked
except for a few freshwater species.
G. brevis (marine) is a toxic form
considered to be responsible for the
"red tide" episodes in Florida and
elsewhere.
B Species of Gonyaulax (catanella and
tamarensis) are responsible for the
paralytic shellfish poisoning.
C Ceratium is distinctive in that the
anterior and posterior ends are con-
tinued as long horns (Figure 16).
1 Seasonal temperature changes have a
pronounced effect on the shape of the
cells of this species.
2 C. hirudinella in high concentration is
reported to produce a "vile stench".
9-3
-------
Green and Other Pigmented Flagellates
D Peridinium is a circular, oval, or
angular form, depending on the view
(Figure 15).
1 Cell wall is thick and heavy.
2 Plates are usually much ornamented.
3 I\ cinctum has been charged with a
fishy odor.
VI The Division Chrysophyta contains two
classes which include flagellates, the
Xanthophyceae or Heterokontae (yellow-
green algae) and the Chrysophyceae (golden-
green algae) (Figures 10-13). The third
class, the diatoms (Bacillarieae or
Bacillariophyceae), is not flagellated.
A None of the Xanthophyceae are included
in the present discussion.
B The Chrysophyceae possess chroma-
tophores of a golden brown color, usually
without pyrenoids. Food reserves are
stored as fats and leucosin. One or two
flagella; if two, they may be of equal or
unequal length. Internal silicious cysts
may be formed. Tend to occur in
relatively pure water. Both holozoic and
holophytic types of nutrition are found.
Certain minute forms considered to be
highly sensitive to pollution.
1 Mallomonas is a solitary, free
swimming genus with one flagellum
(Figure 13).
a Covered with silicious plates, many
of which bear long silicious spines.
b Tends to inhabit clear water lakes
at moderate depths.
c M. caudata imparts a fishy odor
to the water.
2 Chrysococcus cells are minute, with
two yellowish brown chromatophores
and one flagellum.
a Droplets of stored oil present
b Lorica distinct
c C. rufesceus a clean water form
3 Chromulina has a single flagellum,
may accumulate single large granule
of leucosin at posterior end of cell
(Figure 10).
C. rosanoffii is a clean water indicator.
4 Synura is a biflageUate form growing
in radially arranged, naked colonies
(Figure 11).
a Flagella equal in length
b Cells pyriform or egg shaped
c Łi. uvella produces a cucumber or
muskmelon odor
5 Uroglenopsis forms free swimming
colonies of approximately spherical
biflagellate cells embedded near the
periphery of a roughly spherical
gelatinous matrix.
a Flagella are unequal in length.
b U. americana may range up to
. 5 mm in diameter, and contain
1000 or more cells.
c U. am. also causes strong fishy
odor.
6 Dinobryon may be solitary or colonial,
free floating or attached. Colonies
are arborescent (Figure 12).
a Cells attached to bottom of open
roughly cylindrical lorica or sheath.
b Two flagella of unequal length.
c Conspicuous eyespot usually present.
d Taxonomy of the group is involved.
e D_. sertularia may clog filters.
f D. divergens may cause a fishy odor.
9-4
-------
Green juid Other Pigmented Flagellates
(fig 1 - 13 from Lackey and Callaway)
Euglena
Phacus
Lepocinclis
Trachelomonas
GREEN EUGLENOIDS
Chlamydomonas
Chlorogonium
GREEN PHYTOMONADS
11
Dinobryon
YELLOW CHRYSOMONADS
Peridinium
16
Ceratium
YELLOW-BROWN DINOFLAGELLATES
-------
Green and Other Pigmented Flagellates
FLAGELLATES
(MASTIGOPHORA)
PLANT FLAGELLATES
(PHYTOMASTIGINA)
ANIMAL FLAGELLATES
(ZOOMASTIGINA)
1
SOMONADI
CRYPT
YA
3MONADIN
1
PHYTOMONADINA
RmZOli
IASTIGINA
PROTOMONADINA
EUGLENOIDINA
POLYMASTIGINA
Figure 17 Phylogenetic Family Tree of the Plagellates
(from Calaway and Lackey)
VII There are two distinctive groups whose
systematic position is uncertain, the chloro-
monads and the cryptomonads. Only one
genus of the latter group is included here.
A Rhodomonas may range from bright red
through pale brown to olive green.
1 Cells compressed, narrow at the
posterior end
2 Two flagella of unequal length
3 R. lacustris a small form intolerant
of pollution
REFERENCES
1 Calaway, Wilson T. and Lackey, James
B. Waste Treatment Protozoa
Flagellata. Series No. 3. Univ. Fla.
140 pp. 1962.
2 Gojdics, M. The Genus Euglena.
Univ. of Wisconsin Press, Madison.
1953.
This outline was prepared by H. W. Jackson,
former Chief Biologist, National Training
Center, MOTD, OWPO, USEPA, Cincinnati,
Ohio 45268.
Descriptor: Algae, Flagellates
9-6
-------
FILAMENTOUS GREEN ALGAE
I MANY OF THESE FORMS ARE VISIBLE
TO THE UNAIDED EYE
A They may be several inches or even a foot
or more in length. In many cases they are
not found as isolated filaments but develop
in large aggregations to form floating or
attached mats or tufts. The attached
forms are generally capable of remaining
alive after being broken away from the
substrate.
B Included in the group are some of the most
common and most conspicuous algae in
freshwater habitats. A few of them have
been given common names such as pond
silk, green felt, frog-spawn algae, and
stoneworts.
C Specialized structures are present in
some filaments.
1 Some filaments break up into "H"
sections.
2 Apical caps are present in others.
3 Replicate end walls are present in
some.
4 Some filaments are overgrown with a
cortex.
5 Attached filaments have the basal cell
developed into a "hold fast cell"
(hapteron).
II CHARACTERISTICS OF FILAMENTOUS
ALGAE
A These algae are in the form of cylindrical
cells held together as a thread ("filament"),
which may be in large clusters or growing
separately. Some are attached to rocks
or other materials while others are free.
They may be unbranched ("simple") or
branched; the tips are gradually narrowed
("attenuated") to a point. Some are
surrounded by a mucilaginous envelope.
B Each cell is a short or long cylinder with
a distinct wall. The protoplast contains
a nucleus which is generally inconspicuous.
1 The plastid or chloroplast is the
prominent structure. It contains
chlorophyll and starch centers
("pyrenoids"), and varies in size,
shape, and number per cell. It may
be pressed against the wall ("parietal")
or extend through the central axis of
the cell ("axial").
2 Clear areas of cell sap ("vacuoles") are
generally present in the cell.
1 Including a few yellow-brown and red algae.
Ill REPRODUCTION MAY TAKE PLACE
BY SEVERAL METHODS
A Cell division may occur in all cells or
in certain selected ones.
B Spores called akinetes may be formed.
C Zoospores (motile) and aplanospores
(non-motile) are common.
D Fragmentation of filaments may occur.
E Many kinds reproduce sexually, often
with specialized gamete forming cells.
IV EXAMPLES OF FILAMENTOUS GREEN
ALGAE ARE:
A Unbranched forms
*Spirogyra
*Mougeotia
Zygnema
Ulothrix
Microspora
Tribonema
Desmidium
Oedogonium
-i'Planktonic or occasionally planktonic
BI. MIC.cla. 14b.6.76
10-1
-------
Filamentous Green Algae
B Branched forms
Cladophora
Pithopora
Stigeoclonium
Chaetophora
Draparnaldia
Rhizoclonium
Audouinella
Bulbochaete
Nitella
C Specialized and related forms
Schizomeris
Comsopogon
Batrachospermum
Chara
Lemanea
Vaucheria
V Habitats include the planktonic growths as
well as surface mats or blankets and benthic
attached forms on rocks in riffles of streams,
at the shoreline of lakes and reservoirs,
concrete walls, etc.
A Attached forms may break loose to
become mixed with plankton or to form
floating mats.
B Cladophora mats are a nuisance on many
beaches on the Great Lakes.
VI IMPORTANCE OF FILAMENTOUS
GREEN ALGAE
A They may cause clogging of sand filters,
intake screens, and canals.
B They may produce tastes and odors in
water or putrid odor (also producing
H9S which damage painted surfaces) when
washed ashore around lakes and reservoirs.
C They may cause unsightly growths or
interfere with fishing and swimming in
recreation areas.
D Some are useful as indicators of water
quality in relation to pollution.
E Together with other algae, they release
oxygen required by fish, and for self-
purification of streams.
F They may produce a slime which inter-
feres with some industrial uses of water
such as in paper manufacture and in
cooling towers.
VII CLASSIFICATION
A Ulotrichaceae
Ulothrix, Microspora. Hormidium
B Cladophoraceae
Cladophora. Pithophora. Rhizoclonium
C Chaetophoraceae
Chaetophora, Stigeoclonium. Draparnaldia
D Oedogeniaceae
Oedogonium. Bulbochaete
E Schizomeridaceae
1 Schizomeris
F Ulvaceae
Enteromorpha. Monostroma
G Zygnemataceae
Zygnema. Spirogyra. Mougeotia
H Desmidiaceae
Desmidium. Hyalotheca
I Tribonemataceae
Tribonema. Bumilleria
J Characeae
Chara. Nitella, Tolypella
10-2
-------
Filamentous Green Algae
13. GREENS, FILAMENTOUS
-------
Filamentous Green Algae
Vin IDENTIFICATION
A Branching and attenuation are of primary
importance.
B Plastids: shape, location and number per
cell are essential.
C Other characteristics include grouping
of filaments, gelatinous envelope and
special features such as "H" shaped
fragments.
REFERENCES
1 Collins, F.S. 1909. The green algae
of North America. Tufts College
Studies, Scientific Series 2:79-480.
Reprinted Hafner Publ. Co., 1928
(Reprinted, 1968) Lew's Books,
San Francisco.
2 Faridi, M. A monograph of the fresh-
water species of Cladophora and
Rhizoclonium. Ph.D. Thesis.
University Microfilms, Ann Arbor.
3 Hirn, K. E. Monograph of the
Oedogoniaceae. Hafner Publ.,
New York. 1960.
4 Pal, B.P., Kundu, B.C., Sundaralingam,
V. S., and Venkataraman, G. S.
Charophyta. Indian Coun. Agric.
Res., New Delhi. 1962.
5 Soderstrom, J. Studies in Cladophora.
Almquist, Uppsala. 1963.
6 Tilden, J. The Myxophyceae of North
America. Minn. Geol. Surv.
(Reprinted 1967, J. Cramer, Lehre,
Germany) 1910.
7 Transeau, E.N. The Zygnemataceae.
Ohio State Univ. Press. 1951.
8 Van der Hoek, C. Revision of the
European species of Cladophora.
Brill Publ, Leiden, Netherlands.
1963.
9 Wood, R. D. and Imahari, K. A revision
of the Characeae. Volume I.
Monograph (by Wood). Vol. II,
Iconograph (by Wood & Imahari). 1964.
This outline was prepared by C.M. Palmer,
Former Aquatic Biologist, In Charge,
Interference Organisms Studies, Micro-
biology Activities, Research and
Development, Cincinnati Water Research
Laboratory, FWPCA.
Descriptor; Green Algae
10-4
-------
COCCOID GREEN ALGAE
I INTRODUCTION
For the sake of convenience, the non-motile
green algae are to be discussed in two
sections: those that tend to live as relatively
discrete or free floating planktonic units,
and those that tend to grow in masses or
mats of material, often filamentous in nature,
attached or free floating.
n The green or "grass green" algae is one
of the most varied and conspicuous groups
with which we have to deal. The forms
mentioned below have been artificially grouped
for convenience according to cell shape.
Botanists would list these genera in several
different categories in the family "Chloro-
phyceae. "
These algae typically have a relatively high
chlorophyll content, and the food reserves
accumulated are typically starch. Thus
these forms will usually give a typical black
or deep purple color when treated with iodine.
A Individual cells of the following genera are
perfectly round, or nearly so. The first
does not form organized colonies. In the
next two the colonies themselves tend to
be round, and in the last, the colonies are
triangular or irregular, and the cells bear
long slender spines.
1 Chlorella cells are small and spherical
to broadly elliptical. They have a
single parietal chloroplast. This is a
very large genus with an unknown
number of similar appearing species,
living in a great variety of habitats.
Although often accumulating in great
numbers, organized colonies are not
formed.
a Chlorella ellipsoides is reported to
be a common plankton form.
b Chlorella pyrenoidosa and Chlorella
vulgaris are often found in
organically enriched waters.
Indeed a dominance of Chlorella
species is considered in some
places to be an indication that a
sewage stabilization pond is func-
tioning to maximum capacity.
c Chlorella pyrenoidosa is reported
as a filter clogger in water treat-
ment plants.
2 Sphaerocystis colonies are free floating
and almost always with a perfectly
spherical, homogeneous gelatinous
envelope. Up to 32 spherical cells
may be included. Sphaerocystis
scheoeteri, the only species, is of
wide occurrence in the plankton of
lakes and reservoirs.
3 Coelastrum forms coenobial* colonies
of up to 128 cells. Generally spherical
or polygonal in shape--both cells and
colony. Cells connected by protoplasmic
processes of varying length.
Coelastrum microporum is often
reported in the plankton of water
supplies. Not surrounded by gelatinous
envelope as in Sphaerocystis.
4 Micractinium. The cells of this alga
are spherical to broadly ellipsoidal and
are usually united in irregular 4-celled
coenobes. These in turn are almost
always united with other coenobes to
form multiple associations of up to
100 or more cells. The free face of
1 Including miscellaneous yellow-brown algae.
*A coenobe is a colony in which the number of cells does not increase during the life of the
colony. It was established by the union of several independent swimming cells which simply
stick together and increase in size.
Bt.MIC.cla. 9c. 6.76
11-1
-------
Coccoid Green Algae
each cell in a coenobe bears from one
to seven very long slender setae or
hairs.
Micractinium pusillum. This is a
strictly planktonic genus.
Individual cells of the following genera
are elongate. In the first two they are
relatively straight or irregular and pointed.
The next two are also long and pointed,
but bent into a tight "C" shape (one in a
gelatinous envelope, one naked). The last
one (Actinastrum) is long and straight,
but with blunt ends, and with the cells of
a coenobe attached at a point.
1 Ankistrodesmus cells are usually long
and slender, tapering to sharp point at
both ends. They may be straight,
curved, or twisted into loose aggregations.
Ankistrodesmus falcatus is often found
in the plankton in water supplies and is
considered to be one of the forms
indicative of clean water.
2 Schroederia is a solitary, free floating
alga. Cells are long and pointed at
both ends. May be bent in various ways.
Terminal points are continued as long
slender spines which may be forked and
bent back, or end as a plate. Of the
three species reported in this country,
Schroederia setigera has been reported
in water supplies.
3 Selenastrum cells are pointed at both
ends, and bent so that their tips approach
each other. They tend to occur in groups
of 4, 8, or 16, which may be associated
with other groups to form masses of a
hundred or more cells. There is no
gelatinous envelope. Selenastrum
gracile occurs in the plankton of water
supplies.
4 Kirchneriella. The cells of this genus
are generally relatively broad, tapering
to a sharp or rounded point at each end,
and the whole cell bent into a C-shape.
They usually occur in groups of four
to eight in a broad, homogeneous,
gelatinous matrix. Kirchneriella
lunaris is known principally from the
plankton.
5 Actinastrum colonies or "coenobes"
are composed of 4, 8, or 16 elongate
cells that radiate in all directions from
a common center.
Actinastrum is a widely distributed
plankton organism. There are two
species:
Actinastrum gracillimum and
Actinastrum Hantzschii differ only
in the sharpness of the taper toward
the tips of the cells. The former has
relatively little taper, and the latter,
. more.
Cells of the following genera are
associated in simple naked colonies.
The first has elongate cells arranged
with their long axes parallel (although
some cells may be curved). The last
two are flat plate-like coenobes.
Crucigenia has four-celled coenobes
while Pediastrum coenobes may be
larger, appear plate-like, and are much
more ornate.
1 Scenedesmus is a flat plate of elliptical
to double ended pointed cells arranged
with their long axes parallel. Coenobes
consist of up to 32, but usually 4 to 8
cells. The number of cells in a
coenobe may vary from mother to
daughter colony. The appearance of
cells may vary considerably with the
species.
a Scenedesmus bijuga, S. dimorphus,
and Ł>. quadricauda are common
p]anktonic forms.
b Scenedesmus quadricauda is also
common in organically enriched
water, and may become dominant.
c Scenedemus abundans is reported
to impart a grassy odor to drinking
water.
11-2
-------
Coccoid Green Algae
2 Crucigenia forms free floating four-
celled coenobes that are solitary or
joined to one another to form plate-
like multiple coenobes of 16 or more
cells. The cells may be elliptical,
triangular, trapezoidal, or semi-
circular in surface view. Crucigenia
quadrata is a species often reported
from water supplies.
3 Pediastrum. Colonies are free floating
with up to 128 polygonal cells arranged
in a single plane. There may or may
not be open spaces between the cells.
The exact arrangement of the cells
seems to depend largely on the chance
distribution of the original motile
swarming zoaspores at the time the
coenobe was formed. Peripheral cells
may differ in shape from interior cells.
a Pediastrum boryanum and P. duplex
are frequently found in the plankton,
but seldom dominate.
b Pediastrum tetras has been reported
to impart a grassy odor to water
supplies.
D Cells of the following Genera are slightly
elongated.
1 Oocystis. The cells of Oocystis may
be solitary, or up to 16 cells may be
surrounded by a partially gellatinized
and greatly expanded mother cell wall.
Cells may be ellipsoidal or almost
cylindrical, cell wall thin, no spines
or other ornamentation. Oocystis
borgei. for example, is of frequent
occurrence in the plankton.
2 Dimorphococcus cells are arranged in
groups of four, and these tetrads are
united to one another in irregularly
shaped free floating colonies by the
branching remains of old mother-cell
walls. Two shapes of cell are normally
found in each tetrad (hence the name), two
longer ovate cells end to end, and a
pair of slightly shorter, C-shaped cells
on either side. Dimorphococcus
lunatus is a widely distributed plankton
organism, sometimes reported in
considerable numbers.
E A distinctive group of green algae
characterized by a median constriction
dividing the cell into two geometrically
similar halves is known generally as the
"desmids. " (Closterium and Penium do
not have this construction). Each half
of the cell is known as a "semicell. "
The nucleus lies in the "isthmus. "
Extremes of ornamentation and structural
variety exist. Most are unicellular, but
a few are filamentous or have the cells
associated in shapeless colonies. They
are found sparingly in the plankton almost
everywhere, but predominate in acid
waters.
1 Closterium is one of the exceptional
genera without a median constriction.
The cells are elongate, attenuated
toward the tips but not sharply pointed,
usually somewhat bent.
a Closterium aciculare is a planktonic
species.
b Closterium moniliforme is reported
as a filter clogging organism.
2 Cosmarium is a large, poorly defined
genus of over 280 species, many of
which apparently intergrade with other
genera such as Staurastrum. In
general, it can be said that Cosmarium
species are relatively small, with a
length only slightly greater than the
width, and with a deep median con-
striction. Shapes of the semicells
may vary greatly. Although shallow
surface ornamentation may occur,
long spines do not occur.
a Cosmarium botrytis is reported in
plankton from water supply
reservoirs.
b Cosmarium portianum is said to
impart a grassy odor to water.
c Other species have been reported
to be sufficiently resistant to
chlorine to penetrate rapid sand
filters and occur in distribution
systems in considerable numbers.
11-3
-------
Coccoid Green Algae
3 Micrasterias is relatively common,
ornate.
4 Euastrum cells tend to be at least twice
as long as broad, with a deeply con-
stricted isthmus, and a dip or incision
at the tip of each semicell. The cell
wall may be smooth, granulate, or
spine d.
Euastrum oblongum is reported as a
planktonic species from water reser-
voirs. It has also been noted as
intolerant of pollution, and hence an
indicator of clean water.
5 Staurastrum is the commonest of the
desmids in the plankton of fresh waters;
the genus contains upwards of 245 species
in the United States alone. Inter-
gradation with other genera such as
Cosmarium make it a difficult group
to define. Most of the species are
radially symmetrical, and almost all
have a deeply constricted isthmus.
The cell wall may be smooth, orna-
mented, or spined in a variety of ways.
Relatively long truncated processes
extending from the cell body in
symmetrical patterns are common.
a Staurastrum polymorphum is a
typical planktonic form.
b Staurastrum punctulatum is reported
as an indicator of clean water.
c Staurastrum paradoxicum causes a
grassy odor in water.
1 The plant body is a free floating colony
of indefinite shape, with a cartilag-
inous and hyaline or orange-colored
envelope; surface greatly wrinkled
and folded.
2 Individual cells lie close together, in
several aggregates connected in
reticular fashion by strands of the
colonial envelope.
3 The envelope structure tends to
obscure cell structure. Considerable
deep orange colored oil may collect
within the envelope, outside of the
cells, obscuring cell structure.
B Ophiocytium capitatum like Botryococcus,
is widely distributed, but seldom abundant.
1 Both ends of cylindrical cell are
rounded, with a sharp spine extending
therefrom.
2 Many nuclei and several chloroplasts
are present.
REFERENCES
1 Palmer, C.M. Algae in Water Supplies.
Government Printing Office. PHS
Publication No. 657. 1959.
2 Smith, G.S. Phytoplankton of the
Inland Lakes of Wisconsin. Part I.
Bulletin No. 57, Scientific Series
No. 12. 1920.
IE A type of "green" alga known as "golden
green" (Xanthophyceae) is represented in the
plankton by two genera. In these algae there
is a predominance of yellow over green pig-
ments, hence frequently imparting a yellowish
or golden tint to the cell. Reserve food
material is stored as oil and leucosin, rather
than as starch, hence giving a negative test
with iodine in most cases.
A Botryococcus braunii is a widely dis-
tributed plankton alga, though it is
rarely abundant.
This outline was prepared by H. W. Jackson,
former Chief Biologist, National Training
Center, and revised by R. M. Sinclair,
Aquatic Biologist, National Training Center,
MOTD, OWPO, USEPA. Cincinnati, Ohio
45268.
Descriptor: CMorophyta
11-4
-------
DIATOMS
I GENERAL CHARACTERISTICS
A Diatoms have cells of very rigid form due
to the presence of silica in the wall. They
contain a brown pigment in addition to the
chlorophyll. Their walls are ornamented
with markings which have a specific pattern
for each kind.
1 The cells often are isolated but others
a.re in filaments or other shapes of
colonies.
2 The protoplast contains normal cell
parts, the most conspicuous being the
plastids. No starch is present.
B Cell shapes include the elongate ("pennate")
and the short cylindric ("centric") one view
of which is circular.
1 Pennate diatoms may be symmetrical,
transversely unsymetrical, or longitudi-
nally unsymmetrical.
Internal shelves ("septae") extending
longitudinally or transversely.
II REPRODUCTION
A The common method is by cell division.
Two new half cells are formed between the
halves of the parent cell.
B Auxospores and gametes may also be
formed.
Ill EXAMPLES OF COMMON DIATOMS:
A Pennate, symmetrical:
Navicula
Pinnularia
Synedra
Nitzschia
Diatom a
Fragilaria
Tabellaria
Cocconeis
C Wall is formed like a box with a flanged
cover fitting over it.
1 "Valve" view is that of the top of the
cover or the bottom of the box.
2 "Girdle" view is that of the side where
flange of cover fits over the box.
3 End view is also possible for pennate
types.
D Cell markings include:
1 Raphe or false raphe extending
longitudinally.
2 Striations which are lines of pores
extending from the area of the raphe to
the margin. Coarse ones are "costae".
3 Nodules which may be terminal and
central.
B Pennate, unsymmetrical:
Gomphonema
Surirella
Cymbella
Achnanthes
Asterionella
Meridion
C Centric:
Cyclotella
Stephanodiscus
Melosira
IV Habitats include fresh and salt water. Both
planktonic and attached forms occur, the latter
often are broken loose. They may be attached
by stalks or by their slimy surface.
BI.MlC.cla. lOa. 6. 76
12-1
-------
Diatoms
A Many diatoms are more abundant in late
autumn, winter, and early spring than in
the warmer season.
Fragilaria
Synedra
Asterionella
B The walls of dead diatoms generally remain
undecomposed and may be common in water.
Many deposits of fossil diatoms exist.
V Importance of diatoms is in part due to
their great abundance and their rigid walls.
A They are the most important group of
organisms causing clogging of sand filters.
B Several produce tastes and odors in water,
including the obnoxious fishy flavor.
C Mats of growth may cause floors or steps
of swimming pools to be slippery.
D They may be significant in determining
water quality in relation to pollution.
E They release oxygen into the water.
2 Achnanthineae. Group with cells
having one false and one true raphe.
a Representative genera:
Cocconeis
Achnanthes
3 Naviculineae. True raphe group with
raphe in center of valve.
a Representative genera:
Navicula
Pinnularia
Stauroneis
Pleurosigma
Amphiprora
Gomphonema
Cymbella
Epithemia
VI Classification. There are several thou-
sand species of diatoms. Only the most com-
mon of the freshwater forms are considered
here.
A Centrales Group
1 Representative genera:
Cyclotella
Stephanodiscus
Melosira
Rhizosolenia
Biddulphia
B Pennals Group
1 Fragilarineae. The false raphe group.
Representative genera:
Tabellaria
Me rid ion
Diatoma
4 Surirellineae. True raphe group with
raphe near one side of valve.
a Representative genera:
Nitzschia
Cymatopleura
Surirella
Campylodiscus
VII IDENTIFICATION OF DIATOMS
A Some genera are easily recognized by their
distinctive shape.
B Many genera and most species can be
determined only after diatoms are freed
of their contents and observed under the
high magnification of an oil immersion
lens of the compound microscope.
C Contents of the cell are generally not
used in identification. Only the char-
aracteristics of the wall are used.
12-2
-------
Diatoms
D For identification of genera, most im-
portant features include:
1 Cell shape, and form of colony
2 Raphe and false raphe
3 Striations
4 Septa
For identification of species, measure-
ments involving the number of striae per
10 microns, the direction of the striae
and many other characteristics may be
needed.
REFERENCES
1 Boyer, C.S. The Diatomaceae of
Philadelphia and Vicinity. J. B. Lippin-
cott Co. Philadelphia. 1916. p 143.
2 Boyer, C.S. Synopsis of North America
Diatomaceae. Parts 1(1927) and II
(1928). Proceedings of the Academy
of Natural Sciences. Philadelphia.
3 Elmore, C. J. The Diatoms of Nebraska.
University of Nebraska Studies. 21:
22-215. 1921.
4 Hohn, M. H. A Study of the Distribution
of Diatoms in Western New York
State. Cornell University Agricultural
Experimental Station. Memoir 308.
pp 1-39. 1951.
5 Pascher, A. Bacillariophyta (Diatomeae).
Heft 10 in Die Susswasser-Flora
Mitteleuropas, Jena. 1930. p 466.
6 Patrick, R. A Taxonomic and Ecological
Study of Some Diatoms from the
Pocono Plateau and Adjacent Regions.
Farlowia. 2:143-221. 1945.
7 Patrick, Ruth and Reimer, Charles W.
The Diatoms of the United States.
Vol. 1 Fragilariaceae, Eunotiaceae,
Achnanthaceae, Naviculaceae.
Monog. 13. Acad. Nat. Sci.
Philadelphia. 688 pp. 1966.
8 Smith, G.M. Class Bacillariophyceae.
Freshwater Algae of the United
States, pp 440-510, 2nd Edition.
McGraw Hill Book Co. New York.
1950.
9 Tiffany, L. H. and Britton, M.E. Class
Bacillariophyceae. The Algae of
Illinois, pp 214-296. University
of Chicago Press. 1952.
10 Ward, H. B. and Whipple, G. C. Class
I, Bacillariaceae (Diatoms). Fresh-
water Biology, pp 171-189. John
Wiley & Sons. New York. 1948.
11 Weber, C. I. A Guide to the Common
Diatoms at Water Pollution
Surveillance System Stations.
FWPCA. Cincinnati. 101 pp. 1966.
12 Whipple, G.C., Fair, G. M., and
Whipple, M.C. Diatomaceae.
Microscopy of Drinking Water.
Chapter 21. 4th Edition. John Wiley
& Sons. New York. 1948.
This outline was prepared by C.M. Palmer,
Former Aquatic Biologist, In Charge,
Interference Organisms Studies, Microbiology
Activities, Research and Development,
Cincinnati Water Research Laboratory,
FWPCA.
Descriptor: Diatoms
12-3
-------
FILAMENTOUS BACTERIA
I INTRODUCTION
There are a number of types of filamentous
bacteria that occur in the aquatic environment.
They include the sheathed sulfur and iron
bacteria such as Beggiatoa, Crenothrix and
Sphaerotilus, the actinomycetes which are
unicellular microorganisms that form chains
of cells with special branchings, and
Gallionella, a unicellular organism that
secretes a long twisted ribbon-like stalk.
These filamentous forms have at times
created serious problems in rivers,
reservoirs, wells, and water distribution
systems.
II BEGGIATOA
Beggiatoa is a sheathed bacterium that grows
as a long filamentous form. The flexible
filaments may be as large as 25 microns wide
and 100 microns long. (Figure 1)
Figure 1
Beggiatoa alba
up to 1 .OOO/J
Transverse separations within the sheath
indicate that a row of cells is included in
one sheath. The sheath may be clearly
visible or so slight that only special staining
will indicate that it is present.
The organism grows as a white slimy or
felted cover on the surface of various objects
undergoing decomposition or on the surface
of stagnant areas of a stream receiving
sewage. It has also been observed on the
base of a trickling filter and in contact
aerators.
It is most commonly found in sulfur springs
or polluted waters where H^S is present.
Beggiatoa is distinguished by its ability to
deposit sulfur within its cells; the sulfur
deposits appear as large refractile globule's.
(Figure 2)
Figure 2
Filaments of Beggiatoa
containing granules of
sulphur.
When H S is no longer present in the environ-
ment, tne sulfur deposits disappear.
Dr. Pringsheim of Germany has recently
proved that the organism can grow as a true
autotroph obtaining all its energy from the
oxidation of H?S and using this energy to fix
CO into all material. It can also use
certain organic materials if they are present
along with the H0S.
Łt
Faust and Wolfe, and Scotten and Stokes
have grown the organism in pure culture in
this country. Beggiatoa exhibits a motility
that is quite different from the typical
flagellated motility of most bacteria; the
filaments have a flexible gliding motion.
BA. 8a. 6.76
13-1
-------
Filamentous Bacteria
The only major nuisance effect of Beggiatoa
known has been overgrowth on trickling filters
receiving waste waters rich in H2S. The
normal microflora of the filter was suppressed
and the filter failed to give good treatment.
Removal of the H S from the water by blowing
air through the water before it reached the
filters caused the slow decline of the
Beggiatoa and a recovery of the normal
microflora. Beggiatoa usually indicates
polluted conditions with the presence of tLS
rather than being a direct nuisance.
Ill ACTINOMYCETES AND EARTHY ODORS
IN WATER
Actinomycetes are unicellular microorganisms,
1 micron in diameter, filamentous, non-
sheathed, branching monopodially, and
reproduced by fission or by means of special
Figure 4
Egg albumin isolation plate.
'A' an actinomycete colony,
and 'B1 a bacterial colony
Appearance:
Appearance:
conidia. (Figure 3)
Figure 3 Filaments of Actinomycetes
Their filamentous habit and method of
sporulation is reminiscent of fungi. However,
their size, chemical composition, and other
characteristics are more similar to bacteria.
(Figure 4)
dull and powdery smooth and mucoid
These organisms may be considered as a
group intermediate between the fungi and
the bacteria. They require organic matter
for growth but can use a wide variety of
substances and are widely distributed.
Actinomycetes have been implicated as the
cause of earthy odors in some drinking
waters (Romano and Safferman, Silvey and
Roach) and in earthy smelling substance has
been isolated from several members of the
group by Gerber and Lechevalier. Safferman
and Morris have reported on a method for the
"isolation and Enumeration of Actinomycetes
Related to Water Supplies. ". But the actino-
mycetes are primarily soil microorganisms
and often grow in fields or on the banks of a
river or lake used for the water supply.
Although residual chlorination will kill the
organisms in the treatment plant or distribution
13-2
-------
Filamentous Bacteria
system, the odors often are present before
the waier enters the plant. Use of perman-
ganate oxidation and activated carbon filters
have been most successful of the methods
tried to remove the odors from the water.
Control procedures to prevent the odorous
material from being washed into the water
supply by rains or to prevent possible develop-
ment of the actinomycetes in water rich in
decaying organic matter is still needed.
IV FILAMENTOUS IRON BACTERIA
The filamentous iron bacteria of the
Sphaerotilus- Leptothrix group, Crenothrix,
and Gallionella have the ability to either
oxidize manganous or ferrous ions to manganic
or ferric salts or are able to accumulate
precipitates of these compounds within the
sheaths of the organisms. Extensive growths
or accumulations of the empty, metallic
encrusted sheaths devoid of cells, have
created much trouble in -wells or water dis-
tribution systems. Pumps and back surge
valves have been clogged with masses of
material, taste and odor problems have
occurred, and rust colored masses of
material have spoiled products in contact
with water.
Crenothrix polyspora has only been examined
under the microscope as we have never been
able to grow it in the laboratory. The orga-
nism is easily recognized by its special
morphology. Dr. Wolfe of the University of
Illinois has published photomicrographs of
the organism. (Figure 5)
Organisms of the Sphaerotilus- Leptothrix
group have been extensively studied by many
investigators (Dondero ^t. al., Dondero,
Stokes, Waitz and Lackey, Mulder and van
Veen, and Amberg and Cormack.) Under
different environmental conditions the mor-
phological appearance of the organism varies.
The usual form found in polluted streams or
bulked activated sludge is Sphaerotilus natans.
(Figure 6)
Figure 5
Crenothrix polyspora
cells are very variable In
size from small cocci or
polyspores to cells 3X12^
Figure 6
Sphaerotilus natans
3-8 X 1.2 - 1.8/U
cells
13-3
-------
Filamentous Bacteria
This is a sheathed bacterium consisting of
long, unbranched filaments, whereby individual
rod-shaped bacterial cells are enclosed in a
linear order within the sheath. The individual
cells are 3-8 microns long and 1.2-1.8
microns wide. Sphaerotilus grows in great
masses; at times in streams or rivers that
receive wastes from pulp mills, sugar
refineries, distilleries, slaughterhouses,
or milk processing plants. In these conditions,
it appears as large masses or tufts attached
to rocks, twigs, or other projections and the
masses may vary in color from light grey to
reddish brown. In some rivers large masses
of Sphaerotilus break loose and clog water
intake pipes or foul fishing nets. When the
cells die, taste and odor problems may also
occur in the water.
Amberg, Cormack, and Rivers and McKeown
have reported on methods to try to limit the
development of Sphaerotilus in rivers by
intermittant discharge of wastes. Adequate
control will probably only be achieved once
the wastes are treated before discharge to
such an extent that the growth of Sphaerotilus
is no longer favored in the river. Sphaerotilus
grows well at cool temperatures and slightly
low DO levels in streams receiving these
wastes and domestic sewage. Growth is slow
where the only nitrogen present is inorganic
nitrogen; peptones and proteins are utilized
preferentially.
Gallionella is an iron bacterium which appears
as a kidney-shaped cell with a. twisted ribbon-
like stalk emanating from the concavity of the
cell. Gallionella obtains its energy by
oxidizing ferrous iron to ferric iron and uses
only CO9 and inorganic salts to form all of
the cell material; it is an autotroph. Large
masses of Gallionella may cause problems
in wells or accumulate in low-flow low-
pressure water mains. Super chlorination
(up to 100 ppm of sodium hypochlorite for
48 hours) followed by flushing will often
remove the masses of growth and periodic
treatment will prevent the nuisance effects
of the extensive masses of Gallionella.
(Figure 7)
/ A
\iA
Figure 7
!• "\j Galionella furruginea
/
i
i
O.5 X O.7 - 1.1/4
Cefls
REFERENCES
Beggiatoa
1 Faust, L. and Wolfe, R.S. Enrichment
and Cultivation of Beggiatoa Alba.
Jour. Bact., 81:99-106. 1961.
2 Scotten, H. L. and Stokes, J. L.
Isolation and Properties of Beggiatoa.
Arch Fur. Microbiol. 42:353-368.
1962.
3 Kowallik, U. and Pringsheim, E.G.
The Oxidation of Hydrogen Sulfide by
Beggiatoa. Amer. Jour, of Botany.
53:801-805. 1966.
Actinomycetes and Earthy Odors
4 Silvey, J.K. G. etaL Actinomycetes and
Common Tastes and Odors. JAWWA,
42:1018-1026. 1950.
5 Safferman, R. S. and Morris, M. E.
A Method for the Isolation and
Enumeration of Actinomycetes Related
to Water Supplies. Robert A. Taft
Sanitary Engineering Center Tech.
Report W-62-10. 1962.
13-4
-------
Filamentous Bacteria
6 Gerber, N.N. and Lechevalier, H.A.
Geosmin, an Earthy-Smelling Substance
Isolated from Actinomycetes. Appl.
Microbiol. 13:935-938. 1965.
Filamentous Iron Bacteria
7 Wolfe, R.S,, Cultivation, Morphology, and
Classification of the Iron Bacteria.
JAWWA. 50:1241-1249. 1958.
8 Kucera, S. and Wolfe, R.S. A Selective
Enrichment Method for Gallionella
ferruginea. Jour. Bacteriol. 74:344-
349. 1957.
9 Wolfe, R.S. Observations and Studies
of Crenothrix polyspora. JAWWA,
52:915-918. 1960.
10 Wolfe, R.S. Microbiol. Concentration
of Iron and Manganese in Water with
Low Concentrations of these Elements.
JAWWA. 52:1335-1337. 1960.
11 Stokes, J. L. Studies on the Filamentous
Sheathed Iron Bacterium Sphaerotilus
natans. Jour. Bacteriol. 67:278-291.
1954.
12 Waitz, S. and Lackey, J. B. Morphological
and Biochemical Studies on the
Organism Sphaerotilus natans. Quart.
Jour. Fla. Acad. Sci. 21(4):335-340.
1958.
13 Doridero, N.C., Philips, R.A. and
Henkelkian, H. Isolation and
Preservation of Cultures of Sphaerotilus.
Appl. Microbiol. 9:219-227. 1961.
14 Dondero, N. C. Sphaerotilus. Its Nature
and Economic Significance. Advances
Appl. Microbiol. 3:77-107. 1961.
15 Mulder, E.G. and van Veen, W. L.
Investigations on the Sphaerotilus-
Leptothrix Group. Antonie van
Leewenhoek. 29:121-153. 1963.
16 Amberg, H.R. and Cor mack, J. F.
Factors Affecting Slime Growth in
the Lower Columbia River and
Evaluation of Some Possible Control
Measures. Pulp and Paper Mag. of
Canada. 61:T70-T80. 1960.
17 Amberg, H.R., Cormack, J. F. and
Rivers, M.R. Slime Growth Control
by Intermittant Discharge of Spent
Sulfite Liquor. Tappi. 45:770-779.
1962.
18 McKeown, J.J. The Control of
Sphaerotilus natans. Ind. Water
and Wastes. 8:(3) 19-22 and
8:(4)30-33. 1963.
19 Curtis, E. J. C., Sewage Funrus; Its
Nature and Effects. Wat. Res.
3:289-311. 1969.
20 Lechevalier, Hubert A., Actinomycetes
of Sewage Treatment Plants. Envir.
Prot. Tech. Series USEPA,
600/1-75-031. 1975.
This outline was prepared by R. F. Lewis
Bacteriologist, Advanced Waste Treatment
Research Laboratory, NERC, USEPA,
Cincinnati, Ohio 45268.
Descriptors: Aquatic Bacteria, Sphaerotilus
Actinomycetes, Nocardia
13-5
-------
FUNGI AND THE "SEWAGE FUNGUS" COMMUNITY
I INTRODUCTION
A Description
Fungi are heterotrophicachylorophyllous
plant-like organisms which possess true
nuclei with nuclear membranes and nu-
cleoli. Dependent upon the species and
in some instances the environmental
conditions, the body of the fungus, the
thallus, varies from a microscopic
single cell to an extensive plasmodium
or mycelium. Numerous forms produce
macroscopic fruiting bodies.
B Life Cycle
The life cycles of fungi vary from simple
to complex and may include sexual and
asexual stages with varying spore types
as the reproductive units.
C Classification
Traditionally, true fungi are classified
within the Division Eumycotina of the
Phylum Mycota of the plant kingdom.
Some authorities consider the fungi an
essentially monophyletic group distinct
from the classical plant and animal
kingdoms.
Ill ECOLOGY
A Distribution
Fungi are ubiquitous in nature and mem-
bers of all classes may occur in large
numbers in aquatic habitats. Sparrow
(1968) has briefly reviewed the ecology
of fungi in i'reshwaters with particular
emphasis on the zoosporic phycomycetes.
The occurrence and ecology of fungi in
marine and estuarine waters has been
examined recently by a number of in-
vestigators (Johnson and Sparrow, 1961;
Johnson, 1968; Myers, 1968; van Uden
and Fell, 1968).
B Relation to Pollution
Wm. Bridge Cooke, in a series of in-
vestigations (Cooke, 1965), has estab-
lished that fungi other than phycomycetes
occur in high numbers in sewage and
polluted waters. His reports on organic
pollution of streams (Cooke, 1961; 1967)
show that the variety of the Deuteromy-
cete flora is decreased at the immediate
sites of pollution, but dramatically in-
creased downstream from these regions.
II
ACTIVITY
In general, fungi possess broad enzymatic
capacities. Various species are able to
actively degrade such compounds as
complex polysaccharides (e.g., cellulose,
chitin, and glycogen), proteins (casein,
albumin, keratin), hydrocarbons (kerosene)
and pesticides. Most species possess an
oxidative or microaerophilic metabolism,
but anaerobic catabolism is not uncommon.
A few species show anaerobic metabolism
and growth.
Yeasts, in particular, have been found
in large numbers in organically enriched
waters (Cooke, et al., 1960; Cooke and
Matsuura, 1963; Cooke, 1965b; Ahearn,
et al., 1968). Certain yeasts are of
special interest due to their potential
use as "indicator" organisms and their
ability to degrade or utilize proteins,
various hydrocarbons, straight and
branch chained alkyl-benzene sulfonates,
fats, metaphosphates, and wood sugars.
BI.FU. 6a. 6. 76
14-1
-------
Fungi
C "Sewage Fungus" Community (Plate I)
A few microorganisms have long been
termed "sewage fungi. " The most
common microorganisms included in
this group are the iron bacterium
Sphaerotilus natans and the phycomy-
cete Leptomitus lacteus.
1 Sphaerotilus natans is not a fungus;
rather it is a sheath bacterium of
the order chlamydobacteriales.
This polymorphic bacterium occurs
commonly in organically enriched
streams where it may produce
extensive slimes.
a Morphology
Characteristically, S. natans
forms chains of rod shaped
cells (1. 1 -2. On x 2.5- l?n)
within a clear sheath or tri-
chome composed ofaprotein-
polysaccharidae-lipid complex.
The rod cells are frequently
motile upon release from the
sheath;.the flagella are lopho-
trichous. Occasionally two
rows of cells may be present
in a single sheath. Single tri-
chomes may be several mm
in length and bent at various
angles. Empty sheaths, ap-
pearing like thin cellophane
straws, may be present.
b Attached growths
The trichomes are cemented
at one end to solid substrata
such as stone or metal, and
their cross attachment and
bending gives a superficial
similarity to true fungal hyphae.
The ability to attach firmly to
solid substrates gives S. natans
a selective advantage in the
population of flowing streams.
For more thorough reviews of
S. natans see Prigsheim( 1949)
and Stokes (1954).
Leptomitus lacteus also produces
extensive slimes and fouling floes
in fresh waters. This species forms
thalli typified by regular constrictions.
a Morphology
Cellulin plugs may be present
near the constrictions and there
may be numerous granules in
the cytoplasm. The basal cell
of the thallus may possess
rhizoids.
b Reproduction
The segments delimited by. the
partial constrictions are con-
verted basipetally to sporangia.
The zoospores are diplanetic
(i. e., dimorphic) and each
possesses one whiplash and one
tinsel flagellum. No sexual
stage has been demonstrated
for this species.
c Distribution
For further information on the
distribution and systematics
of_L_. lacteus see Sparrow (1960),
Yerkes (1966) and Emerson and
Weston (1967). Both S. natans
and L_. lacteus appear to thrive
in organically enriched cold
waters (5°-22°C) andbothseem
incapable of extensive growth at
temperatures of about 30°C.
d Gross morphology
Their metabolism is oxidative
and growth of both species may
appear as reddish brown floes
or stringy slimes of 30 cm or
more in length.
e Nutritive requirements
Sphaerotilus natans is able to
utilize a wide variety of organic
compounds, whereas L. lacteus
does not assimilate simple
14-2
-------
PLATE I
"SEWAGE FUNGUS" COMMUNITY OR "SLIME GROWTHS"
(Attached "filamentous" and slime growths)
Fungi
Zoogloea
Sphaerotilus natans
' >»'—•* *-*"^
i»!
38^
^ssg^"
Beggiatoa alba
BACTERIA
Fusarium aqueductum
Leptomitus lacteus
Geotrichum candidum
FUNGI
Eplstylia 8
10
Opercularia
PROTOZOA
14-3
-------
Fungi
PLATE II
REPRESENTATIVE FUNGI
Figure •*•
Fusarium aquaeductuum
(Radlmacher and
Rabenhorst) Saccardo
Microconidia (A) produced
from phialides as in Cephalo-
sporium, remaining in slime
balls. Macroconidia (B), with
one to several cross walls,
produced from collared phial-
ides. Drawn from culture.
Figure 3
Geotrichum candidum
Lank ex Persoon
Mycelium with short cells
and arthrospores. Young hy-
pha (A) ; and mature arthro-
spores (B). Drawn from cul-
ture.
Figure :
Achlya americana Humphrey
Ooogonium with three oo-
spores (A); young zoospor-
angium with delimited zoo-
spores (B); and zoosporangia
(C) with released zoospores
that remain encysted in clus-
ters at the mouth of the dis-
charge tube. Drawn from cul-
ture.
Figure
Leptomitiu lacteus (Roth)
Agardh
Cells of the hyphae show-
ing constrictions with cellulin
plugs. In one cell large zoo-
spores have been delimited.
Redrawn from Coker, 1923.
Zoophagus insidians
Sommerstorff
Mycelium with hyphal pegs
(A) on which rotifers will
become impaled; gemmae (B)
produced as conidia on short
hyphal branches; and rotifer
impaled on hyphal peg (C)
from which hyphae have
grown into the rotifer whose
shell will be discarded after
the contents are consumed.
Drawn from culture.
FIGURE / -i-faplosporidium costnlc. A—mature .spoiv;
B—early pln$modium.
•Figures 1 through 5 from Cooke; Figures 6 and 7 from Galtsoff.
1
-------
Fungi
sugars and grows most luxuriantly in
the presence of organic nitrogenous
wastes.
3 Ecological roles
Although the "sewage fungi" on
occasion attain visually noticeable
concentrations, the less obvious
populations of deuteromycetes may
be more important in the ecology of
the aquatic habitat. Investigations of
the past decade indicate that numerous
fungi are of primary importance in the
mineralization of organic wastes; the
overall significance and exact roles of
fungi in this process are yet to be
established.
D Predacious Fungi
1 Zoophagus insidians
(Plate II, Figure 4) has been observed
to impair functioning of laboratory
activated sludge units (see Cooke and
Ludzack).
2 Arthrobotrys is usually found along
with Zoophagus in laboratory activated
sludge units. This fungus is predacious
upon nematodes. Loops rather than
"pegs" are used in snaring nematodes.
IV CLASSIFICATION
In recent classification schemes, classes
of fungi are distinguished primarily on the
basis of the morphology of the sexual and
zoosporic stages. In practical schematics,
however, numerous fungi do not demonstrate
these stages. Classification must therefore
be based on the sum total of the morphological
and/or physiological characteristics. The
extensive review by Cooke (1963) on methods
of isolation and classification of fungi from
sewage and polluted waters precludes the
need herein of extensive' keys and species
illustrations. A brief synopsis key of the
fungi adapted in part from Alexopholous
(1962) is presented on the following pages.
This outline was prepared by Dr. Donald G.
Ahearn, Professor of Biology, Georgia State
College, Atlanta, Georgia 30303.
Descriptor: Aquatic Fungi
PLATE II (Figure 4)
14-5
-------
Fungi
KEY TO THE MAJOR TAXA OF FUNGI
1 Definite cell walls lacking, somatic phase a free living Plasmodium
Sub-phylum Myxomycotina . . (true slime molds). .Class Myxomycetes
I1 Cell walls usually well defined, somatic phase not a free-living Plasmodium
(true fungi) Sub-phylum Eumycotina 2
2 Hyphal filaments usually coenoctytic, rarely septate, sex cells when present forming
oospores or zygospores, aquatic species propagating asexually by zoospores, terrestrial
species by zoospores, sporangiospores conidia or conidia-like sporangia .'.'Phycomycetes". . . 3
The phycomycetes are generally considered to include the most primitive of the true
fungi. As a whole, they encompass a wide diversity of forms with some showing relation-
ships to the flagellates, while others closely resemble colorless algae, and still others
are true molds. The vegetative body (thallus) may be non-specialized and entirely con-
verted into a reproductive organ (holocarpic), or it may bear tapering rhizoids, or be
mycelial and very extensive. The outstanding characteristics of the thallus is a tendency
to be nonseptate and, in most groups, multinucliate; cross walls are laid down in vigorously
growing material only to delimit the reporductive organs. The spore unit of nonsexual re-
production is borne in a sporangium, and, in aquatic and semiaquatic orders, is provided
with a single posterior or anterior flagellum or two laterally attached ones. Sexual activity
in the phycomycetes characteristically results in the formation of resting spores.
2' (I1) Hyphal filaments when present septate, without zoospores, with or without sporangia,
usually with conida; sexual reproduction absent or culminating in the formation of asci
or basidia 8
3 (2) Flagellated cells characteristically produced 4
3' Flagellated cells lacking or rarely produced 7
4 (3) Motile cells uniflagellate 5
4' Motile cells biflagellate 6
5 (4) Zoospores posteriorly uniflagellate, formed inside the sporangium. . . class. . .Chytridiomycetes
The Chytridiomycetes produce asexual zoospores with a single posterior whiplash
flagellum. The thallus is highly variable; the most primitive forms are unicellular and
holocarpic and in their early stages of development are plasmodial (lack cell walls), more
advanced forms develop rhizoids and with further evolutionary progress develop mycelium.
The principle chemical component of the cell wall is chitin, but cellulose is also present.
Chytrids are typically aquatic organisms but may be found in other habitats. Some species
are chitinolytic and/or keratinolytic. Chytrids may be isolated from nature by baiting (e.g.
hemp seeds or pine pollen) Chytrids occur both in marine and fresh water habitats and are
of some economic importance due to their parasitism of algae and animals. The genus
Dermocystidium may be provisionally grouped with the chytrids. Species of this genus
cause serious epidemics of oysters and marine and fresh water fish.
5' Zoospores anteriorly uniflagellate, formed inside or outside the sporangium class
Hyphochytridiomycetes
These fungi are aquatic (fresh water or marine) chytrid-like fungi whose motile cells
possess a single anterior flagellum of the tinsel type (feather-like). They are parasitic on
algae and fungi or may be saprobic. Cell walls contain chitin with some species also demon-
strating cellulose content. Little information is available on the biology of this class and
at present it is limited to less than 20 species.
6 (4') Flagella .nearly equal, one whiplash the other tinsel class Oomycetes
A number of representatives of the Oomycetes have been shown to have cellulosic cell
walls. The mycelium is coenocytic, branched and "well developed in most cases. The sexual
process results in the formation of a resting spore of the oogamous type, i. e. , a type of
fertilization in which two heterogametangia come in contact and fuse their contents through
.a pore or tube. The thalli in this class range from unicellular to profusely branched
•filamentous types. Most forms are eucarpic; zoospores are produced throughout the class
except in the more highly advanced species. Certain species are of economic importance due
to their destruction of food crops (potatoes and grapes) while others cause serious diseases of
fish (e.g. Saprolegina parasitica). Members of the family Saprolegniaceae are the common
-------
Fungi
"water molds1' and are among the most ubiquitous fungi in nature. The order Lagenidiales
includes only a few species which are parasitic on algae, small animals, and other aquatic
life. The somatic structures of this taxon are holocarpic and endobiotic. The sewage fungi
are classified in the order Leptomitales. Fungi of this order are characterized by the
formation of refractile constrictions; ''cellulin plugs" occur throughout the thalli or, at least,
at the bases of hyphae or to cut off reproductive structures. Leptomitus lacteus may
produce rather extensive fouling floes or slimes in organically enriched waters.
6' Flagella of unequal size, both whiplash class. . . Plasmodiophoromycetes
Members of this class are obligate endoparasites of vascular plants, algae, and fungi.
The thallus consists of a plasmodium which develops within the host cells. Nuclear division
at some stages of the life cycle is of a type found in no other fungi but known to occur in
protozoa. Zoosporangia which arise directly from the plasmodium bear zoospores with two
unequal anterior falgella. The cell walls of these fungi apparently lack cellulose.
7(3') Mainly 'saprobic, sex cell when present a zygospo re class.... Zveomycetes
This class has well developed mycelium with septa developed in portions of the
older hyphae; actively growing hyphae are normally non-septate. The asexual spores are
non-motile sporangiospores (aplanospores). Such spores lack flagella and are usually
aerialy disseminated. Sexual reproduction is initiated by the fusion of two gametangia
with resultant formation of a thick-walled, resting spore, the zygospore. In the more
advanced species, the sporangia or the sporangiospores are conidia-like. Many of the
Zygomycetes are of economic importance due to their ability to synthesize commercially
valuable organic acids and alcohols, to transform steroids such as cortisone, and to
parasitize and destroy food crops. A few species are capable of causing disease in man
and animals (zygomycosis).
7' Obligate commensals of arthropods, zygospores usually lacking class. . . . Trichomycetes
The Trichomycetes are an ill-studied group of fungi which appear to be obligate
commensals of arthropods. The trichomycetes are associated with a wide variety of insecta,
diplopods, and Crustacea of terrestrial and aquatic (fresh and marine) habitats. None of
the members of this class have been cultured in vitro for continued periods of times with any
success. Asexual reproduction is by means of sporangiospores. Zygospores have been
observed in species of several orders.
8 (2') Sexual spores borne in asci class Ascomycetes
In the Ascomycetes the products of meiosis, the ascospores, are borne in sac
like structures termed asci. The ascus usually contains eight ascospores, but the number
produced may vary with the species or strain. Most species produce extensive septate
mycelium. This large class is divided into two subclasses on the presence or absence
of an ascocarp. The Hemiascomycetidae lack an ascocarp and do not produce ascogenous
hyphae; this subclass includes the true yeasts. The Euascomycetidae usually are divided
into three series (Plectomycetes, Pyrenomycetes, and Discomycetes) on the basis of
ascocarp structure.
8' Sexual spores borne on basidia class Basidiomycetes
The Basidiomycetes generally are considered the most highly evolved of the fungi.
Karyogamy and meiosis occur in the basidium which bears sexual exogenous spores,
basidiospores. The mushrooms, toadstools, rusts, and smuts'are included in this class.
8" Sexual stage lacking '. Form class.(Fungi Imperfecti).,Peuteromycetes
The Deuteromycetes is a form class for those fungi (with morphological affinities
to the Ascomycetes or Basidiomycetes) which have not demonstrated a sexual stage.
The generally employed classification scheme for these fungi is based on the morphology
and color of the asexual reproductive stages. This scheme is briefly outlined below.
Newer concepts of the classification based on conidium development after the classical
work of S. J. Hughes (1953) may eventually replace the gross morphology system (see
Barren 1968).
-------
Fungi
KEY TO THE FORM-ORDERS OF THE FUNGI IMPERFECT!
1 Reproduction by means of conidia, oidia, or by budding 2
1' No reproductive structures present Mycelia Sterilia
2 (1) Reproduction by means of conidia borne in pycnidia Sphaeropsidales
2' Conidia, when formed, not in cycnidia 3
3 (2') Conidia borne in acervuli Melanconiales
3' Conidia borne otherwise, or reproduction by oidia or by budding Moniliales
KEY TO THE FORM-FAMILIES OF THE MONILIALES
1 Reproduction mainly by unicellular budding, yeast-like; mycelial phase, if present,
secondary, arthrospores occasionally produced, manifest melanin pigmentation lacking 2
1" Thallus mainly filamentous; dark melanin pigments sometimes produced 3
2 (1) Ballistospores produced Sporobolomycetaceae
2' No ballistospores Cryptococcaceae
3 Conidiophores, if present, not united into sporodochia or synnemata 4
3' Sporodochia present Tuberculariaceae
3" Synnemata present Stilbellaceae
4 (3) Conidia and Conidiophores or oidia hyaline or brightly colored Moniliaceae
4' Conidia and/or Conidiophores, containing dark melanin pigment Dematiaceae
-------
Fungi Fungi
SELECTED REFERENCES
Ahearn, D.G., Roth, F.J. Jr., Meyers, S.P.
Ecology and Characterization of Yeasts
from Aquatic Regions of South Florida.
Marine Biology 1:291-308. 1968
Alexopoulos, J. C. Introductory Mycology.
2nd ed. John Wileyand Sons, New York,
613pp. 1962
Barren, G. L. The Genera of Hyphomycetes
from Soil. Williams and Wilkins Co.,
Baltimore. 364 pp. 1968
Cooke, W. B. Population Effects on the
Fungus Population of a Stream.
Ecology 42:1-18. 1961
. A Laboratory Guide to Fungi in
Stagnant waters. I. Morphology and
Occurrence in Nature. Amer. J.
Botany 54:702-719. 1967
Hughes, S.J. Conidiophores, Conidia and
Classification. Can. J. Bot. 31:577-
659. 1953
Johnson, T.W., Jr. Saprobic Marine Fungi.
pp. 95-104. InAinsworth, G.C. and
Sussman, A.S. The Fungi, III.
Academic Press, New York. 1968
and Sparrow, F.K., Jr. . Fungi
Polluted Waters, Sewage, and Sewage
Treatment Systems. U. S. Dept. of
Health, Education and Welfare, Cincinnati,
132 pp. 1963
. Fungi in Sludge Digesters.
Purdue Univ. Proc. 20th Industrial
Waste Conference, pp 6-17. 1965a
. The Enumeration of Yeast
Populations in a Sewage Treatment Plant.
Mycologia 57:696-703. 1965b
. Fungal Populations in Relation
to Pollution of the Bear River, Idaho-Utah.
UtahAcad. Proc. 44(1):298-315. 1967
and Matsuura, George S. A Study
of Yeast Populations in a Waste Stabilization
Pond System. Protoplasma 57:163-187.
1963
, Phaff, H.J., Miller, M.W.,
Shifrine, M., and Khapp, E. Yeasts
in Polluted Water and Sewage.
Mycoiogia 52:210-230. 1960
Emerson, Ralph and Weston, W.H.
Aqualinderella fermentatis Gen. et Sp.
Nov., A Phycomycete Adapted to
in Oceans and Estuaries. Weinheim,
Germany. 668 pp. 1961
Meyers, \S. P. Observations on the Physio-
logical Ecology of Marine Fungi. Bull.
Misaki Mr. Biol. Inst. 12:207-225. 1968
Prigsheim, E.G. Iron Bacteria. Biol. Revs.
Cambridge Phil. Soc. 24:200-245. 1949
Sparrow, F. K., Jr. Aquatic Phycomycetes.
2nd ed. Univ. Mich. Press, AnnArbor.
1187 pp. 1960.
. Ecology of Freshwater Fungi.
pp. 41-93. InAinsworth, G.C. and
Sussman, A.~S. The Fungi, III. Acad.
Press, New York. 1968
Stokes, J. L. Studies on the Filamentous
Sheathed Iron Bacterium Sphaerotilus
natans. J. Bacteriol. 67:278-291. 1954
van Uden, N. and Fell, J.W. Marine Yeasts.
pp. 167-201. In Droop, M.R. and Wood,
E. J.F. Advances in Microbiology of
the Sea, I. Academic Press, New York.
1968
Yerkes, W. D. Observations on an Occurrence
of Leptomitus lacteus in Wisconsin.
Mycologia 58:976-978. 1966
Cooke, William B. and Ludzack, F.J.
Predacious Fungus Behavior in
Activated Sludge Systems. Jour. Water
Poll. Cont. Fed. 30(12): 1490-1495. 1958.
14-9
-------
PROTOZOA, NEMATODES, AND ROTIFERS
I GENERAL CONSIDERATIONS
A Mierobial quality constitutes only one
aspect of water sanitation; microchemicals
and. radionuclides are attracting increasing
amount of attention lately.
B Microbes considered here include bacteria,
protozoa, and microscopic metazoa; algae
and. fungi excluded.
C Of the free-living forms, some are
members of the flora and fauna of surface
waters; others washed into the water from
air and soil; still others of wastewater
origin; nematodes most commonly from
sewage effluent.
D Hard to separate "native" from "foreign"
free-living microbes, due to close
association of water with soil and other
environments; generally speaking, bacteria
adapted to water are those that can grow
on very low concentrations of nutrient
and zoomicrobes adapted to water are
those that feed on algae, and nsmatodes,
especially bacteria eaters, are uncommon
in water but in large numbers in sewage
effluent.
E More species and lower densities of
microbes in clean water and fewer species
and higher densities in polluted water.
F Pollution-tolerance or nontolerance of
microbes closely related to the DO level
required in respiration.
G From pollution viewpoint, the following
groups of microbes are of importance:
Bacteria, Protozoa, Nematoda, and
Rotifera.
II BACTERIA
A No ideal method for studying distribution
and ecology of bacteria in freshwater.
(9)
B According to Collins, Pseudomonas,
Achrombacter, Alcaligenes, Chromobac-
terium, Flavobacterium, and Micrococcus
are the most widely distributed and may be
considered as indigenous to natural
waters. Sulfur and iron bacteria are
more common in the bottom mud.
C Actinomycetes, Bacillus sp. Aerogenes
sp., and nitrogen-fixation bacteria are
primarily soil dwellers and may be washed
into the water by runoffs.
E Nematodes are usually of aerobic sewage
treatment origin.
D E. coji, streptococci, and _C1. perfringens
are true indicators of fecal pollution.
IE PROTOZOA
A Classification
1 Single- cell animals in the most
primitive phylum (Protozoa) in the
animal kingdom.
2 A separate kingdom, Protista, to in-
clude protozoa, algae, fungi, and
bacteria proposed in the 2nd edition
of Ward-Whipple's Fresh-Water
Biology .(10)
3 Four subphyla or classes:
a Mastigophora (flagellates)-Subclass
phytomastigina dealt with under
algae; only subclass Zoomastigina
included here; 4 orders:
1) Rhizomastigina - with flagellum
or flagella and pseudopodia
2) Protomonadina - with 1 to 2
flagella mostly free-living many
parasitic
3) Polymastigina - with 3 to 8
flagella; mostly parasitic in
elementary tract of animals
and man
4) Hypsrmastigina - all inhabitants
of alimentary tract of insects.
W.BA. 45c.6. 76
15-1
-------
Protozoa, Nematodes, and Rotifers
Ciliophora or Infusoria (ciliates) -
no pigmented members; 2 classes:
1) Ciliata - cilia present during the
whole trophic life; containing
majority of the ciliates
2) Suctoria - cilia present while
young and tentacles during trophic
life.
Sarcodina (amoebae) - Pseudopodia
(false feet) for locomotion and food-
capturing; 2 subclasses:
1) Rhizopoda - Pseudopodia without
axial filaments; 5 orders:
a) Proteoniyxa - with radiating
pseudopodia; without test or
shell
b) Mycetozoa - forming plasmodium;
resembling fungi in sporangium
formation
c) Amoebina - true amoeba -
forming lobopodia
d) Testacea - amoeba with single
test or shell of chitinous
material
e) Foraminifera - amoeba with 1
or more shells of calcareous
nature; practically all marine
forms
Sporozoa - no organ of locomotion;
amoeboid in asexual phase; all
parasitic
B General Morphology
1 Zoomastigina:
Relatively small size (5 to 40 n); with
the exception of Rhizomastigina, the
body has a definite shape (oval, leaf-
like, pear-like, etc.); common members
with 1 or 2 flagella and some with 3, 4,
or more; few forming colonies; cyi .:'tome
present in many for feeding.
2 Ciliophora:
Most highly developed protozoa; with
few exceptions, a macro and a micro-
nucleus; adoral zone of membranellae,
mouth, and groove usually present in
swimming and crawling forms, some
with conspicuous ciliation of a disc-like
anterior region and little or no body
cilia (stalked and shelled forms);
Suctoria nonmotile (attached) and with-
out cytostome cysts formed in most.
3 Sarcodina:
Cytoplasmic membrane but no cell wall;
endoplasm and ectoplasm distinct or in-
distinct; nucleus with small or large
nucleolus; some with test or shell;
moving by protruding pseudopodia; few
capable of flagella transformation; fresh-
water actinopods usually sperical with
many radiating axopodia; some Testacea
containing symbiotic algae and mistaken
for pigmented amoebae; cysts with single
or double wall and 1 or 2 nuclei.
4 Sporozoa: to be mentioned later.
C General Physiology
1 Zoomastigina:
Free-living forms normally holozic;
food supply mostly bacteria in growth
film on surfaces or clumps relatively
aerobic, therefore the first protozoa to
disappear in anaerobic conditions and
re-appearing at recovery; reproduction
by simple fission or occasionally by
budding.
2 Ciliophora:
Holozoic; true ciliates concentrating
food particles by ciliary movement
around the mouth part; suctoria sucking
through tenacles; bacteriaand small
15-2
-------
Protozoa, Nematodes, and Rotifers
algae and protozoa constitute main
food under natural conditions; some
shown in laboratory to thrive on dead
organic matter and serum protein; not as
aerobic as flagellates - some surviving
under highly anaerobic conditions, such
as Metopus; reproduction by simple
fission, conjugation or encystment.
3 Sarcodina:
Holozoic; feeding through engulfing by
pseudopodia; food essentially same as
for ciliates; DO requirement somewhat
similar to ciliates - the small amoebae
and Testacea frequently present in large
numbers in sewage effluent and polluted
water; reproduction by simple fission
and encystation.
IV NEMATODES
A Classification
1 All in the phylum Nemata (nonsegment-
ed round worms); subdivided by some
authors into two classes:
Secernentea - 3 orders:
(phasmids)
Tylenchida, Rhabditida, Strongylida,
and Teratocephalida; with papillae on
male tail, caudal glands absent.
Adenophora - 6 orders:
(aphasmids)
Araeolaimida, Dorylaimida,
Chromdorida, Monhysterida, Enoplida,
and Trichosyringida no papillae on
male caudal glands absent.
Orders encountered in water and sewage
treatment - Free-living forms inhabitat-
ing sewage treatment plants are usually
bacteria-feeders and those feeding on
other nematodes; those inhabitating clean
waters feeding on plant matters; they
fall into the following orders:
Tylenchida - Stylet in mouth; mostly
plant parasites; some feed on
nematodes, such as Aphelenchoides.
Rhabditida - No stylet in mouth or caudal
glands in tail; mostly bacteria-feeders;
common genera: Rhabiditis, Diplogaster,
DiplogasteroideSj Monochoides^ Pelodera,
Panagrellus, and Turbatrix.
Dorylaimida - Relatively large nematodes;
stylet in mouth; feeding on other nematodes,
algae and probably zoomicrobes; Dorylaimus
common genus.
Chromadorida - Many marine forms;
some freshwater dwellers feeding on
algae; characterized by strong orna-
mentation of knobs, bristles or
punctations in cuticle.
Monhysterida - Freshwater dwellers;
esophago-intestinal valve spherical to
elongated; ovaries single or paired,
usually straight; common genus in
water - Monhystera.
Enoplida - Head usually with a number
of setae; Cobb reported one genus,
Mononchulus. in sand filters in
Washington, D.C.
B General Morphology
Round, slender, nonsegmented (transverse
markings in cuticle of some) worms;
some small (about | mm long, as Tri-
cephalobus), many 1 to 2 mm long
(Rhabditis. Diplogaster. and Diplogasteriodes
for instance), and some large (2 to 7 mm,
such as Dorylaimus); sex separated but few
parthenogenetic; complete alimentary canal;
with elaborate mouth parts with or without
stylet; complete reproductive system in
each sex; no circulatory or respiratory
system; complex nervous system with
conspicuous nerve ring across oesophagus.
C General Physiology
1 Feeding - Most sewage treatment plant
dwellers feeding on bacteria; others
preying on protozoa, nematodes, rotifers,
15-3
-------
Protozoa, Nematodes, and Rotifers
etc., clean-water species apparently
vegetarians; those with stylet in mouth
use the latter to pierce the body of animal
or plant and suck contents; metabolic
waste mostly liquid containing ammonium
carbonate or bicarbonate; enteric
pathogens swallowed randomly with
suspending fluid, hence remote possi-
bility of sewage effluent-borne nematodes
being pathogen-carriers.
2 Oxygen requirement - DO apparently
diffused through cuticle into body; DO
requirement somewhat similar to
protozoa; Khabditis tolerating reduced
DO better than other Rhabditida members;
all disappear under sepsis in liquid; some
thrive in drying sludge.
3 Reproduction - Normal life cycle requires
mating, egg with embryo formation,
hatching of eggs inside or outside femais,
4 larval stages, and adult; few repro-
duce in the absence of males.
V ROTIFERS
A Classification:
1 Classified either as a class of the phylum
Aschelminth.es (various forms of worms)
or as a separate phylum (Rotifera); com-
monly called wheel animalcules, on
account of apparent circular movement of
cilia around head (corona); corona con-
tracted when crawling or swimming and
expanded when attached to catch food.
2 Of the 3 classes, 2 (Seisonidea and
Bdelloidea) grouped by some authors
under Digononta (2 ovaries) and the
other being Monogononta (1 ovary);
Seisonidea containing mostly marine
forms.
3 Class Digononta containing 1 order
(Bdelloida) with 4 families, Philodinedae
being the most important.
4 Class Monogononta comprising 3 orders:
Notommatida (mouth not near center of
corona) with 14 families, Floscularida
Melicertida(corona with two wreaths of
cilia and furrow between them) with 3
families; most import genera included
in the order Notommatida: Brachionus,
Keratella, Monostyla, Trichocerca,
Asplanchna, Polyarthra, Synchaeta,
Microcodon; common genera under the
order Flosculariaceae: Floscularia,
and Atrochus. Common genera under
order Melicertida: Limnias and
Conochilus.
5 Unfortunately orders and families of
rotifers partly based on character of
coi'jna and trophi (chewing organ),
which are difficult, to study, esp. the
latter; the foot and cuticle much easier
to study.
B General Morphology and Physiology
1 Body weakly differentiated into head,
neck, trunk, and foot, separated by
folds; in some, these regions are
merely gradual changes in diameter
of body and without a separate neck;
segmentation external only.
2 Head with corona, dosal antenna, and
ventral mouth; mastax, a chewing organ,
located in head and neck, connected to
mouth anteriorly by a ciliated gullet and
posteriorly to a large stomach occupying
much of the trunk.
3 Common rotifers reproducing partheno-
genetically by diploid eggs; eggs laid in
water, cemented to plants, or carried
on female until hatching.
4 Foot, a prolongation of body, usually
with 2 toes; some with one toe; some
with one toe and an extra toe-like
structure (dorsal spur).
5 Some, like Phllodina, concentrating
bacteria and other microbes and minute
particulate organic matter by ciliary
movement on corona larger microbes
chewed by mastax; some such as
Monostyla feeding on clumped matter,
such as bacterial growth, fungal masses,
etc. at bottom; virus generally not
ingested - apparently undetected by
cilia.
6 DO requirement somewhat similar to
protozoa; some disappearing under
reduced DO, others, like Philodina,
surviving at as little as 2 ppm DO.
15-4
-------
Protozoa, Nematodesf and Rotifers
VI SANITARY SIGNIFICANCE
A Pollution tolerant and pollution non-
tolerant species - hard to differentiate -
requiring specialist training in protozoa,
nematocles, and rotifers.
B Significant quantitative difference in clean
and polluted waters - clean waters con-
taining large variety of genera and species
but quite low in densities.
C Aerobic sewage treatment processes
(trickling filters and activated sludge
processes, even primary settling) ideal
breeding grounds for those that feed on
bacteria, fungi, and minute protozoa and
present in very large numbers; effluents
from such processes carrying large num-
bers of these zoomicrobes; natural waters
receiving such effluents showing significant
increase in all 3 categories.
D Possible Pathogen arid Pathogen Carriers
1 Naeg_le_ria causing swimming associated
meningoi'iK-rplial ilis and Acanthann:oba:
causing nonswimrning associated cases.
2 Amoebae and nematodes grown on
pathogenic enteric bacteria in lab; none
alive in amoebic cysts; very few alive
in nematodes after 2 days after ingestion;
virus demonstrated in nematodes only
when very high virus concentrations
present; some freeliving amoebae
parasitizing humans.
3 Swimming ciliates and some rotifers
(concentrating food by corona) ingesting
large numbers of pathogenic enertic
bacteria, but digestion rapid; no
evidence of concentrating virus; crawling
ciliates and flagellates feeding on clumped
organisms.
. 4 Nematodes concentrated from sewage
effluent in Cincinnati area showing
live_E_. cpli and streptococci, but no
human enertic pathogens.
VII EXAMINATION OF WATER FOR MICROBES
A Bacteria - not dealt here.
B Protozoa and rotifers - should be included
in examination for planktonic microbes.
C Nematodes
(3)
D Laboratory Apparatus
1 Sampte, Bottles - One-gallon glass or
plastic bottles with metal or plastic
screw caps, thoroughly washed and
rinsed three times with distilled water.
2 C_up_illarv Pipettes and (lubber Bulbs -
\ , ('.) in. ) Pasteur capillary pipettes
and rubber bulbs of 2 rnl capacity,
'* Zil!rŁ?iiPn ^LnJJi " ^ny filter holder
assembly use/1 in bacteriological
examination. The funnel should be
at ieast 650 ml and the filter flask at
least 2 liter capacity.
4 Filter_MernbŁane_s - Millepore SS 'SS
047 MM) type membranes or equivalent.
5 Microscope - Binocular microscope
with 10X eyepiece, 4X, 10X, and 43X
objectives, and mechanical stage.
E Collection of Water Samples
Samples are collected in the same manner.,
as those for bacteriological examination,
except that a dechlorinating agent is not
needed. One-half to one gallon samples are
collected from raw water and one-gallon
samples from, tap water. Refrigeration is
not essential and samples may be transported
without it unless examination is to be delayed
for more than five days.
F Concentration of Samples
1 One gallon of tap water can usually bs
filtered through a single 8-u membrane
within 15 minutes unless the water has
high turbidity. At least one gallon of
sample should be used in a single examina-
tion. Immediately after the last of the
water is disappearing from the membrane,
the saction line is disconnected and the
membrane placed on the wall of a clean
50 to 100 ml beaker and flushed repeatedly
with about 2-5 ml of sterile distilled water
15-5
-------
Protozoa, Nematodes, and Rotifers
with the aid of a capillary pipette and a
rubber bulb. The concentrate is then
pipetted into a clean Sedgewick-Rafter
Counting Cell and is ready for examina-
tion.
2 In concentration of raw water samples
having visible turbidity, two to four
8-mic.ron membranes may be required
per sample, with filtration through each
membrane being limited to not more
than 30 minutes. Samples ranging from
500 ml to 2 liters may be filtered with
ons membrane, depending on degree of
turbidity. After filtration the membranes
are placed on the walls of separated
beakers and washed as above. To
prevent the particulates from obscuring
the nematodes, the washing from each
filter is examined in a separate counting
chamber.
G Direct Microscopic Examination
Each counting chamber containing the
filter concentrate is first examined under
a 4X objective. Unless the concentrate
contains more than 100 worms, the whole
cell area is surveyed for nematodes, with
respect to number, developmental stage,
and motility. When an object having an
outline resembling that of a nematode is
observed, it is re-examined under a 10X
objective for anatomical structures, unless
the object exhibits typical nematode move-
ment, which is sufficient for identifying the
object as a nematode. When the concentrate
contains more than 100 worms, the worm
density can be estimated by counting the
number of worms in representative micro-
scopic fields and multiplying the average
number of worms per field by the number
of fields in the cell area. The nematode
density may be expressed as number of
worms per gallon with or without differenti-
ation as to adult or larval stages or as to
viability. VIII
H General Identification of Nematodes
1 While actively motile nematodes can be
readily recognized by any person who
has some general concept of micro-
scopic animals, the nonmotile or
sluggishly motile nematodes may be
confused with root fibers, plant fila-
ments of various types, elongated
ciliates such as Homalozopn vermi-
culare. or segments of appendages of
small Crustacea. To facilitate a
general identification of nematodes, the
gross morphology of three of the free-
living nematodes that are frequently
found in water supplies is shown in the
attached drawing. The drawing provides
not only the general anatomy for recogni-
tion of nematodes but also most of the
essential structures for guidance to those
who want to use the "Key to Genera" in
chapter No. 15 on Nemata by B. G.
Chitwood and M. W. Allen in the book,
Fresh Water Biology. (1°)
2 Under normal conditions, practically
all nematodes seen in samples of
finished water are in various larval
stages and will range from 100 to 500
microns in length and 10 to 40 microns
in width. Except in the fourth (last)
stage, the larvae have no sexual organs
but show other structural characteristics.
3 If identification of genera is desired,
the filter washings are centrifuged at
500 rpm for a few minutes. The
supernate is discarded, except a few
drops, and the sediment is resuspended
in the remaining water. A drop of the
final suspension is examined under both
10X and 43X objectives for anatomical
characteristics without staining, and for
supplementary study of structures the
rest is fixed in 5% formalin or other
fixation fluid and stained according to
instructions given in Chitwood and
Allen's Chapter on Nemata, (?)
Goodey's Soil and Freshwater Nema-
todes' 11) or other books on nematology.
USE OF ZOOMICROBES AS
POLLUTION INDEX
Idea not new, protozoa suggested long ago;
many considered impractical because of
the need of identifying pollution-intolerant
and pollution-tolerant species - proto-
zoologist required. Method also time
consuming.
15-6
-------
Protozoa, Nematodes. and Rotifers
B Can use them on a quantitative basis -
nematodes, and nonpigmented
protozoa present in small numbers in
clean water. Numbers greatly increased
when polluted with effluent from aerobic
treatment plant or recovering from sewage
pollution; no significant error introduced
when clean-water members included in the
enumeration if a suitable method of com-
puting the pollution index developed.
C Most practical method involves the
equation: A +B + 1000 C = Z.P.I.,
"A
where
A = number ol pigmented protozoa,
B = non pigmented protozoa, and
C = nematodes in a unit volume of sample,
and Z.P.I. = zoological pollution index.
For relatively clean water, the value of
Z.P.I, close to 1; the larger the value
above 1, the greater the pollution by aerobic
effluent (see attached report on zoomicrobial
indicator of water pollution).
IX CONTROL .
A Chlorination of effluent
B Prolongation of detention time of effluent
C Elimination of slow sand filters in
nematode control.
LIST OF COMMON ZOOLOGICAL ORGANISMS
FOUND IN AEROBIC SEWAGE TREATMENT
PROCESS
PROTOZOA
Sarcodina - Amoebae
Arnoe_ba proteus; A radiosa
Hartmannella
Arcella Vulgaris
Noegleria gruberi
Actinophryjs
FLAGELLATA
Bodo caudatus
Pleuromonas jaculans
Oikomonas termo
Cercomonas longicauda
Peranema trichophorum
Swimming type
Ciliophora:
Colpidium colpoda
Colpoda cuculus
Glaucoma pyriformis
Paramecium candatum; P bursaria
Stalked type
Opercularia sp. (short stalk dichotomous)
Vor_ticella_sp. (stalk single and contractile)
Episjy lis pli cat ill s (like opercularia, more
colonial, stalk not contractile)
Carchesium sp. (like vorticella bat colonial,
individual zooids contractile)
_Zopthamnium sp. (entire colony contracts)
Crawling type
Aspicisca costata
Euplotes patella
Stylonychia mylitus
Urostyla sp.
Oxytricha sp.
NEMATODA
pipjogaster sp. Dorylamus sp.
Moiiochoides sp. Chlindrocorpus sp.
Diplogasteroides sp. Cephalobus sp.
Rhabditis sp. 5^^it°j2-HH}iS. SP•
Pelodera_sp. Monhystera sp.
sp. Trilobus sp.
15-7
-------
Protozoa, Nematodes^ and Rotifers
ROTATORIA
Diglena
Monostyla
Polyarthra
Philodina,
Keratella
BrachJLomis_
OLIGOCHAETA (bristle worms)
Aelosoma he_mŁŁichi_
Aulophorus limosa
Tubjfex tubifex
Lumbricillus lineatus
INSECT LARVAE
Chironomus
Psychoda sp. (trickling filter fly)
ARTHROPODA
JLessertia sp.
Pgrrhgmma sp,
Achoratus subuiaticus (collembola)
Folsomia sp. (collembola)
Tomocerus sp. (collembola)
REFERENCES
1 American Public Health Association,
American Water Works Association and
Water Pollution Control Federation.
Standard Methods for the Examination
of Water and Wastewater, 13th ed.
New York". 1971.~
2 Chang, S. L., et al. Survey of Free-
Living Nematodes and Amoabas in
Municipal Supplies. J.A.W.W.A. 52:
613-618.
3 Chang, S. L. Interactions between Animal
Viruses and Higher Forms of Microbes.
Proc. Am. Soc. Civ. Eng. Jl. San. Eng.
96:151. 1970
4 Chang, S. L. Zoomicrobial Indicators
of Water Pollution presented at the
Annual Meeting of Am. Soc. Microbial,
Philadelphia, April 23-28, 1972.
5 Chang, S, L. Pathogenic Free-Living
Amoebae and Recreational Waters.
Presented at 6th International Confer-
ence of Water Pollution Research
Association, Jerusalem, Israel,
June 19-24, 1972.
6 Chang, S. L. Proposed Method for
Examination of Water for Free-Living
Nematodes. J.A.W.W.A. 52:695-698.
1960.
7 Chang, S. L., et al. Survival and Protection
Against Chlorination of Human Enteric
Pathogens in Free-Living Nematodes
Isolated from Water Supplies. Am. Jour.
Trop. Med. and Hyg. 9:136-142. 1960.
8 Chang, S. L. Growth of Small Free-Living
Amoebae in Bacterial and Bacteria-Free
Cultures. Can, J. Microbial.
6:397-405. 1960.
9 Chang, S. L. and Kabler, P. W. Free-Living
Nematodes in Aerobic Treatment Plant
Effluents. J.W.P.C. F. 34:1256-2161.
1963.
10 Chitwood, B. G. and Chitwood, M. B. An
Introduction to Nematology. Section I:
Anatomy. 1st ed. Monumental Printing
Co. Baltimore. 1950. pp 8-9.
11 Cobb, N.A. Contributions to the Science of
Nematology VII. Williams and Wilkins Co.
Baltimore. 1918.
12 Collins, V.G. The Distribution and Ecology
of Bacteria in Freshwater, Pts. I & II,
Proc. Soc. for Water Treatment and Exam.
12:40-73. 1963. (England)
13 Edmondson, W.T., et al. Ward-Whipple's
Fresh Water Biology. 2nd ed. John
Wiley & Sons, New York. 1959. pp 368-401.
15-8
-------
Protozoa, Nematodes, and Rotifers
14 Goodey, T. Soil and Freshwater This outline was prepared by S. L. Chang,
Nematodes. (A Monograph) 1st ed. Chief, Etiology, Criteria Development
Methuen and Co. Ltd. London. 1951. Branch, Water Supply Research Laboratory,
NERC, USEPA, Cincinnati, Ohio 45268.
Descriptors: Protozoa, Nematodes, Rotifers
15-9
-------
Protozoa, Nematodes, and Rotifers
Insects
Oligochaetes &
insect larvae
Nematodes
& rotifers
4-4
Nonpigmented
protozoa *
I I t Iff
Heterotrophic
bacteria
Fungi
Algae
Autotrophic bacteria
Pathogenic organisms
Suspended organic matter
(by hydrolysis)
Raw Sewage
Dissolved organic matter
(respiration,
de animation,
decarboxylation, etc.)
Inorganic C, P, N,
S comp.
, f _ (NH3, NO', CO', P)
(Nitrification, sulfur
& iron bacteria)
Food Chain in Aerobic Sewage Treatment Processes
15-10
-------
ACTIVATED SLUDGE
PROTOZOA
Larger animals (worms, snails, fly larvae,
etc.) dominate trickling filters. Why are
these always absent from the activated
sludge process?
Why are there numerous micro-species
common to both trickling filters and
activated sludge?
What organisms besides protozoans and
animals are present in activated sludge?
What is the advantage(s) of microscopic
examination of activated sludge ?
One sampling site would be the one of choice
in sampling an activated sludge plant for
microscopic analysis. Why? Where?
What organisms predominate in activated
sludge ?
Why are photosynthetic green plants (in
contrast to animals) basically absent from
the activated sludge process in general and
mixeid liquor specifically?
Why are the same identical species of protozoa
found in activated sludge plants all over the
world?
What is the significance of a microscopic
examination of mixed liquor?
Define and characterize: 10
Activated Sludge
Mixed Liquor
Floes
What is the relation between bacterial/ 11
protozoan populations in activated sludge
and the process itself?
At what total magnification were you able to 12
believe the smallest cells observed were in
fact bacteria?
Activated sludge is a dynamic (although 13
man-manipulated) ecosystem. How does
it differ from a natural ecosystem?
BLIND. 14a. 6.76 16_j
-------
Activated Sludge Protozoa
What is the greatest problem(s) with a wet 14
mount slide preparation?
How do you overcome these disadvantages? 15
How do you slow down fast moving protozoans 16
on a wet mount?
Why are quantitative counts of protozoa (like 17
number/ml) generally meaningless?
What is the significance of proportional 18
counts?
Scanning a slide (in making a count) should 19
generally be done at X. (Total
magnification)
The iris diaphragm on the microscope is 20
used to adjust light intensity (true-false).
Why sample the surface film of the 21
settleometer?
Why is the thinnest film most ideal for a 22
wet mount?
What did you learn from the microscopic 23
examination of the activated sludge?
What is the physical nature of the floes 24
observed?
What filamentous organisms were 25
observed?
Why are "rare" species of no practical 26
significance in microscopic analyses of
activated sludge?
Why are there no protozoan indicator species 27
of process efficiency in activated sludge?
Activated sludge biological communities 28
are temporal in contrast to biological
communities in trickling filters which
are spatial (TRUE/FALSE).
"Seeding" a newly started activated sludge 29
plant with cultures or material from other
plants is only a wasted effort (TRUE/FALSE).
Justify your answer.
16-2
-------
Activated Sludge Protozoa
If a wet mount slide of mixed liquor is
prepared and placed in a petri dish with a
wet blotter underneath and allowed to sit
for several hours, what will be the distri-
bution of the protozoa under the cover slip?
30
In a mixed liquor sample nearly all of the
stalked ciliates have "broken off" the stalks
and are free swimming as "telotrochs. "
What does this indicate?
31
What are Monads? And are they good, bad, 32
or indifferent in activated sludge?
What are hypotrichs or crawling ciliates,
and are they good, bad or indifferent in
activated sludge?
33
What are swimming ciliates, and are they 34
good, bad or indifferent in activated sludge?
What are flagellates, and are they good, bad 35
or indifferent in activated sludge?
What are amoebae, and are they good, bad, 36
or indifferent in activated sludge?
What are the ideal characteristics of a wet
mount slide preparation?
37
Why does total community give a better 38
indication of process efficiency in activated
sludge?
In observing and identifying protozoa one looks 39
for what characteristics of an individual
organism?
What is the role of bacteria in activated
sludge?
40
What is the role of protozoa in activated
sludge?
41
Microscopic analysis of the mixed liquor
sample can be very quick, simple, and
meaningful (TRUE/FALSE).
42
16-3
-------
Activated Sludge Protozoa
Protozoan communities present in activated 43
sludge reveal:
a. Plant efficiency
b. Settleability
c. BOD removal
d. Solids removal
e. Plant loading
(Circle applicable descriptions)
Protozoan communities in activated sludge 44
reveal complete and instantaneous conditions;
average of physical and chemical conditions;
extremes of chemical and physical conditions.
(Draw a line through phrases not true.)
Rank in increasing plant efficiency the 45
following protozoan group which would pre-
dominate.
Rotifers
Stalked ciliates
Amoebae
Swimming ciliates
Crawling ciliates
Flag ellate s
(For example, use number 1-6. One would be
startup conditions or least efficient, and six
would be the most efficient.)
Identification is usually done at X and 46
sometimes requires X.
Immersion oil should be used sparingly at 47
what two points on a slide?
Which comes first in microscopic examina- 48
tion; scanning at low power to pick out
unknowns or higher power to identify?
In making proportional count, which total 49
number to count would be better; total of ten
organisms or a total of 100 organisms? Why?
Why not kill the organisms so you can 50
identify and count them on the slide?
What simple chemical solutions are useful 51
to immobilize protozoa if methyl cellulose
or poly vinyl alcohol is not available?
16-4
-------
Activated Sludge Protozoa
Initially the wet mount slide should be
racked up close to the low power objective:
by your eye on the eyepiece through the
scope; or by glancing at the actual distance
with the naked eye while you rotate the
coarse adjustment knob. (Underline which)
52
What are par-focal objectives on the
microscope?
53
Why should water on the microscope and all 54
its parts be carefully avoided?
If activated sludge is a man manipulated
system, are there comparable natural
ecosystems? Example?
55
What is the " community" concept in exami- 56
nation of activated sludge?
What are the applications of direct micro- 57
scopist examination of activated sludge?
What are rotifers, and are they good, bad
or indifferent in activated sludge?
58
List the five kingdoms of organisms and give 59
a specific example for each.
What techniques are most useful in 60
identifying an unknown organism, and why
is correct identification important?
Scanning and counting is done at X
magnification. Identification of most
PROTOZOA usually requires X
magnification and occassionally X
magnification.
61
OBJ.
3.5 X
10 X
TOTAL MAG. USE
62
(10 X eyepieces)
16-5
-------
Activated Sludge Protozoa
hand is constantly operating the 63
hand is constantly operating the
The microscope is manually operated and
requires skill and understanding on the part
of the operator. A microscope no matter
how costly is only as good as the micro-
scopist operating it.
List the basic skills required in utilizing the 64
optimum capability of your microscope.
This outline was prepared by R. M. Sinclair,
National Training Center, MOTD, OWPO,
USEPA, Cincinnati, Ohio 45268.
Descriptors: Microorganisms, Protozoa,
Rotifers, Activated Sludge, Biota
16-6
-------
FREE-LIVING AMOEBAE AND NEMATODES
I FREE-LIVING AMOEBAE
A Importance of Recognizing Small,
Free-Living Amoebae in Water
Supplies
1 Commonly found in soil, aerobic
sewage effluent and natural, fresh
waters - hence, frequently en-
countered in examination of raw
water.
2 Cysts not infrequsntly found in
municipal supplies - not pathogen
carriers.
3 Flagellate-amoebae NaegJLeria
involved in 50 some cases of
meningoencephalitis, about half
in the U. S.; associated with
swimming in small warm lakes.
Acanthamoeba rhyjsodes parasitizing
hyman throats and causing (3 cases)
nonswimming- associated meningo-
encephalitis .
4 Cysts not to be confused with those
of Endamoeba histolytica in water-
borne epidemics.
B Classification of Small, Free-Living
Amoebae
1 Recognized classification based
on characteristics in mitosis.
2 Common species fall into the
following families and genera:
Family Schizopyrenidae: Genera
Naegleria, Didascalus, and
Schizopyrenus - first two being
flagellate amoebae.
Family Hartmannellidae: Genera
jiartmanella (Acanthamoeba)
3 How to prepare materials for
studying mitosis - Feulgen stain
C Morphological Characteristics of
Small, Free-Living Amoebae
1 Morphology of Trophozoites -
Ectoplasm and endoplasm usually
distinct; nucleus with large nucleolus.
2 Morphology of cysts - Single or
double wall with or without pores
D Cultural Characteristics of Small,
Free-Living Amoebae
1 How to cultivate these amoebae -
plates with bacteria; cell cultures,
axenic culture.
2 Growth characteristics on plate,
cell, and axenic culture
3 Complex growth requirements
for most of these amoebae
E Resistance of Amoebic Cysts to
Physical and Chemical Agents
II FREE- LIVING NEMATODES
A Classification of Those Commonly
Found in Water Supplies
1 Phasmidia (Secerneutes):
Genera Rhabditis, Dip_logaster,
Diplogasteroides, Chsilobus^
Panagrolaimus
2 Aphasmidia (Adenophoro): Genera
^onjivjtera^ Aphelenclras, Turbatrix_
(vinegar eel), Dorylaimus, and
Rhab dolaimus
B Morphological Features
1 Phasmids: papilla on tail of males,
mouth adapted to feed on bacteria,
few exceptions.
2 Aphasmids: no papilla on male tail;
glandular cells in male.
BI.AQ. 14b.6.76
17-1
-------
Amoebae and Nematodes in Water Supplies _
C Life Cycle
1 Methods of mating
2 Stages of development
3 Parthenogenesis
D Cultivation
1 Bacteria-fed cultures
2 Axenic cultures
E Occurrence in Water Supplies
1 Relationship between their
appearance in finished water
and that in raw water.
2 Frequency of occurrence in
different types o.? raw water
and sources.
3 Survival of human enteric path-
ogenic bacteria and viruses in
nematodes.
4 Protection of human enteric
pathogenic bacteria and viruses
in .lematode-carriers.
F Control
1 Chlorination of sewags effluent
2 Flocculation and sedimentatioa
of water
3 Chlorination of water
4 Other methods of destruction
REFERENCES
Amoebae
1 Singh, B. N., "Nuclear Division in Nine
Species of Small, Free-Living Amoe-
bae and its Bearing on the Classifica-
tion of the Order Amoebida", Philos.
Trans. Royal Soc, London, Series B,
236:405-461, 1952.
2 Chang, S, L., et al. "Survey of Free-
Living Nematodes and Amoebas in
Municipal Supplies". J. A.W . W. A.
_52:613-618, 1960.
3 Chang, S. L., "Growth of SmaU Free-
Living Amoebae in Various Bacterial
and in Bacteria-Free Cultures". Can,
Jour. Microbiol. j>:397-405, 1960.
Nematodes
1 Goodey, T., "Freshwater Nematodes",
1st. Edition, Methuen&Co., London,
1951.
2 Edmondson, W.T., Ed., Ward & Whipple's
"Fresh-Water Biology" 10th Edition,
page 397, 1955.
3 Chang, S. L., et al., "Occurrence Of a
Nematode Worm in a City Water Supply".
J.A.W.W.A., Ł1:671-676, 1959.
4 Chang, S. L., etal., "Survival, and
Protection Against Chlorination, of
Human Enteric Pathogens in Free-
Living Nematodes Isolated From Water
Supplies". Am. Jour. Trop, Medicine
& Hygiena. J): 136-142, 1960.
5 Chang, S. L., etal., "Survey of Free-
Living Nematodes and Amoebas in
Municipal Supplies". J.A.W.W.A.,
52^:613-618, 1960.
6 Chang, S. L., "Proposed Method for
Examination of Water for Free- Living
Nematodes". J.A.W.W.A., 5_2:695-698,
1950.
7 Chang, S. L., "Viruses, Amoebas,
and Nematodes and Public Water
Supplies". J.A.W.W.A., 53:283-296,
1961.
8 Chang, S. L., and Kabler, P.W., "Free-
Living Nematodes in Sewage Effluent
from Aerobic Treatment. Plants". To
be published.
This outline was prepared by Shin L. Chang,
M. D., Chief, Etiology, Criteria Development
Branch, Water Supply Research Laboratory,
NERC, EPA, Cincinnati. OH 45238.
Descriptors: Amoebae, Nematodes
17-2
-------
SUGGESTED CLASSIFICATION OF _SMALL AMOEBAE
Subphylum: Sarcodina Hertwig and Lesser
Class: Rhizopoda von Siebold
Subclass; Amoebaea Butschli
Order: Amoebida Calkins and Ehrenberg
Superfamily: Amoebaceae - free-living
(Endamoebaceae - parasitic in animals)
Family: Schizopyrenidae - active limax form common; transcient
flagellates present or absent; nucleonus-origin of
polar masses; polar caps and interzonal bodies present
or absent
Genus: Schizopyrenus - no transcient flagellates; single-walled
cysts; no polar caps or interzonal bodies in mitosis
Species: S,, erythaenusa - reddish orange pigment formed in agar
cultures with gram-negative baciliary bacteria
j3. ŁU83eIli - no pigment produced in agar cultures
Genus: Didascalus - morphology and cytology similar to Schizopyrenus^
but small numbers of transcient flagellates formed at times
Species: D. thorntoni - only species described by Singh (1952)
Genus: Naegleria Alexeieff - double-walled cysts; transcient
flagellates formed readily; polar caps and interzonal
bodies present in mitosis
Species: N. gruberi (Schardinger) - only species established;
Singh (1952) disclaimed the N. soli_he described in 1951
Family: Hartmannellidae - no transcient flagellate formed; motility
sluggish; no Mmax form; nucleolu.3 disappearing, probably
forming spindle in mitosis; no polar caps or masses, aster
and centrosome not known
Genus: Hartmannella - ectoplasm clear or less granular than
endoplasm; single-walled cysts; single vacuole
Species: H. glebae - clear ectoplasm
H. _agricola_- ectoplasm less granular than endoplasm
Genus: Acanthamoeba - filamentous processes from ecto- or
endoplasm; growing axenically in fluid bacteriological
media
17-3
-------
Suggested Classification of Small Amoebae
Species: A. rhjrsode_3_
Genus: Slnghella - double-walled cysts; ecto- and endoplastn
indistinguishable; many vacuDles
Species: Singhella leptpcnemus
17-4
-------
ANIMAL PLANKTON
I INTRODUCTION
A Planktonic animals or zooplankton are
found in nearly every major group of
animals.
1 Truly planktonic species (euplanktcn)
spend all or most of their active life
cycle suspended in the water. Three
groups are predominantly involved in
fresh water; the protozoa, rotifers,
and microcrustacea.
2 Transient planktonic phases such as
floating eggs and cysts, and larval
stages occur in many other groups.
B Many forms are strictly seasonal in
occurrence.
C Certain rare forms occur in great numbers
at unpredictable intervals.
D Techniques of collection, preservation,
and identification strongly influence the
species reported.
E In oceanographic work, the zooplankton is
considered to include many relatively large
animals such as siphonophores, ctenophores,
hepteropods., pteropods, arrowworms, and
euphausid shrimp.
F The plant-like or phytoplankton on the
other hand are essentially similar in all
waters, and are the nutritional foundation
for the animal community.
II PHYLUM PROTOZOA
A The three typically free living classes,
Mastigophora, Rhizopoda, and Ciliophora,
all have planktonic representatives. As
a group however, the majority of the phylum
is benthic or bottom-loving. Nearly any
of the benthic forms may occasionally be
washed up into the overlying waters and
thus be collected along with the euplankton.
B Class mastigophora, the nonpigmented
zooflagellates.
These have frequently been confused with
the phytomastigina or plant-like flagellates.
The distinction is made here on the basis
of the presence or absence of chlorophyll
as suggested by Palmer and Ingram 1955.
(Note Figure: Nonpigmented, Non-Oxygen
Producing Protozoan Flagellates in the
outline Oxygen Relationships.)
1 Commonly encountered genera
Bodo
Peranema
2 Frequently associated with eutrophic
conditions
C Class Rhizopoda - amoeboid protozoans
1 Forms commonly encountered as
plankton:
Chaos
Arcella
Difflugia
Euglypha
(Amoeba)
Centropyxis
Heliozoa
2 Cysts of some types may be encountered
in water plants or distribution systems;
rarely in plankton of open lakes or
reservoirs.
D Class Ciliophora
1 Certain "attached" forms often found
floating freely with plankton:
Vorticella
Carchesium
2 Naked, unattached ciliates. Halteria
one of commonest in this group'. Various
heavily ciliated forms (holotrichs) may
occur from time to time such as
Colpidium, Enchelys, etc.
3 Ciliates protected by a shell or test
(testaceous) are most often recorded
from preserved samples. Particularly
common in the experience of the National
Water Quality Sampling Network are:
Codpnella fluviatile
Codonella cratera
Tintinnidium (usually with organic matter)
Tintinnopsis
BI.AQ.20c. 6. 76
18-1
-------
Animal Plankton
III PHYLUM ROTIFERA
A Some forms such as Anuraea cochlearis
and Asplanchna pridonta~tehd to be present
at all times of the year. Others such as
Notholca striata, N._ longispina and Poly-
arthra pTafypTera ar e~ reportecTto be essen-
tially winter lorms.
B Species in approximate order of descending
frequency currently recorded by National
Water Quality Sampling Network are:
Keratella cochlearis
Polyarthra vulgaris
Synchaeta pectinata
Brachionus quadridentata
Trichocerca longiseta
Rotaria sp.
Filinia longiseta
Kellicottia longispina
Pompholyx sp.
C Benthic species almost without number may
be collected with the plankton from time to
time.
IV PHYLUM ARTHROPODA
A Class Crustacea
1 The Class Crustacea includes the larger
common freshwater euplankton. They
are also the greatest planktonic consum-
ers of basic nutrients in the form of
phytoplankton, and are themselves the
greatest planktonic contribution to the
food of fishes. Most of them are herb-
ivorous. Two groups, the cladocera
and the copepods are most conspicuous.
2 Cladocera (Subclass Branchiopoda,
Order Cladocera) or Water Fleas
a Life History
1) During most of the year, eggs
which will develop without fertil-
ization (parthenogenetic) are
deposited by the female in a dorsal
brood chamber. Here they hatch
into minature adults which escape
and swim away.
2) As unfavorable conditions develop,
males appear, and thick-walled
sexual eggs are enclosed in egg
cases called ephippia which can
often endure freezing and drying.
3) Sexual reproduction may occur
at different seasons in different
species.
4) Individuals of a great range of
sizes, and even ephippia, are
thus encountered in the plankton,
but there is no "larval" form.
b Seasonal variation - Considerable
variation may occur between winter
and summer forms of the same
species in some cases. Similar
variation also occurs between arctic
and tropical situations.
c Forms commonly encountered as
open water plankton include:
Bosmina longirostris and others
Daphnia galeata and others
Other less common genera are:
Diaphanosoma, Chydorus, Sida,
TScroperus/ Ceriodaphnla7 Bytho-
tr ephe s,~ and" theTcafniyor ous
LepTocfora and Polyphemus.
d Heavy blooms of Cladocerans may
build up in eutrophic waters.
The copepods (order Copepoda) are the
perennial microcrustacea of open waters,
both fresh and marine. They are the
most ubiquitous of animal plankton.
a Cyclops is the genus most often
TcmricJ by the National Water Quality
Sampling Network activities. Eucy-
clops, Paracyclops. Diaptomus,
CanthQcamptus, "Epischura,~ and
Limnocalanus are other forms
reported TcTEe planktonic.
b Copepods hatch into a minute char-
acteristic larvae called a nauplius
which differs considerably from the
adults. After five or six moults, the
copepodid stage is reached, and after
six more moults, the adult. These
larval stages are often encountered
and are difficult to identify.
18-2
-------
Animal Plankton
B Class Insecta
1 Only a few kinds of insect that can be
ranked as a truly planktonic. Mainly
•the phantom midge fly Chaborus.
2 The larva of this insect has hydrostatic
organs that enable it to remain suspended
in the water, or make vertical ascents in
the water column.
3 It is usually benthic during the daytime,
but ascends to the surface at night.
V OCCASIONAL PLANKTERS
A While the protozoa, rotifers, and micro-
crustacea make up the bulk of the plankton,
there are many other groups as mentioned
above that may also occur. Locally or
periodically these may be of major import-
ance. Examples are given below.
B Phylum Coelenterata
1 Polyps of the genus Hy_dra may become
detached and float aTJouFnanging from
the surface film or floating detritus.
2 The freshwater medusa Craspedacusta
occasionally appears in lakes or reser-
voirs in great numbers.
C Phylum Platyhelminthes
1 Minute Turbellaria (relatives of the
well known Planaria) are sometimes
taken with the plankton in eutrophic
conditions. They are often confused
with ciliate protozoa.
2 Cercaria larvae of Trematodes (flukes)
parasitic on certain wild animals,
frequently appear in great numbers.
When trapped in the droplets of water
on a swimmer's skin, they attempt to
bore in. Man not being their natural
host, they fail. The resultant irritation
is called "swimmer's itch". Some can
be identified, but many unidentifiable
sspecies may be found.
3 In many areas of the world, cercaria
larvae of human parasites such as the
blood fluke Schistosoma japonicum may
live as plankton,~an3~penefrate"fhe~human
skin directly on contact.
D Phylum Nemathelminthes
1 Nematodes (or nemas) or roundworms
approach the bacteria and the blue-green
algae in ubiquity. They are found in
the soil and in the water, and in the air
as dust. In both marine and fresh waters
and from the Arctic to the tropics.
2 Although the majority are free living,
some occur as parasites of plants,
animals, and man, and some of these
parasites are among our most serious.
3 With this distribution, it is obvious that
they will occasionally be encountered as
plankton. A more complete discussion
of nematodes and their public health
implications in water supplies will be
found elsewhere (Chang, S. L.).
E Additional crustacean groups sporadically
met with in the plankton include the following:
1 Order Anostraca or fairy shrimps
(formerly included with the two
following orders in the Euphyllopoda)
primarily planktonic in nature.
a Extremely local and sporadic, but
when present, may be dominating.
b Artemia, the brine shrimp, can
tolerate very high salinities.
c Very widely distributed, poorly
understood.
2 Order Notostraca, the tadpole shrimps.
Essentially southern and western in
distribution.
3 Order Conchostraca, the clam shrimps.
Widely distributed, sporadic in occur-
rence. Many local species.
4 Subclass Ostracoda, the seed shrimps.
Up to 3 in. in length. Essentially
benthic but certain species of Cypris,
and Notodromas may occur in corisTd"-
erabTe~numb"ers as plankton at certain
times of the year.
5 Certain members of the large subclass
Malacostraca are limnetic, and thus,
planktonic to some extent.
a The scuds, (order Amphipoda) are
essentially benthic but are sometimes
collected in plankton samples around
18-3
-------
Animal Plankton
weed beds or near shore. Nekto-
planktonic forms include Pontoporeia
and some species of Gammarus.
b The mysid, or opossum shrimps are
represented among the plankton by
Mysis relicta, which occurs in the
deeper waters, large lakes as far
north as the Arctic Ocean.
F The Class Archnoidea, Order Hydracarina
(or Acari) the mites. Frequent in plankton
tows near shore although Unionicola crass-
ipes has been reported to be virtually
planktonic.
G The phylum Mollusca is but scantily
represented in the freshwater plankton,
in contrast to the marine situation.
Glochidia (ciliated) larvae are occasion-
ally collected, and snails now and then
glide out on a quiet surface film and are
taken in a plankton net. An exotic
bivalve Corbicula has a planktonic
veliger stage.
H Eggs and other reproductive structures
of many forms including fish, insects, and
rotifers may be found in plankton samples.
Special reproductive structures such as
the statoblasts of bryozoa and sponges,
and the ephippia of cladocerans may also
be included.
I Adventitious and Accidental Plankters
Many shallow water benthic organisms
may become accidentally and temporarily
incorporated into the plankton. Many of
those in the preceding section might be
listed here, in addition to such forms as
certain free living nematodes, small
oligochaetes, and tardigrades, Collembola
and other surface film livers are also
taken at times but should not be mistaken
for plankton. Fragments and molt skins
from a variety of arthropods are usually
observed.
Pollen from terrestrial or aquatic plants
is often unrecognized, or confused with
one of the above. Leaf hairs from
terrestrial plants are also confusing to
the uninitiated, they are sometimes
mistaken for fungi or other organisms
(and vice versa).
In flowing waters, normally benthic
(bottom living) organisms are often found
drifting freely in the stream. This
phenomenon may be constant or periodic.
When included in plankton collections,
they must be reported, but recognized
for what they are.
Surfuc'' films are especially rich in
micro ''biological garbage" and these
enrich the plankton.
REFERENCES
1 Edmondson, W. F., ed. Ward and
Whipples's Freshwater Biology, 2nd
Edition, Wiley & Sons, Inc., New York.
1959.
2 Hutchinson, G. Evelyn. A Treatise on
Limnology. Vol. 2. Introduction to
Lake Biology and the Limnoplankton.
Wiley. 1115 pp. 1967.
3 Lackey, J. B. Quality and Quantity of
Plankton in the South End of Lake
Michigan in 1952. JAWWA.
36:669-74. 1944.
4 McGauhey, P.H., Eich, H.F., Jackson,
H. W., and Henderson, C. A Study
of the Stream Pollution Problem in the
Roanoke, Virginia, Metropolitan
District. Virginia Polytech. Inst.,
Engr. Expt. Sta.
5 Needham, J. G. and Lloyd, J.T. The
Life of Inland Waters. Ithaca, New
York, Comstock Publishing Co., Inc.
1937.
6 Newell, G.E. and Newell, R. C.
Marine Plankton. Hutchinson Educ.
Ltd. London. 221pp. 1963.
7 Palmer, C.M. and Ingram, W.M.
Suggested Classification of Algae and
Protozoa in Sanitary Science.
Sew. & Ind. Wastes. 27:1183-88.
1955.
18-4
-------
Animal Plankton
8 Penriak, R.W. Freshwater Invertebrates 10 Welch, P.S. Limnology, McGraw-Hill
d:f the United States. The Ronald Press, Book Co., Inc., New York. 1935.
New York. 1953.
9 Sverdrup, H. W., Johnson, M.W., and
Fleming, R.H. The Oceans, Their
Physics, Chemistry and General This outline was prepared by H. W. Jackson,
Biology. Prentice-Hall, Inc., New York. former Chief Biologist, National Training
1942. Center, and revised by R. M. Sinclair,
Aquatic Biologist, National Training Center
MOTD, OWPO, USEPA, Cincinnati, Ohio
45268.
Descriptor: Zooplankton
18-5
-------
Animal Plankton
3/k
Phylum PROTOZOA
Free Living Representatives
I. Flagellated Protozoa, Class Hastigophora
Ahthophysis
Pollution tollerant
Pollution tollerant
19/1
Colony of Poteriodendron
Pollution tollerant, 35/1
II. Ameboid Protozoa, Class Saroodina
Pimastigamoeta
Pollution tollerant
10-50/j
Nuelearia.reported
to be intollerant of
pollution, 45 /*•
III. Ciliated Protozoa, Class Ciliophora
Colpoda
Pollution tollerant
20-120 /i
Holophrya.reported
to be intollerant of
pollution, 35 >»
Difflugia
Pollution tollerant
60-500/,
EpistyliB. pollution
tollerant. Colonies often
naorosoopio.
H.W.Jaokson
-------
Animal Plankton
PLANKTONIC PROTOZOA
Peranema trichophorum
Top
Side
Chaos
Arcella
vulgaris
Actinosphaerium
Vorticella
Codonella
cratera
Tintinnidium
fluviatile
-------
Animal Plankton
PLANKTONIC ROTIFERS
Various Forms of Keratella cochlearis
Synchaeta
pectinata
Polyarthra
vulgaris
Rotaria sp
Brachionus
quadridentata
18-8
-------
Animal Plankton
SOME PLANKTONIC CRUSTACEANS
CRUSTACEANS
Copepod; Cyclops. Order Copepoda
2-3 mm
Water Flea;
Daphnia
A Nauplius larva of a Copepod
1-5 mm
Order Cladocera
2-3 mm
OSTRACODE
Left: Shell closed Right: Appendages extended
1-2 mm
-------
Animal Plankton
PLANKTONIC ARTHROPODA
A mysid shrimp - crustacean
A water mite - arachnid
Chaoborus midge larva - Insect
Aspects in the life cycle of the human tapeworm
Diphyllobothrium latum, class Cestoda. A. adult as inhuman
intestine; B. procercoid larva in copepod; C. plerocercoid
larva in flesh of pickerel (X-ray view).
H.W. Jackson
10
-------
TECHNIQUES OF PLANKTON SAMPLING PROGRAMS
I INTRODUCTION
A A plan is necessary. "If you fail to plan,
you are planning to fail. " Overall objec-
tives, integration with other survey units,
statistical design.
B A planned program of plankton analysis
should involve periodic sampling at weekly
intervals or more often.
1 Most interference organisms are small,
and hence have relatively short-life
histories.
2 Populations of such organisms may
fluctuate rapidly in response to chang-
ing water, weather, or seasons.
3 Seasonal growth patterns of plankton
tend to repeat themselves from year to
year, thus they are relatively predictable.
C A well-planned study or analysis of the
growth pattern of plankton in one year will
provide a basis for predicting conditions
the following year.
1 Since the seasons and the years differ,
the more records are accumulated, the
more useful can they become.
2 As the time for an anticipated bloom of
some troub.le maker approaches, the
frequency of analysis may be increased.
D Detection of a bloom in its early stages
will facilitate more economical control.
II FIELD ASPECTS OF THE ANALYSTS
PROGRAM
A Two general aspects of sampling are com-
monly recognized: quantitative and
qualitative.
1 Qualitative examination tells what is
present.
2 Quantitative tells how much.
3 Either approach is useful, a combination
is best.
BI. MIC.enu. 9h. 6. 76
B Equipment of collecting samples in the
field is varied.
1 A half-liter bottle will suffice for sur-
face samples of phytoplankton if carefully
taken. If zooplankton also are of interest,
2 or more liters should be collected.
(See below).
2 Plankton nets concentrate the sample
in the act of collecting, and capture
certain larger forms which escape from
the bottles. Only the more elaborate
types are quantitative however,
3 A kemmerer-type sampler is suggested
for depth samples.
4 Other methods such as the Clark-Bumpus
sampler or the Juday plankton trap may
be employed for special purposes.
C The location of sampling points is
important
1 Both shallow and deep samples are
suggested.
a "Shallow" samples should be taken
at a depth of 6 inches to one foot.
b "Deep" samples should be taken at
such intervals as the depth of the
reservoir permits. There should be
at least one open water sampling
point.
c Each major bay or shoal area should
have at least one sampling point.
d Additional sampling stations should
be established on the basis of ex-
perience and resources.
e Samples may be composited if nec-
essary to give an overall summary of
conditions. Such summaries are not
advised and should be interpreted
with care.
19-1
-------
Techniques of Plankton Sampling Programs
A standardized vertical haul however,
can be useful for routine comparisons.
Ill FACTORS WHICH INCLUENCE SAMPLING
AND DATA COLLECTION
A Physical Features
1 Temperature
a Lakes are warmed in spring princi-
pally by the action of wind forcing
the warmer water down into the
cooler water against the forces of
gravity.
b Thermal stratification
2 Turbidity
3 Color
4 Water movement
5 Light penetration
a A factor of turbidity, color, biolog-
ical activity, and time of day
(1) Effective length of daylight
diminishes with the depth of
the lake.
6 Wind velocity and direction
7 Bottom materials
8 Size, shape, and slope of lake basin
B Chemical Factors
1 Alkalinity, pH, and dissolved minerals
excluding nitrogen and phosphorus
2 Dissolved oxygen
a From photosynthesis in sunlight
b From contact of lake surface with
the air
c Fluctuates seasonally because of
temperature and biological activity,
and diurnally because of biological
activity.
3 Nutrients for biological growth -
especially nitrogen and phosphorus
a A given body of water will produce
a given quanity of aquatic life.
Biological production is determined
primarily by the nutrients in solu-
tion in the water, and an increase
in basic fertility will increase
biological activity.
b Basic suppliers of nutrients
include tributary streams, precip-
itation from the atmosphere, and
interchange with lake bottom sedi-
ments .
IV FIELD PRESERVATION OF SAMPLES
Provision should be made for the field
stabilization of the sample until the laboratory
examination can be made. Techniques and
materials are listed below. No "ideal" pre-
servative or technique has yet been developed
each has its virtues.
A Refrigeration or icing. The container
containing the sample can be cooled, but
under no circumstances should ice be
dropped into the sample.
B Preservation by 3-5% formalin is time-
tested and widely used. Formalin shrinks
animal tissue, fades colors, and makes all
forms brittle.
C Ultra-violet sterilization is useful in the
laboratory to retard decomposition of
plankton.
D Lugol's solution is often used.
E A special merthiolate preservative
developed by the FWPCA Water Pollution
Surveillance System which has proved very
satisfactory and is described in reference
No. 9.
19-2
-------
Techniques of Plankton Sampling Programs
V SUMMARY AND CONCLUSIONS
A The field sampling program should be
carefully planned to evaluate all signifi-
cant locations in the reservoir or stream,
giving due consideration to the capacity
of the laboratory.
B Adequate records and notes should be
made of field conditions and associated
with the laboratory analyses in a permanent
file,
C Once a procedure for processing plankton
is adopted, it should be used exclusively
by all workers at the plant.
D Such a procedure should enable the water
plant operator to prevent plankton troubles
or at least to anticipate them and have
corrective materials or equipment
stockpiled.
ACKNOWLEDGMENT:
Portions of this outline were prepared by
K. M. Mackenthun, Biologist, formerly with
Technical Advisory and Investigation Activities,
FWPCA, SEC, Cincinnati, Ohio.
REFERENCES
1 APHA. Standard Methods for the
Examination of Water and Wastewater
14-th Ed, NY, 1976.
2 Hutcheson, George E. A Treatise on
Limnology. John Wiley and Co. New
York. 1957.
3 Jackson, H. W. Biological Examination
(of plankton) Part III in Simplified
Procedures for Water Examination.
AWWA Manual M12. Am. Water
Works Assoc., N.Y. 1964.
4 Lackey, J. B. The Manipulation and
Counting of River Plankton and Changes
in Some Organisms Due to Formalin
Preservation. Public Health Reports
,53: 2080-93. 1938.
5 Mackenthun, K. M., Ingram, W. M.,
and Ralph Forges. Limnological
Aspects of Recreation Lakes, DHEW,
PHS Publication No. 1167, 1964.
6 Olson, Theodore A. and Burgess, Fred-
erick J. Pollution and Marine Ecology.
Interscience Publishers. 364 pp. 1967.
7 Palmer, C. M. Algae in Water Supplies.
U. S, Department of Health, Education,
and Welfare, Public Health Service
Publication No. 657, Superintendent of
Documents, Washington 25, D. C.
8 Schwoerbel, J. Methods of Hydrobiology
(Freshwater Biology). Pergamon
Press, 1970,
9 Websr, C. I. Methods of Collection and
Analysis of Plankton and Periphyton
Samples in the Water Pollution
Surveillance System. App. and Devel.
Rep. (AQCLab., 1014 Broadway,
Cincinnati, OH 45202) 19 pp 1966.
10 Welch, P. S. Limnological Methods.
The Blakiston Co., Phila. Toronto.
1948.
11 Williams, L. G. Plankton Population
Dynamics, in National Water Quality
Network, Supplement 2, U.S.. PHS
Pub. No. 663. 1962.
This outline was prepared by H. W. Jackson,
former Chief Biologist, National Training
Center, and revised by R. M. Sinclair,
Aquatic Biologist, National Training Center,
MOTD. OWPO. USEPA, Cincinnati, Ohio 45268.
Descriptor: Plankton
19-3
-------
PREPARATION AND ENUMERATION OF PLANKTON IN THE LABORATORY
I RECEPTION AND PREPARATION OF
SAMPLES
A Preliminary sampling and analysis is an
essential preliminary to the establish-
ment of a permanent or semi-permanent
program,
B Concentration or sedimentation of pre-
served samples may precede analysis.
1 Batch centrifuge
2 Continuous centrifuge
3 Sedimentation
C Unpreserved (living) samples should be
analyzed at once or refrigerated for
future analysis.
II PREPARATION OF MERTHIOLATE
PRESERVATIVE
A The Water Pollution Surveillance System
of the FWPCA has developed a modified
merthiolate preservative. (Williams,
1967) Sufficient stock to make an approx-
imately 3.5% solution in the bottle when
filled is placed in the sample bottle in
the laboratory. The bottle is then filled
with water in the field and returned to
the laboratory for analysis.
B Preparation of Merthiolate Preservative
1 Merthiolate is available from many
chemical laboratory supply houses;
one should specify the water soluble
sodium salt.
2 Merthiolate stock: dissolve approxi-
mately 1. 5 gram of sodium borate
(borax and approximately 1 gram of
merthiolate in 1 liter of distilled water.
The amount of sodium borate and
merthiolate may be varied slightly to
adjust to different waters, climates,
and organic contents.
3 Prepare a saturated aqueous Lugol1 s
solution as follows:
a Add 60 grams of potassium iodide
(KI) and 40 grams of iodine crystals
to 1 liter of distilled water.
4 Prepare the preservative solution by
adding approximately 1. 0 ml of the
Lugol's solution to 1 liter of merthi-
olate stock.
Ill SAMPLE ANALYSIS
Microscopic examination is most frequently
employed in the laboratory to determine
what plankton organisms are present and
how many there are:
1 Optical equipment need not be elaborate
but should include.
a Compound microscope with the
following equipment:
1) Mechanical stage
2) Ocular: 10X, with Whipple type
counting eyepiece or reticule
3) Objectives:
approx. 10X(16mm)
approx. 20X(8 mm)
approx. 40X(4 mm)
approx. 95X(1.8 mm)(optional)
A 40X objective with a working
distance of 12.8 mm and an erect
image may be obtained as special
equipment. A water immersion
objective (in addition to oil) might
be considered for use with water
mounts.
Binocular eyepieces are optional.
BI. MIC.enu.15f. 6. 76
20-1
-------
Preparation and Enumeration of Plankton
Stage micrometer (this may be
borrowed, if necessary, as it is
usually used only once, when the
equipment is calibrated)
b Inverted microscopes offer certain
advantages but are not widely
available. The same is true of
some of the newer optical systems
such as phase contrast microscopy.
These are often excellent but ex-
pensive for routine plant use.
2 Precision made counting chambers
are required for quantitative work with
liquid mounts.
a Sedgwick-Rafter cells (hereafter
referred to as S-R cell) are used
for routine counts of medium and
larger forms.
b Extremely small forms or "nanno-
plankton" may be counted by use of
the nannoplankton (or Palmer) cell,
a Fisher- Littman cell, a hemacyto-
meter, the Lackey drop method, or
by use of an inverted microscope.
3 Previous to starting serious analytical
work, the microscope should be cali-
brated as described elsewhere. Di-
mensions of the S-R cell should also
be checked, especially the depth.
4 Automatic particle counters may be
useful for coccoid organisms.
B Quantitative Plankton Counts
1 All quantitative counting techniques
involve the filling of a standard cell
of known dimensions with either
straight sample or a concentrate or
dilution thereof.
2 The organisms in a predetermined
number of microscope fields or other
known area are then observed, and by
means of a suitable series of multi-
plier factors, projected to a number or
quantity per ml gallon, etc.
Direct counting of the unconcentrated
sample eliminates manipulation, saves
time, and reduces error. If frequency
of organisms is low, more area may
need to be examined or concentration
of the sample may be in order.
Conventional techniques employing
concentration of the sample provide more
organisms for observation, but because
they involve more manipulations, intro-
duce additional errors and take more
time.
C Several methods of counting plankton are
in general use.
1 The numerical or clump count is
regarded as the simplest.
a Every organism observed must be
enumerated. If it cannot be identi-
fied, assign a symbol or number
and make a sketch of it on the back
of the record sheet.
b Filaments, colonies and other
associations of cells are counted
as units, equal to single isolated
cells. Their identity as indicated
on the record sheet is the key to
the significance of such a count.
2 Individual cell count. In this method,
every cell of every colony or clump
of organisms is counted, as well as
each individual single-celled organism.
3 The areal standard unit method offers
certain technical advantages, but also
involves certain inherrent difficulties.
a An areal standard unit is 400 square
microns. This is the area of one
of the smallest subdivided squares
in the center of the Shipple eyepiece
at a magnification of 100X.
b In operation, the number of areal
units of each species is recorded on
the record sheet rather than the
number of individuals. Average
areas of the common species are
20-2
-------
Preparation and Enumberation of Plankton
are sometimes printed on record
sheets for a particular plant to
obviate the necessity of estimating
the area of each cell observed
individually.
c The advantage of the method lies in
the cognizance taken of the relative
masses of the various species as
indicated by the area presented to
the viewer. These areas, however,
are often very difficult to estimate.
4 The cubic standard unit method is a
logical extension of the areal method,
but has achieved less acceptance.
5 Separate field count
a In counting separate fields, the
question always arises as to how
to count organisms touching or
crossed by the edge of the Whipple
field. Some workers estimate the
proportion of the organism lying
inside the field as compared to that
outside. Only those which are over
half way inside are counted.
b Another system is to select two
adjacent, sides of the square for
reference, such as the top and left
boundaries. Organisms touching
these lines in any degree, from
outside or inside, are then counted,
while organisms touching the opposite
sides are ignored. It is important
to adopt some such system and
adhere to it consistently.
c It is suggested that if separate
microscopic fields are examined,
a standard number of ten be adopted.
These should be evenly spaced in two
rows about one-third of the distance
down from the top and one-third of
the distance up from the bottom of
the S-R cell.
6 Multiple area count. This is an ex-
tension of the separate field count.
A considerable increase in accuracy
has recently been shown to accrue by
emptying and refilling the S-R cell,
D
after each group of fields are counted
and making up to 5 additional such
counts. This may not be practical with
high counts.
The strip count. When a rectangular
slide such as the S-R cell is used, a
strip (or strips) the entire length (or
known portion thereof) of the cell may
be counted instead of separate isolated
fields. Marking the bottom of the cell
by evenly spaced cross lines as ex-
plained elsewhere greatly facilitates
counting.
a When the count obtained is multi-
plied by the ratio of the width of
the strip counted to the width of
the cell, the product is the esti-
mated number of organisms in the
cell, or per ml.
b When the material in the cell is
unconcentrated sample water, this
count represents the condition of
the water being evaluated without
further calculation.
Survey count. A survey count is an
examination of the entire area of a
volumetric cell using a wide field low
power microscope. The objective is
to locate and record the larger forms,
especially zooplankton such as copepods
or large rotifers which may be present
in size. Special large capacity cells
are often employed for this purpose.
For still larger marine forms, numerous
special devices have been created.
Once a procedure for concentration
and/or counting is adopted by a plant
or other organization it should be
used consistently from then on so
that results from year to year can be
compared.
Differential or qualitative "counts" are
essentially lists of the kinds of organisms
found.
20-3
-------
Preparation and Enumeration of Plankton
E Proportional or relative counts of special
groups are often very useful. For ex-
ample, diatoms. It is best to always
count a standard numbers of cells.
F Plankton are sometimes measured by
means other than microscopic counts.
1 Settled volume of killed plankton in an
Imhoff cone may be observed after a
standard length of time. This will
evaluate primarily only the larger forms.
2 A gravimetric method employs drying
at 60° C for 24 hours followed by
ashing at 600° C for 30 minutes. This
is particularly useful for chemical
and radiochemical analysis.
3 Chemical and physical evaluation of
plankton populations employing various
instrumental techniques are coming to
be widely used. Both biomass and
productivity rates can be measured.
Such determinations probably achieve
their greatest utility when coordinated
with microscopic examination.
4 The membrane (molecular) filter has
a great potential, but a generally
acceptable technique has yet to be
perfected.
a Bacteriological techniques for
coliform determination are
widely accepted.
b Nematodes and larger organisms
can readily be washed off of the
membrane after filtration.
c It is also being used to measure
ultraplankton that pass treatment
plant operations.
d Membranes can be cleared and
organisms deposited thereon
observed directly, although
accessory staining is desirable.
e Difficulties include a predilec-
tion of extremely fine membranes
to clog rapidly with silt or
increase in plankton counts, and
the difficulty of making observations
on individual cells when the
organisms are piled on top of each
other. It is sometimes necessary
to dilute a sample to obtain suitable
distribution.
IV SUMMARY AND CONCLUSIONS
A The field sampling program should be
carefully planned to evaluate all significant
locations in the reservoir or stream,
giving due consideration to the capacity
of the laboratory.
B Adequate records and notes should be
made of field conditions and associated
with the laboratory analyses in a
permanent file.
C Optical equipment in the laboratory should
be calibrated.
D Once a procedure for processing plankton
is adopted, it should be used exclusively
by all workers at the plant.
E Such a procedure should enable the water
plant operator to prevent plankton troubles
or at least to anticipate them and have
corrective materials or equipment stockpiled.
REFERENCES
1 Ely Lilly Company. Merthiolate as a
Preservative. Ely Lilly & Co.
Indianapolis 6, Indiana.
2 Gardiner, A. C. Measurement of
Phytoplankton Population by the
Pigment Extraction Method. Jour.
Marine Biol. Assoc. ^5(4):739-744. 1943.
3 Goldberg, E. D., Baker, M., and Fox, D. L.
Microfiltration in Oceanographic
Research Sears Foundation. Jour.
Mar. Res. 11:194-204. 1952.
20-4
-------
Preparation and Enumeration of Plankton
Ingram, W. M., and Palmer, C. M.
Simplified Procedures for Collecting,
Examining, and Recording Plankton
in Water. Jour. AWWA. 44(7):
617-624. 1952.
Jackson, H. W. Biological Examination
(of plankton) Part III in Simplified
Procedures for Water Examination.
AWWA Manual M 12. Am. Water
Works Assoc. N. Y. 1964.
Lund, J. W. G., and Tailing, J. F.
Botanical Limnological Methods with
Special References to the Algae.
Botanical Review. Ł3(8&9):489-583.
October, 1957.
7 Weber, C. I. The Preservation of
Plankton Grab Samples. Water
Pollution Surveillance Systems,
Applications and Development Report
No. 26, USDI, FWPCA, Cincinnati,
Ohio. 1967
8 Williams, L. G. Plankton Population
Dynamics. National Water Quality
Network Supplement 2. U. S. Public
Health Service Publ. No. 663. 1962
9 Wohlschag, D. D., and Hasler, A. D.
Some Quantitative Aspects of Algal
Growth in Lake Mendota. Ecology.
32(4):581-593. 1951
'This outline was prepared by H. W. Jackson,
former Chief Biologist, National Training
Center, and revised by R. M. Sinclair,
Aquatic Biologist, National Training Center,
MOTD, OWPO, USEPA, Cincinnati, Ohio 45268
Descriptor: Plankton
20-5
-------
ATTACHED GROWTHS
(Periphyton or Aufwuchs)
I The community of attached microscopic
plants and animals is frequently investigated
during water quality studies. The attached
growth community (periphyton) and suspended
growth community (plankton) are the principal
primary producers in waterways--they con-
vert nutrients to organic living materials and
store light originating energy through the
processes of photosynthesis. In extensive
deep waters, plankton is probably the pre-
dominant primary producer. In shallow lakes,
ponds, and rivers, periphyton is the predominant
primary producer. During the past two
decades, investigators of microscopic
organisms have increasingly placed emphasis
on periphytic growths because of inherent
advantages over the plankton when interpreting
data from surveys on flowing waters:
A Blum (1956) ". . . .workers are generally
agreed that no distinctive association of
phytoplankton is found in streams, although
there is some evidence of this for individual
zooplankters (animals) and for a few
individual algae and bacteria. Plankton
organisms are often introduced into the
current from impoundments, backwater
areas or stagnant arms of the stream....
Rivers whose plankton is not dominated by
species from upstream lakes or ponds are
likely to exhibit a majority of forms which
have been derived from the stream bottom
directly and which are thus merely
facultative or opportunistic plankters. "
B "The transitory nature of stream plankton
makes it nearly impossible to ascertain at
which point upstream agents producing
changes in the algal population were
introduced, and whether the changes
occurred at the sampling site or at some
unknown point upstream. In contrast,
bottom algae (periphyton) are true com-
ponents of the stream biota. Their
sessile-attached mode of life subjects
them to the quality of water continuously
flowing over them. By observing the
longitudinal distribution of bottom algae
within a stream, the sources of the agents
producing the change can be traced
(back-tracked)" (Keup, 1966).
II TERMINOLOGY
A Two terms are equally valid and commonly
in use to describe the attached community
of organisms. Periphyton literally means
around plants such as the growths over-
growing pond-weeds; through usage this
term means the attached film of growths
that rely on substrates as a "place-to-
grow" within a waterway. The components
of this growth assemblage consists of
plants, animals, bacteria, etc. Aufwuchs
is an equally acceptable term [probably
originally proposed by Seligo (1905)] .
Aufwuchs is a German noun without
equivalent english translation; it is
essentially a collective term equivalent
to the above American (Latin root) term -
Periphyton. (For convenience, only,
PERIPHYTON, with its liberal modern
meaning will be used in this outline.)
B Other terms, some rarely encountered in
the literature, that are essentially
synonymous with periphyton or describe
important and dominant components of the
periphytic community are: Nereiden,
Bewuchs, Laison, Belag, Besatz, attached,
sessile, sessile-attached, sedentary,
seeded-on, attached materials, slimes,
» slime-growths, and coatings.
The academic community occasionally
employs terminology based on the nature
of the substrates the periphyton grows on
(Table 1).
TABLE 1
Periphyton Terminology Based
on Substrate Occupied
Substrate Adjective
various epiholitic, nereiditic, sessile
plants epiphytic
animals epizooic
wood epidendritic, epixyIonic
rock epilithic
[After Srameck-Husek( 1946) and via Sladeckova
(1962)] Most above listed latin-root adjectives
are derivatives of nouns such as epihola,
epiphyton, spizoa, etc.
BI.MIC.enu. 19b.7.76
21-1
-------
Attached Growths (Periphyton or Aufwuchs)
III Periphyton, as with all other components
of the environment, can be sampled quali-
tatively (what is present) and quantitatively
(how much or many are present).
A Qualitative sampling can be performed by
many methods and may extend from direct
examination of the growths attached to a
substrate to unique "cuttings" or scrapings.
It may also be a portion of quantitative
sampling.
B Quantitative sampling is difficult because
it is nearly impossible to remove the
entire community from a standardized or
unit area of substrate.
1 Areas scraped cannot be determined
precisely enough when the areas are
amorphous plants, rocks or logs that
serve as the principal periphyton
substrates.
2 Collection of the entire community within
a standard area usually destroys individual
specimens thereby making identification
difficult (careful scraping can provide
sufficient intact individuals of the species
present to make qualitative determinations);
or the process of collection adds sufficient
foreign materials (i. e. detritus, sub-
strate, etc. ) so that some commonly
employed quantitative procedures are
not applicable.
IV Artificial substrates are a technique
designed to overcome the problems of direct
sampling. They serve their purpose, but
cannot be used without discretion. They are
objects standardized as to surface area,
texture, position, etc. that are placed in the
waterway for pre-selected time periods during
which periphytic growths accumulate. They
are usually made of inert materials, glass
being most common with plastics second in
frequency. Over fifty various devices and
methods of support or suspension of the
substrates have been devised (Sladeckova,
1962) (Weber, 1966) (Thomas, 1968).
V ARTIFICIAL SUBSTRATE PLACEMENT
A Position or Orientation
1 Horizontal - Includes effects of settled
materials.
2 Vertical - Eliminates many effects of
settled materials.
B Depth (light) - A substrate placed in lighted
waters may not reflect conditions in a
waterway if much of the natural substrate
(bottom) does not receive light or receives
light at reduced intensity. (Both excessive
light and a shortage of light can inhibit
growths and influence the kinds of organisms
present. )
C Current is Important
1 It can prevent the settling of smothering
materials.
2 It flushes metabolic wastes away and
introduces nutrients to the colony.
VI THE LENGTH OF TIME THE SUBSTRATE
IS EXPOSED IS IMPORTANT.
A The growths need time to colonize and
develop on the recently introduced
substrate.
B Established growths may intermittently
break-away from the substrate because
of current or weight induced stresses, or
"over-growth" may "choke" the attachment
layers (nutrient, light, etc. restrictions)
which then weaken or die allowing release
of the mass.
C A minimum of about ten days is required
to produce sufficient growths on an
artificial substrate; exposures exceeding
a longer time than 4-6 weeks may produce
"erratic results" because of sloughing or
the accumulation of senile growths in
situations where the substrate is
artificially protected from predation and
other environmental stresses.
21-2
-------
Attached Growths (Periphyton or Aufwuchs)
VII Determining the variety of growths present
is presently only practical with microscopic
examination. (A few micro-chemical pro-
cedures for differentiation show promise--
but, are only in the early stages of development. )
VIII DETERMINING THE QUANTITY OF
GROWTH(S)
A Direct enumeration of the growths while
attached to the substrate can be used, but
is restricted to the larger organisms
because (1) the problem of maintaining
material in an acceptable condition under
the short working distances of the objective
lenses on compound microscopes, and
(2) transmitted light is not adequate
because of either opaque substrates and/or
the density of the colonial growths.
B Most frequently, periphyton is scraped
from the substrate and then processed
according to several available procedures,
the selection being based on the need, and
use of the data.
1 Aliquots of the sample may be counted
using methods frequently employed in
plankton analysis.
a Number of organisms
b Standardized units
c Volumetric units
d Others
2 Gravimetric
a Total dry weight of scrapings
b Ash-free dry weight (eliminates
inorganic sediment)
c A comparison of total and ash-free
dry weights
3 Volumetric, involving centrifugation of
the scrapings to determine a packed
biomass volume.
4 Nutrient analyses serve as indices of
the biomass by measuring the quantity
of nutrient incorporated.
a Carbon
1) Total organic carbon
2) Carbon equivalents (COD)
b Organic nitrogen
c Phosphorus - Has limitations
because cells can store excess
above immediate needs.
d Other
5 Chlorophyll and other bio-pigment
extractions.
6 Carbon-14 uptake
7 Oxygen production, or respiratory
oxygen demand
EK EXPRESSION OF RESULTS
A Qualitative
1 Forms found
2 Ratios of number per group found
3 Frequency distribution of varieties
found
4 Autotrophic index (Weber)
5 Pigment diversity index (Odum)
B Quantitative
1 Areal basis--quantity per square
inch, foot, centimeter, or meter.
For example:
a 16 mgs/sq. inch
b 16,000 cells/sq. inch
2 Rate basis. For example:
a 2 mgs/day, of biomass accumulation
b 1 mg O2/mg of growth/hour
21-3
-------
Attached Growths (Periphyton or Aufwuchs)
REFERENCES
1 Blum, J. L. The Ecology of River Algae.
Botanical Review. 22:5:291. 1956.
2 Dumont, H. J. A Quantitative Method for
the Study of Periphyton. Limnol.
Oceanogr. 14(2):584-595.
3 Keup, L.E. Stream Biology for Assessing
Sewage Treatment Plant Efficiency.
Water and Sewage Works. 113:11-411.
1966.
4 Seligo, A. Tiber den Ursprung der
Fischnahrung. Mitt. d. Westpr.
Fisch. -V. 17:4:52. 1905.
5 Sladeckova, A. Limnological Investigation
Methods for the Periphyton Community.
Botanical Review. 28:2:286. 1962.
6 Srameck-Husek. (On the Uniform
Classification of Animal and Plant
Communities in our Waters).
Sbornik MAP 20:3:213. Orig. in
Czech. 1946.
7 Thomas, N.A. Method for Slide
Attachment in Periphyton Studies.
Manuscript. 1968.
8 Weber, C.I. Methods of Collection and
Analysis of Plankton and Periphyton
Samples in the Water Pollution
Surveillance System. Water Pollution
Surveillance System Applications and
Development Report No. 19, FWPCA,
Cincinnati. 19-lTpp. (multilith). 1966.
9 Weber, C.I. Annual Bibliography
Midwest Benthological Society.
Periphyton. 1014 Broadway,
Cincinnati, OH 45202.
10 Hynes, H.B.N. The Ecology of Running
Waters. Univ. Toronto Press.
555 pp. 1970.
11 Spoon, Donald M. Microbial Communities
of the Upper Potomac Estuary: The
Aufwuchs in.- The Potomac Estuary,
Biological Resources, Trends and
Options. 1CPRB Tech Pub. No. 76-2,
1976.
This outline was prepared by Lowell E. Keup,
Chief, Technical Studies Branch, Division of
Technical Support, EPA, Washington, DC 20242.
Descriptor: Periphyton
21-4
-------
DETERMINATION OF PLANKTON PRODUCTIVITY
I INTRODUCTION
Primary production is the synthesis of organic
matter from inorganic raw materials. The
energy required for this process may come
from light (photosynthesis), or from chemical
sources (chemosynthesis). The primary
synthesis of organic matter in lakes and
streams is carried on by planktonic and ben-
thic algae and bacteria, and aquatic
macrophytes.
II PHOTOSYNTHESIS
The photosynthetic process involves the up-
take of CO2 and the release of O2. The
reactions are enzyme catalyzed and are af-
fected by the following factors:
A Temperature
B Light Intensity
C Light Quality
D pH
E Nutrients
F Trace Elements
III MEASURING PRODUCTIVITY
Methods employed to measure plankton pro-
ductivity are:
A Standing Crop
B Oxygen
C pH
D Carbon-14
IV STANDING CROP METHOD
The productivity of a body of water is indicated,
in a general way, by the density of the plankton
population. The standing crop of plankton is
commonly measured by determining one or
more of the following:
A Dry and Ash-free Weight of Seston
B Cell or Unit Counts
C Cell Volume
D Chlorophyll
E Particulate and Dissolved Carbohydrate
F Particulate and Dissolved Organic Carbon
Increases in the standing crop over a period
of time may be used to determine productivity.
However, this method provides only a rough
approximation of the rate of primary
production.
V OXYGEN METHOD
The use of dissolved oxygen to determine
short-term rates of primary production was
introduced by Gaardner and Gran (1927).
Estimates of the amount of carbon fixed are
based on the premise that one molecule of
oxygen is given off for each atom of carbon
assimilated.
C0
H20 -
CH20
A "Light" and "dark" bottles are filled with
sample and resuspended at various depths
for 4-24 hours.
B The concentration of dissolved oxygen is
determined (using the Winkler Method) at
RT. KC.O. oro. la. 6. 76
22-1
-------
Determination of Plankton Productivity
the beginning and end of the incubation
period. The values obtained are as
follows:
1 Final "light" bottle O2 - initial O2 =
net photosynthesis
2 Initial O^ - Final "dark" bottle O2 =
respiration
3 Net photosynthesis + respiration =
gross photosynthesis
This method has some serious disadvantages:
A The bottles provide an artificial substrate
for the proliferation of bacteria which
use up large amounts of C>2, resulting in
erroneously high respiration and low net
photosynthesis values.
B The lower limit of sensitivity of the Winkler
Method is 0.02 mg 02/liter. This is a
serious handicap when working in oligo-
tropic lakes and the open sea.
VI CARBON-14 METHOD
The use of carbon-14 for the measurement
of the rate of carbon assimilation by phyto-
plankton was pioneered by E. Steemann
Nielsen (1952). The method is simple and
very sensitive.
A Carbon-14 labelled sodium bicarbonate
(4 - lOjic/liter) is added to "light" and
"dark" bottles, which are resuspended in
the water for 4-24 hours.
B An aliquot of the sample is passed through
a membrane filter (1.2 upore diameter),
and the filters are treated with acid to
remove any inorganic labelled carbon.
C The (beta) activity of the filter is deter-
mined with an end-window Geiger tube,
or with gas flow or liquid scintillation
techniques.
D The carbon fixed is determined as
follows:
carbon _ activity on filter
fixed " total activity added
There are several important disadvantages
in this method.
A Some of the labelled photosynthesis pro-
ducts will be broken down immediately by
respiration, and the liberated carbon-14
reused in photosynthesis. Therefore, it
is generally agreed that the method mea-
sures only net photosynthesis.
B It has been found that the algae rapidly ex-
crete up to 50% of the photosynthate in the
form of organic acids, carbohydrates,
and amino acids. Since these labelled
materials are not retained by the filter,
they escape detection.
VII pH METHOD
The uptake of CO2 by the algae during photo-
syntheses results in an increase in the pH of
the surrounding medium. Periodic pH measure-
ments are made of the body of water being
studied, and the carbon uptake is determined
using published nomographs.
Verduin (1952) used this method in a study
of the productivity of Lake Erie. However,
the method has not gained wide acceptance
because it can be used only in waters with
low alkalinity.
REFERENCES
1 Allen, M.B. Excretion of Organic Com-
pounds by Chlamydomonas. Arch. f.
Mikrobiol. 24:163-168. 1956.
2 Curl, H. Jr., and Small, L. F. Variations
in Photosynthetic Assimilation in Natural
Marine Photoplankton Communities.
Limnol. Oceanogr. 10(Suppl.):R67-R73.
1965.
3 Gaardner, T. , and Gran, H. H. Investi-
gations of the Production of the Plankton
in the Oslo Fjord. Rapp. et Proc. -
Verb., Con. Internal. Explor. Mer.
42:1-48. 1927.
X
available
HCO:
X
correction for
isotope
discrimination
22-2
-------
Determination of Plankton Productivity
4 Goldman, C. R. Molybdenum as a Factor
Limiting Primary Productivity in
Castle Lake, California. Science 132:
1016-1017. 1960.
5 Kamen, M. D. Primary Processes in
Photosynthesis. Academic Press,
New York. 1963.
6 Marshall, S.M., and Orr, A. P. Carbo-
hydrate as a Measure of Photoplankton.
J. Mar. Biol. Assoc. U.K. 42:511-519.
1962.
7 Ryther, J. H. Photosynthesis in the Ocean
as a Function of Light Intensity.
Limnol. Oceanogr. 1:61-70. 1956.
8 S'teemann Nielsen, E. The Use of Radio-
active Carbon (C-14) for Measuring
Organic Production in the Sea. J. Con.
Internat. Explor. Mer. 18:117-140. 1952.
9 Strickland, J. D. H. Measuring the
Production of Marine Phytoplankton.
Bull. Fish..Res. Bd. Can. No. 122:
1-172. 1960.
10 Verduin, J. Photosynthesis and Growth
Rates of Two Diatom Communities in
Western Lake Erie. Ecology 33(2):
163-168. 1952.
11 Vernon, L. P. Bacterial Phytosynthesis. '
Ann. Rev. Plant. Physiol. 15:73-100.1962
12 Wetzel, R. G. A Comparative Study of the
Primary Productivity of Higher Aquatic
Plants, Periphyton, and Phytoplankton
in a Large, Shallow Lake. Internat.
Rev. Hydrobiol. 49:1-61. 1964.
13 Yentsch, Charles S. The Measurement
of Chloroplastic Pigments- Thirty
Years of Progress? pp. 255-270 in
Chemical Environment in the Aquatic
Habitat. Proc. IBP Symposium.
Amsterdam. 1967. (N.V. Noord-
Hollandsche Uitgevers Maatschappij.
Amsterdam, Netherlands. 8.95)
This outline was prepared by C. I. Weber,
Chief, Biological Methods Branch,
Analytical Quality Control Laboratory,
NERC, EPA, Cincinnati, OH 45268.
Descriptors: Productivity, Plankton
22-3
-------
ALGAL GROWTH POTENTIAL TEST
I INTRODUCTION
Dense growths of algae in surface waters are
aesthetically undesirable, cause problems in
water treatment, produce changes in the aquatic
environment that are harmful to fish and other
aquatic life, and are symptomatic of pollution.
The density of phytoplankton populations is
directly related to the concentration of
nutrients. This relationship has been well
documented, and is now embodied in the
concept of trophic level or trophic status of
surface waters. One or more of the following
parameters are commonly used to describe
the trophic status: (a) nutrient concentration -
principally N and P, (b) algal count,
(c) chlorophyll concentration, (d) primary
productivity, (e) particulate organic matter,
(f) oxygen depletion in the hypolimnion, and
(g) phytoplankton species composition or
indicator species (Rawson 1956; Davis 1964;
Goldman & Carter 1965; Oglesby & Edmondson
1966; Fruh, Steward, Lee & Rohlich 1966).
II EUTROPHICATION
Three general trophic levels now recognized,
here arranged in ascending order, are:
oligotrophic (low), mesotrophic (intermediate),
and eutrophic (high). The addition of nutrients
to surface waters raises the trophic level and
results in an increase in phytoplankton density
and changes in the species composition.
This process, commonly referred to as
eutrophicatiori, is greatly accelerated by the
discharge of nutrient-laden domestic and
industrial wastes (Hasler 1947), Edmondson
& Anderson 1956).
Ill MEASUREMENTS OF TROPHIC LEVELS
Although chemical analyses provide information
on the concentration of nutrients, their
availability to the algae can be determined
only by biological assay. Biological assays
to determine the potential (algal) productivity
of surface water were first used in the late
twenties (Schreiber 1927) and early thirties
(Strom 1933), but until recently had been
used only infrequently (Potash 1956;
Skulberg 1964, 1967; Shelef & Halperin 1970).
In 1967, the Joint Industry-Government Task
Force on Eutrophication took steps to develop
a standardized algal growth potential (AGP)
test. Using this test, one can:
A Evaluate the effectiveness of waste
treatment processes in removing elements
that support or stimulate the growth of
algae.
B Determine at what point along the time
scale of progressing eutrophication the
water of a given lake or stream happens
to lie (trophic status).
C Anticipate the effect on algal production
of introducing extraneous nutrients.
D Determine the extent to which nutrient
levels must be reduced in a body of water
to effect an acceptable remedy.
IV BASIC STEPS OF ALGAL GROWTH
POTENTIAL TEST
A A surface (test) water sample is collected
and the indigenous microorganisms are
removed by filtration (0. 45 micron
membrane filter at 15 inches of mercury)
or ultracentrifugation.
B The surface water and standard medium
(Table 1) are inoculated with 1000 cells/ml
of Selenastrum capricornutum, or 50, 000
cells/ml of Anabaena flos-aquae or
Microcystis aerugingsa.
C The cultures are prepared in triplicate
and incubated 7-10 days at 24QC, 200 fc
(blue-greens) or 400 fc (Selenastrum)
continuous illumination, with shaking at
100 oscillations/min (culturing may be by
flask, chemostat, or in situ technique).
D Algal growth is measured daily by
(1) cell counts, (2) determining the
BI.BIO. alg. lb.6.76
23-1
-------
Algal Growth Potential Test
TABLE 1
MAY, 1970 VERSION OF PAAP NUTRIENT BASAL MEDIUM
(This formula consists of 30% of the concentrations of the macroelements
listed in the February, 1969, PAAP Booklet. The Na CO was replaced by
NaHCO-, and the EDTA was reduced to 333 /ug/1.)
o
MACROELEMENTS: (milligrams per liter)
Compound
NaNOQ
O
K.HPO.
2 4
MgCl2
MgSO • 7H O
CaCl0-2H0O
6t Łi
NaHCO,
O
If the medium is to be
solution from a single
Final Cone.
25.500
1.044
5.700
14.700
4.410
15.000
filtered, add
combination
filtration, K HPO should be added
solutions of individual salts may be
Element
Furnished
N
P
K
Mg
Mg
S
Ca
Na
Element
Cone.
4.200
0.186
0.469
1.456
1.450
1.911
1.202
11.001
the following trace- element -ir on- EDTA
stock solution after
filtration.
last to avoid iron precipitation
made up in 1000 X 's final cone
With no
. Stock
. or less.
MICROELEMENTS: (micrograms per liter)
H3B°3
MnCl2
ZnCl2
CoCl2
CuCl2
Na2MoO4- 2H2O
FeCl3
Na0EDTA- 2H0O
185.5
264.3
32.7
0.780
0.009
7.26
96.0
300.0
B
Mn
Zn
Co
Cu
Mo
Fe
32.5
115.4
15.7
0.354
0.004
2.88
33.05
23-2
-------
Algal Growth Potential Test
E
chlorophyll content, in vivo fluorescence,
light scattering or optical density
(600 nm) of the culture, (3) measuring
the C-14 uptake, or (4) determining the
dry weight of the algae at the end of the
Incubation period. Regardless of the
parameter used to measure growth
response, the result should always be
expressed in terms of the final dry weight
of the culture.
The growth response of the alga in the
test water is compared to its growth in
the standard medium.
V PHASES OF THE TEST STILL UNDER
STUDY INCLUDE:
A Composition of the standard growth
medium.
B Effects of ventilation and shaking on the
growth response of batch cultures.
C Techniques of measuring growth response.
D Techniques of removing indigenous
microorganisms from test surface waters.
VI For copies of the Provisional Algal Assay
, Procedure and information on the availability
of subcultures of the test organism, contact:
Dr. A. F. Bartsch, Chairman
JTF Research Program Group
Director, Pacific Northwest
Water Research Laboratory
Corvallis, Oregon 97330
REFERENCES
1 . Provisional Algal Assay
Procedure. Joint Industry-Government
Task Force on Eutrophication, P.O.
Box 3011, Grand Central Station,
N.Y. 10017. 1969.
Davis, C.C. Evidence for the eutrophication
of Lake Erie from phytoplankton records.
Limnol. Oceanogr. 9:275. 1964.
3 Edmondson, W. T. and Anderson, G. C.
Artificial eutrophication of Lake
Washington. Limnol. Oceanogr.
l(l):47-53. 1956.
4 Fruh, E.G., Stewart, K.M., Lee, G. F.,
and Rohlich, G.A. Measurements of
Eutrophication and Trends. JWPCF
38(8):1237-1258. 1966.
5 Goldman, C.R. and Carter, R.C.
An investigation by rapid C14
bioassay of factors affecting the
cultural eutrophication of Lake Tahoe,
California. JWPCF 37:1044-1063.
1965.
6 Hasler, A.D. Eutrophication of lakes by
domestic drainage. Ecology 28(4):
383-395. 1947.
7 Oglesby, R. T. and Edmondson, W. T.
Control of Eutrophication. JWPCF
38(9):1452-1460. 1966.
8 Potash, M. A biological test for
determining the potential productivity
of water. Ecology 37(4):631-639.
1956.
9 Rawson, D. S. Algal indicators of lake
types. Limnol. Oceanogr. 1:18-25.
1956.
10 Schreiber, W. Der Reinkultur von
marinem Phytoplankton und deren
Bedeutung fur die Erforschung der
Produktions-fahigkeit des Meerwassers.
Wissensch. Meeresunters., N. F.
16:1-34. 1927.
11 Shelef, G. and Halperin, R. 1970. Wastewater
nutrients and algae growth potential.
In: H.I. Shuval, ed., "Developments
in Water Quality Research", Proc.
Jerusalem Internat'l. Conf. on Water
Quality and Poll. Res., June, 1969.
Ann Arbor-Humphrey Science Publ.,
p. 211-228.
23-3
-------
Algal Growth Potential Test
12 Skulberg, O.M. Algal problems related
to the eutrophication of European water
supplies, and a bioassay method to
assess fertilizing influences of pollution
on inland waters. In: D.F. Jackson,
ed., "Algae and Man", Plenum Press,
N. Y. p. 262-299. 1964.
13 Skulberg, O.M. Algal cultures as a means
to assess the fertilizing incluence of
pollution. In: Advances in Water
Pollution Research, Volumn 1,
Pergamoa Press, Washington, D. C.
1967.
14 Strom, K.M. Nutrition of algae. Experi-
ments upon; the feasibility of the
Sehreiber method in fresh waters;
the relative inportance of iron and
manganese in the nutritive medium;
the nutritive substance given off by
lake bottom muds. Arch. Hydrobiol.
25:38-47. 1933.
ADDITIONAL RECENT REPORTS:
1 . Algal Assay Procedure
Bottle Test. 82 pp. Environmental
Protection Agency, National Eutrophica-
tion Research Program, Corvallis,
Oregon. 1971.
2 . Inter-Laboratory
Precision Test. An Eight-Laboratory
Evaluation of the Provisional Algal
Assay Procedure Bottle Test. 70 pp.
Environmental Protection Agency,
National Eutrophication Research
Program, Corvallis, Oregon. 1971.
3 Berge, G., Predicted Effects of
Fertilizers Upon the Algae Production
in Fern Lake. Fisk Dir. Skr. Serv.
Hav. Unders., 15:339-355. 1969.
4 Johnson, J. M., T.O. Odlaug, T.A. Olson,
andO.R. Ruschmeyer. The Potential
Productivity of Freshwater Environ-
ments as Determined by an Algal
Bioassay Technique. Water Resources
Research Center Bulletin No. 20,
University of Minnesota, Minneapolis.
1970.
5 Maloney, T.E., W.E. Miller, and T.
Shiroyama. Algal Responses to
Nutrient Additions in Natural Waters.
I. Laboratory Assays. In: Special
Symposia 1:134-140. Amer. Soc.
Limnol. Oceanogr. 1972.
6 Miller, W.E., andT.E. Maloney.
Effects of Secondary and Tertiary
Wastewater Effluents on Algal Growth
in a Lake-River System. JWPCF
43(12)2361-2365. 1971.
7 Murray, S., J. Scherfig, andP.S. Dixon.
Evaluation of Algal Assay Procedures-
PAAP Batch Test. JWPCF 43(10):
1991-2003. 1971.
8 Shapiro, J., and R. Riberiro. Algal
Growth and Sewage Effluent in the
Potomac Estuary. JWPCF 37(7):
1034-1043. 1965.
9 Toerien, D. F., C.H. Huang, J. Rad:;msky,
E.A. Pearson, and J. Scherfig. Final
Report, Provisional Algal Assay
Procedures. 211 pp. Sanitary Engineer-
ing Research Laboratory Report No.
71-6, University of California,
Berkeley. 1971.
This outline has been prepared by Dr. C. I.
Weber, Chief, Biological Methods Section,
Analytical Quality Control Laboratory,
NERC, EPA, Cincinnati, OH 45268.
Descriptors: Plankton, Productivity
23-4
-------
ALGAE AND ACTINOMYCETES IN WATER SUPPLIES
I Water treatment always should include
detection and control of microorganisms.
A Two types of microorganisms are involved:
1 Pathogenic types include such forms as
the typhoid bacteria, the dysentery
ameba, and the infectious hepatitis
virus.
2 Interference types include taste and
odor organisms, filter-clogging
organisms, pipe-infesting organisms,
and others.
B Water treatment practices are closely
associated with these organisms.
1 For pathogens, practices include
coliform tests, use of chlorine, and
guarding the water supply against fecal
pollution.
2 For interference organisms, practices
include plankton enumeration, use of
copper sulfate and the covering of
reserviors.
3 Many of the other treatment practices
have significant effects on the organisms.
B At Indianapolis, copepods were present in
parts of the distribution system in numbers
sufficient to be visible in the drinking
water. The eggs of the copepods were
found to pass through the filters and to
hatch in the distribution system.
C At Oklahoma City, prominent earthy odors
have appeared frequently. The organisms
blamed for this trouble are the mold-like
actinomycetes.
D At Peoria, white wigglers up to 3/8" long
were reported in the tap water, during
early March, 1956. These chironomid
larvae had hatched in the city's open
reservoir, requiring that the reservoir be
drained, cleaned and treated with a larvicide.
E At Chicago, diatoms are a very important
cause of short filter runs. The one diatom
Tabellaria is considered to be more
responsible than any other organism for
this trouble.
F In Ontario, the alga Cladophora often
grows in large numbers attached to rocks
on the shoreline of lakes. When the alga
is broken loose it collects near the shore-
line and gives rise to very offensive odors.
C This discussion will be limited to the inter-
ference organisms.
II EXAMPLES OF PROBLEMS CAUSED BY
INTERFERENCE ORGANISMS
A At Chicago, the alga Dinobryon reappears
almost every year, generally in June and
July in numbers sufficient to impart a
prominent fishy odor to the water. In
1951, it required an estimated $70, 500
worth of activated carbon to control the odor
of this organism for a period of two months.
G In a water supply impoundment in Utah the
plankton algae frequently cause the pH of
the water to increase to 8. 3 or higher,
requiring that the water be treated with
acid to obtain the desired pH of 8 or lower.
H In Texas a water supply from underground
sources was stored in a large open settling
basin. Oscillatoria and unicellular green
algae developed in large numbers in the
stored water, turning it green and pro-
ducing a strong odor.
I Los Angeles has more than 25 open reser-
voirs of various sizes and ranging in
elevation from almost sea level to over
BI.MIC. 12c.6.76
24-1
-------
Algae and Actinomycetes in Water Supplies
7,000 feet. Many tons of copper sulfate
are used every year in these reservoirs
for rigid control of plankton, chiefly
diatoms and occassionally blue-green
algae. This treatment is carried out to
improve the water quality including the
reduction of tastes and odors.
Ill TYPES OF PROBLEMS CAUSED BY
INTERFERENCE ORGANISMS
A Tastes and Odors
1 May be caused by algae, actinomycetes,
Crustacea, and anaerobic bacteria.
2 Common algal odors imparted to water
are ones described as fish, earthy,
musty, grassy, cucumber, geranium,
nasturtium, and septic.
3 Common actinomycete odor is earthy.
4 Tastes produced in water by algae
include sweet and bitter.
5 Other causative agents of tastes and
odors may be industrial wastes, sludge,
and compounds dissolved from soil and
rock, and chemicals used in treatment.
B Filter Clogging
1 Both rapid and slow sand filters are
affected.
2 Diatoms are the organisms most
frequently involved but blue-green
algae, filamentous green algae and
other organisms as well as silt may
cause it.
C Other Problems in the Treatment Plant
1 Algae may cause variation in the pH,
hardness, color, and organic content
of the water.
2 Amount of plankton organisms often
influences the rate and effectiveness
of coagulation.
3 Chlorine dosage may depend upon
amount of plankton organisms present.
4 Growths of algae may reduce the flow
through influent channels and screens.
5 Organisms may be responsible for
increasing the quantity of sludge to be
disposed of in sedimentation basins.
6 Microcrustacea "spot" paper in paper
mill rolls.
D Infestation of Distribution Systems
1 Attached organisms reduce the rate of
flow in the pipes.
2 Iron and sulfur bacteria may initiate
or stimulate corrosion of pipes.
3 Organisms may appear as visible
bodies in tap water.
4 Tastes and odors may result from
presence of organisms.
5 Chlorine residual is difficult to main-
tain when organic matter is present.
6 Organisms could theoretically harbor
and protect against chlorine certain
pathogenic bacteria.
E Profuse Growths of Organisms in Raw
Water Supplies
1 A limited and balanced growth of
various organisms is generally an
asset.
2 Extensive surface mats, blooms and
marginal growths often cause troubles
along the shoreline and eventually in
the treatment plant.
3 Some fish kills may be caused by
profuse growths of algae by reducing the
DO during the night.
4 Certain massive growths of blue-green
algae are deadly poisonous to animals.
IV ORGANISMS INVOLVED
A Animal forms include protozoa, rotifers,
crustaceans, worms, bryozoaris, fresh water
24-2
-------
Algae and Actinomycetes in Water Supplies
V
sponges, water mites and larval stages of
various insects.
Plant forms include algae, actinomycetes
and other bacteria, molds and larger
aquatic green plants.
IMPORTANCE OF BIOLOGICAL
PROBLEMS
A The increased use of surface water supplies
increases the problems caused by organ-
isms. Biological problems are less
common with ground water supplies.
B Standards of water quality requested by
domestic and industrial patrons are rising.
C Procedures for detection, control and
prevention of problems caused by organisms
are improving and are receiving more
extensive use.
VI A number of methods may be used to
control the interference organisms or their
products;
A Addition to water or an algicide or pesticide
such as copper sulfate, chlorine dioxide
or copper-chlorine-ammonia.
B Mechanical cleaning of distribution lines,
settling basins, sand filters, screens, and
reservoir walls.
C Modification of coagulation, filtration,
chemical treatment, or location of intake.
D Use of absorbent, such as activated
carbon, for taste and odor substances.
E Modification of Reservoir to Reduce the
Opportunities for Massive Growths of
Algae
1 By covering treated water reservoir to
exclude sunlight
2 By increasing the depth of the water in
reservoirs
3 By eliminating shallow marginal areas
4 By reducing the amount of fertilizing
nutrients entering the reservoir.
VII It is generally more satisfactory to
anticipate and prevent problems due to these
organisms than it is to cope with them later.
A Routine biological tests are essential to
detect the initial development or presence
of interference organisms.
1 Control measures can then be used
before problem becomes acute.
2 These tests should be applied to the
raw treatment plant water supply and
distribution system.
B In the Reservoir or Other Raw Water Supply
1 Routine plankton counts should be made
of water samples from selected loca-
tions. Plankton counter should be
aware of the particular organisms
known to be most troublesome.
2 During the warmer months routine
surveys of the reservoir, lake or
stream should be made to record any
visible growths of algae and other
organisms.
3 Odor tests of water from several
locations should be made to obtain
advance notice of potential trouble at
the treatment plant.
C In the Treatment Plant
1 Records of plankton counts and threshold
odor between each step in treatment
gives data on effectiveness of each
procedure.
2 Coagulation and filtration can be
adjusted to remove up to 95% or more
of organisms in water.
24-3
-------
Algae- and Actinomycetes in Water Supplies
Microscopic analysis of samples of
filter material for organisms can
supply data useful in modifying sand
filtration and treatment of finished
water.
D In the Distribution System With Its
Finished Water
1 Open reservoirs require constant
attention especially during summer.
2 Parts of the system farthest from the
treatment plant or adjacent to dead
ends require most frequent sampling
for organisms and tastes and odors.
VIII SUMMARY
A Interference organisms cause problems
in distribution systems, treatment plants,
raw water supplies.
B Organisms involved include algae, actino-
mycetes, other bacteria, and minute
aquatic animals.
C Control is by special chemicals, mechanical
cleaning, adjustment of chemical or
mechanical treatment and by modification
of reservoirs, intakes, etc., for the raw
water supply.
D Facilities for detection of problems in
their early stages are required for most
efficient and satisfactory control.
REFERENCES
1 Palmer, C. M. Algae in Water Supplies.
An Illustrated Manual on the Identification,
Significance, and Control of Algae in
Water Supplies. U.S. Public Health
Service Publication No. 657. 1959.
p. 88.
2 Palmer, C.M. and Poston, H.W.
Algae and Other Interference
Organisms in Indiana Water Supplies.
Jour. Amer. Water Works Assn.
48:1335-1346. 1956.
3 Palmer, C.M. Algae and Other Inter-
ference Organisms in New England
Water Supplies. Jour. New England
Water WorksAssn. 72:27-46. 1958.
4 Palmer, C.M. Algae and Other Orga-
nisms in Waters of the Chesapeake
Area. Jour. Amer. Water Works
Assn. 50:938-950. 1958.
5 Palmer, C.M. Algae and Other Inter-
ference Organisms in the Waters of
the South Central United States. Jour.
Amer. Water Works Assn. 52:897-
914. 1960.
6 Silvey, J.K. and Roach, A.W.
Actinomycetes May Cause Tastes
and Odors in Water Supplies. Public
Works 87. 5:103-106,210,212. 1956.
7 Ingram, W.M. and Bartsch, A.F.
Operators Identification Guide to
Animals Associated with Potable
Water Supplies. Jour. Amer. Water
WorksAssn. 52:1521-1550. 1960.
8 Otto, N. E. and Bartley, T.R. Aquatic
Pests on Irrigation Systems.
Identification Guide. Bur. of
Reclamation. USDI. 72 pp. 1965.
9 Herbst, Richard P. Ecological Factors
and the Distribution of Cladophera
glomerata in the Great Lakes.
Amer. Midi. Nat. 82:90-98. 1969.
This outline was prepared by C.M. Palmer,
formerly Aquatic Biologist, In Charge,
Interference Organism Studies, Microbiology
Activities, Research & Development,
Cincinnati Water Research Laboratory,
FWPCA.
Descriptors: Algae, Water Supplies,
Actinomycetes
24-4
-------
Algae and Actinomycetes in Water Supplies
ALGAE IMPORTANT IN WATER SUPPLIES
TASTE AND ODOR ALGAE
PLATE I
-------
Algae and Actinomycetes in Water Supplies
FILTER CLOGGING ALGAE
CHROOCOCCUS
PLATE 2
-------
Algae and Actinomycetes in Water Supplies
POLLUTED WATER ALGAE
PLATE 3
-------
Algae and Actinomycetes in Water Supplies
CLEAN WATER ALGAE
CLAOOPHORA
.«*•>-
PLATE 4
-------
Algae and Actinomycetes in Water Supplies
SURFACE WATER ALGAE
PLATE 5
-------
Algae and Actinomycetes in Water Supplies
ALGAE GROWING ON RESERVOIR WALLS
PHORMIDIUM
PLATE 6
10
-------
ALGAE AS INDICATORS OF POLLUTION
I LIMITATIONS
A Algae are only one of a number of types
of organisms present which could be
considered.
B Forms recognized here as algae are
comparatively simple, pigmented, aquatic
organisms, including blue-greens, greens,
diatoms and pigmented flagellates.
C Various pollutants react differently on
algae. Organic pollutants such as house-
hold sewage will be dealt with here.
D No algae are intestinal organisms. They
therefore are not indicators of pollution
in the same way that coliform bacteria
are.
B Wastes may have physical effects on
certain algae. May cause plasmolysis,
change in rate of absorption of nutrients,
etc.
C Wastes may reduce available light,
increase the water temperature, and
cover up the areas for attachment to
rocks.
D Wastes may prevent algal respiration at
night by reducing the DO of water.
E Wastes may stimulate other organisms
at the expense of certain algae.
F Products of waste decomposition may
act as powerful growth stimulants for
certain algae.
II ALGAE AND ORGANIC POLLUTION
A Heavy pollution may tend to limit various
kinds of algae to certain zones in the
affected area.
B These zones are distinguished according
to the degree of change which has
occurred in the organic wastes. One set
of names for these zones includes the
Polysaprobic, alpha-mesosaprobic, beta-
mesosaprobic and oligosaprobic.
C A few "pollution" algae are common in
the first two zones. Many algae are
common in and often limited to one or
both of the last two zones.
D Some workers have listed separately
those algae indicative of each of the four
zones.
Ill REASONS FOR SELECTIVITY OF
POLLUTANTS TO ALGAE
A Certain components of wastes are chemi-
cals toxic to some algae but not to others.
IV ALGAE AS INDICATORS OF POLLUTION
A Selection of list of "pollution" algae
follows an evaluation of the kinds re-
ported in published reports by numerous
workers as relatively prominent in, or
representative of, the polysaprobic and
alpha-mesosaprobic zones in a stream
polluted with sewage. It includes also
other conditions or areas approximating
these zones.
B A total list of more than 1000 kinds of
algae has been compiled to date.
1 In order to tabulate the information,
an arbitrary numerical value is
allotted to each author's record of
each pertinent alga.
2 The algae are then arranged in order
of decreasing emphasis by the
authors as a whole.
BI. IND. lOa. 6. 76
25-1
-------
Algae as Indicators of Pollution
VI SOME GENERA AND SPECIES OF ALGAE
HIGH ON THE LIST ARE AS FOLLOWS:
A Genera: Oscillatoria, Euglena, Navicula,
Chlorella, Chlamydomonas, Nitzschia,
Stigeoclonium, Phormidium, Scenedesmus,
Ankistrodesmus, Phacus.
B Species: Euglena viridis, Nitzschia
palea, Oscillatoria chlorina,
Oscillatoria limosa, Oscillatoria tenuis
Scenedesmus quadricauda, Stigeoclonium
tenue, Synedra ulna and Pandorina morum.
VII SOME ALGAE REPRESENTATIVE OF
CLEAN WATER ZONES IN STREAMS:
Chrysococcus rufescens, Cocconeis
placentula, Entophysalis lemaniae, and
Rhodomonas lacustris.
VIII RELIABILITY IN USE OF INDICATORS
DEPENDS IN PART UPON ACCURATE
IDENTIFICATION OF SPECIMENS
REPRESENTATIVE LITERATURE
1 Brinley, F.J. Biological Studies. Ohio
River Pollution Survey. I.
Biological Zones in a Polluted Stream.
II. Plankton Algae as Indicators of
the Sanitary Condition of a Stream.
Sewage Works Journal, 14:147-159.
1942.
2 Butcher, R.W. Pollution and
Repurification as Indicated by the
Algae. Fourth International
Congress for Microbiology (held) 1947.
Report of Proceedings. 1949.
3 Fjerdingstad, E. The Microflora of the
River Moelleaa with Special Reference
to the Relation of the Benthal Algae
to Pollution. Folia Limnological
Scandinavia. No. 5. 1950.
4 Fjerdingstad, E. Taxonomy and Saprobic
Valency of Benthic Phytomicro-
Organisms. Intern. Rev. Ges.
Hydrobiol. 50:475-604. 1965.
25-2
5 Hawkes, H.A. The Biological Assess-
ment of Pollution in Birmingham
Streams. The Institute of Sewage
Purification, Journal and Proceedings.
177-186. 1956.
6 Kolkwitz, R. Oekologie der Saprobien.
Schriftenreiche des Vereins fUr
Wasser-, Boden-, und Lufthygiene
Berlin-Dahlem. Piscator - Verlage,
Stuttgart.
7 Lackey, J. B. The Significance of
Plankton in Relation to the Sanitary
Condition of Streams. Symposium
on Hydrobiology. University of
Wisconsin. 311-328. 1941.
8 Liebmann, H. Handbuch der
Frischwasser - und Abwasserbiologie.
R. Oldenbourg, Munchen.
9 Palmer, C.M. Algae as Biological
Indicators of Pollution. In
Biological Problems in Water
Pollution. Trans, of 1956 Seminar.
Robert A. Taft Sanitary Engineering
Center. 1957.
10 Palmer, C.M. The Effect of Pollution
on River Algae. Annal. N.Y. Acad.
Sci. 108:389-395. 1963.
11 Palmer, C.M. A Composite Rating of
Algae Tolerating Organic Pollution.
Jour. Phycology 5 (l):78-82. 1969.
12 Palmer, C.M. Algae in Water Supplies
of the United States. In: Algae and
Man,Ch 12, Plenum Press. N.Y.
pp. 239-261. 1964.
13 Patrick, R. Factors Effecting the
Distribution of Diatoms. Botanical
Review. 14: 473-524. 1948.
14 Whipple, G.C., Fair, G.M. and
Whipple, M. C. The Microscopy of
Drinking Water, 4th ed. J. Wiley
and Sons. New York. 1948.
This outline was prepared by C.M. Palmer,
Aquatic Biologist, Cincinnati Water Research
Laboratory, FWPCA.
Descriptors: Bioindicators, Algae
-------
Algae as Indicators of Pollution
POLLUTED WATER ALGAE
PHORMIDIUM
PLATE 3
-------
Algae as Indicators of Pollution
CLEAN WATER ALGAE
CLADOPHORA
PLATE 4
-------
ODOR PRODUCTION BY ALGAE AND OTHER ORGANISMS
I Most biological odors present in our water
supplies are derived from algae, actinomycetes,
and bacteria.
A The odor produced by algae and actino-
mycetes is generally the result of
intracellular metabolic activity while
the odor caused by bacteria usually
results from extracellular enzymatic
activity upon other organisms.
B The odors produced by actinomycetes are
usually earthy while those produced by the
algae are aromatic, grassy, and fishy.
H SOME SPECIES OF ALGAE CAUSING
ODORS
A Diatoms
1 Asterionella (aromatic, fish)
2 Cyclotella (aromatic)
B Pigmented Flagellates
1 Synura (cucumber)
2 Dinobryon (fishy)
C Blue-green Algae
1 Anabaena (grassy, green corn,
nasturtium)
2 Aphanizomenon (grassy, nasturtium)
D Green Algae
1 Chlorococcum (grassy)
IE RESEARCH ON A LGAE ODORS
A Growing Algae for Odor Research
1 Obtaining unialgal bacteria-free
cultures
a Plating out on semi-solid medium
b Single cell isolation
c Use of antibiotics
d Exposure to ultra-violet light
2 Determining nutritional requirements
a Inorganic salts
b Organic growth factors
B Methods of extracting odoriferous
material from algal cultures
1 Distillation - steam and vacuum
2 Solvent extraction
3 Use of ion exchange resins
4 Freeze out methods
C Some Results of Research
1 Effect of culture age upon odor
production
2 Effect of pH on odor intensity
3 Comparison of odor intensity in intact
and broken cells
4 Groups of chemicals which may be
responsible for causing algal odors
IV RESEARCH ON ACTINOMYCETE ODORS
A A number of actinomycetes were isolated
from water and muds of rivers and lakes.
BI.MIC.to. lOc.6.76
26-1
-------
Odor Production by Algae and Other Organisms
1 Large numbers were found to
be present in muds, while there
were relatively few in the water.
2 Most, species belonged to tha
Streptomyces and a few to the
Micromonospora.
B Extraction of Odoriferous Material
1 Streptomyces griseoluteus was
used in this work.
a Cultured in a defined medium
(1) Cultures have threshhold
odor of 20, 000 to 50, 000
2 Primary extraction was by
distilling the culture at 100°C
at atmospheric pressure.
a Distillation of 10% of the
culture volume resulted
in 90% odor removal.
3 Odor was further concentrated
by two methods
a Ether extraction of the
distilling off of the ether
in vacuo.
(1) Re suite d in y ello wish
brown concentrate
having a threshold odor
of approximately 6 billion.
b Absorption on activated carbon
followed by elution of material
with chloroform
C Effect of Activated Carbon in Re-
moving the Earthy Odor
1 The odor is practically elimi-
nated by 10 ppm carbon.
D Effect of Chlorine on Odor
1 Chlorine does not eliminate
the odor but does not intensify
the odor.
E Soil perfusion Tests
1 Conducted to determine the
extent to which actinomycetes
impart odors to a water environ-
ment.
REFERENCES
1 Fogg., G.E., "The Metabolism of
Algae", John Wiley and Sons, Inc.,
New York, N. Y., 1953.
2 Fox, Leo, ''Microscopic Organisms
in Drinking Water", Taste arid Odor
Journal, Vol. 19, No. 10, 1953.
3 Palmer, C. M., and Tarzwell, C. M.,
"Algae of Importance in Water
Supplies", Public Works Magazine,
1955.
4 Whipple, G. C., Fair, G. M., and
Whipale, M. C., "The Microscopy
of Drinking Water", Fourth Edition,
John Wiley and Sons, Inc., New York,
N.Y., 1948.
This outline was prepared by T. E. Maloney,
P'ormer Research Biologist, Aquatic Biology
Activities, Research and Development,
Cincinnati Water Research Laboratory, FWPCA.
Descriptor: Odor Producing Algae
26-2
-------
PLANKTON IN OLIGOTROPHIC LAKES
I INTRODUCTION
The term oligotrophic was taken from the
Greek words oligos -- small and trophein --
to nourish, meaning poor in nutrients.
Lakes with low nutrient levels have low
standing crops of plankton. The term is now
commonly applied to any water which has a
low productivity, regardless of the reason.
II PHYSICAL AND CHEMICAL CHARACTER-
ISTICS OF OLIGOTROPHIC LAKES*
A Very deep; high volume to surface ratio
B Thermal stratification common; volume
of the hypolimnium large compared to the
volume of the epilimnion
C Maximum surface temperature rarely
greater than 15OC
D Low concentrations of dissolved minerals
and organic matter.
1 Phosphorus, less than 1 microgram
per liter
2 NO -Nitrogen, less than 200 micrograms
per liter
E Dissolved oxygen near saturation from
surface to bottom
F Water very transparent, Secchi disk
readings of 20-40 meters are common
G Color dark blue, blue-green, or green
IH PLANKTON
A Quantity
1 Standing crop very low
a Ash-free weight of plankton, less
than 0. 1 mg per liter (compared to
1 mg per liter or more in eutrophic
lakes).
b Chlorophyll, 1 mg per M or less
c Cells counts, less than 500 per ml
2 Zooplankton to phytoplankton volume
ratio, 19:1.
B Quality
1 European biologists have found
oligotrophic lakes to be dominated by
Chlorophyta (usually desmids),
chrysophyta (such as Dinobryon), and
Diatomaceae (Cyclotella and Tabellaria).
Eutrophic lakes are dominated by
Synedea, Fragilaria, Asterionella,
Melosira, blue-green algae, Ceratium,
and Pediastrum. Nygaard devised
several phytoplankton quotients based
on these relationships
a Simple quotient
Number of species of
Chlorococcales _ if <1, oligotrophic
Desmidiaceae if > 1, eutrophic
b Compound index
Myxophyceae+Chlorococcales+Centrales+Eugleniaceae
Desmidiaceae
if <1, oligotrophic
if 1-2.5, mesotrophic
if > 2. 5, eutrophic
c Diatom quotient
Centrales _ if 0-0.2, oligotrophic
Pennales "if 0.2-3.0, eutrophic
BI. ECO. mic.2. 6.76
27-1
-------
Plankton in Qligotrophic Lakes
2 Several lists of trophic indicators have
been published:
Two are listed here
Teiling,
Swedish Lakes
Rawson,
Canadian Lakes
Oligotrophic Tabelleria flocculosa
Dactylococcopsis
ellipsoideus
Mesotrophic Kirchneriella lunaris
Tetraeadon spp.
Pediastrum spp.
Fragilaria crotonensis
Attheya zachariasii
Melosira granulata
Eutrophic
Pronounced
Eutrophy
Aphanizomenon spp.
Anabaena flos-aquae
Anabaena circinalis
Microcystis aeruginosa
Microcystis viridis
Oligotrophic Asterionella formosa
Melosira islandica*
Mesotrophic
Tabellaria fenestrata
Tabellaria flocculosa
Dinobryon divergens
Fragilaria capucina
Stephanodiscus niagarae
Staurastrum spp.
Melosira granulata
Fragilaria crotonensis
Ceratium hirundinella
Pediastrum boryanum
Pedia strum duplex
Coelosphaerium
naegelianum
Anabaena spp.
A phani zom enon flos-aquae
Microcystis aeruginosa
Eutrophic
Microcystis flos-aquae
-------
Plankton in Oligotrophic Lakes
Some discrepancies can be seen in the
ranking of species in the lists. These
may be the result of true differences in
the composition of the plankton, or may
be only apparent differences which
resulted from different sampling methods.
Many studies (e.g. those by Milliard,
Olive, and Rawson) have been based on
netted samples, which may be highly
biased because they contain little of the
nannoplankton. Also, it is not uncommon
to characterize populations on the basis
of one or two samples collected during
the summer months.
The dominant plankton in four
oligotrophic North American lakes are
listed below. The Great Slave Lake
and Karluk Lake data are from netted
samples taken during the summer, and
monthly, respectively. The Lake
Superior and Lake Tahoe data are from
grab samples taken twice monthly, and
quarterly, respectively.
The dominant diatoms are generally
similar in the four lakes. Asterionella
formosa and Fragilaria crotonensis
are common to all. There are also
some obvious differences. Melosira
islandica, the dominant diatom in the
Great Slave Lake and Lake Superior,
is absent from Lake Tahoe and Karluk
Lake. It was not found in Crater Lake
by Sovereign (1958), in the Mountain
lakes of Colorado by Olive (1955) or
Brinley (1950), and does not occur in
WPSS samples in streams west of the
Great Lakes. Tabellaria is also
absent from Lake Tahoe. It was
reported in Colorado lakes by Olive,
but was not abundant. Brinley makes
no reference to it, and Sovereign
indicated that it was rare in Crater
Lake samples. It is apparent that the
absence of these two diatoms from
Lake Tahoe is not related to the lake.
Except for the absence of Keratella
cochlearis from Lake Tahoe, the
rotifer populations are very similar.
Data on other segments of the zoo-
plankton population are insufficient to
permit comparison.
27-3
-------
-J
Dominant
Phytoplankton
Raw son.
Great Slave Lake
Melosira islandica
Asterionella formosa
Dinobryon divergens
Ceratium hirundinella
Pediastrum boryanum
Tabellaria fenestrata
Cyclotella meneghiniana
Fragilaria crotonensis
Fragilaria capucina
Synedra ulna
Eunotia lunaris
USPHS,
Lake Superior
Melosira islandica
Tabellaria fenestrata
Cyclotella kutzingiana
Melosira granulata
Melosira ambigua
Asterionella formosa
Synedra nana
Scenedesmus spp.
Ankistrodesmus spp.
Dictyosphaerium spp.
Hilliard,
Karluk Lake
Asterionella formosa
Tabellaria flocculosa
Fragilaria crotonensis
Cyclotella bodanica
Cymbella turgida
Dictyosphaerium spp.
Sphaerocystis spp.
Staurastrum spp.
WPSS,
Lake Tahoe
Fragilaria crotonensis
Synedra nana
Fragilaria construens
Fragilaria pinnata
Nitzschia acicularis
Asterionella formosa
O
}-'•
o
o
M.
o
Dominant
Zooplankton
Keratella cochlearis
Kellicottia longispina
Diaptomus tenuicaudatus
Limnocalanus macrurus
Senecella calanoides
Daphnia longispina
Bosmina obtusirostris
Keratella cochlearis
Kellicottia longispina
Not reported
Kellicottia longispina
Daphnia spp.
Diaptomus tyrelli
Epischura nevadensis
-------
Plankton in Oligotrophic Lakes
REFERENCES
1 Brinley, F.J. 1950. Plankton population
of certain lakes and streams in the
Rocky Mountain National Park,
Colorado. Ohio J. Sci. 50:243-250.
2 Milliard, O.K., 1959. Notes on the
phytoplankton of Karluk Lake, Kodiak
Island, Alaska. Canadian Field-
Naturalist 43:135-143.
3 Jarnefelt, H., 1952. Plankton als
Indikator der Trophiegruppen der seen.
Ann. Acad. Sci. Fennicae A.IV:l-29.
4 Knudson, B.M., 1955. The distribution of
Tabellaria in the English Lake District.
Proc. Int. Assoc. Limnol. 12:216-218.
5 Nygaard, G., 1949. Hydrobiological studies
in some ponds and lakes II. The
quotient hypothesis and some new or
little known phytoplankton organisms.
Klg. Danske Vidensk. Selsk. Biol.
Skrifter 7:1-293.
6 Olive, J.R., 1955. Some aspects of
plankton associations in the high
mountains lakes of Colorado. Proc.
Int. Assoc. Limnol. 12:425-435.
7 Rawson, D.S., 1953. The standing crop
of net plankton in lakes. J. Fish. Res.
Bd. Can. 10:224-237.
8 Rawson, D. S., 1956.
Great Slave Lake.
Can. 13:53-127.
The net plankton of
J. Fish. Res. Bd.
9 Rawson, D. S., 1956. Algal indicators
of trophic lake types. Limnol.
Oceanogr. 1:18-25.
10 Rodhe, W., 1948. Environmental
requirements of fresh-water plankton
algae. Symb. Hot. Upsal. 10:1-149.
11 Ruttner, F., 1953. Fundamentals of
Limnology, 2nd ed., Univ. Toronto
Press, Toronto.
12 Sovereign, H.E., 1958. The diatoms of
Crater Lake, Oregon. Trans. Amer.
Microsc. Soc. 77:96-134.
13 Teiling, E., 1955. Some mesotrophic
phytoplankton indicators. Proc. Int.
Assoc. Limnol. 12:212-215.
14 USPHS, 1962. National Water Quality
Network, Annual Compilation of Data,
PHS Publ. No. 663.
15 Welch, P.S., 1952. Limnology, 2nded.,
McGraw Hill Book Co., New York.
This outline was prepared by C.I. Weber,
Chief, Biological Methods Section,
Analytical Quality Control Laboratory,
NERC,. EPA,. Cincinnati, OH 45268.
Descriptors: Oligotrophy, Plankton
27-5
-------
BIOLOGICAL INTEGRITY OF STREAM COMMUNITIES
I BENTHOS ARE ORGANISMS GROWING
ON OR ASSOCIATED PRINCIPALLY
WITH THE BOTTOM OF WATERWAYS
Benthos is the noun.
Benthonic, benthal and benthic are
adjectives.
II THE BENTHIC COMMUNITY
A Composed of a wide variety of life
forms that are related because they
occupy "common ground"--substrates
of oceans, lakes, streams, etc.
They may be attached, burrowing, or
move on the interface.
1 Bacteria
A wide variety of decomposers work
on organic materials, breaking them
down to elemental or simple com-
pounds.
2 Algae
Photo synthetic plants having no true
roots, stems, and leaves. The basic
producers of food that nurtures the
animal components of the community.
3 Flowering Aquatic Plants, (Riverweeds,
Pondweeds)
The largest flora, composed of
complex and differentiated tissues.
May be emersed, floating, or sub-
mersed according to habit.
4 Microfauna
Animals that pass through a U. S.
Standard Series No. 30 sieve, but
are retained on a No. 100 sieve.
Examples are rotifers and micro-
crustaceans. Some forms have
organs for attachment to substrates,
while others burrow into soft materi^lc
or occupy the interstices between rocks,
floral or faunal materials.
5 Meioiauna
Meiofauna occupy the interstitial zone
(like between sand grains) in benthic
and hyporheic habitats. They are inter-
mediate in size between the microfauna
(protozoa and rotifers) and the macro-
fauna (insects, etc.). They pass a No. 30
sieve (0. 5 mm approximately). In fresh-
water they include nematodes, copepods,
tardigrades, naiad worms, and some flat
worms. They are usually ignored in fresh-
water studies, since they pass the standard
sieve and/or sampling devices.
6 Macrofauna (macroinvertebrates)
Animals that are retained on a No. 30 mesh
sieve (0. 5 mm approximately). This group
includes the insects, worms, molluscs, and
occasionally fish. Fish are not normally
considered as benthos, though there are bottom
dwellers such as sculpins, settles
darters, and madtoms.
B The benthos is a self-contained community,
though there is interchange with other
communities. For example: Plankton
settles to it, fish prey on it and lay their
eggs there, terrestrial detritus and leaves
are added to it, and many aquatic insects
migrate from it to the terrestrial environ-
ment for their mating cycles.
c It is an in-situ water quality monitor. The
low mobility of the biotic components requires
that they "live with" the quality changes of the
over-passing waters. Changes imposed in the
long-lived components remain visible for
extended periods, even after the cause has
been eliminated. Only time will allow a cure
for the community by drift, reproduction, and re-
cruitment from the hyporheic zone.
D Between the benthic zone (substrate/water
interface) and the underground water table
is the hyporheic zone. There is considerable
interchange from one zone to another.
Ill HISTORY OF BENTHIC OBSERVATIONS
A Ancient literature records the vermin associ-
ated with fouled waters.
BI.MET.fm.8j. 3.80
28-1
-------
Biological Integrity of Stream Communities
B 500 -year- old fishing literature refers
to animal forms that are fish food and
used as bait.
C The scientific literature associating
biota to water pollution problems is
over 100 years old (Mackenthun and
Ingram, 1964).
D Early this century, applied biological
investigations were initiated.
1 The entrance of state boards of health
into water pollution control activities.
2 Creation of state conservation agencies.
3 Industrialization and urbanization.
4 Growth of limnological programs
at universities.
E A decided increase in benthic studies
occurred in the 1950's and much of
today's activities are strongly influenced
by developmental work conducted during
this period. Some of the reasons for this
are:
1 Movement of the universities from
"academic biology" to applied
pollution programs.
2 Entrance of the federal government
into enforcement aspects of water
pollution control.
3 A rising economy and the development
of federal grant systems.
4 Environmental Protection Programs
are a current stimulus.
IV WHY THE BENTHOS?
A It is a natural monitor
B The community contains all of the
components of an ecosystem.
1 Reducers
a bacteria
b fungi
2 Producers (plants)
28-2
3 Consumers
a Detritivores and bacterial feeders
b Herbivores
c Predators
C Economy of Survey
1 Manpower
2 Time
3 Equipment
D Extensive Supporting Literature
E Advantages of the Macrobenthos
1 Relatively sessile
2 Life history length
3 Fish food organisms
4 Reliability of Sampling
5 Dollars/information
6 Predictability
7 Universality
8 Sensitivity to perturbation
F "For subtle chemical changes,
unequivocal data, and observations
suited to some statistical evaluation will
be needed. This requirement favors the
macrofauna as a parameter. Macro-
invertebrates are easier to sample
reproductively than other organisms,
numerical estimates are possible and
taxonomy needed for synoptic investi-
gations is within the reach of a non-
specialist. '' (Wuhrmann)
G "It is self-evident that for a multitude of
non-identifiable though biologically active
changes of chemical conditions in rivers,
small organisms with high physiological
differentiation are most responsive.
Thus the small macroinvertebrates
(e. g. insects) are doubtlessly the most
sensitive organisms for demonstrating
-------
Biological Integrity of Stream Communities
V
unspecified changes of water
chemistry called 'pollution' .
Progress in knowledge on useful
autecological properties of
organisms or of transfer of such
knowledge into bioassay practice
has been very small in the past.
Thus, the bioassay concept
(relation of organisms in a
stream to water quality) in
water chemistry has brought not
much more than visual demon-
stration of a few overall chemical
effects. Our capability to derive
chemical conditions from biological
observations is, therefore, almost
on the same level as fifty years ago.
In the author's opinion it is idle to
expect much more in the future because
of the limitations inherent to natural bio-
a,ssay systems (relation of organisms
In a stream to water quality). " (Wuhrmann)
REACTIONS OF THE BENTHIC MACRO-
INVERTEBRATE COMMUNITY TO
PERTURBATION
A Destruction of Organism Types
1 Beginning with the most sensitive
forms, pollutants kill in order of
sensitivity until the most tolerant form
is the last survivor. This results in a
reduction of variety or diversity of
organisms.
2 The generalized order of macro-
invertebrate disappearance on a
sensitivity scale below pollution
sources is shown in Figure 2.
Water
Quality
Deteriorating
Stoneflies
Mayflies
Caddisflies
Amphipods
Isopods
Midges
Oligochaetes
Vater
Duality
improving
As water quality improves, these
reappear in the same order.
B The Number of Survivors Increase
1 Competition and predation are reduced
between different species.
2 When the pollutant is a food (plants,
fertilizers, animals, organic materials).
C The Number of Survivors Decrease
1 The material added is toxic or has no
food value.
2 The material added produces toxic
conditions as a byproduct of decom-
position (e.g., large organic loadings
produce an anaerobic environment
resulting in the production of toxic
sulfides, methanes, etc. )
D The Effects May be Manifest in Com-
binations
1 Of pollutants and their effects.
2 Vary with longitudinal distribution
in a stream. (Figure 1)
E Tolerance to Enrichment Grouping
(Figure 2)
Flexibility must be maintained in the
establishment of tolerance lists based
on the response of organisms to the
environment because of complex relation-
ships among varying environmental
conditions. Some general tolerance
patterns can be established. Stonefly
and mayfly nymphs, hellgrammites,
and caddisfly larvae represent a grouping
(sensitive or intolerant) that is generally
quite sensitive to environmental
changes. Blackfly larvae, scuds, sow-
bugs, snails, fingernail clams, dragon-
fly and damselfly naiads, and most
kinds of midge larvae are facultative
(or intermediate) in tolerance.
Sludge-worms, some kinds of midge
larvae (bloodworms), and some leeches
28-3
-------
Biological Integrity of Stream Communities
DIRECTION OF FLOW
X
ui
03
U
I-
4
Ul
B.
/-•*
W i t
E ' '
<
(0
ui
W
D.
w
Ul
K
(0
S
I
Pi:
TIME OR DISTANCE
..NUMBER OF KINDS
..NUMBER OF ORGANISMS
.SLUDGE DEPOSITS
Four basic responses of bottom animals to pollution.
A. Organic wastes eliminate the sensitive bottom animals
and provide food in the form of sludges for the surviving toler-
ant forms. B. Large quantities of decomposing organic wastes
eliminate sensitive bottom animals and the excessive quanti-
ties of byproducts of organic decomposition inhibit the tolerant
forms; in time, with natural stream purification, water quality
improves so that the tolerant forms can flourish, utilizing the
sludges as food. C. Toxic materials eliminate the sensitive
bottom animals; sludge is absent and food is restricted to that
naturally occurring in the stream, which limits the number of
tolerant surviving forms. Very toxic materials may eliminate
all organisms below a waste source. D. Organic sludges with
toxic materials reduce the number of kinds by eliminating
sensitive forms. Tolerant survivors do not utilize the organic
sludges because the toxicity restricts their growth.
Figure 1
are tolerant to comparatively heavy loads
of organic pollutants. Sewage mosquitoes
and rat-tailed maggots are tolerant of
anaerobic environments for they are
essentially air-breathers.
F Structural Limitations
1 The morphological structure of a
species limits the type of environment
it may occupy.
a Species with complex appendages
and exposed complicated respiratory
structures, such as stonefly
nymphs, mayfly nymphs, and
caddisfly larvae, that are subjected
to a constant deluge of setteable
particulate matter soon abandon
the polluted area because of the
constant preening required to main-
tain mobility or respiratory func-
tions; otherwise, they are soon
smothered.
b Benthic animals in depositing zones
may also be burdened by "sewage
fungus" growths including stalked
protozoans. Many of these stalked
protozoans are host specific.
2 Species without complicated external
structures, such as bloodworms and
sludgeworms, are not so limited in
adaptability.
a A sludgeworm, for example, can
burrow in a deluge of particulate
organic matter and flourish on the
abundance of "manna. "
b Morphology also determines the
species that are found in riffles, on
vegetation, on the bottom of pools,
or in bottom deposits.
28-4
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Biological Integrity of Stream Communities
VI SAMPLING PROCEDURES
A Fauna
1 Qualitative sampling determines the
variety of species occupying an area.
Samples may be taken by any method
that will capture representatives of the
species present. Collections from
such samplings indicate changes in the
environment, but generally do not
accurately reflect the degree of change.
Mayflies, for example, may be re-
duced from 100 to 1 per square meter.
Qualitative data would indicate the
presence of both species, but might not
necessarily delineate the change in pre-
dominance from mayflies to sludge-
worms. The stop net or kick sampling
technique is often used.
2 Quantitative sampling is performed to
observe changes in predominance.
The most common quantitative sampling
tools are the Petersen, Ekman, and Ponar
grabs and the Surber stream bottom or
square-foot sampler. Of these, the
Petersen grab samples the widest variety
of substrates. The Ekman grab is limited
to fine-textured and soft substrates, such
as silt and sludge, unless hydraulically
operated.
The Surber sampler is designed for
sampling riffle areas; it requires
moving water to transport dislodged
organisms into its net and is limited
to depths of two feet or less.
Kick samples of one minute duration will
usually yield around 1, 000 macroinvert-
ebrates per square meter (10. 5 X a one
minute kick= organisms/m2).
Manipulated substrates (often referred to
as "artificial substrates") are
placed in a stream and left for a specific
time period. Benthic macroinvertebrates
readily colonize these forming a manipu-
lated community. Substrates may be con-
structed of natural materials or synthetic;
may be placed in a natural situation or
unnatural; and may or may not resemble
the normal stream community. The
point being that a great number of envi-
ronmental variables are standardized and
thus upstream and downstream stations
may be legitimately compared in terms of
water quality of the moving water column.
They naturally do not evaluate what may
or may not be happening to the substrate
beneath said monitor. The latter could
easily be the more important.
A
B
C
D
E
F
G
H
REPRESENTATIVE BOTTOM-DWELLING MACROANIMALS
Drawings from Geckler, J., K. M. Mackenthun and W. M. Ingram, 1963.
Glossary of Commonly Used Biological and Related Terms in Water and
Waste Water Control, DHEW, PHS. Cincinnati, Ohio, Pub. No. 999-WP-2.
(Plecoptera)
(Ephemeroptera)
Stonefly nymph
Mayfly nymph
Hellgrammite or
Dobsonfly larvae (Megaloptera)
Caddisfly larvae (Trichoptera)
Black fly larvae (Simulildae)
Scud (Amphipoda)
Aquatic sowbug (Isopoda)
Snail (Gastropoda)
I
J
K
L
M
N
O
P
Fingernail clam (Sphaeriidae)
Dams elf ly naiad (Zygoptera)
Dragonfly naiad (Anisoptera)
Bloodworm or midge
fly larvae
Leech
Sludgeworm
Sewage fly larvae
Rat-tailed maggot
KEY TO FIGURE 2
(Chironomidae)
(Hirudinea) •
(Tubificidae)
(Psychodidae)
(Tubifera-Eristalis)
28-5
-------
B X^ C
SENSITIVE
1—\
',. _. J c
F G
INTERMEDIATE
H
M
-------
Biological Integrity of Stream Communities
Invertebrates which are part of the
benthos, but under certain conditions
become carried downstream in
appreciable numbers, are known as
Drift.
Groups which have members forming
a conspicuous part of the drift
include the insect orders Ephemeroptera,
Trichoptera, Plecoptera and the
crustacean order Amphipoda.
Drift net studies are widely used and
have a proven validity in stream
water quality studies.
The collected sample is screened with
a standard sieve to concentrate the
organisms; these are separated from
substrate and debris, and the number
of each kind of organism determined.
Data are then adjusted to number per
unit area, usually to number of bottom
organisms per square meter.
Independently, neither qualitative not
quantitative data suffice for thorough
analyses of environmental conditions.
A cursory examination to detect damage
may be made with either method, but
a combination of the two gives a more
precise determination. If a choice must
be made, quantitative sampling would
be best, because it incorporates a
partial qualitative sample.
Studies have shown that a significant
number and variety of macroinverte-
brates inhabit the hyporheic zone in streams.
As much as 80% of the macroinverte-
brates may be below 5 cm in this
hyporheic zone. Most samples and
sampling techniques do not penetrate
the substrate below the 5 cm depth.
All quantitative studies must take this
and other substrate factors into account
when absolute figures are presented on
standing crop and numbers per square
meter, etc.
Flora
Direct quantitative sampling of natu-
rally growing bottom algae is difficult.
It is basically one of collecting algae
from a standard or uniform area of the
bottom substrates without disturbing
the delicate growths and thereby dis-
tort the sample. Indirect quantitative
sampling is the best available method.
Manipulated substrates, such as wood
blocks, glass or plexiglass slides,
bricks, etc., are placed in a stream.
Bottom-attached algae will grow on
these artificial substrates. After two
or more weeks, the artificial sub-
strates are removed for analysis.
Algal growths are scraped from the
substrates and the quantity measured.
Since the exposed substrate area and
exposure periods are equal at all of
the sampling sites, differences in the
quantity of algae can be related to
changes in the quality of water flowing
over the substrates.
VII ANALYSES OF MICROFLORA
A Enumeration
1 The quantity of algae on manipulated
substrates can be measured in several
ways. Microscopic counts of algal
cells and dry weight of a algal mater-
ial are long established methods.
2 Microscopic counts involve thorough
scraping, mixing and suspension of
the algal cells. From this mixture
an aliquot of cells is withdrawn for
enumeration under a microscope.
Dry weight is determined by drying
and weighing the algal sample, then
igniting the sample to burn off the
algal materials, leaving inert inorganic
materials that are again weighed.
The difference between initial dry weight
and weight after ignition is attributed to
algae.
3 Any organic sediments, however,
that settle on the substrate along
with the algae are processed also.
28-7
-------
Biological Integrity of Stream Communities
Thus, if organic wastes are present
appreciable errors may enter into
this method.
B Chlorophyll Analysis
1 During the past decade, chlorophyll
analysis has become a popular method
for estimating algal growth. Chloro-
phyll is extracted from the algae and
is used as an index of the quantity of
algae present. The advantages of
chlorophyll analysis are rapidity,
simplicity, and-vivid pictorial results.
2 The algae are scrubbed from the
placed substrate samples, ground,
then each sample is steeped in equal
volumes, 90% aqueous acetone, which
extracts the chlorophyll from the algal
cells. The chlorophyll extracts may
be compared visually.
3 Because the cholorophyll extracts fade
with time, colorimetry should be used
for permanent records. For routine
records, simple colorimeters will
suffice. At very high cholorophyll
densities, interference with colori-
metry occurs, which must be corrected
through serial dilution of the sample
or with a nomograph.
C Autotrophic Index
The chlorophyll content of the periphyton
is used to estimate the algal biomass and
as an indicator of the nutrient, content.
(or trophic status) or toxicity of the water
and the taxonomic composition of the
community. Periphyton growing in sur-
face water relatively free of organic
pollution consists largely of algae,
which contain approximately 1 to 2 percent
chlorophyll a by dry weight. If dissolved
or particulate organic matter is present
in high concentrations, large populations
of filamentous bacteria, stalked protozoa,
and other nonchlorophyll bearing micro-
organisms develop and the percentage
of chlorophyll is then reduced. If the
biomass-chlorophyll a relationship
is expressed as a ratio (the autotro-
phic index), values greater than 100
may result from organic pollution
(Weber and McFarland, 1969; Weber,
1973).
Autotrophic Index
Ash-free Wgt (mg/m )
Chlorophyll a (mg/m2)
VIII MACROINVERTEBRATE ANALYSES
A Taxonomic
The taxonomic level to which animals are
identified depends on the needs, experience,
and available resources. However, the
taxonomic level to which identifications are
carried in each major group should be
constant throughout a given study.
B Biomass
Macroinvertebrate biomass (weight of
organisms per unit area) is a useful
quantitative estimation of standing crop.
C Reporting Units
Data from quantitative samples may be used
to obtain:
1 Total standing crop of individuals, or
biomass, or both per unit area or unit
volume or sample unit, and
2 Numbers of biomass, or both, of individual
taxa per unit area or unit volume or sample
unit.
3 Data from devices sampling a unit area
of bottom will be reported in grams dry
weight or ashrfree dry weight per square
meter (gm/m ), or numbers of indi-
viduals per square meter, or both.
4 Data from multiplate samplers will be
reported in terms of the total surface
area of the plates in grams dry weight
or ash-free dry weight or numbers of
individuals per square meter, or both.
5 Data from rock-filled basket samplers
will be reported as grams dry weight
or numbers of individuals per sampler,
or both.
28-8
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Biological Integrity of Stream Communities
IX FACTORS INVOLVED IN DATA INTER-
PRETATION
Two very important factors in data evalua-
tion are a thorough knowledge of conditions
under which the data were collected and a
critical assessment of the reliability of the
data's representation of the situation.
A Maximum-Minimum Values
The evaluation of physical and chemical
data to determine their effects on aquatic
organisms is primarily dependent on
maximum and minimum observed values.
Tne mean is useful only when the data are
relatively uniform. The minimum or
maximum values usually create acute
conditions in the environment.
B Identification
Precise identification of organisms to
species requires a specialist in that
taxonomic groups. Many immature
aquatic forms have not been associated
with the adult species. Therefore, one
who is certain of the genus but not the
species should utilize the generic name,
not a potentially incorrect species name.
The method of interpreting biological
data on the basis of numbers of kinds
and numbers of organisms will typically
suffice.
C Lake and Stream Influence
Physical characteristics of a body of
water also affect animal populations.
Lakes or impounded bodies of water
support different faunal associations
than rivers. The number of kinds
present in a lake may be less than that
found in a stream because of a more
uniform habitat. A lake is all pool,
but a river is composed of both pools
and riffles. The nonflowing water of
lake exhibits a more complete set-
tling of particulate organic matter that
naturally supports a higher population
of detritus consumers. For these
reasons, the bottom fauna of a lake or
impoundment, or stream pool cannot be
directly compared with that of a flowing
stream riffle.
D Extrapolation
How can bottom-dwelling macrofauna data
be extrapolated to other environmental
components? It must be borne in mind
that a component of the total environment
is being sampled. If the sampled com-
ponent exhibits changes, then so must the
other interdependent components of the
environment. For example, a clean stream
with a wide variety of desirable bottom
organisms would be expected to have a
wide variety of desirable bottom fishes;
when pollution reduces the number of bottom
organisms, a comparable reduction would
be expected in the number of fishes. More-
over, it would be logical to conclude that
any factor that eliminates all bottom organ-
isms would eliminate most other aquatic
forms of life. A clean stream with a wide
variety of desirable bottom organisms
would be expected to permit a variety of
recreational, municipal and industrial uses.
E Expression of Data
1 Standing crop and taxonomic composition
Standing crop and numbers of taxa (types
or kinds) in a community are highly
sensitive to environmental perturbations
resulting from the introduction of contam-
inants. These parameters, particularly
standing crop, may vary considerably in
unpolluted habitats, where they may range
from the typically high standing crop of
littoral zones of glacial lakes to the
sparse fauna of torrential soft-water
streams. Thus, it is important that
comparisons are made only between truly
comparable environments.
28-9
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Biological Integrity of Stream Communities
2 Diversity
Diversity indices are an additional tool
for measuring the quality of the environ-
ment and the effect of perturbation on
the structure of a community of macro-
invertebrates. Their use is based on
the generally observed phenomenon that
relatively undisturbed environments
support communities having large
numbers of species with no individual
species present in overwhelming
abundance. If the species in such a
community are ranked on the basis of
their numerical abundance, there will
be relatively few species with large
numbers of individuals and large
numbers of species represented by only
a few individuals. Perturbation tends
to reduce diversity by making the
environment unsuitable for some species
or by giving other species a competitive
advantage.
3 Indicator-organism scheme ("rat-tailed
maggot studies")
a For this technique, the individual
taxa are classified on the basis of
their tolerance or intolerance to
various levels of putrescible wastes.
Taxa are classified according to
their presence or absence of
different environments as deter-
mined by field studies. Some
reduce data based on the presence
or absence of indicator organisms
to a simple numerical form for ease
in presentation.
i;
b Biologists are engaging in fruit-
less exercise if they intend to make
any decisions about indicator
organisms, by operating at the
generic level of macroinvertebrate
identifications." (Resh and Unzicker)
4 Reference station methods
Comparative or control station methods
compare the qualitative characteristics
of the fauna in clean water habitats with
those of fauna in habitats subject to stress.
Stations are compared on the basis of
richness of species.
If adequate background data are avail-
able to an experienced investigator,
these techniques can prove quite useful—
particularly for the purpose of demon-
strating the effects of gross to moderate
organic contamination on the macro-
invertebrate community. To detect
more subtle changes in the macroinver-
tebrate community, collect quantitative
data on numbers or biomass of organisms.
Data on the presence of tolerant and
intolerant taxa and richness of species
may be effectively summarized for evalu-
ation and presentation by means of line
graphs, bar graphs, pie diagrams,
histograms, or pictoral diagrams.
X IMPORTANT ASSOCIATED ANALYSES
A The Chemical Environment
1 Dissolved oxygen
2 Nutrients
3 Toxic materials
4 Acidity and alkalinity
5 Etc.
B The Physical Environment
1 Suspended solids
2 Temperature
3 Light penetration
4 Sediment composition
5 Etc.
XI AREAS IN WHICH BENTHIC STUDIES
CAN BEST BE APPLIED
A Damage Assessment or Stream Health
If a stream is suffering from abuse the
biota will so indicate. A biologist can
determine damages by looking at the
"critter" assemblage in a matter of
minutes. Usually, if damages are not
found, it will not be necessary to alert
the remainder of the agency's staff,
28-10
-------
Biological Integrity of Stream Communities
pack all the equipment, pay travel and per
diem, and then wait five days before
enough data can be assembled to begin
evaluation.
B By determining what damages have been
done, the potential cause "list" can be
reduced to a few items for emphasis and
the entire "wonderful worlds" of science
and engineering need not be practiced with
the result that much data are discarded
later because they were not applicable to
the problem being investigated.
C Good benthic data associated with chemi-
cal, physical, and engineering data can
be used to predict the direction of future
changes and to estimate the amount of
pollutants that need to be removed from
the waterways to make them productive
and useful once more.
D The benthic macroinvertebrates are an
easily used index to stream health that
citizens may use in stream improve-
ment programs. "Adopt-a-stream"
efforts have successfully used simple
macroinvertebrate indices.
E The potential for restoring biological
integrity in our flowing streams using
macroinvertebrates has barely been
touched.
REFERENCES
1 Freed, J. Randall and Slimak, Michael \\ .
Biological Indices in Water Quality
Assessment. (In The Freshwater
Potomac Aquatic Communities and
Environmental Stresses). Interstate
Commission on the Potomac River
Basin. 1978.
2 Hellawell, J. M. , Biological Surveillance
of Rivers. Water Research Center.
Stevenage and Medenham. 333 pp.
1978.
3 Hynes, H. B. N. The Ecology of Running
Waters. Univ. Toronto Press. 1970
4 Mackenthun, K. M. The Practice of
Water Pollution Biology. FWQA.
281 pp. 1969.
5 Weber, Cornelius I., Biological Field
and Laboratory Methods for Measuring
the Quality of Surface Waters and
Effluents. U.S. Environmental Pro-
tection Agency, NERC, Cincinnati,
OH . Environmental Monitoring Series
670/4.73.001 July 1973
6 Keup, L. E. and Stewart, R. K. Effects
of Pollution on Biota of the Pigeon River,
North Carolina and Tennessee. U. S. EPA,
National Field Investigations Center. 35 pp.
1966. (Reprinted 1973, National Training
Center)
7 v/uhrmann, K., Some Problems and
Perspectives in Applied Limnology
Mitt. Internat. Verein Limol. 20:324-402.
1974.
,'i Armitag, P. D., Machale, AngeluM., and
Crisp, Diane C. A Survey of Stream
Invertebrates in the Cow Green Basin
(Upper Teesdale) Before Inundation.
Freshwater Biol. 4:369-398. 1974.
9 Resh, Vincent H. andUnzicker, John D.
Water Quality Monitoring and Aquatic
Organisms: the JWPCF 47:9-19. 1975.
This outline was prepared by Lowell Keup,
Chief, Technical Studies Branch,
Division of Technical Support, EPA,
Washington, D. C. 20460, and revised by
R. M. Sinclair, National Training and
Operational Technology Center, OWPO,
US EPA, Cincinnati, Ohio 45268.
Descriptors: Aquatic Life, Benthos, Water
Quality, Degradation, Environmental Effects,
Trophic Level, Biological Communities,
Ecological Distributions
28-11
-------
ECOLOGY PRIMER
(from Aldo Leopold's A SAND COUNTY ALMANAC)
I Ecology is a belated attempt to convert
our collective knowledge of biotic materials
into a collective wisdom of biotic manage-
ment.
II The outstanding scientific discovery of
the twentieth century is not television or
radio, but rather the complexity of the
land organism.
Ill One of the penalties of an ecological edu-
cation is that one lives alone in a world
of wounds. Much of the damage inflicted
on land is quite invisible to laymen. An
ecologist must either harden his shell
and make believe that the consequences
of science are none of his business, or
he must be the doctor who sees the marks
of death in a community that believes
itself well and does not want to be told
otherwise.
IV Elcosystems have been sketched out as
pyramids, cycles, and energy circuits.
The concept of land as an energy circuit
conveys three basic ideas:
A That land is not merely soil.
B That the native plants and animals kept
the energy circuit open; others may or
may not.
C That man-made changes are of a different
order than evolutionary changes, and have
effects more comprehensive than is intend-
ed or foreseen (See figures 1-4).
D To keep every cog and wheel is the first
precaution of intelligent tinkering.
V The process of altering the pyramid for
human occupation releases stored energy,
and this often gives rise, during the
pioneering period, to a deceptive exuber-
ance of plant and animal life, both wild
and tame. These releases of biotic
capital tend to becloud or postpone the
penalties of violence.
VI A thing is right when it tends to preserve
the integrity, stability, and beauty of the
biotic community. It is wrong when it
tends otherwise.
VII Every farm is a textbook on animal
ecology; every stream is a textbook
on aquatic ecology; conservation is
the translation of the book.
VIII There are three spiritual dangers in not
owning a farm
A One is the danger of supposing that break-
fast comes from the grocery.
B Two is that heat comes from the furnace.
C And three is that gas comes from the
pump.
IX Tn general, the trend of the evidence
indicates that in land, just as in the
fishes body, the symptoms may lie in
one organ and the cause in another. The
practices we now call conservation are,
to a large extent local alleviations of
biotic pain. They are necessary, but
they must not be confused with cures.
X An Atom at large in the biota is too free
to know freedom; an atom back in the sea
has forgotten it. For every atom lost to
the sea, the prairie pulls another out of
the decaying rocks. The only certain
truth is that its creatures must suck
hard, live fast, and die often, lest its
losses exceed its gains.
REFERENCES
1 Leopold, Luna B. (ed.) Round River.
Oxford University Press. 1953.
2 Leopold, Aldo. A Sand County Almanac.
Oxford University Press. 1966.
3 United States Environmental Protection
Agency. The Integrity of Water.
Washington, B.C. 1977.
BI..ECO. 26b. 9.79
29-1
-------
Ecology Primer (from Aldo Leopold's A Sand County Almanac)
REFERENCES (Continued)
4 United States Geological Survey.
"Topographic Maps"
Reston, Virginia. 1978.
This outline was prepared by R. M. Sinclair
National Training and Operational Technology
Center, OWPO, USEPA, Cincinnati, Ohio
45268.
Descriptor: Ecology
Mapped In 1949
Figure 1.
Revised In 1956
Figure 2.
^.if?^
i-.l.t»3taji'i.-iV:i
Photorevised in 1969
Figure 3.
Photorevised in 1973
Figure 4.
29-2
-------
GLOBAL ENVIRONMENTAL QUALITY
I FROM LOCAL TO REGIONAL TO GLOBAL
PROBLEMS
A Environmental problems do not stop at
national frontiers, or ideological barriers.
P'ollution in the atmosphere and oceans
taints all nations, even those benignly
favored by geography, climate, or natural
resources.
1 The smokestacks of one country often
pollute the air and water of another.
2 Toxic effluents poured into an inter-
national river can kill fish in a
neighboring nation and ultimately
pollute international seas.
B In Antarctica, thousands of miles from
.pollution sources, penguins and fish
contain DDT in their fat. Recent layers
of snow and ice on the white continent
contain measurable amounts of lead.
The increase can be correlated with the
earliest days of lead smelting and com-
bustion of leaded gasolines. PCB's are
universally distributed.
C International cooperation, therefore, is
necessary on many environmental fronts.
1 Sudden accidents that chaotically
damage the environment - such as oil
spills from a tanker at sea - require
international cooperation both for
prevention and for cleanup.
2 Environmental effects cannot be
effectively treated by unilateral action.
3 The ocean can no longer be considered
a dump.
D "One of the penalties of an ecological
education is that one lives alone in a
world of wounds. Much of the damage
inflicted on land is quite invisible to
laymen. An ecologist must either harden
his shell and make believe that the conse-
quences of science are none of his
II
business, or he must be the doctor who
sees the marks of death in a community that
believes itself well and does not want to
be told otherwise. " Aldo Leopold
CHANGES IN ECOSYSTEMS ARE
OCCURRING CONTINUOUSLY
A Myriad interactions take place at every
moment of the day as plants and animals
respond to variations in their surroundings
and to each other. Evolution has produced
for each species, including man, a genetic
composition that limits how far that
species can go in adjusting to sudden
changes in its surroundings. But within
these limits the several thousand species
in an ecosystem, or for that matter, the
millions in the biosphere, continuously
adjust to outside stimuli. Since inter-
actions are so numerous, they form long
chains of reactions.
B Small changes in one part of an ecosystem
are likely to be felt and compensated for
eventually throughout the system.
Dramatic examples of change can be seen
where man has altered the course of
nature. It is vividly evident in his well-
intentioned but poorly thought out tampering
with river, lake, and other ecosystems.
1 The Aswan High Dam
2 The St. Lawrence Seaway
3 Lake Kariba
4 The Great Lakes
5 Valley of Mexico
6 California earthquake (Scientific
American 3981, p. 333)
7 Everglades and the Miami, Florida
Jetport
8 Copper hill, Tennessee (Copper Basin)
9 (You may add others)
BI. ECO. hum. 2f. 7. 79
30-1
-------
'Global Environmental Quality
C Ecosystem Stability
1 The stability of a particular ecosystem
depends on its diversity. The more
interdependencies in an ecosystem, the
greater the chances that it will be able
to compensate for changes imposed
upon it.
2 A cornfield or lawn has little natural
stability. If they are not constantly
and carefully cultivated, they will not
remain cornfields or lawns but will
soon bs overgrown with a wide variety
of hardier plants constituting a more
stable ecosystem.
3 The chemical elements that make up
living systems also depend on complex,
diverse sources to prevent cyclic
shortages or oversupply.
4 Similar diversity is essential for the
continued functioning of the cycle by
which atmospheric nitrogen is made
available to allow life to exist. This
cycle depends on a wide variety of
organisms, including soil bacteria and
fungi, which are often destroyed by
pesticides in the soil.
5 A numerical expression of diversity
is often used in defining stream water
quality.
D Biological Pollution
Contamination of living native biotas by
introduction of exotic life forms has been
called biological pollution by Lachner
et al. Some of these introductions are
compared to contamination as severe as
a dangerous chemical release. They
also threaten to replace known wildlife
resources with species of little or un-
known value.
1 Tropical areas have especially been
vulnerable. Florida is referred to as
"a biological cesspool of introduced life. "
2 Invertebrates
a Asian Clams have a pelagic veliger
larvae, thus, a variety of hydro
installations are vulnerable to sub-
sequent pipe clogging by the adult
clams.
b Melanian snails are intermediate
hosts for various trematodes
parasitic on man.
3 Vertebrates
a At least 25 exotic species of fish
have been established in North
America.
b Birds, including starlings and
cattle egrets.
c Mammals, including nutria.
4 Aquatic plants
Over twenty common exotic species
are growing wild in the United States.
The problem of waterway clogging has
been especially severe in parts of the
Southeast.
5 Pathogens and Pests
Introduction of insect pests and tree
pathogens have had severe economic
effects.
Ill LAWS OF ECOLOGY
A Four principles have been enunciated by
Dr. Barry Commoner.
1 Everything is connected to everything
else.
2 Everything must go somewhere.
3 Nature knows best.
4 There is no such thing as a free lunch.
B These may be summarized by the principle,
"you can't do just one thing.
30-2
-------
Global Environmental Quality
IV THE THREE PRINCIPLES OF
ENVIRONMENTAL CONTROL (Wolman)
A You can't escape.
B You have to organize.
C You have to pay.
V LEOPOLD'S PRINCIPLE OF BIOTIC
CAPITAL
"The releases of biotic capital tend to
becloud or postpone the penalties of
violence". Can you apply this to other
parts of this outline?
VI POLLUTION COMES IN MANY PACKAGES
A The sources of air, water, and land
pollution are interrelated and often
interchangeable.
1 A single source may pollute the air
with smoke and chemicals, the land
with solid wastes, and a river or lake
with chemical and other wastes.
2 Control of air pollution may produce
more solid wastes, which then pollute
the land or water.
3 Control of wastewater effluent may
convert it into solid wastes, which
must be disposed of on land, or by
combustion to the air.
4 Some pollutants - chemicals, radiation,
pesticides - appear in all media.
B "Disposal" is as important and as costly
as purification.
VII PERSISTENT CHEMICALS IN THE
ENVIRONMENT
Increasingly complex manufacturing processes,
coupled with rising industrialization, create
greater amounts of exotic wastes potentially
toxic to humans and aquatic life.
They may also be teratogenic (toxicants
responsible for changes in the embryo with
resulting birth defects, ex., thalidomide),
mutagenic (insults which produce mutations,
ex., radiation), or carcinogenic (insults
which induce cancer, ex., benzopyrenes) in
effect. Most carcinogens are also muta-
genic. For all of these there are no thresh-
hold levels as in toxicity. Fortunately there
are simple rapid tests for mutagenicity using
bacteria. Tests with animals are not always
conclusive.
A Metals - current levels of cadmium, lead,
and other substances are a growing concern
for they affect not only fish and wildlife but
ultimately man himself. Mercury pollution,
for example, has become a serious problem,
yet mercury has been present on earth since
time immemorial.
B Pesticides
1 A pesticide and its metabolites may
move through an ecosystem in many
ways. Hard (pesticides which are
persistent, having a long half-life in
the environment includes the organo-
chlorines, ex., DDT) pesticides
ingested or otherwise borne by the
target species will stay in the
environment, possibly to be recycled
or concentrated further through the
natural action of food chains if the
species is eaten. Most of the volume
of pesticides do not reach their target
at all.
2 Biological magnification
Initially, low levels of persistent
pesticides in air, soil, and water
may be concentrated at every step
up the food chain. Minute aquatic
organisms and scavengers, which
screen water and bottom mud having
pesticide levels of a few parts per
billion, can accumulate levels
measured in parts per million -
a thousandfold increase. The sediments
including fecal deposits are continuously
recycled by the bottom animals.
a Oysters, for instance, will con-
centrate DDT 70, 000 times higher
in their tissues than it's concentration
in surrounding water. They can
also partially cleanse themselves
in water free of DDT.
30-3
-------
Global Environmental Quality
b Fish feeding on lower organisms
build up concentrations in their
visceral fat which may reach several
thousand parts per million and levels
in their edible flesh of hundreds of
parts per million.
c Larger animals, such as fish-
eating gulls and other birds, can
further concentrate the chemicals.
A survey on organochlorine residues
in aquatic birds in the Cnadian
prairie provinces showed that
California and ring-billed gulls were
among the most contaminated.
Since gulls breed in colonies, breed-
ing population changes can be
detected and related to levels of
chemical contamination. Ecological
research on colonial birds to monitor
the effects of chemical pollution on
the environment is useful.
C "Polychlorinated biphenyls" (PCB's).
PCB's are used in plasticizers, asphalt,
ink, paper, and a host of other products!
Action has been taken to curtail their
release to the environment, since their
effects are similar to hard pesticides.
D Other compounds which are toxic and
accumulate in the ecosystem:
1 Phalate esters - may interfere with
pesticide analyses
2 Benzopyrenes
E Refractory compounds like pentachloro-
phenal and hexachlorophene are poorly
removed by both water treatment plants
and wastewater treatment plants.
F It is estimated that 80% to 90% of cancers
are caused by chemicals both in the work-
ing environment and total environment.
This is shown by high risk industries and
living areas.
G Most of the problems of persistent and
dangerous chemicals in the environment
are "after-the-fact". The solution
obviously is tied to prevention. This is
extremely complicated by economics,
H
ignorance, and decision as to risks
involved. Some advertising slogans now
have more than an intended meaning.
Wittingly or unwittingly we have all become
a King Mithridates. And even a fish is no
longer a fish!
VIII ACID RAIN
Acid rain is also becoming a problem
in this country.
IX EXAMPLES OF SOME EARLY WARNING
SIGNALS THAT HAVE BEEN DETECTED
BUT FORGOTTEN, OR IGNORED.
A Magnetic micro-spherules in lake sediments
now used to detect changes in industriali-
zation indicate our slowness to recognize
indicators of environmental change.
B Salmonid fish kills in poorly buffered clean
lakes in Sweden. Over the past years there
had been a successive increase of SO? in the
air and precipitation. Thus, air-borne con-
tamination from industrialized European
countries had a great influence on previously
unpolluted waters and their life.
C Minimata, Japan and mercury pollution.
D Organochlorine levels in commercial and
sport fishing stocks, ex., the lower
Mississippi River fish kills.
.X SUMMARY
A Ecosystems of the world are linked
together through biogeochemical cycles
which are determined, by patterns of
transfer and concentrations of substances
in the biosphere and surface rocks.
B Organisms determine or strongly influence
chemical and physical characteristics of
the atmosphere, soil, and waters.
C The inability of man to adequately predict
or control his effects on the environment
is indicated by his lack of knowledge con-
cerning the net effect of atmospheric
pollution on the earth's climate.
30-4
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Global Environmental Quality
D Serious potential hazards for man which
are all globally dispersed, are radio-
nuclides, organic chemicals, pesticides,
and combustion products.
E Environmental destruction is in lockstep
with our population growth.
REFERENCES
1 Lachner, Ernest A., Robins, C. Richard,
and Courtenay, Walter R., Jr.
Exotic Fishes and Other Aquatic
Organisms Introduced into North
America. Smithsonian Contrib. to
Zool. 59:1-29. 1970
2 Commoner, Barry. The Closing Circle,
Nature, Man, and Technology. Alfred
A. Knopf. 326 p. 1971.
3. Dansereau, Pierre ed. Challenge for
Survival. Land, Air, and Water for
Man in Megalopolis, Columbia Univ.
Press. 235 p. 1970.
4 Wiens, John A. ed. Ecosystem Structure
and Function. Oregon State Univ. Press.
176 p. 1972.
5 Leopold, Aldo. A Sand County Almanac
with Essays on Conservation from
Round River. Sierra Club/Ballantine
Books. 295 p. 1970.
6 Whiteside, Thomas. The Pendulum and
the Toxic Cloud, The course of Dioxin
Contamination. Yale University Press.
1979.
7 Butler, G. C. (editor) Principles of
Ecotoxicology.. Scope 12. Int. Council
of Sci. Unions. J. Wiley & Sons. 1978.
This outline was prepared by R. M. Sinclair,
National Training and Operational Technology
Center, MOTD, OWPO, USEPA, Cincinnati,
Ohio 45268.
Descriptors:
Ecosystems
Environmental Effects,
30-5
-------
THE EFFECTS OF POLLUTION ON LAKES
I INTRODUCTION
The pollution of lakes inevitably results in a
number of undesirable changes in water
quality which are directly or indirectly
related to changes in the aquatic community.
A Industrial Wastes may contain the following:
1 Sewage
2 Dissolved organics--synthetics, food
processing wastes, etc.
3 Dissolved minerals--salts, metals
(toxic and nontoxic), pigments, acids, etc.
4 Suspended solids--fibers, minerals,
degradable and non-degradable organics
5 Petroleum products--oils, greases
6 Waste heat
B The Materials in Domestic Wastes which
affect Water Quality are:
1 Pathogenic fecal microorganisms
2 Dissolved nutrients: minerals, vitamins,
and other dissolved organic substances
3 Suspended solids (sludge)--degradable
and non-degradable organic materials
4 Toxic materials which line the counters
of supermarkets, drugstores, and
discount stores
C Pollution and Eutrophication
The discharge of domestic wastes often
renders the receiving water unsafe for
contact water sports and water supplies.
For example, some beaches on the eastern
seaboard and in metropolitan regions of
the Great Lakes are unfit for swimming
because of high coliform counts. Other
effects of domestic pollution include
changes in the abundance and composition
of populations of aquatic organisms.
1 As the nutrient level increases, so does
the rate of primary production.
2 Shore-line algae and rooted aquatics
become more abundant. For example,
problems have been experienced with
Cladophora and Dichotomosiphon along
the shores of Lakes Ontario, Erie,
and Michigan. These growths interfere
with swimming, boating, and fishing,
and cause odors when the organisms
die and decay.
3 The standing crop of phytoplankton
increases, resulting in higher counts
and greater chlorophyll content.
Increases in phytoplankton abundance
may result in taste and odor problems
in water supplies, filter clogging,
high turbidity, changes in water color,
and oxygen depletion in the hypolimnion.
4 Populations of fish and larger swimming
invertebrates increase, based on the
increase in basic food production.
5 Changes in dominant species
a Diatom communities give way to
blue-greens. Toxic blue-greens may
pose a problem.
b Zooplankton changes include
replacement of Bosmina coregoni
by B^ longirostris.
c Trout and whitefish are replaced by
perch, bass, and rough fish.
d Hypolimnion becomes anaerobic in
summer; bottom sludge buildup
results in loss of fish food organisms,
accompanied by increase in density
of sludgeworms (oligochaeta).
II HISTORICA L REVIEW
The cultural eutrophication of a number of
lakes in Europe and America has been well
documented.
A Zurichsee, Switzerland
WP. LK. Id.3. 80
31-1
-------
The Effects of Pollution on Lakes
1 1896 - sudden increase in Tabellaria
fenestrata
2 1898 - sudden appearance of Oscillatoria
rubescens which displaced Fragilaria
capucina
3 1905 - Melosira islandica var. helvetica
appeared
4 1907 - Stephanodiscus hantzschil
appeared
5 1911 - Bosmina longirostris replaced
B. coregoni
6 1920
1924 - O. rubescens occurred in great
quantities
7 1920 - milky-water phenomenon;
precipitation of CaCCL crystals (40[i)
due to pH increase resulting from
photosynthesis
8 Trout and whitefish replaced by perch,
bass, and rough fish
B Hallwilersee, Switzerland
1 1897 - Oscillataria rubescens not
observed up to this time
2 1898 - O. rubescens bloomed,
decomposed, formed H S, killing off
trout and whitefish
C Lake Windermere, England (core study)
1 Little change in diatoms from glacial
period until recent times
2 Then A sterionella appeared, followed
by Synedra
3 About 200 years ago, A sterionella
again became abundant
4 A sterionella abundance ascribed to
domestic wastes
D Finnish Lakes
Aphanizomenon, Coelosphaerium,
Anabaena, Microcystis, are the most
common indication of eutrophy.
TABLE 1 CHANGES IN PHYSIO-CHEMICAL PARAMETERS
Zurichsee, Switzerland
Parameter Date
Chlorides
Dissolved organics
1888
1916
1888
1914
Value
1.3mg/l
4.9 mg/1
9.0mg/l
20.0 mg/1
Secchi Disk
Dissolved oxygen, at
100 M, mid-summer
before 1910
1905 - 1910
1914 - 1928
1910 - 1930
1930 - 1942
Max.
16. 8M
10. OM
10. OM
Minimum
Min.
3. 1M
2.1M
1.4M
100% saturation
9% saturation
31-2
-------
The Effects of Pollution on Lakes
E Linsley Pond, Connecticut
1 Species making modern appearance
include Asterionella formosa,
Cyclotella glomerata, Melosira
italica, Fragilaria crotonensis,
Synedra ulna
2 Asterionella formosa and Melosira
italica were considered by Patrick to
indicate high dissolved organics
3 Bosmlna coregoni replaced by B.
longirostris
F Lake Monona, Wisconsin
1 Began receiving treated sewage in 1920,
developed blue-green algal blooms.
G Lake Washington, Washington
1 1940 - Bosmina longirostris appeared
2 1955 - Oscillatoria rubescens seen for
the first time, and constituted 96% of
phytoplankton, July 1
H Lake Erie
1 Phytoplankton counts at Cleveland have
increased steadily from less than
500 cells/ml in the 1920's to over
1500 cells/ml in the 1960's
2 Abundance of burrowing mayflies
(Hexagenia spp.)in Western Lake Erie
decreased from 139/m2 in 1930, to
less than 1/m2 in 1961.
I Lake Michigan
1 Milky water observed in south end, and
in limnetic region in mid-1950's and
again in 1967.
2 During the period 1965-1967 the Chicago
water treatment plant has found it
necessary to increase the carbon dosage
from 23 Ibs/mil gal to 43 Ibs/mil gal,
and the chlorine dosage from 20 Ibs/mil
gal to 25 Ibs/mil gal.
Phytoplankton counts in the south end
now exceed 10, 000/ml during the
spring bloom.
Ill FACTORS AFFECTING THE RESPONSE
OF LAKES TO POLLUTION INCLUDE:
A Depth-surface area ratio: A large
hypolimnion will act as a reservoir to
keep nutrients from recirculating in the
trophogenic zone during the summer
stratification period. Rawson found an
inverse relationship between the standing
crop of plankton, benthos, and fish, and
the mean depth.
B Climate: Low annual water temperatures
may restrict the response of the
phytoplankton to enrichment.
C Natural color or turbidity: Dystrophic
(brown-water) lakes may not develop
phytoplankton blooms because of the low
transparency of the water.
IV TROPHIC LEVEL
Except in cases where massive algal blooms
occur, the trophic status of lakes is often
difficult to determine. Core studies are
used to determine trends in diatom populations
which might indicate changes in nutrient
levels over an extended period of time.
'V CONTROL OF POLLUTION
The success of efforts to arrest the
eutrophication process, and where desirable,
reduce the trophic level of a lake, will
depend on a thorough knowledge of the
nutrient budget.
A Significant quantities of nutrients may
enter a lake from one or more of the
following sources:
1 Rainfall
2 Ground water
31-3
-------
The Effects of Pollution on Lakes
TABLE 2 PARAMETERS COMMONLY USED TO DESCRIBE CONDITIONS
1 Transparency
2 Phosphorus
3 NO - Nitrogen
O
4 Minimum annual
hypolimnetic oxygen concentration
5 Chlorophyll
6 Ash-free weight of seston
7 Phytoplankton count
8 Phytoplankton quotients
a number of species of Chlorococcales
number of species of Desmids
Oligotrophic Condition
> 10 meters
< lug/1
< 200 ng/1
near 100% saturation
3
< 1 mg/m
< 0. 1 mg/1
< 500/ml
<1
b Myxophycease+Chlorococcales+Centrales+Euglenaceae <1
Desmidaceae
c Centrales 0-0.2
Pennales
9 Phytoplankton species present (see outline on
plankton in oligotrophic lakes).
3 Watershed runoff
4 Shoreline domestic and industrial outfalls
5 Pleasure craft and commercial vessels
6 Waterfowl
7 Leaves, pollen, and other organic
debris from riparian vegetation
B The supply of nutrients from "natural"
sources in some cases may be greater
than that from cultural sources, and be
sufficient to independently cause a rapid
rate of eutrophication regardless of the
level of efficiency of treatment of domestic
and industrial wastes.
C Many methods have been employed to
treat the symptoms, reduce the
eutrophication rate, or completely
arrest and even reverse the eutrophication
process.
1 Use of copper sulfate, sodium arsenite,
and organic algicides: It is not
economically feasible to use algicides
in large lakes.
2 Addition of carbon black to reduce
transparency. This is likewise
frequently impractical.
3 Harvesting algae by foam fractionation
or chemical precipitation.
31-4
-------
The Effects of Pollution on Lakes
4 Reducing nutrient supply by (a) removal
of N and P from effluents, (b) diversion
of effluents, and (c) dilution with
nutrient-poor water.
D Examples of lakes where control has been
attempted by reducing the nutrient supply,
are:
1 Lake Washington, Seattle
The natural water supply for this lake
is nutrient poor
(Ca = 8 mg/1, P < 5 Mg/1, TDS=76mg/l).
Since the turnover time of the water in
this lake is only three years, it was
expected that diversion of sewage
would result in a rapid improvement of
water quality. Diversion began in 1963,
and improvements were noticeable by
1965 - including an increase in
transparency, and a reduction in seston,
chlorophyll, and epilimnetic phosphorus.
TABLE 3
PHOSPHORUS REDUCTION IN LAKE WASHINGTON
3 Lake Tahoe
This lake is still decidedly oligotrophic.
To maintain its high level of purity,
tertiary treatment facilities were
installed in the major sewage treat-
ment plant, and construction is now
underway to transport all domestic
wastes out of the lake basin.
REFERENCES
Year
1963
1964
1965
Maximum phosphorus in
upper 10 meters
(Mg/D
70
66
63
2 Green Lake, Washington
The lake has a long history of heavy
blooms of blue-green algae. Beginning
in 1959, low-nutrient city water was
added to the lake, reducing the con-
centration of phosphorus by 70% in the
inflowing water. By 1966, the lake had
been flushed three times. Evidence of
improvement in water quality was noted
in 1965, when Aphanizomenon was
replaced by Gleotrichia.
Eds.
1 Ayers, J. C. and Chandler, D. C.
Studies on the environment and
eutrophication of Lake Michigan.
Special Report No. 30. Great Lakes
Research Division, Institute of
Science and Technology, University
of Michigan, Ann Arbor. 1967.
2 Brezonik, P.L., Morgan, W.H.,
Shannon, E.E., and Putnam, H.D.
Eutrophication factors in North
Central Florida Lakes. University
of Florida Water Res. Center.
Pub. #5, 101 pp. 1969.
3 Carr, J.F., Hiltunen, J. K. Changes
in the bottom fauna of Western Lake
Erie from 1930 to 1961. Limnol.
Oceanogr. 10(4):551-569. 1965.
4 Frey, David G. Remains of animals
in Quaternary lake and bog sediments
and their interpretation.
Schweizerbartsche Verlagsbuchhandlung.
Stuttgart. 1964.
5 Edmondson, W.T., and Anderson, G.C.
Artificial eutrophication of Lake
Washington. Limnol. Oceanogr.
l(l):47-53. 1956.
6 Fruh, E.G. The overall picture of
eutrophication. Paper presented
at the Texas Water and Sewage
Works Association's Eutrophication
Seminar, College Station, Texas.
March 9, 1966.
7 Fruh, E.G., Stewart, K.M., Lee, G.F.,
and Rohlich, G.A. Measurements
of eutrophication and trends.
J.W.P.C.F. 38(8):1237-1258. 1966.
31-5
-------
The Effects of Pollution on Lakes
8 Hasler, A.D. Eutrophication of lakes
by domestic drainage. Ecology
28(4):383-395. 1947.
9 Hasler, A.D. Cultural Eutrophication
is Reversible. Bioscience 19(5):
425-443. 1969.
10 Herbst, Richard P. Ecological Factors
and the Distribution of Cladophora
glomerata in the Great Lakes.
Amer. Midi. Nat. 82(l):90-98. 1969.
11 National Academy of Sciences.
Eutrophication: Causes, Consequences,
Correction. 661pp. 1969.
(Nat. Acad. Sci. ,2101 Constitution
Avenue, Washington, DC 20418, 13.50).
12 Neel, Joe Kendall. Reservoir
Eutrophication and Dystrophication
following Impoundment. Reservoir
Fisheries Res. Symp. 322-332.
13 Oglesby, R.T. and Edmondson, W.T.
Control of Eutrophication.
J.W.P.C.F. 38(9):1452-1460. 1966.
14 Stewart, K.M. and Rohlich, G.A.
Eutrophication - A Review.
Publication No. 34, State Water
Resources Control Board, The
Resources Agency, State of California.
1967.
This outline was prepared by C. I. Weber,
Chief, Biological Methods Section,
Analytical Quality Control Laboratory,
NERC, EPA,. Cincinnati, OH 45268.
Descriptor: Eutrophication
31-6
-------
APPLICATION OF BIOLOGICAL DATA
I ECOLOGICAL DATA HAS TRADITIONALLY
BEEN DIVIDED INTO TWO GENERAL
CLASSES:
A Qualitative - dealing with the taxonomic
composition of communities
B Quantitative - dealing with the population
density or rates of processes occurring
in the communities
Each kind of data has been useful in its own
way.
II QUALITATIVE DATA
A Certain species have been identified as:
1 Clean water (sensitive) or oligotrophic
2 Facultative, or tolerant
3 Preferring polluted regions
(see: Fjerdinstad 1964, 1965; Gaufin
& Tarzwell 1956; Palmer 1963, 1969;
Rawson 1956; Teiling 1955)
B Using our knowledge about ecological
requirements the biologist may compare
the species present
1 At different stations in the same river
(Gaufin 1958) or lake (Holland 1968)
2 In different rivers or lakes (Robertson
and Powers 1967)
or changes in the species in a river or/lake
over a period of several years. (Carr
& Hiltunen 1965; Edmondson & Anderson
1956; Fruh, Stewart, Lee & Rohlich 1966;
Hasler 1947).
C Until comparatively recent times taxonomic
data were not subject to statistical treat-
ment.
Ill QUANTITATIVE DATA; Typical
Parameters of this type include:
2
A Counts - algae /ml; benthos/m ;
fish/net/day
3
B Volume - mm algae/liter
C Weight - dry wgt; ash-free wgt.
D Chemical content - chlorophyll;
carbohydrate; ATP; DNA; etc.
E Calories (or caloric equivalents)
F Processes - productivity; respiration
IV Historically, the chief use of statistics
in treating biological data has been in the
collection and analysis of samples for these
parameters. Recently, many methods have
been devised to convert taxonomic data into
numerical form to permit:
A Better communication between the
biologists and other scientific disciplines
B Statistical treatment of taxonomic data
C In the field of pollution biology these
methods include:
1 Numerical ratings of organisms on the
basis of their pollution tolerance
(saprobic valency: Zelinka & Sladecek
1964)
(pollution index: Palmer 1969)
2 Use of quotients or ratios of species in
different taxonomic groups (Nygaard
1949)
BI.EN. 3a. 6.76
32-1
-------
Application of Biological Data
3 Simple indices of community diversity:
a Organisms are placed in taxonomic
groups which behave similarly under
the same ecological conditions. The
number of species in these groups
found at "healthy" stations is com-
pared to that 'found at "experimental"
stations. (Patrick 1950)
b A truncated log normal curve is
plotted on the basis of the number
of individuals per diatom species.
(Patrick, Hohn, & Wallace 1954)
j Information theory:
The basic equation used for
information theory applications was
developed by Margalef (1957).
N!
_
N g2 N ! N'. . . . N !
where I - information/individual;
N , N . . .N are the number of
individuals in species a, b, ...
s, and N is their sum.
c Sequential comparison index.
(Cairns, Albough, Busey & Chanay
1968). In this technique, similar
organisms encountered sequentially
are grouped into "runs".
SCI =
runs
total organisms examined
Ratio of carotenoids to chlorophyll
in phytoplankton populations:
°D430/°D665(Margalef 1968)
OD67()(Tanaka, et al 1961)
e The number of diatom species present
at a station is considered indicative
of water quality or pollution level.
(Williams 1964)
number of species (S)
number of individuals (N)
_ number of species (S) _
square root of number of individuals (N/ N)
This equation has also been used
with:
1) The fatty acid content of algae
(Mclntire, Tinsley, and Lowry
1969)
2) Algal productivity (Dickman 1968)
3) Benthic biomass (Wilhm 1968)
S - 1
(Menhlnick 1964)
d =
En. (n. - 1) (Simpson 1949)
N (N - 1)
where n. = number of individuals
belonging to the i-th species,
and
N = total number of individuals
REFERENCES
1 Cairns, J., Jr., Albough, D.W.,
Busey, F, and Chaney, M.D.
The sequential comparison index -
a simplified method for non-biologists
to estimate relative differences in
biological diversity in stream pollution
studies. J. Water Poll. Contr. Fed.
40(9):1607-1613. 1968.
2 Carr, J. F. and Hiltunen, J.K. Changes
in the bottom fauna of Western Lake
Erie from 1930 to 1961. Limnol.
Oceanogr. 10(4):551-569. 1965.
3 Dickman, M. Some indices of diversity.
Ecology 49(6): 1191-1193. 1968.
32-2
-------
Application of Biological Data
4 Edmondson, W.T. and Anderson, G. C.
Artificial Eutrophication of Lake
Washington. Limnol. Oceanogr.
l(l):47-53. 1956.
5 Fjerdingstad, E. Pollution of Streams
estimated by benthal phytomicro-
organisms. I. A saprobic system
based on communities of organisms
and ecological factors. Internat'l
Rev. Ges. Hydrobiol. 49(1):63-131.1964.
6 Fjerdingstad, E. Taxonomy and saprobic
valency of benthic phytomicro-
organisms. Hydrobiol. 50 (4):475-604.
1965.
7 Fruh, E.G., Stewart, K.M., Lee, G.F.
and Rohlich, G.A. Measurements of
eutrophication and trends. J. Water
Poll. Contr. Fed. 38(8):1237-1258.
1966.
8 Gaufin, A.R. Effects of Pollution on a
midwestern stream. Ohio J. Sci.
58(4):197-208. 1958.
9 Gaufin, A.R. and Tarzwell, C.M. Aquatic
macroinvertebrate communities as
indicators of organic pollution in Lytle
Creek. Sew. Ind. Wastes. 28(7):906-
924. 1956.
10 Hasler, A.D. Eutrophication of lakes by
domestic drainage. Ecology 28(4):383-
395. 1947.
11 Holland, R.E. Correlation of Melosira
species with trophic conditions in Lake
Michigan. Limnol. Oceanogr.
13(3):555-557. 1968.
12 Margalef, R. Information theory in
ecology. Gen. Syst. 3:36-71. 1957.
13 Margalef, R. Perspectives in ecological
theory. Univ. Chicago Press. 1968.
14 Mclntire, C.D., Tinsley, I.J. and
Lowry, R.R. Fatty acids in lotic
periphyton: another measure of
community structure. J. Phycol.
5:26-32. 1969.
15 Menhinick, E.F. A comparison of some
species - individuals diversity indices
applied to samples of field insects.
Ecology 45:859. 1964.
16 Nygaard, G. Hydrobiological studies in
some ponds and lakes. II. The
quotient hypothesis and some new or
little-known phytoplankton organisms.
Klg. Danske Vidensk. Selsk. Biol.
Skrifter 7:1-293. 1949.
17 Patten, B.C. Species diversity in net
plankton of Raritan Bay. J. Mar.
Res. 20:57-75. 1962.
18 Palmer, C.M. The effect of pollution on
river algae. Ann. New York Acad.
Sci. 108:389-395. 1963.
19 Palmer, C.M. A composite rating of
algae tolerating organic pollution.
J. Phycol. 5(l):78-82. 1969.
20 Patrick, R., Hohn, M.H. and Wallace,
J.H. A new method for determining
the pattern of the diatom flora. Not.
Natl. Acad. Sci., No. 259.
Philadelphia. 1954.
21 Rawson, D. S. Algal indicators of trophic
lake types. Limnol. Oceanogr.
1:18-25. 1956.
22 Robertson, S. and Powers, C.F.
Comparison of the distribution of
organic matter in the five Great Lakes.
in: J. C. AyersandD.C. Chandler,
eds. Studies on the environment and
eutrophication of Lake Michigan.
Spec. Rpt. No. 30, Great Lakes Res.
Div.,Inst. Sci. &Techn., Univ.
Michigan, Ann Arbor. 1967.
23 Simpson, E.H. Measurement of diversity.
Nature (London) 163:688. 1949.
24 Tanaka, O. H., Irie, S. Izuka, and Koga, F
The fundamental investigation on the
biological productivity in the Northwest
of Kyushu. I. The investigation of
plankton. Rec. Oceanogr. W. Japan,
Spec. Rpt. No. 5, 1-57. 1961.
32-3
-------
Application of Biological Data
25 Tailing, E. Some mesotrophic phyto-
plankton indicators. Proc. Intern.
Assoc. Limnol. 12:212-215. 1955.
26 Wilhm, J. L. Comparison of some
diversity indices applied to populations
of benthic macroinvertebrates in a
stream receiving organic wastes. J.
Water Poll. Contr. Fed. 39(10):1673-1683.
1967.
27 Wilhm, J. L. Use of biomass units in
Shannon's formula. Ecology 49:153-156.
1968.
28 Williams, L. G. Possible relationships
between diatom numbers and water
quality. Ecology 45(4):810-823. 1964.
29 .Zelinka, M. and Sladecek, V. Hydro-
biology for water management.
State Publ. House for Technical
Literature, Prague. 122 p. 1964.
This outline was prepared by C.I. Weber,
Chief, Biological Methods Section, Analytical
Quality Control Laboratory, NERC, EPA,
Cincinnati, Ohio, 45268
Descriptors: Analytical Techniques, Indicators
32-4
-------
SIGNIFICANCE OF "LIMITING FACTORS" TO POPULATION VARIATION
I INTRODUCTION
A All aquatic organisms do not react uniformly
to the various chemical, physical and
biological features in their environment.
Through normal evolutionary processes
various organisms have become adapted
to certain combinations of environmental
conditions. The successful development
and maintenance of a population or community
depend upon harmonious ecological balance
between environmental conditions and
tolerance of the organisms to variations
in one or more of these conditions.
B A factor whose presence or absence exerts
some restraining influence upon a population
through incompatibility with species
requirements or tolerance is said to be a
limiting factor. The principle of limiting
factors is one of the major aspects of the
environmental control of aquatic organisms
(Figure 1).
II PRINCIPLE OF LIMITING FACTORS
This principle rests essentially upon two basic
concepts. One of these relates organisms to
the environmental supply of materials essential
for their growth and development. The second
pertains to the tolerance which organisms
exhibit toward environmental conditions.
/UNLIMITED GROWTH
' DECREASE IN
POPULATION GROW
/
LTWTfATIOMNS
EQUILIBRIUM WITH
/X" xs ENVIRONMENT
/ ^^ INCREASE IN
'/ ^^ "TlMTtXriONS
,/ * POPULATION DECLINE
TIME
L J
Figure 1. The relationships of limiting factors
to population growth and development.
Liebig's Law of the Minimum enunciates
the first basic concept. In order for an
organism to inhabit a particular environ-
ment, specified levels of the materials
necessary for growth and development
(nutrients, respiratory gases, etc.) must
be present. If one of these materials is
absent from the environment or present
in minimal quantities, a given species
will only survive in limited numbers, if
at all (Figure 2).
Copper, for example, -j
is essential in trace amounts for
many species.
OPTIMUM
LOW —
CRITICAL RANGE
MAGNITUDE OF FACTOR —
"men
Figure 2. Relationships of environmental
factors and the abundance of organisms.
The subsidiary principle of factor
interaction states that high concentration
or availability of some substance, or
the action of some factor in the environ-
ment, may modify utilization of the
minimum one. For example:
a The uptake of phosphorus by the
algae Nitzchia closterium is influenced
by the relative quantities of nitrate
and phosphate in the environment;
however, nitrate utilization appears
to be unaffected by the phosphate
(Reid, 1961).
b The assimilation of some algae is
closely related to temperature.
c The rate of oxygen utilization by fish
may be affected by many other sub-
stances or factors in the environment.
BI.ECO. 20a. 7. 79
33-1
-------
Significance of "Limiting Factors" to Population Variation
B
d Where strontium is abundant, mollusks
are able to substitute it, to a partial
extent, for calcium in their shells
(Odum, 1959).
2 If a material is present in large amounts,
but only a small amount is available for
use by the organism, the amount available
and not the total amount present deter-
mines whether or not the particular
material is limiting (calcium in the form
of CaCO ).
O
Shelford pointed out in his Law of Tolerance
that there are maximum as well as minimum
values of most environmental factors which
can be tolerated. Absence or failure of an
organism can be controlled by the deficiency
or excess of any factor which may approach
the limits of tolerance for that organism
(Figure 3).
Ł
<
Minimum Limi'. of
Toleration
Absent
Decreasing
Abundance
Range of Optimum
of Factors
Greatest Abundance
Maximum Limit of
Toleration
Decreasing
Abundance
Absent
Figure 3. Shelford's Law of Tolerance.
Organisms have an ecological minimum
and maximum for each environmental
factor with a range in between called
the critical range which represents the
range of tolerance (Figure 2). The
actual range thru which an organism can
grow, develop and reproduce normally
is usually much smaller than its total
range of tolerance.
Purely deleterious factors (heavy metals,
pesticides, etc.) have a maximum
tolerable value, but no optimum (Figure 4).
CONCENTRATION
Figure 4. Relationship of purely harmful
factors and the abundance of
organisms.
3 Tolerance to environmental factors
varies widely among aquatic organisms.
a A species may exhibit a wide range
of tolerance toward one factor and a
narrow range toward another. Trout,
for instance, have a wide range of
tolerance for salinity and a narrow
range for temperature.
b All stages in the life history of an
organism do not necessarily have the
same ranges of tolerance. The
period of reproduction is a critical
time in the life cycle of most
organisms.
c The range of tolerance toward one
factor may be modified by another
factor. The toxicity of most sub-
stances increases as the temperature
increases.
d The range of tolerance toward a given
factor may vary geographically within
the same species. Organisms that
adjust to local conditions are called
ecotypes.
-------
Significance of "Limiting Factors" to Population Variation
e The range of tolerance toward a given
factor may vary seasonally. In general
organisms tend to be more sensitive
to environmental changes in summer
than in other seasons. This is
primarily due to the higher summer
temperatures.
A wide range of distribution of a species
is usually the result of a wide range of
tolerances. Organisms with a wide
range of tolerance for all factors are
likely to be the most widely distributed,
although their growth rate may vary
greatly. A one-year old carp, for
instance, may vary in size from less
than an ounce to more than a pound
depending on the habitat.
To express the relative degree of
tolerance for a particular environmental
factor the prefix eury (wide) or steno
(narrow) is added to a term for that
feature (Figure 5).
Ill
The law of the minimum as it pertains to
factors affecting metabolism, and the law
of tolerance as it relates to density and
distribution, can be combined to form a
broad principle of limiting factors.
1 The abundance, distribution, activity
and growth of a population are deter-
mined by a combination of factors, any
one of which may through scarcity or
overabundance be limiting.
2 The artificial introduction of various
substances into the environment tends
to eliminate limiting minimums for
some species and create intolerable
maximums for others.
3 The biological productivity of any body
of water is the end result of interaction
of the organisms present with the
surrounding environment.
VALUE AND USE OF THE PRINCIPLE OF
LIMITING FACTORS
o
z
<
0
z
>
Ł?
•<
STENOTHERMAL -...„,........ STENOTHERMAL
(OLIGOTHERMAL|EUIIY™EIIMAl (POLYTHERMAl]
TEMPERATURE
The organism-environment relationship
is apt to be so complex that not all factors
are of equal importance in a given situation;
some links of the chain guiding the organism
are weaker than others. Understanding
the broad principle of limiting factors and
the subsidiary principles involved make
the task of ferreting out the weak link in
a given situation much easier and possibly
less time consuming and expensive.
1 If an organism has a wide range of
tolerance for a factor which is
relatively constant in the environment
that factor is not likely to be limiting.
The factor cannot be completely
eliminated from consideration, however,
because of factor interaction.
Figure 5. Comparison of relative limits of
tolerance of stenothermal and
eurythermal organisms.
If an organism is known to have narrow
limits of tolerance for a factor which is
also variable in the environment, that
factor merits careful study since it
might be limiting.
-------
Significance of "Limiting Factors" to Population Variation
B Because of the complexity of the aquatic
environment, it is not always easy to
isolate the factor in the environment that
is limiting a particular population.
Premature conclusions may result from
limited observations of a particular
situations. Many important factors may
be overlooked unless a sufficiently long
period of time is covered to permit the
factors to fluctuate within their ranges of
possible variation. Much time and money
may be wasted on control measures without
the real limiting factor ever being dis-
covered or the situation being improved.
C Knowledge of the principle of limiting
factors may be used to limit the number
of parameters that need to be measured or
observed for a particular study. Not all
of the numerous physical, chemical and
biological parameters need to be measured
or observed for each study undertaken.
The aims of a pollution survey are not to
make and observe long lists of possible
limiting factors but to discover which
factors are significant, how they bring
about their effects, the source or sources
of the problem, and what control measures
should be taken.
D Specific factors in the aquatic environment
determine rather precisely what kinds of
organisms will be present in a particular
area. Therefore, organisms present or
absent can be used to indicate environ-
mental conditions. The diversity of
organisms provides a better indication of
environmental conditions than does any
single species. Strong physio-chemical
limiting factors tend to reduce the diversity
within a community; more tolerant species
are then able to undergo population growth.
REFERENCES
1 Odum, Eugene P. Fundamentals of
Ecology, W. B. Saunders Company,
Philadelphia. (1959)
2 Reid, George K. Ecology of Inland Waters
and Estuaries. Reinhold Publishing
Corporatiua, New York. (1961)
3 Rosenthal H. and Alderdice, D. F.
Sublethal Effects of Environmental
Stressors, Natural and Pollutional,
on Marine Fish Eggs and Larvae.
J. Fish. Res. Board Can. 33:2047-2065,
1976.
Thorp, James H. and Gibbons, J.
Whitfield (editors), Energy and
Environmental Stress in Aquatic
Systems. Tech Inform Ctr,
U. S. Dept of Energy. 1978.
This outline was prepared by John E.
Matthews, Aquatic Biologist, Robert S. Kerr
Water Research Center, Ada, Oklahoma.
Descriptors: Population, Limiting Factors
33-4
-------
ALGAE AND CULTURAL EUTROPHICATION
I INTRODUCTION
This topic covers a wide spectrum of items
often depending upon the individual discussing
the subject and the particular situation or
objectives that he is trying to "prove".
Since the writer is not a biologist, these
viewpoints are "from the outside-looking in".
Any impression of bias is intentional.
A Some Definitions are in Order to Clarify
Terminology:
1 Eutrophication - a process or action of
becoming eutrophic, an enrichment.
To me, this is a dynamic progression
characterized by nutrient enrichment.
Like many definitions, this one is not
precise; stages of eutrophication are
classified as olig-, meso-, and eutrophic
depending upon increasing degree. Just
how a given body of water may be
classified is open to question. It
depends upon whether you look at quiet.
or turbulent water, top or bottom
samples, season of the year, whether
it is a first impression or seasoned
judgement. It also depends upon the
water use in which you are interested,
such as for fishing or waste discharge.
The transitional stages are the major
problems - it is loud and clear to a
trout fisherman encountering carp and
scum.
2 Culture
Fostering of plant or animal growth;
cultivation of living material and
products of such cultivation, both fit.
Some degree of control is implied but,
the control may have limitations as
well as advantages. Human cultural
development has fostered human num-
bers successfully, but, has promoted
rapid degradation of his natural environ-
ment.
3 Nutrients
A component or element essential to
sustain life or living organisms. This
includes many different materials,
some in gross quantities - others in
minor quantities. Deficiency of any
one essential item make living
impossible. Nutrients needed in large
quantities include carbon, hydrogen,
oxygen, nitrogen, phosphorus, sulfur
and silica. N and P frequently are
loosely considered as "the "nutrients
because of certain solubility, con-
version and "known" behavior
characteristics.
4 Algae
A group of nonvascular plants, capable
of growth on mineralized nutrients with
the aid of chlorophyll and light energy -
known as producer organisms, since
the food chain is based directly or
indirectly upon the organic material
produced by algae.
B Now that we have "backed into" the title
words via definitions, some of the
ramifications of eutrophication, nutrient
enrichment, and cultural behavior are
possible.
II NUTRIENTS INTERRELATIONSHIPS
A All nutrients are interchangeable in form,
solubility, availability, etc. There are
no "end" products. We can isolate, cover,
convert to gas liquid or solid, oxidize,
reduce, complex, dilute, etc. - some
time, some place, that nutrient may
recycle as part of cultural behavior.
1 Water contact is a major factor in
recycle dynamics just as water
represents two-thirds or more of cell
BI. ECO. hum. 3. 6.76
34-1
-------
Algae and Cultural Eutrophication
mass and appears to be the medium in
which living forms started. Waste
disposal interrelationships (Figure 1)
suggests physical interrelationships of
soil, air and water. The wet apex of
this triangle is the basis for life. It's
difficult to isolate water from the soil
or atmosphere - water contact means
solution of available nutrients.
WASTi: DISPOSAL
INTERRELATIONSHIPS
ATMOSPHERE
X
WATER
2 Figure 2 takes us into the biosphere (1)
via the soluble element cycle. This
refers mainly to phosphorus interchange.
Phosphorus of geological origin may be
solubilized in water, used by plants or
animals and returned to water. Natural
movement is toward the ocean. Less
phosphorus returns by water transport.
Phosphorus does not vaporize; hence,
atmospheric transport occurs mainly
as windblown dust. Man and geological
upheaval, partially reverse the flow of
phopshorus toward the ocean sink.
SOLUDLE ELEMENT CYCLE
ATMOSPHERE
LITHOSPHERE
HYDROSPHERE
3 The nitrogen cycle starts with ele-
mental nitrogen in the atmosphere.
It can be converted to combined form
by electrical discharge, certain
bacteria and algae, some plants and
by industrial fixation. Nitrogen gas
thus may go directly into plant form
or be fixed before entry. Denitrification
occurs mainly via saprophytes.
(Figure 3) Industrial fixation is a
relatively new contribution to
eutrophication.
NITROGEN CYCLE
-------
Algae and Cultural Eutrophication
Carbon Conversions (Figure 4) show
most of the carbon in the form of
geological carbonate (1) but bicarbonate
and CO readily are converted to plant
cell mass and into other life forms.
Note the relatively small fraction of
carbon in living mass.
CIRCULATION
IN BIOSPHERE
B Nutrient - Growth Relationships
Nutrient cycles could go on, but, life
depends upon a mixture of essential
nutrients under favorable conditions.
Too much of any significant item in the
wrong place may be considered as
pollution. Since toxicity is related to
chemical concentration, time of exposure
and organism sensitivity, too much
becomes toxic. If it happens to be too
much growth, its a result of eutrophication.
'How much' is generally more important
than the 'what'? Both natural and manmade
processes lead to biological conversions,
to pollution, to eutrophication and to
toxicity. Man is the only animal that can
concentrate, speed up, invent, or otherwise
alter these conversions to make a collossal
mess.
1 Life forms have been formulated in
terms of elemental or nutrient com-
ponents many times. The simplest is
C HgO-N. A more complex formula
is C10oS6°80N20 Ca6C17P2CuF2
SiMgMn2K2NaS21Zn. This includes
16 elements. More than 30 have been
implicated as essential and they still
would not "live", unless they were
correctly assembled. Asa nutrient
Mnemonic H. COPKINS - - Mg(r)-
CaFe-MoB does fairly well. It also
indicates Iodine-I, Iron-Fe,
Molybdenum-Mo, and Boron-B that
were not included earlier.
The Law of Distribution states that
"Any given habitat tends to favor all
suitable species - any given species
tends to be present in all suitable
habitats. " Selection tends to favor the
most suitable species at a given place
and time.
Liebigs Law of the Minimum, states
that "The essential material available
in amounts most closely approaching
the critical minimum will tend to be
the limiting growth factor. "
Shelfords law recognizes that there
will be some low concentration of any
nutrient that will not support growth.
Some higher concentration will stimulate
growth. Each nutrient will have some
still higher concentration that will be
bacteriostatic or toxic. This has been
discussed earlier but was considered in
a different manner.
Ill BIO LOGICAL PROGRESSIONS
The biological "balance" appears to be a very
transitory condition in cultural behavior.
Man favors production. A steady state
"balance" does not persist very long unless
energy of the system is too low to permit
significant growth. A progression of species
where each predominent form thrives for a
time, then is displaced by another temporarily
favored group is usual. Yearly events in the
lawn start with chickweed, then dandelion,
plantain, crab grass, ragweed, etc., in
successive predominence. Occasionally,
more desirable grasses may appear on the
lawn. Grass is a selected unstable "culture".
-------
Algae and Cultural Eutrophication
A Figure 3 shows a biological progression (2)
following introduction of wastewater in an
unnamed stream. Sewage or slime bacteria
proliferate rapidly at first followed by
ciliates, rotifers, etc.
THE BIOTA
SEWAGE BACTERIA
NO. PER ml.
300 r-
CILIATES
NO. PER ml. x 1000 ROTIFERS
' &CRUSTACEANS
NO. PER ml.x25,000
200-
Q 100
2 1
24 12
23456789
DAYS
12 24 36 48 60 72 84 96 108
MILES
5. Bacteria thrive and finally become prey of the ciliates, which in turn are food for the rotifers and crustaceans.
B Figure 4 shows another progression of
bottom dwelling larva. Here the sequence
of organisms changes after^wastewater
introduction from aquatic insects to sludge
worms, midges, sow bugs and then to
re-establishment of insects.
THE BIOTA
SLUDGE WORMS
I I
14 12
I 1
I I 7
> 4
DAYS
It 14 31 41 II 11 14
MILES
I
III
Figure 6. The population curve of Figure 7 is composed of a series of maxi—
for individual species, each multiplying and dying off as stream conditions vary.
-------
Algae and Cultural Eutrophication
C Another progression after waste
introduction changes the biota from
an algal culture to sewage moulds with
later return to algal predominence.
"CTOQIO*WFT"CT'" THE BIOTA
24 12
DAYS
12 24 36 48
MILES
60 72 84 96 108
9 Figure /Shortly after sewage discharge, the moulds attain maximum growth.
These are associated with sludge deposition shown in the tower curve. The sludge is
decomposed gradually; as conditions clear up, algae gain a foothold and multiply.
Figures 5, 6, and 7 are shown separately
only because one visual would be unreadable
with all possible progressions on it. There
are progressions for fungi, protista, insect
larvae, worms, fish, algae, etc. Each
species will perform as it may perform.
It it cannot compete successfully, it will
be replaced by those that can compete
under prevailing conditions at the time.
Conditions shift rapidly with rapid growth.
IV The interactions of bacteria or fungi and
algae (Figure 8) are particularly
significant to eutrophication.
A The bacteria or the saprophytic group
among them tend to work on preformed
organic materials - pre-existing organics
from dead or less favored organisms.
Algal cells produce the organics from
light energy chlorophyll and mineralized
nutrients. This is a happy combination
for both: The algae release the oxygen
for use by the bacteria while the bacteria
release the CO needed by the algae.
Since the algae also acquire CO_ from
the atmosphere, from wastewater and
from geological sources, it always ends
up with more enrichment of nutrients in
the water - more enrichment means more
growth and growing organisms eventually
clump and deposit. The nature of growth
shifts from free growth to rooted forms,
starting in the shallows. Another
progression occurs (Figures 9 and 10).
It is this relationship that favors profuse
nuisance growth of algae below significant
waste discharges. There is a tremendous
pool of carbon dioxide available in
geological formations and in the air.
Transfer to the water is significant and
encourages algal productivity and eventual
eutrophication of any body of water, but,
this does not occur as rapidly as when the
water body is super saturated with CO_
from bacterial decay of wastewater
discharges or benthic deposits from them.
-------
AIgae and Cultural Eutrophication
NATION
DEAD
ALGAE
SEWAGE
DEAD
BACTERIA
PROFUNDAL
PHOTOSYNTHESIS
-------
CHARAPHYTES
LADOPHORA
Nitrogen and phosphorus are essential
for growth. They also are prominently
considered in eutrophication control.
Algal cell mass is about 50% carbon,
15% nitrogen and approximately 1%
phosphorus not considering luxury uptake
in excess of immediate use. Phosphorus
is considered as the most controllable
limiting nutrient. It's control is com-
plicated by the feedback of P from benthic
sediments and surface wash. Phosphorus
removal means solids removal. Good
clarification is essential to obtain good
removal of P. This also means improved
removal of other nutrients- a major
advantage of the P removal route. Both
N & P are easily converted from one form
to another; most forms are water soluble.
V SUMMARY
Control of eutrophication is not entirely
possible. Lakes must eventually fill with
benthic sediments, surface wash and
vegetation. Natural processes eventually
cause filling. Increased nutrient discharges
from added activities grossly increase filling
rate.
A We produce more nutrients per capita per
day in the United States than in other
nations and much more today than 100
years ago. More people in population
centers accentuate the problem.
B Technology is available to remove most
of the nutrients from the water carriage
system.
1 This technology will not be used unless
water is recognized to be in short
supply.
2 It will not be used unless we place a
realistic commodity value on the water
and are willing to pay for cleanup for
reuse purposes.
C Removal must be followed by isolation of
acceptable gases to the atmosphere
acceptable solids into the soil for reuse
or storage. Water contact cannot be
prevented, but it must be limited or the
enrichment of the water body is hastened.
-------
Algae and Cultural Eutrophication
REFERENCES
This outline was prepared by F. J. Ludzack,
1 A collection of articles on the Biosphere Chemist, National Training Center,
Sci. Am. 223:(No. 3). pp. 44-208. MOTD, OWPO, USEPA, Cincinnati, Ohio
September 1970. 45268.
2 Bartch, A.E. and Ingram, W.M. Descriptors: Algae, Eutrophication
Stream life and the Pollution Environ-
ment. Public Works 90:(No. 7) 104-
110. July 1959.
34-8
-------
CONTROL OF PLANKTON IN SURFACE WATERS
I PHILOSOPHICAL CONSIDERATIONS
A Plankton growths are as natural to aquatic
areas as green plants are to land areas
and respond to the same stimuli.
B Man is currently harnessing plankton forms
to accomplish useful work.
1 For generation of oxygen
a Stabilization of waste waters in
oxidation ponds
b Oxygen recovery from CO2 in space
travel
2 For augmentation of food supply
a Fish ponds
b Nitrogen fixation in rice growing
c Harvesting of algae for direct use
as food
A. growing knowledge of the nutrient re-
quirements of plankton organisms will
lead to a more enlightened approach to
ways and means of controlling their growth
when desirable.
II CLASSICAL METHODS OF CONTROL
A Chemical
1 Inorganic
a Copper sulfate is used most exten-
sively. It is most effective in pre-
ventive rather than curative treat-
ment. It has long lasting effects in
soft waters but is short-lived in hard
waters due to precipitation of the
Cu++ as a basic carbonate. The pre-
cipitated material accumulates in
bottom muds and is toxic to certain
benthal forms, some of which serve
as important fish food.
Dosages are normally based on the
alkalinity of the water. When alka-
linity is < 40 mg/1, the recommended
dosage is 0. 3 mg/1 of CuSO^ 5H2O
in total volume of water. When
alkalinity is > 40 mg/1, recommended
dosage is 2. 0 mg/1 in surface foot
of water.
b Chlorine is preferable to copper
sulfate in the control of certain
forms of algae. However, it is
difficult to apply in most instances
and is very short-lived due to photo
catalytic decomposition of HC1O —
HC1 + O.
Organic - Numerous organic compounds
have been evaluated, especially in re-
lation to control of blue-green algae.
"Phygon", 2, 3-dichloronaphthoquinone,
has been field tested but is too specific
in its action for general application.
Ill ECOLOGICAL CONTROL
A Theory - Ecological control is based upon
the principle of preventing or restricting
growth by limiting one or more of the
essential requirements. This is an ap-
plication of Liebig's Law of the Minimum.
The logical avenues of control are as
follows:
1 Elimination of light
2 Limiting nutrient materials
B Light - Many cities have solved the prob-
lem of plankton growths by the use of
covered reservoirs, underground and
elevated. Concurrently, they have solved
contamination problems created by birds
and atmospheric fallout. In open reservoirs,
BI. MIC. coh. lOb. 6.76
35-1
-------
Control of Plankton in Surface Waters
some success has been obtained by
limiting light through the use of a film of
activated carbon.
C. Nutrients - Since phytoplankton (algae)
serve as the base of the food chain, know-
ledge concerning their nutrient require-
ments is required for ecological control,
when limitation of light is impractical.
The nutrient requirements of phytoplankton
are as follows:
1 Nature of - The major nutrients are:
a Carbon dioxide
b Nitrogen - ammonia and nitrates
(also
c Phosphorus - phosphates.
Minor nutrients are:
d Sulfur - sulfates
e Potassium
f Trace inorganics - magnesium, iron,
etc.
g Trace organics -vitamins, amino
acids
2 Sources of - See Fig. 1
a Atmosphere
b Groundwater - springs
c Storm water or surface runoff
d Waste waters - domestic sewage and
industrial wastes.
3 Significance of each major nutrient
a Carbon dioxide - See Fig. 2
Usually present in great abundance.
Rapidly replenished from atmosphere
and bacterial decomposition of organ-
ic matter. No reasonable possibility
of human control. Nature, however,
does provide some control through
elevated pH levels if carbon dioxide
becomes depleted rapidly.
Nitrogen - Like land plants, certain
algal forms prefer nitrogen in the
form of NH3(NH4"f") and others prefer
it in the form of NC>3~. Both forms
often become depleted during the
growing season and reach maximum
concentrations during the winter
season. A level of 0. 30 mg/1 of
inorganic nitrogen at the time of the
spring turnover is considered to be
the maximum permissible level .
All natural surface waters are
saturated with nitrogen gas. This
serves as a source of nitrogen for
bacteria and algae capable of fixing
it.
Phosphorus - A key element in all
plant and animal nutrition. The
critical level is considered to be
0.01 mg/1 at the time of the spring
turnover . Phosphorus is needed
to sustain nitrogen fixing forms .
D Practice Of
1 Exclusion of light - Practice well
established in distribution system
reservoirs but impractical on large
storage reservoirs.
2 Nutrient limitation
a Control of surface run-off quality
1) Agricultural
2) Other
b Diversion of sewage plant effluents
1) Madison, Wisconsin
2) Detroit Lakes, Minnesota
3) Pending - State College, Pa.
c Tertiary treatment of sewage
1) Nitrogen removal - Because of
the several forms is very difficult.
35-2
-------
ATMOSPHERE
STORM
WATER
WASTE
WATER
GROUND
WATER
(SPRINGS)
(SURFACE A (DOM. SEW.
RUN-OFF )/^IND. WASTE
LAKE
OR
RESERVOIR
FIG. I SOURCES OF FERTILIZING
MATERIALS OF CONCERN
IN SURFACE WATERS
o
JO
o
I—'
o
p
FT
O
o
fD
P_
iS"
I'-i
-------
n
o
ATMOSPHERE
&
o
ORGANIC
CARBON
^ HCO-
o
3
3
C
o
(D
P
0)
1
en
FIG. 2 CARBON DIOXIDE - BICARBONATE - CARBONATE - HYDROXIDE
RELATIONSHIPS IN NATURAL WATERS
-------
Control of Plankton in Surface Waters
Also, may be unsuccessful in
control unless phosphorus is con-
trolled, too, because of nitrogen
fixing forms.
2) Phosphorus removal - Phosphorus
can be effectively removed by
coagulation methods employing
lime, alum or ferric salts. It
is expensive and no one has
proven its value beyond laboratory
experiments.
d By Biological Engineering
Laboratory studies have shown that
effluents essentially free of plant
fertilizing elements can be produced
by biological treatment of wastes
with proper ratios of C to N and P.
3 Experiences
a Madison
b Detroit Lakes
c State College
d Lake Winnisquam, N. H.
E Practical Aspects
1 Diversion
2 Nutrient control
REFERENCE
Mullican, Hugh F. (Cornell Univ.)
Management of Aquatic Vascular Plants
and Algae, pp. 464-482. (in Eutro-
phication; Causes, Consequences, and
Correction. Nat. Acad. Sci.) 1969.
This outline was prepared by C. N. Sawyer,
Director of Research, Metcalf & Eddy
Engineers, Boston, Massachusetts.
Descriptors: Algicides, Eutrophication
35-5
-------
CONTROL OF INTERFERENCE ORGANISMS IN WATER SUPPLIES
I NECESSITY FOR DATA
A Information on the number, kinds, and
effects of interference organisms in a
particular water supply is essential for
determining adequate control measures.
B Collection of the biological data should be
on a regular routine basis.
C Interpretation of data requires information
on relationship of number and kinds of
organisms to the effects produced.
D It is generally more satisfactory to an-
ticipate and prevent problems due to these
organisms than it is to cope with them later.
II CONTROL IN RAW WATER SUPPLY
A Use of algicides
1 Application of an algicide is to prevent
or destroy excessive growths of algae
which occur as blooms, mats or a high
concentration of plankton.
21 Algicide may be applied to control even
low concentrations of certain algae such
as Synura.
3 Copper sulfate is the only algicide in
common use at present.
a Application may be by dusting,
spraying or dissolving from a porous
container over all or part of the water
surface, or by continuous feeding
of the algicide at the intake of the
reservoir or pre-treatment basin.
b Effective dosage depends upon the
Alkalinity and pH and temperature
of the water and the amount and
kinds of algae to be controlled.
Bartsh states that the following
arbitrary dosages have been found
to be generally effective and safe:
M.O. alkalinity > 50 p.p. m. =
2 p. p. m. in the surface foot of
water only (5.4 pounds per acre).
M. O. alkalinity < 50 p. p. m. = 0. 3
p. p. m. in total volume of water
(0. 9 pound per acre foot).
c Application of copper sulfate should
be limited to the minimum effective
dosage because of its corrosive
properties, and its toxicity to fish and
other aquatic animals.
4 Other algicides
a Promising types include inorganic
salts, organic salts, rosin amines,
antibiotics, quinones, substituted
hydrocarbons, quaternary ammonium
compounds, amide derivatives and
phenols. Cuprichloramine which is
a combination of copper, chlorine and
ammonia, and also chlorine dioxide
have shown promise as general algi-
cides.
b For domestic water supplies they will
have to be not only economically fea-
sible but nontoxic to animal life and
to green plants other than algae.
c Due to higher costs they will prob-
ably be used only when adequate plank-
ton and algal records are kept, which
would permit early localized treat-
ment.
d Algicides selectively toxic to the
particular algae of greatest signifi-
cance would be useful.
5 Mechanical removal or spreading out
to permit rapid drying may be the sim-
plest way of handling massive growths
which are detached and washed ashore.
6 Turbidity due to silt keeps down the
plankton population. In shallow reservoirs,
fish which stir up the bottom mud will
aid in keeping turbidity due to silt high.
7 Provisions for keeping the amounts of
nutrients to a minimum may be em-
phasized more in the future.
8 For new reservoirs, clearing the site
BI. MIC. con. 6b. 6.76
36-1
-------
Control of Interference Organisms in Water Supplies
of vegetation and organic debris before
filling will reduce the algal nutrients.
Steep rather than gentle slopes will
reduce the areas which allow marginal
growths to occur.
Ill CONTROL IN TREATMENT PLANT
A Coagulation and sedimentation
1 When well regulated they often will re-
move 90 per cent or more of the plank-
ton.
2 With low plankton counts, a coagulant
aid may be required.
3 Frequent removal of sludge from the
basins, especially during the warm
seasons may help to reduce tastes and
odors originating from decomposing
organic sediment.
B Sand filtration
1 Both slow and rapid sand filters tend to
reduce the plankton count of the effluent by
90 per cent or more, when well regu-
lated.
2 For rapid filters, accumulated plankton
can be removed or reduced by surface
scraping and by back washing.
C Micro-straining
1 This involves the passing of the water
through a finely woven fabric of stain-
less steel. All but the smaller plankton
organisms tend to be removed from the
water. It is being used in some treat-
ment plants in England and elsewhere.
D Activated carbon
1 The slightly soluble, organic, taste
and odor compounds tend to be readily
adsorbed by the activated carbon. It
is probably most often applied prior to
coagulation, but may be used prior to
filtration or in the raw water.
E Chlorination
1 Treatment with chlorine is practiced
primarily to destroy pathogenic organ-
isms. The dosages commonly used are
toxic also to many algae and to some of
the other groups of aquatic organisms.
However, dead as well as living organ-
isms are often capable of causing tastes
and odors and of clogging filters.
The depth and position of the intake for
entrance of raw water into the treatment
plant may determine the kinds and amount
of plankton which will be drawn into the
plant. Plankton algae generally are more
concentrated near the surface of the water
in lakes and reservoirs.
IV CONTROL IN DISTRIBUTION SYSTEM
A Maintenance of a chlorine residual con-
trols the chlorine sensitive organisms.
B Other pesticides such as cuprichloramine
have been used in attempts to control the
resistant organisms such as worms,
nematodes and copepod eggs.
C Flushing of infested portions of the system,
especially dead ends may be practiced.
D Covering of treated water reservoirs to
prevent the entrance of light will stop the
growth of algae.
E Organisms associated with pipe corrosion
are probably the most active when the water
itself is corrosive.
F Mechanical cleaning of the distribution
system may be an effective but expensive
method of reducing infestations of attached
organisms.
V SUMMARY
A Adequate control is dependent upon ade-
quate procedures for detecting and record-
ing of organisms.
B Control may involve the following:
1 Use of an algicide or pesticide.
36-2
-------
Control of Interference Organisms in Water Supplies
2 Mechanical cleaning of distribution
lines, settling basins, and filters,
screens, intake channels and reservoir
margins.
3 Modification of coagulation, filtration,
chemical treatment or location of raw
water intake.
4 Use of adsorbent, such as activated
carbon, for taste and odor substances.
5 Modification of reservoir to reduce the
opportunities for massive growths.
a By covering treated water reservoirs
b By increasing the depth of the water
c By eliminating shallow marginal
areas
By reducing the amount of fertilizing
nutrients entering the reservoir
By encouraging a balanced develop-
ment of the aquatic organisms
REFERENCE
Mackenthun, Kenneth M. The Practice of
Water Pollution Biology. FWPCA.
U.S. Dept. of Interior, Washington, DC.
1969.
Smalls, I.C. and Greaves, G.F., A Survey
of Animals in Distribution Systems.
Water Treat. Exam. 17 (3): 150-186.
1968.
Houghton, G. U. , Observations on the Asellus
Problem in South Essex. Water Treat.
Exam. 17 (2): 127-133. 1968.
Bellinger, E. C., A Key to the Identification of
the More Common Algae Found in Water
Undertakings in Britain. Water Treat. Exam.
18 (2): 106-127. 1969. (see also 23 (1)
76-131. 1974)
Bays, L. R. , Pesticide Pollution and the
Effects on the Biota of Chew Valley Lake.
Water Treat. Exam. 18 (4): 295-326. 1969.
Blogoslawski, Walter J. and Rice, Rip G..
Aquatic Applications of Ozone. International
Ozone Institute. Syracuse Univ. 1975.
This outline was prepared by C. M. Palmer,
former Aquatic Biologist, Biological Treat-
ment Research Activities, Cincinnati Water
Research Laboratory, FWPCA, SEC.
Descriptor: Nuisance Organisms
36-3
-------
THE BIOLOGY OF PIPES, CONDUITS, AND CANALS
I INTRODUCTION
Water moving in man made structures of
metal and concrete offers another niche
for over 100 types of aquatic organisms
from protozoa, to five centimeter clams.
Unfortunately these structures are
planned, constructed, and managed by
people who are unaware of the biolog-
ical potential for mischief and this be-
comes translated into often severe
economic liabilities.
II CRUSTACEA
A Copepods
Often appear in finished water and clear-
wells, because the minute eggs pass
rapid sand filters.
B Isopods
Are often present in numbers up to 100
per meter of conduit. Their presence
may go undetected unless special
sampling procedures are used, such as
foam plugs sent hydraulically through
a. line with a sieving device at the other
end to capture the dislodged organisms.
In England, where the problem appears tc
be more acute, it is associated with sur-
face water sources and rapid sand filters.
Apparently only a chance introduction of
an individual is needed, then populations
propagate within the mains and smaller
lines.
Ill MOLLUSCS
Bivalves (clams and mussels) are often
more spectacular when invading a water
distribution system because of their shell
size and greater biomass.
A Life History
The problem here relates to the "D"
stage larvae (see Fig. 1) or veliger
(around 200 microns in size) which is
free living and thereby passes screens
and obstructions along with the water
mass. The adults live in or on the
substrate and during breeding periods
billions of these tiny veligers are
discharged into the water currents.
All hydro installations thereby are
very vulnerable to an infestation of
clams.
B Veliger to Byssiger
Notice in figure one how the larval
mollusc changes from a swimming
and/or floating plankter to a byssus
attached benthic form. This life
history (shared by none of our native
bivalves) graphically demonstrates
how the numerous veligers in the
water are drawn in with the intake
water and dispersed through the system.
The transitional stage, the pediveliger,
can opt for another substrate if the
first is unsuitable, for it still retains the
velum for free movement while having
a ciliated notched foot for climbing and
exploring the substrate. When the velum
is finally lost as development proceeds
the byssiger can still explore about by
foot while retaining elastic anchored life
lines. A study of this figure explains
the severe mechanical problem in stopping
water by heavy shelled adults.
C Pest Species
The worst are usually exotic, that is
imported, and exotics are nearly always
bad whether it be plants or animals.
1 Dreissena polymorpha the Zebra Clain.
Not yet in North America but has
created many problems in Europe where
it took over a century to spread.
2 Corbicula manilensis the Asian Clam.
or Good Luck Clam. (Figures 2 and 3).
Initially it became a problem in the
40's in California, and now it is found
BI. MIC. con. 13. 3.80
37-1
-------
VELIGER
PEDIVELIGER BYSSIGER
BENTHIC
Figure 1 D-Stage
Bivalve Larval Stages (app. 200 microns)
Figure 2
Corbicula or Exotic Asian Clam
Approximately 6 cm maximum size. Notice
serrated "teeth".
Figure 3
Corbicula or Exotic Asian Clam
Approximately 6 cm maximum size. Notice
heavy corrugated outer shell.
37-2
-------
The Biology of Pipes. Conduits, and Canals
D
in most North American drainage
systems. Literature on this species
is voluminous. It has been a severe
pest in TVA steam plants and numerous
water diversion schemes. Most
probably it was introduced through
immigrants from Canton, China. In
its native range it is of value as a
commercial food species.
3 Limnoperna fortune!
A serious pest in Hong Kong water
supplies.
4 Modiolus striatulus
A serious pest in Calcutta water
supplies.
As Morton points out these species are
problems in water supplies and distribu-
tion systems because they are/or have a
1 Opportunist
2 Grow fast
3 Long breeding season
4 High reproductive potential
5 Free swimming larval phase (the
veliger).
6 Quick to colonize all available
substrates.
E Treatment and prevention has largely
(and successfully) been limited to
chlorine.
IV Pipe Ecology
A pipe is simply a place to live.
A Habitat
Even under great velocities a pipe's inner
surface offers a place of attachment.
Rough surfaces afford micro-habitats.
B Niche
Even though potable water may be very
low in nutrients and particulate organic
matter, the constant velocity makes it
a rich food supply. Predators may be
completely absent.
C It may be dark inside but a link to the
outside photosynthetic world of food
plants and decomposing bacteria
(bacteria are food to a variety of
pipe dwelling animals) is in constant
motion.
V In conclusion it is no surprise
to biologists to discover a variety and
abundance of organisms (micro and
macro in size) well adapted to living in
just about any pumped water supply,
even when lines are subject to
chlorine.
REFERENCES
1 Morton, Brian. The Colonization of
Hong Kong's Raw Water Supply System
by Limnoperna fortunei. (Dunker 1857)
(Bivalvia; Mytilacea) from China.
Malacol. Rev. 8:91-105. 1975.
2 Clarke, K. B. The Infestation of Water-
works by Dreissena polymorpha. a
freshwater mussel. J. Inst. Water Engrs.
6:370-379. 1952.
3 Sinclair, Ralph M. Annotated Bibliography
of The Exotic Bivalve Corbicula in North
America. Sterkiana 43:11-18. 1971.
Mattice, J. S.
Newsletter .
and Tilly, L. J. Corbicula
Envir. Sci. Div., Oak Ridge
National Laboratory, Oak Ridge, TN 37830.
Issued irregularly, names added to mailing
list by request to Dr. Mattice at address
above. Contains summary s of ongoing
research on control of Corbicula.
Smalls, I.C. and Greaves, G. F. A Survey
of Animals in Distribution Systems. Water
Tr. and Exam. 17:150-186. 1968
(Thirty six water supply systems were
examined taking flush samples from the
distribution system. Over 100 types of
animals were taken. )
This outline was prepared by R. M. Sinclair,
National Training Center, MOTD, OWPO,
USEPA, Cincinnati, Ohio 45268.
Descriptors: Molluscs, Isopods, Fouling,
Nuisance Organisms, Pipelines
37-3
-------
SAN FRANCISCO EXPERIENCE WITH NUISANCE ORGANISMS
I INTRODUCTION
In order to have a clear picture of the
problems in the San Francisco Water Supply
system by nuisance organisms an understand-
ing of the basic system should be helpful.
The largest quantity of water is produced in
the Hetch Hetchy watershed, located in
Yosemite National Park. This water is
transmitted some 150 miles by tunnel and
pipe to the San Francisco Bay Area, where
the water not sold enroute is discharged
into Crystal Springs Reservoir. From
Crystal Springs Reservoir, water either
flows by gravity to the lower elevations
of the San Francisco Peninsula and the City
proper, or is pumped to nearby San Andreas
Reservoir. This latter reservoir supplies
the higher areas. The capacity of Hetch
Hetchy reservoir is 117 billion gallons,
Crystal Springs 22. 5 billion gallons and
San Andreas 6 billion gallons. All water
flowing from the local reservoirs is chlor-
inated and fluoridated along with the custom-
ary copper sulphate treatment for algae
control of surface waters.
Two other parts of the system should be
mentioned, although these waters have not
been involved particularly with nuisance
organisms. On the East Side of San Fran-
cisco Bay the San Francisco Water Depart-
ment owns and operates two large reservoirs,
San Antonio and Calaveras. The water from
these reservoirs passes through the 80 m. g. d.
dual media, Sunol Valley Water Filtration
Plant capable of complete treatment.
All watersheds tributary to Crystal Springs
and San Andreas Reservoirs are owned by
the Water Department and only seven water-
shed keepers live on the 25, 000 acres. The
other reservoirs are quite remote and human
activity is small compared to'the area
involved.
The distribution and transmission system
within San Francisco consists of eighteen
pressure zones; ten large covered reservoirs
with capacities ranging from 2. 5 to 176. 7
million gallons; 1, 163 miles of pipe and the
usual pumping stations, valves, etc. The
goal of this presentation is to describe the
problems caused by nuisance organisms in
the San Francisco system and briefly relate
what was done about them, if anything.
The following described outbreaks of nuisance
organisms occurred during the period 1934
to the present.
II AQUATIC ACTINOMYCETES
During Spring of 1956 there appeared in the
distribution system increasing incidents of
earthy taste and odor complaints, many by
our staff. Even the management was of the
opinion that the water was becoming poorer
and poorer; so a graduate student in micro-
biology was hired for the summer to investi-
gate the possibility of actinomycetes being the
source. Positive results were obtained from
many samples of water but a definite pattern
could not be established that would implicate
any part of the system.
Before finite data could be established the
need to raise our chlorine residuals to com-
bat persistant coliforms became our over-
whelming problem, and in the course of events
chlorine taste complaints took the place of
earthy and woody complaints. No doubt the
chlorine residuals of lmg/1 and better
distribution maintenance with regards to
water quality were responsible for the control
of these organisms.
Those having complaints of this nature are
referred to the many articles in the Journal
by Professor J. K. G. Silvey and his co-
workers. (1)
III BRYOZOAN
This outbreak occurred during the Spring
of 1956.
BI. MET. con. 6. 6.76
38-1
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San Francisco Experience With Nuisance Organisms
A routine complaint was turned over to the
Department Laboratory for inspection. A
customer had complained that little black
specks were caught in her nylons after
washing. Inspection showed that they were
coming from the tap and flushing of nearby
fire hydrant produced clusters of the black
organisms up to the size of a quarter.
The black specks were identified as
statoblasts of Bryozoan, and Whipples
description of a Brooklyn Water Depart-
ment outbreak in 1897 really shook the staff
up. His description states, "in a number
of instances this material stopped up the
taps, and even large pipes were choked". (2)
Great black masses of these statoblasts
could be imagined blocking our pipes and
valves.
The area for several blocks around was
flushed until no further statoblasts were
observed. In spite of a close inspection
of other parts of the system, including
distribution and impounding reservoirs no
additional organisms were found. In fact
these Bryozoans have never been encountered
again.
In the laboratory, attempts were made to
germinate the statoblasts to no avail and
it was assumed that the organisms were
dead. Several months later a test tube of
statoblasts in water which had laid on a
table formed colonies.
Although the San Francisco Water Supply has
experienced only the one outbreak, Bryozoans
are a common nuisance in water systems.
Prokopovich and Hebert (3) described a
problem in California's Delta-Mendota
Canal and Whipple also described outbreaks
in Hartford, Connecticut and Boston,
Massachusetts.
IV CHLOROPHYTA: BULBOCHAETA AND
SPIROGRYRA
Although plankton net catches from the large
Hetch Hetchy reservoir contain high counts
of Crustacea the reservoir has never
required copper sulphate treatment.
During November 1964 a number of complaints
from the Department wholesale customers
were received, stating water meters were
clogging with a growth. At the time both
Hetch Hetchy and Calaveras Reservoirs
were supplying the Bay Division Lines and
Department personnel jumped to the con-
clusion that the growth must be originating
in Calaveras Reservoir which was not
filtered at this time and routinely needs
copper sulphate treatment. Accordingly,
Calaveras was shut down and all customers
were supplied from Hetch Hetchy, but meters
continued to clog. Further investigations were
made and the trouble traced to the source
which was a short section of the Tuolumne
River where the Hetch Hetchy water ran in
the river a distance of twelve miles before
entering the tunnel and pipe system.
As this section of the system was in the
Yosemite National Park, permission to
treat parts of the river with copper sulphate
was requested of the Department of Interior,
and tests were run at the nearby Moccasin
Fish Hatchery. These tests showed treat-
ment could be effective without killing trout.
Prior to the conclusion of the above tests a
telegram was received from Washington
which read "Technicians this Service and
Bureau of Sport Fisheries and Wildlife
consider knowledge about use of the chem-
ical inadequate at this time to insure pre-
servation of ecological conditions based on
potential threat to the river's native aquatic
organisms and possible fish kill. We
cannot grant approval for this program. "
As the purpose of the treatment was to kill
some of the native aquatic organisms, the
project to copper sulphate the river was
abandoned without argument, but two small
regulating reservoirs were treated.
Luckily the organisms disappeared through-
out the system and have not reoccurred.
Since the above incident, this section of river
has been by-passed by a tunnel and the water
from Hetch Hetchy Reservoir enters the pipe
and tunnel system directly.
38-2
-------
San Francisco Experience With Nuisance Organisms
V HYDROIDES
Within the boundries of the City and County
of San Francisco lies the 2-f billion gallon
Lagana de la Merced or as the Water
Department calls it, Lake Merced.
Lake Merced, formerly connected with the
Pacific Ocean by a Channel which was
closed sometime between 1869 and 1894 is
now a freshwater lake and was used for
domestic water purposes from 1895 to 1932
at which time it was placed on a standby
basis. The lake has characteristic fresh-
water fauna, except for five species of
definitely marine affinities. The organism
which could give trouble in the system if
this source were ever used again is
Cordylophora lacustris (Allman)
(Coelenterata Hydroidea). (4)
Hydroides were first noticed by the author
when the City's boating concessionaire
complained of growths covering the bottoms
of his row boats. This was solved by using
a non-fouling paint, but one cannot help
speculating on the problems which would be
encountered if an earthquake severed the
normal water supply lines to the city, in
which case Lake Merced would be the sole
source until repairs were made.
An experimental microstrainer was installed
to treat water from Crystal Springs Reservoir
in conjunction with coliform investigations in
1963 and after a number of months of operation
hyclroides established themsleves in the tanks.
Although this organism did not cause opera-
tional difficulties, it was unsightly and the
tanks had to be manually cleaned. Strangely,
these organisms have never become
established in the distribution system even
though there are distribution tanks and
reservoirs in the system with approximately
the same light intensity. It can only be
assumed that the chlorine residual is keep-
ing the hydroides from becoming a problem.
VI MYRIOPHYLLUM OR EURASIAN
WATERMILFOIL
Over a number of years this fern like plant
growth has been a problem in a 13. 5 million
gallon open distribution reservoir within the
City of San Francisco. Every two to three
years the growth would be so abundant that
the weed would require harvesting by
dragging large rakes across the reservoir.
Of course, the solution was to clean.line
and roof the reservoir which was done in
1960.
Myriophyllum has now thoroughly established
itself in San Andreas Reservoir and because
of its size, 550 acres, it is impossible to
control it by dragging. The only effective
control has been to lower the reservoir and
let the banks dry out killing the surface
growth but, of course, not the roots and the
following year if the reservoir water level
remains relatively constant the cycle is
repeated.
With the construction of an 80 m. g. d. water
treatment plant employing coagulation, sedi-
mentation and dual media filtration, problems
are anticipated when the stems fragment
break off and either settle in the basins or
mat the filters thus shortening the filter runs.
This will at least transfer the problem from
the water consumer to ourselves. At the
present many consumers find the small fern
like leaves in their tap water and become
most unhappy when told they are not
receiving filtered water and there is nothing
that can be done to resolve the problem;
although if the problem seems severe and
localized, the mains in the area are flushed.
This summer some experiments are to be
performed utilizing a blanket of air bubbles
rising around the intake structure in an
attempt to keep the floating debris from
being sucked into the intake adits.
San Francisco is not alone with this problem
as the Watermilfoil has established itself in
reservoirs throughout the country. The
TV A project has fought the problem for
over ten years. If you are confronted with
this weed and your management asks where
it came from, Smith of the Vector Control
Branch TVA states, "We suspect that the
original TVA milfoil infestation in Peny
River embayment of Watts Bar Reservoir
started either intentionally or otherwise
from a misplaced fish bowl plant. From
such a modest beginning, it thrived but
remained unnoticed until its amazing spread
began to interfere with fishing and boating.
38-3
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San Francisco Experience With Nuisance Organisms
Within a very short time (probably 3 to 5
years) it embraced about 1, 500 acres." (5)
VII PLANKTON
This group of organisms gives trouble in almost
any unfiltered surface supply by being observed
by the consumer as a white swimming speck
in a glass of water; by dying off in the dis-
tribution piping and adding to the organic load
or, as has been found in San Francisco,
protecting coliform bacteria from the action
of chlorine. The author presented a paper
before this Association in 1966 detailing this
problem wherein Cyclops. Daphnia, etc. were
so protecting the coliform bacteria that 5 tubes
positive could be obtained from samples which
had chlorine contact times of 2 hours at a free
residual of 1.4 mg/1. (6)
To the present time this problem continues
and laboratory tests confirm the original
hypothesis. Since the publication of the
original paper, discussions with the operators
of water systems similar to San Francisco's
also support this thinking.
Vlll SLIME ORGANISMS
Hetch Hetchy water began to flow into the San
Francisco Water System in October 1934,
carrying a flow of 45 m. g. d. Part of this
flow, 16 m.g. d., was diverted into a 36-inch
wrought iron pipe that had been laid in 1887.
Three weeks after this diversion the carrying
capacity started to drop off at the rate of 0. 2
m. g. d. After another three week period the
flow decreased from 16. 2 to 13. 6 m. g. d. a
capacity loss of 16 per cent. Tests failed to
indicate any air pockets or other obstructions
along the line and in March 1935 the line was
opened for inspection. A slimy, gelatinous
growth was found, light brown in color
covering the entire inner surface of the pipe
from 1/8 to 1/4 inch thick.
Microscopic examination showed this growth
to contain the iron bacteria Crenothrix
and the sulphur bacteria Beggiatoa.
Experiments were performed utilizing 4-inch
pipes, varying flows and chemical dosages.
Hydrated lime to raise the pH of the water to
10; and copper sulphate treatment did not
produce beneficial results. Treating the
water with l-Ł lb. of ammonia and 6 Ib. of
chlorine per m. g. was effective in controlling
the growth.
A large chlorination plant was then built and
growths have been controlled since by this
treatment with the only change being the use
of chlorine alone. (7, 8) This use of chlorine
alone has been effective probably due to the
higher flows of 100 - 275 m.g. d. now required
by consumption. Generally only a slight
taste or odor of chlorine is encountered.
At least once since the initial start of treat-
ment an outbreak of slime has occurred and this
was caused by lowering the chlorine dosage
below the required level for 100% control.
A visual inspection was made by shutting
down the tunnel system. This inspection
showed strings of mucoid slime hanging
from the tunnel ceiling. Heavy chlorination
cleaned the tunnel and maintenance of . 5 to
. 75 mg/1 chlorine residual keeps the tunnel
system clean of these slime organisms.
IX FRESHWATER SPONGES
During July 1961 water being withdrawn
from San Andreas Reservoir through Outlet
No. 3 had a very objectionable odor. The
outlet system was drained and visual
inspection showed large freshwater sponges
growing on the walls of the 72-inch bitumastic
lined steel pipe upstream from the point of
chlorine injection. None of these growths
could be found downstream from the point
of chlorination but numerous growths could
be found all the way upstream to the adit
shut-off valve. No growths were ever found
on the intake screens.
Microscopic examination showed this growth
to be a freshwater sponge. Because growths
could not be found below the point of chlorine
injection the solution obviously was to move
the point of chlorine injection as far upstream
as possible, namely 1276 feet. Crews brushed
the walls of the pipes free of growths, the
line was flushed and placed back in service.
Funds were budgeted for a new chlorine
station and prior to its being placed into
service the pipeline was again inspected, and
found to have sponge growths, this required
38-4
-------
San Francisco Experience With Nuisance Organisms
another cleaning and the new chlorine
station was then placed in service. No
problems have been encountered since.
Strangely, there are two other outlets from
this same reservoir and neither of these two
have ever been found to have a sponge problem
although all points of chlorine injection
originally were about the same. Possibly
the different velocities in the three lines
could be a factor, but one line has a
greater velocity and the other a lower
velocity.
The author was interested to learn of a
similar outbreak which was observed during
1966 in the St. Louis County Water District.
Those with a particular interest in fresh-
water sponges and the resultant problems
are particularly referred to the article in
the Journal by King, Ray and Tuepker. (9)
This article goes into scientific description
of the freshwater sponge Trochospongilla
Leidyi and their methods of control with
chlorine, and there is no need to repeat
them here.
X SUMMARY
As San Francisco's experience with the
common blue-green and green algae is typical,
this paper has not included any discussion of
these algae. Although the local impounding
reservoirs do have growths which are easily
controlled through the normal bluestone
treatment, in a few instances the more
exotic organisms just vanished before control
methods were instituted.
Operators needing assistance in identification
or additional references are referred to the
work of Ingram and Bartsch '10) as excellent
source material.
Almost all the nuisance organisms encountered
in the San Francisco Water Supply System have
been susceptible to control by chlorination but
the resulting complaints of excessive chlorine
taste must be accepted. These complaints
become less numerous as water users become
accustomed to the chlorinous taste. The
ultimate goal, of course, is filtration and
judicious use of post chlorination.
REFERENCES
1 Silvey, J. K. G. and Roach, A. W.
Laboratory Culture and Odor Producing
Aquatic Actinomycetes. Journal AWWA,
51:20 (January 1959).
2 Microscopy of Drinking Water, by G. C.
Whipple. Revised by G. M. Fair and
M. C. Whipple (4th ed., 1927).
3 Prokopovich, N. P. and Herbert, D. J.
Sedimentation in the Delta Mendota
Canal. Journal AWWA, 57:375
(March 1965).
4 Miller, R. C. The Relict Fauna of Lake
Merced, San Francisco. Sears
Foundation: Journal of Marine Research.
17:375 (November 1958)
5 Smith, Gordon E. Eurasian Watermilfoil
(Myriophyllum spicatum) in the
Tennessee Valley, Paper presented at
the meeting of Southern Weed Con-
vention. Chattanooga, Tennessee.
(January 1962).
6 Tracy, H.W. et. al. Coliform Persistance
in Highly Chlorinated Waters. Journal
AWWA 58:1151 (September 1966).
7 Arnold, G. E. Crenothrix Chokes Conduits.
Engineering News - Record (May 28,
1936).
8 Arnold, G. E. Tesla Portal Chloramination
Station. Water Works and Sewage
(April 1938).
9 King, D. L. et. al. Freshwater Sponges
in Raw-water Transmission Lines.
Journal AWWA 61:473 (September 1969).
10 Ingram, W. M. and Bartsch, A.F.
Operator's Identification Guide to
Animals Associated with Potable Water
Supplies. Journal AWWA 52:1521
(December 1960).
This outline was prepared by Harry W. Tracy,
Manager Purification Division, San Francisco
Water Department.
Descriptor: Nuisance Organisms
38-5
-------
LABORATORY: IDENTIFICATION OF DIATOMS
I OBJECTIVES
A To become familiar with important
structural features of diatoms.
B To learn to recognize some common
forms at sight.
C To learn to identify less common forms
using technical keys.
II PROCEDURE
A Transfer a drop of the water sample con-
taining diatoms to a microscope slide.
Cover with cover glass and observe under
low power (10X) of microscope.
1 Do all of the diatom cells appear to
have the same shape? Do some have
square ends and some rounded ends?
Touch the cover glass with your pencil
several times as you observe through
the microscope and note the relationship
of the two types of ends to one another.
2 Find a place where a round-ended and a
square-ended cell are close together
and observe these under oil power
(90X). The round-ended view is that of
the top or bottom of the diatom cell and
is called the "valve" view. The square
ended view is that of the side of the cell
and is called the "girdle" view.
3 In the valve view note the cross lines
in the wall. In this diatom there are
many fine lines and a smaller number
of coarse lines. The former are present
in all diatoms and are called "striae" or
"striations. " The latter are present
only in some genera of diatoms and are
called "septa, " or in other genera,
"costae. " Which of the two types of
lines are continuous from side to side?
The space left in the center by the in-
terrupted lines is known as a "false
(pseudo) raphe."
4 What is the predominant color of the
diatom? How many plastids? In
diatoms, the identification is based
almost entirely on the characteristics
of the cell wall.
5 Make an outline drawing, at least 3
inches long, of a valve view and a girdle
view of the diatom. Show the markings
in the upper third of each. Label the
striae, septa, and false-raphe. Make
a drawing of what you imagine an end
view or cross (tiansverse) section view
would be like.
6 Using the key, identify your specimen,
listing the alternatives selected.
B Use the key to identify other unknowns as
far as possible, listing the alternatives
selected in the key. Make a sketch of
Navicula and Cyclotella if you identify these
forms.
Ill IMPORTANT TERMS
Capitate - having a known-like end.
Costae - coarse transverse ribs in wall.
False raphe - (see pseudoraphe)
Frustule - the wall of the diatom.
Girdle view - the side view, in which the
diatom appears to have square or blunt ends.
Nodule - a lump-like swelling in the center or
ends of the valve.
Pseudoraphe - a clear space extending the
length of the diatom and bordered on both
sides by striae.
Punctae - the dots which comprise the
striae.
BI.MIC.cla.lab. 9. 6.76
39-1
-------
Laboratory: Identification of Diatoms
Raphe - a longitudinal line (cleft) bordered on
both sides of striae.
Septa - a self-like partition in the diatom,
appearing often as a coarse line.
Striae - fine transverse lines especially
evident in the valve view.
Valve view - the top or bottom view, in which
the diatom has rounded ends, or is circular
in outline.
REFERENCES
1 Boyer, C. S. The Diatomaceae of
Philadelphia and Vicinity. J. B. Lippin-
cott Co. Philadelphia. 1916. p 143.
2 Boyer, C.S. Synopsis of North America
Diatomaceae, Parts I (1927) and II
(1928). Proceedings of the Academy
of Natural Sciences; Philadelphia.
3 Elmore, C.J. The Diatoms of Nebraska.
University of Nebraska Studies, 21:22-
215. 1921.
4 Hohn, M. H. A Study of the Distribution
of Diatoms in Western New York State.
Cornell University Agricultural Experi-
mental Station. Memoir 308, pp 1-39.
1951.
5 Pascher, A. Bacillariophyta (Diatomeae).
Heft 10 in Die Susswasser-Flora
Mitteleuropas, Jena. 1930. p 466.
6 Patrick, R. A Taxonomic and Ecological
Study of Some Diatoms from the
Pocono Plateau and Adjucant Regions,
Farlowia. 2:143-221. 1945.
7 Smith, G. M. Class Bacillariophyceae.
Freshwater Algae of the United States,
McGraw-Hill Book Co. New York.
pp 440-510 2nd Ed. 1950.
8 Tiffany, L. H., and Britton, M. E. Class
Bacillariophyceae. The Algae of
Illinois, University of Chicago Press.
pp 214-296. 1952.
9 Ward, H. B., and Whipple, G. C. Class I,
Bacillariaceae (Diatoms). Freshwater
Biology, J. Wiley & Sons. New York.
pp 171-189. 1948.
10 Weber, C.I. A Guide to the Common
Diatoms at Water Pollution Surveillance
System Stations. USDI. FWPCA,
Cincinnati, OH. 1966.
11 Whipple, G. C., Fair, G. M., and Whipple,
M. C. Diatomaceae. Microscopy of
Drinking Water. Chapter 21, 4th ed.
J. Wiley and Sons, New York. 1948.
This outline was prepared by L. G. Williams,
Aquatic Biologist, Formerly with Research
and Development, Cincinnati Water Research
Laboratory, FWPCA, SEC.
Descriptors: Diatoms, Analytical Techniques
39-2
-------
PREPARATION OF PERMANENT DIATOM MOUNTS
I The identification of many diatoms to
genus and all diatoms to species requires
that the cells be free of organic contents.
This is necessary because the taxonomy of
the diatoms is based on the structure of the
frustule (shells) of the organisms and many
features are masked by the presence of
organic materials which may remain inside.
It is also necessary that at least 1000X
magnification (oil immersion) be used to
detect the structural features used in
identification. No simple procedure for the
accurate routine counting of diatoms has yet
been developed.
II MATERIALS NECESSARY
A Sample Concentration
1 Centrifuge (such as Universal DU)
2 100 ml centrifuge tubes
3 Membrane filter apparatus
4 Vacuum
B Slide Preparation
1 Slides. 1X3 inch, frosted-end
2 Cover glasses, circular #1, 18mm,
0. 13 - . 16 mm thick
3 Resinous mounting medium (such as
Harleco microscope mounting medium)
4 Hot plates
a 1800 p
b 7000 F
5 Disposable pipettes
6 3X6X1/4 inch steel plate
E PROCEDURE
A The volume of sample needed will vary
according to the density of diatoms and
silt, and only with experience can the
correct sample size be determined. In
most cases, 100 ml will be sufficient.
1 Spin 100 ml at 1000 G for 20 minutes.
2 Withdraw the supernatant liquid with
an aspirator, being careful not to
disturb the concentrate at the bottom
of the centrifuge tube. (Draw off all
but 2-3 ml.)
3 Transfer the concentrate to a labelled
10 ml disposable vial. Label the vial
with a magic marker, diamond pencil,
or "time" label.
4 If the sample has been preserved with
formalin, or contains more than
1.0 gram per liter dissolved solids,
it will be necessary to wash the
concentrate with distilled water. In
this case, transfer the entire concen-
trate to a 15 ml centrifuge tube.
Dilute to 15 ml with distilled water,
making certain that the sample is well
mixed. Spin for 10 minutes at full
speed in a clinical centrifuge. With-
draw the supernatant liquid, and refill
with distilled water. Spin again for 10
minutes. Withdraw the supernatant
liquid as before, return the concentrate
to the rinsed vial in 2-3 ml of distilled
water and proceed with the mounting.
5 If more than 200 ml of sample must be
centrifuged to obtain sufficient material
to prepare a diatom slide, concentrate
the diatoms by filtering the sample
through a 1.2 micron pore diameter
membrane filter. Transfer the filter
to a 15 ml centrifuge tube, and dissolve
with 90% acetone. Centrifuge 10
minutes (full speed) and decant with an
aspirator. Refill with 90% acetone,
BI. MIC. enu. lab. 5b. 6. 76
40-i
-------
Preparation of Permanent Diatom Mounts
agitate, and spin again for 10 minutes.
Repeat until three fresh acetone washes
have been used. Replace the acetone
with 2-3 ml of distilled water and
transfer to a labelled vial as described
in #4.
B If the loss of minute forms in supernatant
is suspected, spin 100 ml at 1000 gs in
a batch centrifuge for as long as may be
necessary, then proceed as below.
C Mounting
1 Heat the hot plates to the prescribed
temperatures.
2 Place one cover glass on the steel plate
for each sample.
3 Place the steel plate on the 18QOF hot
plate.
4 Transfer a drop of sample to a cover
glass.
5 Allow the water to evaporate (caution:
do not allow it to boil.)
6 Continue to add more sample until a
thin layer of material is noticeable on
the dry cover glass, or until all of the
concentrate has been used. This step
is especially critical, and can be
learned only by trial and error.
7 Transfer the steel plate to the 700op
hot plate for 20-30 minutes. (The
plate should be hot enough to incinerate
paper.)
8 While the material is on the high
temperature hot plate, label the
microscope slides (use a #2 pencil
or a fine point drawing pen); place
them on the low temperature hot plate,
which now has been reset to approxi-
mately 2750 p.
9 Place a drop of mounting resin on the
microscope slides and allow the solvent
to evaporate.
10 When the incineration of the material
on the cover glasses is complete,
transfer the cover glasses, while still
hot, to the mounting medium.
11 Allow the resin to penetrate the
frustules (1-2 minutes).
12 Remove the slide, place it on a cool
desk top, and press the cover glass
lightly with a pencil eraser for a few
seconds. The medium will harden in
5-10 seconds.
13 Scrape off the excess resin with a
razor blade.
D The preparation is now ready for exam-
ination under an oil immersion objective.
ACKNOWLEDGEMENT:
Certain portions of this outline contains
training material from a prior outline by
M.E. Bender.
This outline was prepared by Dr. C.I.
Weber, Chief, Biological Methods Section,
Analytical Quality Control Laboratory,
1014 Broadway, Cincinnati, OH 45202.
Descriptors- Diatoms, Analytical
Techniques
40-2
-------
LABORATORY: IDENTIFICATION OF ANIMAL PLANKTON
I INTRODUCTION
A The great majority of organisms commonly
encountered in plankton analysis work are
plants or at least plant-like (holophytic).
Animals, however, (holozoic or nonchloro-
phyll bearing forms) are an important part
of the community, and the ability to recog-
nize them may be quite important.
B Many animals are soft bodied and so are
best observed in the living condition, as
they shrink and become otherwise distorted
on preservation. There are consequently
many which will not be available in a
suitable form for the following exercise.
Only such forms will be dealt with as can
readily be obtained alive, or which retain
essential characteristics on preservation.
Examine your specimen carefully,
then read the first couplet of
statements in the key (la and Ib).
Since the specimen is large enough
to see, it obviously could not be the
object of statement la. Therefore
due to the nature of the key (as
explained in the second paragraph of
the introduction) the second alternative
(lb) must apply. This alternative
instructs us to proceed to couplet 2.
From here on, follow from couplet
to couplet, considering each couplet
by itself, until a final selection leads
to a name. If this name or couplet
is, followed by another couplet
number, this means that the group
named is further subdivided.
II OBJECTIVES
A To Study the nature and use of a key for
identifying organisms
B To Introduce the Beginners to the Use of
the Microscope
C To Learn to Recognize Basic Animal Types
D To Identify Animal Plankton Species as
Available, and to Become Familiar with
the Literature
III PROCEDURE
A The Use of the Biological Key
1 Obtain a "Basic Invertebrate Collection"
from the instructor.
2 Select a specimen designated by the
instructor, and turn to the "Key to
Selected Larger Groups of Aquatic
Animals. "
Identify the other specimens in the
Basic Invertebrate Collection in the
same way.
Carry the identification further, to
genus and species if possible, in one
or more of the more detailed keys
listed at the end of the "Key to Selected
Larger Groups of Aquatic Animals. "
B The Use of the Microscope
1 Obtain preliminary information from
the instructor as to how to set up and
operate the instrument.
2 Place a prepared slide of a printed letter
on the stage and observe it successively
under low (100X) and high (45X) powers.
When the letter is right side up to you,
how does it appear through the microscope?
3 Place a prepared slide of a micro-
crustacean on the stage and identify it
using the "Key to Selected Larger Groups
of Aquatic Animals. " Continue your
BI.MIC.cla.lab.5c.6.76
41-1
-------
Lab oratory: Identification of Animal Plankton
identification as far as possible using
Eddy and Hodson's "Taxonomic Keys. "
Prepare a "wet mount" under the
direction of the instructor and identify
the organism. Confirm your identifica-
tion in one or more of the technical
reference books available.
Identify each of the specimens in the
reference collection as to phylum and
class, and then genus and species if
possible (do not spend undue time on the
species without assistance).
Make a flash card sketch of at least
one organism of each phylum observed
as an example of a type.
D Examine the living material provided.
Sketch and identify animal forms
encountered as far as time permits.
Can you draw any conclusions as to the
types of animal life found in the various
habitats indicated?
This outline was prepared by H.W. Jackson,
former Chief Biologist, National Training
Center, and revised by R. M. Sinclair,
Aquatic Biologist, National Training Center,
MOTD, OWPO, USEPA, Cincinnati, Ohio
45268
Descriptors:
Zooplankton
Analytical Techniques,
41-2
-------
LABORATORY: PROPORTIONAL COUNTING OF PLANKTON
I OBJECTIVE
To learn and practice the techniques of
proportional counting of mixed plankton
samples.
II MATERIALS
A Several plankton samples, each con-
taining a number of plankton forms.
B Class slides, cover slips, and dropping
pipets.
Ill PROCEDURES
A Make an ordinary wet mount of the
sample provided.
B Scan the slide. Identify and lists all
types of plankton present.
C Proportional Counting (use clump count)
1 Field count
a Count and tally all individuals of
each type present in a field. The
best way to do this is to list the
most common types separately
and record the counts and the
enumerate the other forms.
b Move the slide at random and
repeat the process. Do this for
5 or 10 fields, or for one or
two strips.
c Tally the results and compute
the percent of each type.
2 Five hundred count
a Moving the slide at random count
and tally all the types of plankton
as before until a total of 500 cells
or clumps have been counted.
b Tally the results and compute the
percentage of each type as before.
IV RESULTS
A Record your results for both methods
on the board.
B Discuss the two methods and the use of
the proportional count results.
This outline was prepared by M. E. Bender,
Biologist, formerly with FWPCA Training
Activities, SEC.
Descriptors: Plankton, Analytical
Techniques
BL MIC. enu.lab. 6a. 6. 76
42-1
-------
CALIBRATION AND USE OF PLANKTON COUNTING EQUIPMENT
I INTRODUCTION
A With the exception of factory-set
instruments, no two microscopes can
be counted upon to provide exactly the
same magnification with any given com-
bination of oculars and objectives. For
accurate quantitative studies, it is there-
fore necessary to standardize or "calibrate"
each instrument against a known standard
scale. One scale frequently used is a
microscope slide on which two millimeters
are subdivided into tenths, and two addi-
tional tenths are subdivided into hundredths.
Figure 3.
B In order to provide an accurate measuring
device in the microscope, a Whipple
Plankton Counting Square or reticule
(Figure 2a) is installed in one ocular
(there are many different types of reticules).
This square is theoretically of such a size
that with a 10X objective, a 10X ocular,
and a tube length of 160 mm, the image
of the square covers a square area on the
slide one mm on a slide. Since this
objective is rarely attained however, most
.microscopes must be standardized or
"calibrated" as described below in order
to ascertain the actual size of the Whipple
Square as seen through the microscope
(hereinafter referred to as the "Whipple
field"). This process is schematically
represented in Figures 5 and 7. If the
Whipple eyepiece is to be used at more
than one magnification, it must be recali-
brated for each. A basic type of monocular
microscope is shown in Figure 1.
C Microscopes with two eyepieces (binocular)
are a convenience but not essential. Like
modern cars they are not only great
"performers, " but also complicated to
service or, in this instance, calibrate.
On some instruments, changing the inter-
pupillary distance also changes the tube
length, on others it does not. The "zoom"
feature on certain scopes is also essentially
a system for changing the tube length.
The resultant is that in addition to calibra-
tion at each combination of eyepiece and
objective, any other factor which may
affect magnification must also be considered.
In some instances this may mean setting up
a table of calibrations at a series of micro-
scope settings.
Another procedure is to select a value
for each of the variables involved (inter-
pupillary distance, zoom, etc.) and
calibrate the scope at that combination.
Then each time the scope is to be used for
quantitative work, re-set each variable to
the value selected. A separate multipli-
cation factor must be calculated for each
adjustment which changes the magnification
of the instrument.
Since the Whipple Square can be used to
measure both linear dimensions and
square areas, both should be recorded on
an appropriate form. A suggested format
is shown in Figure 6.
(Data written in are used as an illustration
and are not intended to apply to any
particular microscope. An unused form
is included as Figure 6-A. )
II THE CALIBRATION PROCEDURE
A Installing the Whipple Square or Reticule
To install the reticule in the ocular
(usually the right one on a binocular
microscope), carefully unscrew the upper
lens mounting and place the reticule on
the circular diaphragm or shelf which will
be found approximately half way down inside
(Figure 4). Replace the lens mounting and
observe the markings on the reticule. If
they are not in sharp focus, remove and
turn the reticule over.
On reticules with the markings etched on
one side of a glass disc, the etched sur-
face can usually be recognized by shining
the disc at the proper angle in a light.
The markings will usually be in the best
focus with the etched surface down. If the
markings are sandwiched between two glass
discs cemented together, both sides are
alike, and the focus may not be quite as
sharp.
B Observation of the Stage Micrometer
Replace the ocular in the microscope and
observe the stage micrometer as is illus-
trated schematically in Figure 5: Calibration
of the Whipple Square. On a suitably ruled
form such as the one illustrated, Figure 6,
Calibration Data, record the actual distance
in millimeters subtended by the image of
BI, MET.mic. Id. 6. 76
43-1
-------
Calibration and Use of Plankton Counting Equipment^
the entire Whipple field and also by each
of its subdivisions. This should be
determined for each significant settling of
the interpupillary distance for a binocular
microscope, and also for each combination
of lenses employed. Since oculars and
objectives marked with identical magnifi-
cation, and since microscope frames too
may differ, the serial or other identifying
number of those actually calibrated should
be recorded. It is thus apparent that the
determinations recorded will only be valid
when used with the lenses listed and on that
particular microscope.
C Use of the 2OX Objective
Due to the short working distance beneath
a 46X (4mm) objective, it is impossible
to focus to the bottom of the Sedgewick-
Rafter plankton counting cell with this lens.
A 10X (16mm) lens on the other hand
"wastes" space between the front of the
lens and the coverglass, even when focused
on the bottom of the cell. In order to make
the most efficient use possible of this cell
then, an objective of intermediate focal
length is desirable. A lens with a focal
length of approximately 8 mm, having a
magnification of 20 or 2IX will meet these
requirements. Such lenses are available
from American manufacturers and are
recommended for this type of work.
in CHECKING THE CELL
The internal dimensions of a Sedgewick-Rafter
plankton counting cell should be 50 mm long
by 20 mm wide by 1 mm deep (Figure 8).
The actual horizontal dimensions of each new
cell should be checked with calipers, and the
depth of the cell checked at several points
around the edge using the vertical focusing
scale engraved on the fine adjustment knob of
most microscopes. One complete rotation of
the knob usually raises or lowers the objective
1 mm or 100 microns (and each single mark
equals 1 micron). Thus, approximately ten
turns of the fine adjustment knob should raise
the focus from the bottom of the cell to the
underside of a coverglass resting on the rim.
Make these measurements on an empty cell.
The use of a No. 1 or 1-1/2, 24 X 60 mm
coverglass is recommended rather than the
heavy coverglass that comes with the S-R
cell, as the thinner glass will somewhat con-
form to any irregularities of the cell rim
(hence, also making a tighter seal and reduc-
ing evaporation when in actual use). Do not
attempt to focus on the upper surface of the
rim of an empty cell for the above depth
measurements, as the coverglass is supported
by the highest points of the rim only, which
are very difficult to identify. Use the average
of all depth measurements as the "true" depth
of the cell. To simplify calculations below, it
will be assumed that we are dealing with a
cell with an average depth of exactly 1. 0 mm.
IV PROCEDURE FOR STRIP COUNTS USING
THE SEDGEWICK-RAFTER CELL
A Principles
Since the total area of the cell is 1000 mm2,
the total volume is 1000 mm3 or 1 ml. A
"strip" the length of the cell thus constitutes
a volume (V.) 50 mm long, 1 mm deep, and
the width of the Whipple field.
o
The volume of such a strip in mm is:
V1 = 50 X width of field X depth
= 50 XwX 1
= 50 w
In the example given below on the plate
entitled Calibration Data, at a magnification
of approximately 20OX with an interpupillary
setting of "60", the width of the Whipple
field is recorded as approximately 0. 55 mm
(or 550 microns). In this case, the volume
of the strip is:
Vj = 50 w = 50 X 0. 55 = 27. 5 (mm3)
B Calculation of Multiplier Factor
In order to convert plankton counts per
strip to counts per ml, it is simply
necessary to multiply the count obtained
by a factor (F..) which represents the
number of times the volume of the strip
examined (Vi) would be contained in 1 ml or
1000 mm3. Thus in the example given
above:
3
F - volume of cell in mm
1 volume examined in mnv*
1000
V
1000
27.5
= 36.36
= approx. 36
If more than one strip is to be counted,
the factor for two, three, etc., strips
could be calculated separately using the
same relationships outlined above, changing
only the measurement for the length of
43-2
-------
Calibration and Use of Plankton Counting Equipment
Figure 1. THE COMPOUND MICROSCOPE
A) coarse adjustment; B) fine adjustment;
C) arm or pillar; D) mechanical stage which
holds slides and is movable in two directions
by means of the two knobs; E) pivot or joint.
This should not be used or "broken" while
counting plankton; F) eyepiece (or ocular cf:
figure 4); G) draw tube. This will be found
on monocular microscopes only (those having
only one eyepiece). Adjustment of this tube
is very helpful in calibrating the microscope
for quantitative counting (Sec. 5. 5. 2. 2. ).
H) body tube. In some makes of microscopes
this can be replaced with a body tube having
two eyepieces, thus making the 'scope into
a "binocular. " I) revolving nosepiece on
which the objectives are mounted; J) through
M are objectives, any one of which can be
turned toward the object being studied. In
this case J is a 40X, K is a 100X, L is a 20X,
and M is a 10X objective. The product of
the magnification power of the objective being
used times the magnification power of the
eyepiece gives the total magnification of the
microscope. Different makes of microscopes
employ objectives of slightly different powers,
but all are approximately equivalent. N) stage
of the microscope; O) Sedgwick-Rafter cell in
place for observation; P) substage condenser;
Q) mirror; R) base or stand; note: for
information on the optical system, consult
reference 3. (Photo by Don Moran.).
-------
Calibration and Use of Plankton Counting Equipment
Figure 2
Types of eyepiece micrometer discs or
reticules (reticules, graticules, etc.).
When dimensions are mentioned in the
following description, they refer to the
markings on the reticule discs and not to
the measurements subtended on the micro-
scope slide. The latter must be determined
by calibration procedures such as those
described elsewhere, (a) Wnipple plankton
counting eyepiece. The fine rulings in the
subdivided square are sometimes extended to
the margin of the large square to facilitate
the estimation of sizes of organisms in
different parts of the field, (b) Quadrant
ruling with 8. 0 mm circle, for counting
bacteria in milk smears for example, (c)
Linear scale 5. 0 mm divided into tenths.
For measurement of linear dimensions.
(d) Porton reticule for estimating the size
of particles. The sizes of the series of discs
is based on the square root of two so that the
areas of successive discs double as they
progress in size.
43-4
-------
Calibration and Use of Plankton Counting Equipment
strip counted. Thus for two strips in the
example cited above:
V2= 100W = 100 XO. 55 = 55 mm3
_ 1000 _ 1000 _
' - --- -
55-
_ „
- 18'2
It will however be noted that F = -=i .
Likewise a factor F for three strips
Fl
would equal -5- or approximately 12, etc.
C An Empirical "Step-Off" Method
A simpler but more empirical procedure
for determining the factor is to consider
that if a strip 20 mm wide were to be
counted the length of the cell, that the
entire 1000 mm3 would be included since
the cell is 20 mm wide and 1 mm deep.
This 20 mm strip width can be equated to
1000 mm3. If a strip (or the total of 2 or
more strips) is less than 20 mm in width,
the quotient of 20 divided by this width will
be a multiplier factor for converting from
count per strip(s) to count per ml.
V
Thus in the example cited above where at
an approximate magnification of 200X and
with an interpupillary setting of 60, the
width of the Whipple field is . 55 mm. Then:
on
Fl=
(as above)
or approx. 36
If two strips are counted:
.55
.55
1.10
= 18.2 = approx. 18,etc.
This same value could be obtained without
the use of a stage micrometer by carefully
moving the cell sidewise across the field
of vision by the use of a mechanical stage.
Count the number of Whipple fields in the
width of the cell. There should be approxi-
mately 36 in the instance cited above.
SEPARATE FIELD COUNT USING THE
SEDGEWICK-RAFTER CELL
A Circumstances of Use
The use of concentrated samples, local
established programs, or other circumstances
Figure 3. STAGE MICROMETER
The type illustrated has two millimeters divided into tenths, plus two additional
tenths subdivided into hundredths.
Micrometer Scale,
Enlargement of Micrometer Scale
43-5
-------
Calibration and Use of Plankton Counting Equipment
Figure 4. Method of Mounting the Whipple Disc in an Ocular. Note the upper
lens of the ocular which has been carefully unscrewed, held in the left
hand, and the Whipple disc, held in the right hand. (Photo by
Don Moran).
-------
Calibration and Use of Plankton Counting Equipment
CALIBRATION OF WHIPPLE SQUARE
as seen with 10X Ocular and 43X Objective
(approximately 430X total magnification)
Whipple Square as
seen through ocular
("Whipple field")
"Small squares" subtend
one fifth of large squares-
. 0052 mm or 5. 2n
"Large square" subtends
one tenth of entire Whipple
Square: .026 mm or 26|i
Apparent lines of sight
subtend . 26 mm or 260>i
on stage micrometer
scale
PORTION OF MAGNIFIED IMAGE OF STAGE MICROMETER SCALE —
Figure 5
CALIBRATION OF THE WHIPPLE SQUARE
The apparent relationship of the Whipple
Square is shown as it is viewed through a
microscope while looking at a stage
micrometer with a magnification of
approximately 43OX (10X ocular and 43X
objective).
43-7
-------
Calibration and Use of Plankton Counting Equipment
MICROSCOPE CALIBRATION DATA
Microscope No.
Apr"oxirnate
Mollification
Tube
Length, or
"nterpupillary
Setting
Linear dimensions of Whipple
squares in millimeters*
Whole
Large
Small
Factor for
Conversion
to count/ ml
100X. obtained with
(2 S-R Strips)
Objective
Serial No.
and Ocular
Serial No
/3Qt,74L6hX\
SO
(,0
10
1. /3o
l.llŁ
1. 100
0.113
D.lll
o. no
0.03 at*
6.0J.3.Z
0.03.22
Ł9
9.0
9J
l^^i-^yl1-"0.?1-^^
Objective
Serial No.
and Ocular
Serial No.
400X, obtained with
(2 S-R Stripe)
Ł~0
(*Q
70
O.StoO
0. S5'0
O.SVs
O.O5L,
0. GSS
o. $sy
0, 0 //A
0.0110
0.0109
/7.1
/f.A
/J>.3
(Nannoplankton)
(cell-20 fields )'
Objective
Serial No.
and Ocular
Serial No.
/39Ł>7yt.('ot)
^0
(,0
'7/9
0.3.6,7
0.U2
0.3LO
&GU?
/).6263
n.OAUO
,00-53
.0053
. 0052
/734.
lift,.
*1 mm - 1000 irij.•.!•!
Microscope calibration data. The form
shown is suggested for the recording of
data pertaining to a particular microscope.
Headings could be modified to suit local
situations. For example, "Interpupillary
Setting" could be replaced by "Tube Length"
or the "2S-R Strips could be replaced by
"per field" or "per 10 fields. "
Figure 6
43-8
-------
Calibration and Use of Plankton Counting Equipment
MICROSCOPE CALIBRATION DATA
Microscope No.
Approximate
IVI 3. unification
Tube
Length, or
Inte rpupillary
Setting
Linear dimensions of Whipple
squares in millimeters*
Whole 1 Large 1 Small
Factor for
Conversion
to count/ ml
100X. obtaine
Objective
Serial No.
and Ocular
Serial No.
J with
<2 S-H Strips)
200X, obtained with
(2 S-R Strips)
Objective
Serial No.
and Ocular
Serial No.
400X, obtained with
(Nannoplankton)
(cell-20 fields )
Objective
Serial No.
and Ocular
Serial No.
*lrnm = 1000 microns
BI. AQ.pl. 8. 10. 60.
Figure 6-A
MICROSCOPE CALIBRATION DATA
Suggested work sheet for the calibration of a microscope. Details will need to be adapted
to the particular instrument and situation.
43-9
-------
Calibrn I OMU nt I
^^ _______
S-R COVER
GLASS —
WATER IN 1MM
S-R CELL
WHIPPLE SQUARE
PLANKTERS
THICKNESS S-R SLIDE
Figure 7
A cube of water as seen through a Whipple square at 100X magnification in
a Sedgewick-Rafter cell. The figure is drawn as if the microscope were
focused on the bottom of the cell, making visible only those organisms lying
on the bottom of the cell. The little "bug" (copepod) halfway up, and the
algae filament at the top would be out of focus. The focus must be moved up
and down in order to study (or count) the entire cube.
43-10
-------
Calibration and Use of Plankton Counting Equipment
may make it necessary to employ the more
conventional technique of counting one or
more separate Whipple fields instead of
the strip count method. The basic relation
ships outlined above still hold, namely:
volume cell in mm
f~3
volume examined in mfh~
B Principles Involved
The volume examined in this case will
consist of one or more squares the dimen-
sions of the Whipple field in area and 1 mm
in depth (Figure 7). Common practice
for routine work is to examine 10 fields,
but exceptionally high or low counts or
other circumstances may indicate that
some other number of fields should be
employed. In this case a "per field"
factor may be determined to be subsequently
divided by the number of fields examined
as with the strip count. The following
description however is based on an assumed
count of 10 fields.
NANNOPLANKTON COUNTING
For counting nannoplankton using the high
dry power (10X ocular and 43X objective)
and the "nannoplankton counting cell"
(Figure 9) which is 0. 4 mm deep, a minimum
of 20 separate Whipple fields is suggested.
The same general relationships presented
above (Section IV) can be used to obtain a
multiplier or factor (F5) to convert counts
per 20 fields to counts per ml.
To take another example from Figure 4, at
an approximate magnification of 400X and an
interpupillary setting of 70 (see also Figure 3)
we observe that one side of the Whipple field
measures 0. 260 mm. The volume of the
fields examined is thus obtained as follows:
V5 = side2 X depth X no. of fields
= 0. 26 X 0.26 X 0.4 X 20 = .54 mm3
and F
= (approx. ) 1850
C Calculation of Multiplier Factor
As stated above, the total volume
represented in the fields examined con-
sists of the total area of the Whipple fields
multiplied by the depth.
V4 = (side of Whipple field)2 X depth
(1 mm) X no. of fields counted)
For example, let us assume an approxi-
mate magnification of 100X (see Figures
6 and 7 and an interpupillary setting of
"50". The observed length of one side
of the Whipple field in this case is 1. 13
mm. The calculation of V. is thus:
V4= side X depth X no. of fields
= 1.13 X 1.13 X 1 X 10 = 12.8 mm3
The multiplier factor is obtained as
above (Section IV A):
3
F4 =
volume cell in mm"
volume examined in mm"
= ~ = (approx.) 78
(If one field were counted, the factor
would be 781, for 100 fields it would
be 7.8. )
It should be noted that the volume of the
nannoplankton cell, . 1 ml, is of no significance
in this particular calculation.
REFERENCES
1 American Public Health Association, et. al.
Standard Methods for the Examination
of Water, Sewage, and Industrial Wastes.
14th Edition. Am. Public Health Assoc.
New York. 1976.
2 Jackson, H.W. and Williams, L. G.
The Calibration and Use of Certain
Plankton Counting Equipment. Trans.
Am. Mic. Soc. LXXXI(1);96-103. 1962.
3 Ingram, W. M. and Palmer, C. M.
Simplified Procedures for Collecting,
Examining, and Recording Plankton in
Water. Jour. Am. Water Works.
Assoc. 44(7): 617-724. 1952.
4 Palmer, C. M. Algae in Water Supplies.
U. S. D. H. E. W. Public Health Service
Pub. No. 657. 1959.
5 Palmer, C. M. and Maloney, T. E. A
New Counting Slide for Nannoplankton.
American Soc. Limnol. and Oceanog.
Special Publications No. 21. pp. 1-6.
1954.
43-11
-------
Calibration and Use of Plankton Counting Equipment
Area
Uncounted
Figure 8
Sedgewick-Rafter counting cell showing bottom scored across for ease in counting
strips. The "strips" as shown in the illustration simply represent the area counted,
and are not marked on the slide. The conventional dimensions are 50 X 20 X 1 mm, but
these should be checked for accurate work.
Figure 9
Nannoplankton cell. Dimensions of the circular part of the cell are 17.9 mm diameter
X 0. 4 mm depth. When covered with a coverglass, the volume contained is 0. 1 ml.
The channels for the introduction of sample and the release of air are 2 mm wide and
approximately 5 mm long. This slide is designed to be used with the 4 mm or 43X
(high dry) objective.
6 Welch, Paul S. Limnological Methods.
Blakiston Company. Phila. Toronto.
1948.
7 Whipple, G. C., Fair, G. M., and
Whipple, M. C. The Microscopy of
Drinking Water. John Wiley and Sons.
New York. 1948.
This outline was prepared by H. W. Jackson,
former Chief Biologist, National Training
Center, and revised by R. M. Sinclair,
Aquatic Biologist, National Training Center
MOTD, OWPO. USEPA, Cincinnati, Ohio 45268
Descriptors: Plankton, Microscopy
43-12
-------
LABORATORY: FUNDAMENTALS OF QUANTITATIVE COUNTING
I OBJECTIVE
To learn and practice the basic techniques of
quantitative plankton counting
II MATERIALS
Plankton Samples Containing a Variety of
Plankton Forms
S-R Cells and Coverglasses, Large Bore
1 ml Pipettes, Whipple Discs, Plankton
Record Form
III PROCEDURE
Fill the S-R cell with sample number 1 as
follow s:
Place the coverglass diagonally across
the S-R cell. This leaves the other two
corners uncovered; one for putting in
the sample fluid, the other to allow
air to be driven out as it is replaced
by the incoming aliquot. Shake the
sample to disperse the plankton. Before
settling occurs in the sample draw about
1-1/4 ml of the fluid into the pipette
and quickly fill the S-R cell by delivering
the aliquot into one of the open corners
of the chamber.
Starting from one end of the S-R cell and
preceding to the opposite (this is called a
strip count, begin counting (clump counts)
the plankton forms. The length of the
cell may be traversed in several ways.
1 Count all the forms in the Whipple
square or in a portion of the square,
record the count and move the slide so
that the square covers the adjoining
area.
2 Move the slide very slowly counting
and recording the various forms as
they pass the leading edge of the
Whipple disc.
IV RESULTS
A Using the conversion factor obtained in
the previous laboratory compute the
number of plankton organisms per ml.
B Record the results on the board.
C Discussion of Results
D Refill the slide with a fresh aliquot and
recount the sample. Compare results
with the first count.
E Count the other samples of mixed plankton
as assigned, following the same procedure.
Using lOOx focus on the sample. After
focus has been obtained switch to 200x.
Scan the slide and list the plankton forms
present.
This outline was prepared by M. E. Bender,
Former Biologist, FWPCA, Water Pollution
Training Activities, SEC.
Descriptors: Plankton, Analytical Techniques
BI. MIC. enu. lab. 7. 6. 76
44-1
-------
Laboratory: Fundamentals of Quantitative Counting
idy of Water: .
PLANKTON COUNT RECORD
Date Collected:.
, Date Analyzed.
. Analyst
TOTAL COUNT:
Organisms,
Differential
Count 1
Notes, Talleys
Total
FIELD CONDITIONS
Tlno nf Hay ,, ,
Vol, Area.
or Type of Count
Air Tenor Vater Tenp*
Voather tndav •
Previous Weather •
Turbidity Met ho
lr T. reading-
Preservative •
Filanentou
Other Plan
Surface Sc
Dead Fish
Odor of Wa
Other Physic
s Alffaer,
tB •
al nr Chemical Dat
a
LABORATORY
Method of Pr<
Departure fr
Significance
Treatment Re
ANALYSIS
Count
per
ml.
per
liter
Group
Totals
PLANT OR OTHER DATA, FOR B
Treatment fo, J?Ł,tSJ
A * r
Other Cnevic
X:
.1.
Taate and Odor:
Filter Runs:
Othgr
SUGGESTED BASIC FORM FOR PLANKTON RECORDS
HWJ
4/68
.UIC.enu.pl.2.4.68
-------
KEY TO SELECTED GROUPS OF FRESHWATER ANIMALS
The following key is intended to provide
an introduction to some of the more
common freshwater animals. Technical
language is kept to a minimum.
In using this key, start with the first
couplet (la, Ib), and select the alternative
that seems most reasonable. If you
selected "la" you have identified the
animal as a member of the group, Phylum
PROTOZOA. If you selected "ib", proceed
to the couplet indicated. Continue this
process until the selected statement is
terminated with the name of a group.
If you wish more information about the
group, consult references. (See reference
list.)
. 2j.b.6.76
45-1
-------
Key to Selected Groups of Freshwater Animals
la The body of the organism comprising
a single microscopic independent
cell, or many similar and indepen-
dently functioning cells associated
in a colony with little or no differ-
ence between the cells, i. e. , with-
out forming tissues; or body com-
prised of masses of multinucleate
protoplasm. Mostly microscopic,
single celled animals.
Phylum PROTOZOA
Ib The body of the organism com-
prised of many cells of different
kinds, i.e., forming tissues.
May be microscopic or macro-
scopic.
2a Body or colony usually forming
irregular masses or layers some-
times cylindrical, goblet shaped,
vase shaped, or tree like. Size
range from barely visible to
large.
2b Body or colony shows some type
of definite symmetry.
3a Colony surface rough or bristly
in appearance under microscope
or hand lens. Grey, green, or
brown. Sponges.
Phylum PORIFERA (Fig. 1)
3b Colony surface relatively smooth.
General texture of mass gelatinous,
transparent. Clumps of minute
individual organisms variously
distributed. Moss animals,
bryozoans.
Phylum BRYOZOA (Fig. 2)
4a Microscopic. Action of two
ciliated (fringed) lobes at an-
terior (front) end in life often
gives appearance of wheels.
Body often segmented, accordian-
like. Free swimming or attached.
Rotifers or wheel animalcules.
Phylum TROCHELMINTHES
(Rotifera) (Fig. 3)
4b Larger, wormlike, or having
strong skeleton or shell.
5a Skeleton or shell present. Skel-
eton may be external or internal.
5b Body soft and/or wormlike.
Skin may range from soft to
parchment-like.
6a Three or more pairs of well
formed jointed legs present.
Phylum ARTHROPODA (Fig. 4)
6b Legs or appendages, if present,
limited to pairs of bumps or hooks.
Lobes or tenacles, if present,
soft and fleshy, not jointed.
7a Body strongly depressed or
flattened in cross section.
7b Body oval, round, or shaped like
an inverted "U" in cross section.
8a Parasitic inside bodies of higher
animals. Extremely long and flat,
divided into sections like a Roman
girdle. Life history may involve
an intermediate host. Tape worms.
Class CESTODA (Fig. 5)
8b Body a single unit. Mouth and
digestive system present, but no
anus.
9a External or internal parasite of
higher animals. Sucking discs
present for attachment. Life his-
tory may involve two or more in-
termediate hosts or stages. Flukes.
Class TREMATODA
9b Free living. Entire body covered
with locomotive cilia. Eye areas
in head often appear "crossed".
Free living flatworms.
Class TURBELLARIA (Fig. 6)
lOa Long, slender, with snake-like
motion in life. Covered with glis-
tening cuticle. Parasitic or free-
living. Microscopic to six feet in
length. Round worms.
Phylum NEMATHELMINTHES
(Fig. 7)
lOb Divided into sections or segments
15
19
10
11
45-2
-------
Key to Selected Groups of Freshwater Animals
lOc Unsegmented, head blunt, one 18
or two retractile tentacles.
Flat pointed, tail.
lla Head a. more or less well-formed,
hard, capsule with jaws, eyes,
and antennae.
Class INSECTA order DIPTERA
(Figs. 8A, 8C)
lib Head structure soft, except 12
jaws (if present). Fig. 8E.)
12a Head conical or rounded, lateral 13
appendages not conspicuous or
numerous.
12b Head somewhat broad and blunt. 14
Retractile jaws usually present.
Soft fleshy lobes or tentacles,
often somewhat flattened, may be
present in the head region. Tail
usually narrow. Lateral lobes
or fleshy appendages on each
segment unless there is a large
sucker disc at rear end.
Phylum ANNELIDA (Fig. 9)
13a Minute dark colored retractile
jaws present, body tapering
somewhat at both ends, pairs or
rings of bumps or "legs" often
present, even near tail.
Class INSECTA Order DIPTERA
(Fig. 8)
13b No jaws, sides of body generally 14
parallel except at ends. Thicken-
ed area or ring usually present
if not all the way back on body.
Clumps of minute bristles on most
segments. Earthworms, sludge-
worms „
Order OLIGOCHAETA
14a Segments with bristles and/or fleshy
lobes or other extensions. Tube
builders, borers, or burrowers.
Often reddish or greenish in
color. Brackish or fresh water.
Nereid worms.
Order POLYCHAETA (Fig. 9A)
14b Sucker disc at each end, the large
one posterior. External blood-
sucking parasites on higher animals,
often found unattached to host.
Leaches.
Class HIRUDINEA (Fig. 9B)
15a Skeleton internal, of true bone. 40
(Vertebrates)
15b Body covered with an external 16
skeleton or shell.
(Figs. 10, 13, 17, 18, 24,
25, 28)
16a External skeleton jointed, shell 19
covers legs and other appendages,
often leathery in nature.
Phylum ARTHROPODA
16b External shell entire, not jointed, 17
unless composed of two clam-
like halves.
(Figs. 10, 11, 12)
17a Half inch or less in length. Two
leathery, clam-like shells. Soft
parts inside include delicate,
jointed appendages. Phyllopods
or branchiopods.
Class CRUSTACEA, Subclasses
BRANCHIOPODA (Fig. 12)
and OSTRACODA (Fig. 11)
17b Soft parts covered with thin 18
skin, mucous produced, no jointed legs.
Phylum MOLLUSCA
18a Shell single, may be a spiral cone.
Snails.
Class GASTROPODA (Fig. 13)
18b Shell double, two halves, hinged
at one point. Mussels, clams.
Class BIVALVIA (Fig. 10)
19a Three pairs of regular walking 29
legs, or their rudiments. Wings
present in all adults and rudiments
in some larvae.
Class INSECTA (Figs. 22, 24D,
25, 26, 28, 29)
19b More than three pairs of legs 20
apparently present.
20a Body elongated, head broad and flat
45-3
-------
Key to Selected Groups of Freshwater Animals
with strong jaws. Appendages follow-
ing first three pairs of legs are round-
ded tapering filaments. Up to 3
inches long. Dobson fly and fish fly
larvae.
Class INSECTA Order
MEGALOPTERA (Fig. 14)
20b Four or more pairs of legs. 21
21a Four pairs of legs. Body rounded,
bulbous, head minute. Often
brown or red. Water mites.
Phylum ARTHROPODA, Class
ARACHNIDA, Order ACARI
(Fig. 15)
21b Five or more pairs of walking 22
or swimming legs; gills, two
pairs of antennae. Crustaceans.
Phylum ARTHROPODA,
Class CRUSTACEA
22a Ten or more pairs of flattened,
leaflike swimming and respiratory
appendages. Many species swim
constantly in life; some swim
upside down. Fairy shrimps,
phyllopods, or branchipods.
Subclass BRANCHIOPODA
(Fig. 16)
22b Less than ten pairs of swimming 23
or respiratory appendages.
23a Body and legs inclosed in bi- 24
valved (2 halves) shell which may
or may not completely hide them.
23b Body and legs not enclosed in 26
bivalve shell. May be large or
minute.
(Figs. 17, 18, 19)
24a One pair of branched antennae
enlarged for locomotion, extend
outside of shell (carapace).
Single eye usually visible.
"Water fleas"
Subclass CLADOCERA (Fig. 12)
24b Locomotion accomplished by 25
body legs, not by antennae.
25a Appendages leaflike, flattened,
more than ten pairs.
Subclass BRANCHIOPODA
(See 22 a)
25b Animal less than 3 mm, in length.
Appendages more or less slender
and jointed, often used for walking.
Shells opaque. Ostracods.
(Fig. 11) Subclass OSTRACODA
26a Body a series of six or more 27
similar segments, differing
mainly in size.
26b Front part of body enlarged into 28
a somewhat separate body unit
(cephalothorax) often covered
with a single piece of shell (cara-
pace). Back part (abdomen) may be
relatively small, even folded
underneath front part.
-------
Key to Selected Groups of Freshwater Animals
29b No functional wings, though 30
pads in which wings are develop-
ing may be visible. Some may
resemble adult insects very
closely, others may differ ex-
tremely from adults.
30a External pads or cases in which 35
wings develop clearly visible.(Figs.
24,26,27)
30b More or less wormlike, or at 31
least no external evidence of
wing development.
31a No jointed legs present. Other
structures such as hooks, sucker
discs, breathing tubes may be
present. Larvae of flies,
midges, etc.
Order DIPTERA (Fig. 8)
31b Three pairs of jointed thoracic 32
legs, head capsule well formed.
32a Minute (2-4mm) living on the
water surface film. Tail a
strong organ that can be hooked
into a "catch" beneath the
thorax. When released animal
jumps into the air. No wings
are ever grown. Adult spring-
tails.
Order COLLEMBOLA (Fig. 20)
32b Larger (usually over 5 mm) 33
wormlike, living beneath the
surface.
33a Live in cases or webs in water.
Cases or webs have a silk
foundation to which tiny sticks,
stones, and/or bits of debris
are attached. Abdominal segments
often with minute gill filaments.
Generally cylindric in shape.
Caddisfly larvae.
Order TRICHOPTERA (Fig. 21)
33b Free living, build no cases. 34
34a Somewhat flattened in cross
section and massive in appear-
ance. Each abdominal segment
with rather stout, tapering, lateral
filaments about as long as body
is wide. Alderflies, fishflies, and
dobsonflies.
Order MEGALOPTERA (Fig. 22, 14)
34b Generally rounded in cross section.
Lateral filaments if present tend
to be long and thin. A few forms
extremely flattened, like a suction
cup. Beetle larvae.
Order COLEOPTERA (Fig. 23)
35a Two or three filaments or other 37
structures extending out from
end of abdomen.
35b Abdomen ending abruptly, unless 36
terminal segment itself is extended
as single structure.(Figs. 24A, 24C)
36a Mouth parts adopted for chewing.
Front of face covered by extensible
folded mouthparts often called a
"mask". Head broad, eyes widely
spaced. Nymphs of dragonflies
or darning needles.
Order ODONATA (Figs.24A, 24C, 24E)
36b Mouthparts for piercing and sucking.
Legs often adapted for water lo-
comotion. Body forms various.
Water bugs, water scorpions, water
boatmen, backswimmers, electric
light bugs, water striders, water
measurers, etc.
Order HEMIPTERA (Fig. 25)
37a Tail extensions (caudal filaments)
two. Stonefly larvae.
Order PLECOPTERA (Fig. 26)
37b Tail extensions three, at times
greatly reduced in size.
38a Tail extensions long and slender.
Rows of hairs may give extensions
a feather-like appearance.
Mayfly larvae.
Order EPHEMEROPTERA
(Fig. 27)
38b Tail extensions flat, elongated
plates. Head broad with widely
spaced eyes, abdomen relatively
long and slender. Damselfly
nymths.
Order ODONATA (Fig.
38
45-5
-------
Key to Selected Groups of Freshwater Animals
39a External wings or wing covers
form a hard protective dome
over the inner wings folded
beneath, and over the abdomen.
Beetles.
Order COLEOPTERA
(Fig. 28)
39b External wings leathery at base,
Membranaceous at tip. Wings
sometimes very short. Mouth-
parts for piercing and sucking.
Body form various. True bugs.
Order HEMIPTERA (Fig. 25)
40a Appendage present in pairs.
(fins, legs, wings),
40b No paired appendages. Mouth
a round suction disc.
41a Body long and slender. Several
holes along side of head.
Lampreys,
Sub Phylum VERTEBRATA,
Class CYCLOSTOMATA
41b Body plump, oval, Tail extending
out abruptly. Larvae of frogs and
toads. Legs appear one at a time
during metamorphosis to adult
form. Tadpoles.
Class AMPHIBIA
42a Paired appendages are legs 43
42b Paired appendages are fins,
gills covered by a flap
(operculum). True fishes.
Class PISCES
43a Digits with claws, nails, or hoofs 44
43b Skin naked. No claws or digits.
Frogs, toads, and salamanders.
Class AMPHIBIA
42 44a Warm blooded
41 44b Cold blooded. Body covered
with horny scales or plates.
Class REPTILIA
45a Body covered with feathers.
Birds.
Class AVES
45b Body covered with hair.
Mammals.
Class MAMMALIA
45
45-6
-------
Key to Selected Groups of Freshwater Animals
REFERENCES - Invertebrates
1 Eddy, Samuel and Hodson, A.C.
Taxonomic Keys to the Common
Animals of the North Central States.
Burgess Pub. Company, Minneapolis.
162 p. 1961.
2 Edmondson, W. T. (ed.) and Ward and
Whipple's Freshwater Biology. John
Wiley & Sons, New York. pp. 1-1248.
1959.
3 Jahn, T. L. and Jahn, F. F. How to Know
the Protozoa. Wm. C. Brown Company,
Dubuque, Iowa. pp. 1-234. 1949.
4 Klots, Elsie B. The New Field Book of
Freshwater Life.
398pp. 1966.
G.P. Putnam's Sons.
5 Kudo, R. Protozoology. Charles C.
Thomas, Publisher, Springfield, Illinois.
pp. 1-778. 1950.
6 Palmer, E. Lawrence. Fieldbook of
Natural History. Whittlesey House,
McGraw-Hill Book Company, Inc.
New York. 1949.
7 Pennak, R.W. Freshwater Invertebrates
of the United States. The Ronald Press
Company, New York. pp. 1-769. 1953.
8 Pimentel, Richard A. Invertebrate
Identification Manual. Reinhold
Publishing Corp. 151pp. 1967.
9 Pratt, H.W. A Manual of the Common
Invertebrate Animals Exclusive of
Insects. The Blaikston Company,
Philadelphia, Pa. pp. 1-854. 1951.
REFERENCES - Fishes
1 American Fisheries Society. A List of
Common and Scientific Names of Fishes
from the United States and Canada.
Special Publication No. 2, Am. Fish
Soc. Executive Secretary AFS.
Washington Bid. Suite 1040, 15th &
New York Avenue, N.W. Washington,
DC 20005. (Price $4. 00 paper,
$7. 00 cloth). 1970.
2 Bailey, Reeve M. A Revised List of
the Fishes of Iowa with Keys for
Identification, IN: Iowa Fish and
Fishing. State of Iowa, Super, of
Printing. 1956. (Excellent color
pictures).
3 Eddy, Samuel. How to Know the
Freshwater Fishes. Wm. C. Brown
Company, Dubuque, Iowa. 1957.
4 Hubbs, C.L. and Lagler, K.F. Fishes
of the Great Lakes Region. Bull.
Cranbrook Inst. Science, Bloomfield
Hills, Michigan. 1949.
5 Lagler, K.F. Freshwater Fishery
Biology. Wm. C. Brown Company,
Dubuque, Iowa. 1952.
6 Trautman, M.B. The Fishes of Ohio.
Ohio State University Press, Columbus.
1957. (An outstanding example of a
State study).
Descriptors: Aquatic Life, Systematics.
45-7
-------
Key to Selected Groups of Freshwater Animals
1. Spongilla spicules
Up to .2 mm. long.
3A. Rotifer. Polyarthra
Up to . 3 mm.
3B. Rotifer. Keratella
Up to . 3 mm.
3C. Rotifer, Philodina
Up to . 4 mm.
4A. Jointed leg
Caddisfly
4B. Jointed leg
Crayfish
2B. Bryozoal mass. Up to
several feet diam.
2A. Bryozoa, Plumatella. Individuals up
to 2 mm. Intertwined masses maybe
very extensive.
4C. Jointed leg
Ostracod
5. Tapeworm head,
Taenia. Up to
25 yds. long
45-8
' aria, Meaostoma
L i,m.
6B. Turbellaria, Dugesia
Up to 1. 6 cm.
7. Nematodes. Free living
forms commonly up to
1mm., occasionally
more.
-------
Key to Selected Groups of Freshwater Animals
8B. Diptera, Mosquito
pupa. Up to 5mm.
8A. Diptura, Mosquito larvae
Up to 15 mm. long.
8C. Diptera, chironomid 8E'
larvae. Up to 2 cm.
9D. Diptera, Rattailed maggot
Up to 25mm. without tube.
9A. Annelid,
segmented
worm, up to
1/2 meter
10B. Alasmidonta. end view.
10A. Pelecyopod, Alasmidonta
Side view, up to 18 cm. long.
9B. Annelid, leech up to 20 cm.
12A. Branchiopod,
Daphnia. Up
to 4mm.
11A. Ostracod, Cypericus
Side view, up to 7 mm.
11B. Cypericus, end view.
12 B. Branchiopod,
Bosmina. Up
to 2mm.
45-9
-------
Key to Selected Groups of Freshwater Animals
13. Gastropod, Campeloma
Up to 3 inches.
15. Water mite,
up to 3 mm.
14. Megaloptera, Sialis
Alderfly larvae
Up to 25 mm.
16. Fairy Shrimp, Eubranchipus
Up to 5 cm.
17."Amphipod, Pontoporeia
to 25 mm.
18. Isopod, Asellus
Up to 25 mm.
20. Collembola, Podura
Up to 2 mm. long
45-10
19A. Calanoid copepod,
Female 19B. Cyclopoid cope pod-
Up to 3 mm. Female
Up to 25 mm.
-------
Key to Selected Groups of Freshwater Animals
21A.
21B.
21C,
21D. 21E.
21. Trichoptera, larval cases,
mostly 1-2 cm.
22. Megaloptera,--alderfly
Up to 2 cm.
23A. Beetle larvae, 23B. Beetle larvae, 24A. Odonata, dragonfly
Dytisidae, Hydrophilidae nymph up to 3 or
Usually about 2 cm. Usually about 4 cm
1 cm.
24E. Odonata, tail
of damsel fly ,,. ^ _._ ^J
nymph >=^ 24E, Odonata, front view
(side view) ///"• I of dragonfly nymph
Suborder \5& showing "mask"
Zygoptera ^^ partially extended
(24B, D) |—^__, Suborder
T"f Anisoptera
24D. Odonata, damselfly V —V (24A, E, C)
nymph (top view) V—•—y
\f]j24C. Odonata, tail of
dragonfly nymph
(top view)
45-11
-------
Key to Selected Groups of Freshwater Animals
25A. Hemiptera,
Water Boatman
About 1 cm.
25B. Hemiptera,
Water Scorpion
About 4 cm.
26. Plecoptera,
Stonefly nymph
Up to 5cm.
27.Ephemeroptera,
Mayfly nymph
Up to 3cm.
28A. Coleoptera.
Water scavenger
beetle. Up to 4 cm.
28B. Coleoptera,
Dytiscid beetle
Usually up to 4
cm,
45-12
29A. Diptera, Crane
fly. Up to 2i cm.
Diptera, Mosquito
Up to 20 mm.
-------
KEY TO FRESH WATER ALGAE
COMMON IN WATER SUPPLIES AND IN POLLUTED WATER
2a.
Beginning with "1a" and "1b," choose one of the two
contrasting statements and follow this procedure with the
"a" and "b" statements of the number given at the end of
the chosen statement. Continue until the;.name of the alga
is given instead of another key number. (Where recent
changes in names of algae have been made, the new name
is given followed by the old name in brackets.)
la. Plastid (separate color body) absent; com-
plete protoplast pigmented; generally blue-
green; iodine starch test* negative
(blue-green algae) 4
1b. Plastid or plastids present; parts of proto-
plast free of some or all pigments; gener-
ally green, brown, red, etc., but not
blue-green; iodine starch test* positive or
negative 2
Cell wall permanently rigid (never showing
evidence of collapse), and with regular pat-
tern of fine markings (striations, etc.); plas-
tids brown-to-green; iodine starch test*
negative; flagella absent; wall of two essen-
tially similar halves, one placed over the
other as a cover (diatoms)
Cell wall is present, capable of sagging,
wrinkling, bulging, or rigidity, depending on
existing turgor pressure of cell, protoplast;
regular pattern of fine markings oh wall gen-
erally absent; plastids green, red, brown,
etc.; iodine starch test* positive or negative;
flagella present or absent; cell wall continu-
ous and generally not of two parts
Cell or colony motile; flagella present (often
not readily visible); anterior and posterior
ends of cell different from one another in
contents and often in shape
(flagellate algae)
Non-motile; true flagella absent; ends of
cells often not differentiated
(green algae and associated forms)
2b.
3a.
3b.
Blue-Green Algae
4a. Cells in filaments (or much elongated to
form a thread)
75
198
262
'Add one drop Lugol's (iodine) solution, diluted 1:1 with distilled
water. In about 1 min, if positive, starch is stained blue.
4b. Cells not in (or as) filaments 61
5a. Heterocysts present 6
5b. Heterocysts absent 25
6a. Heterocyst located at one end of filament.. 7
6b. Heterocyst at various locations-in filament. . 15
7a. Filaments radially arranged in a gelatinous
bead 8
7b. Filaments isolated or irregularly grouped... 11
8a. Akinetes present (C/oeotr/chia) 9
8b. Akinetes absent (Rivularia) 10
9a. Gelatinous colony a smooth bead
G/oeotr/cn/a ech/nu/ata
9b. Gelatinous colony irregular
Gloeotrichia natans
10a. Cells near the narrow end as long as wide..
Rivularia dura
10b. Cells near the narrow end twice as long as
wide Rivularia haematites
11a. Filament gradually narrowed to one end....
(Calothrix) 12
11b. Filament not gradually narrowed to one end 13
12a. Cells adjacent to heterocyst wider than het-
erocyst Calothrix braunii
12b. Cells adjacent to heterocyst narrower than
heterocyst Calothrix parietina
13a. Heterocysts at both ends; filaments bent. . .
/Anafaaenops/s
13b. Heterocysts at one end; filaments straight
(Cylindrospermum) 14
14a. Heterocysts round
Cylindrospermum muscicola
14b. Heterocysts elongate
Cylindrospermum stagnate
15a. Filaments unbranched or with true branches 16
15b. Filament with occasional false branches.... 24
16a. True branching present; filament all or
partly multiseriate ... .Stigonema minutum
16b. Branching absent; filaments uniseriate 17
17a. Cross-walls much closer together than width
of filament Nodularia spumigena
17b. Cross-walls at least as far apart as width of
filament 18
18a. Filaments normally in tight parallel clusters;
heterocysts and spores cylindric to long oval
Aphanizomenon flos-aquae
BLMIC.cla. 23.4. 80
46-1
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Key to Fresh Water Algae Common in Water Supplies and in Polluted Water
Key
18b. Filaments not in tight parallel clusters; het-
erocysts and spores often round to oval.... 19
19a. Filaments in a common gelatinous mass ..
(Nostoc) 20
19b. Filaments not in a common gelatinous mass
(Anabaena) 21
20a. Heterocysts and vegetative cells rounded..
Nostoc pruniforme
20b, Heterocysts and vegetative cells oblong —
Nostoc carneum
21a. Cells elongate, depressed in the middle; het-
erocysts rare Anabaena constricta
21b. Cells rounded; heterocysts common 22
22a. Heterocysts with lateral extensions
Anabaena p/anctom'ca
22b. Heterocysts without lateral extensions 23
23a. Threads 4-8 microns wide
Anabaena flos-aquae
23b. Threads 8-14 microns wide
Anabaena drdnalis
24a, False branches in pairs
Scytonema to/ypothr/coides
24b. False branches single.. . . To/ypothnx tenuis
25a. Filament or elongated cell attached at one
end and with one or more round cells
(spores) at the other end
Entophysalis lemaniae
25b. Filament generally not attached at one end;
no terminal spores present 26
26a. Filament with regular spiral form throughout 27
26b. Filament not spiral or with spiral limited to
a portion of filament 30
27a. Filament septate Arthrospira jenneri
27b. Filaments not septate (Spirulina) 28
28a. Thread 0.9 micron or less in diameter
Spirulina subtillissima
28b. Thread 1.2 microns or more in diameter... 29
29a. Thread 1.2-1.7 microns in diameter
Spirulina major
29b. Thread 2.0 microns in diameter
Spirulina nordstedtii
30a. Filament aggregates forming conical tufts..
Symp/oca muscorum
30b. Filament aggregates not forming conical'
tufts 31
31a. Filament very narrow, only 0.5-2.0 microns
wide Schizothrix caldcola
31 b. Filament 3.0-95.0 microns wide 32
32a. Filaments loosely aggregated or not in clus-
ters 33
32b. Filaments tightly aggregated and surrounded
by a common gelatinous secretion that may
be invisible 56
33a. Filament surrounded by a wall-like sheath
that frequently extends beyond the ends of
the filament of cells; filament generally
without movement 34
33b. Filament not surrounded by a wall-like
sheath; filament may show movement 41
34a. False branching present
P/ectonema tomas/n/ana
34b. False branches absent 35
35a. Cells separated from one another by a space
/ohannesbapt/st/a
35b. Cells in contact with adjacent cells
(Lyngbya) 36
36a. Threads in part forming spirals
Lyngbya lagerheimii
36b. Straight or bent but not in spirals 37
37a. Threads colored yellowish to brown 38
37b. Sheaths colorless 39
38a. Cells rounded Lyngbya ocnracea
38b. Cells short discs Lyngbya aestuarii
39a. Cells constricted at the joints
Lyngbya putealis
39b. Cells not constricted at the joints 40
40a. Sheath very thick Lyngbya versicolor
40b. Sheath very thin Lyngbya digueti
41 a. All filaments short, with less than 20 cells;
one or both ends of filament sharp pointed
Raphidiopsis
41 b. Filaments long with more than 20 cells;
filaments commonly without sharp-pointed
ends (Osdllatoria) 42
42a. Cells very short, generally less than one-
third the thread diameter 43
42b. Cells generally one-half as long to longer
than thread diameter 46
43a. Cross walls constricted
Osdllatoria ornata
43b. Cross walls not constricted 44
44a. Ends of mature threads curved 45
44b. Ends of mature threads straight
Osdllatoria limosa
45a. Threads 10-14 microns thick
Osdllatoria curv/ceps
45b. Threads 16-60 microns thick
Osdllatoria princeps
46a. Threads appearing red to purplish
Osdllatoria rubescens
46b. Threads yellow-green to blue-green 47
47a. Threads blue-green 48
47b. Threads yellow-green 53
48a. Cells 1A-2 times as long as thread diameter. 49
48b. Cells 2-3 times as long as thread diameter. 55
49a. Cell walls between cells thick and trans-
parent Osdllatoria pseudogeminata
49b. Cell walls thin, appearing as a dark line.... 50
50a. Ends of thread straight
Osdllatoria agardhii
50b. Ends of mature threads curved 51
51a. Prominent granules present especially at
both ends of each cell
Osdllatoria tenuis
46-2
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Key to Fresh Water Algae Common in Water Supplies and in Polluted Water
ALGAE AND WATER POLLUTION
51 b. Cells without prominent granules 52
52a. Cross walls constricted
Oscillatoria chalybea
52b. Cross walls not constricted
Oscillatoria tormosa
53a. Cells 4-7 times as long as thread diameter..
Osc///ator/a putr/da
53b. Cells less than 4 times as long as the thread
diameter 54
54a. Prominent granules (pseudovacuoles) in cen-
ter of each cell .... Oscillatoria lauterbornii
54b. No prominent granules in center of cells ..
Oscillatoria chlorina
55a. End of thread long tapering ....;
Oscillatoria splendida
Ł>5b. End of thread not tapering
Oscillatoria amphibia
56a. Filaments arranged in a tight, essentially par-
allel bundle Microcoleus subterulosus
56b. Filaments arranged in irregular fashion, often
forming a mat (Phormidium) 57
;>7a. Ends of some threads with a rounded swol-
len "cap" cell 58
57b. Ends of all threads without a "cap" cell. . . 60
58a. Cells quadrate Phormidium autumnale
58b. Cells much shorter than broad 59
!>9a. Ends of some threads with round cap and
abruptly bent Phormidium uncinatum
59b. Ends of some threads with conical cap and
straight Phormidium subfuscum
60a. Threads"3-5 microns in width
Phormidium inundatum
60b. Threads 5-12 microns in width
Phormidium retzii
61 a. Cells in a regular pattern of parallel rows,
forming a plate
(Agmene//um quadriduplicatum) 62
61 b. Cells not regularly arranged to form a plate 63
62a. Cell diameter 1.3-2.2 microns Agmen-
e//um quadriduplicatum, tenuissima type
62b. Cell diameter 3-5 microns
Agmenellum quadriduplicatum, glauca type
63a. Cells regularly arranged near surface of a
spherical gelatinous bead 64
63b. Gelatinous bead, if present, not spherical.. 68
64a. Cells ovate to heart-shaped; connected to
center of bead by colorless stalks
(Gomphosphaer/a) 65
64b. Cells round; without gelatinous stalks
(Gomphosphaer/a [Coelosphaerium type]) 65
65a. Cells with pseudovacuoles
Gomphosphaer/a w/'churae
65b. Cells without pseudovacuoles 66
66a. Cells 2-4 microns diameter
(Gomphosphaer/a lacustris) 67
66b. Cells 4-15 microns diameter
Gomphosphaer/'a aponina
67a. Cells spherical Gom-
phosphaer/a lacustris, kuetzingianum type
67b. Cells ovate
.... Gomphosphaer/a lacustris, collinsii type
68a. Cells attached Dermocarpa
68b. Cells unattached 69
69a. Cells cylindric-oval .. Coccoch/or/s stagn/na
69b. Cells spherical 70
70a. Two or more distinct layers of gelatinous
sheath around each cell or cell cluster
(Anacystis [G/oeocapsap 72
70b. Gelatinous sheath around cells not distinctly
layered 71
71a. Cells isolated or in colonies of 2-32 cells..
(Anacystis [Chroococcus],) 72
71b. Cells in colonies of many cells
(Anacystis [Microcystis]) 72
72a. Cell containing pseudovacuoles
Anacystis cyanea
72b. Cell not containing pseudovacuoles 73
73a. Cell 2-6 microns diameter; sheath often
colored Anacystis montana
73b. Cell 6-50 microns diameter; sheath colorless 74
74a. Cell 6-12 microns diameter; cells in colonies
are mostly spherical . . . .Anacystis thermalls
74b. Cell 12-50 microns diameter; cells in colo-
nies are often irregular. Anacystis dimidiata
Diatoms
75a. Transverse wall markings not in one or two
longitudinal rows; front (valve) view gener-
ally circular in outline; markings, if present,
radial in arrangement; cells may form a fila-
ment (centric diatoms) 76
75b. Front (valve) view elongate, not circular;
transverse wall markings in one or two longi-
tudinal rows; cells if grouped, not forming
a filament but a ribbon, star, etc
(pennate diatoms) 107
76a. Cells pillow shaped in girdle view with a
blunt process at each corner
Biddulphia laevis
76b. Cells without blunt processes 77
77a. Cells very long, cylindrical in girdle view,
with a long spine at each end
.' (Rhizosolenia) 78
77b. Cells a disc or short cylinder in girdle view
with no long spine at each end of side.... 79
78a. Setae shorter than cell length
Rhizosolenia eriensis
78b. Setae longer than cell length
Rhizosolenia gracilis
79a. Cells in persistent filaments with valve faces
in contact; therefore, cells commonly seen
in side (girdle) view (Melosira) 80
79b. Cells isolated or in fragile filaments, often
seen in front (valve) view 88
46-3
-------
Key to Fresh Water Algae Common in Water Supplies and in Polluted Water
Key
80a. Distinct pores on valve mantle (shoulder)..
Me/os/ra binderana
80b. No distinct pores on valve mantle (shoulder) 81
81a. No visible ornamentation. .Me/os/ra var/ans
81 b. Ornamentation visible 82
82a. Terminal cells with long spines 83
82b. Terminal cells without long spines 84
83a. Diameter 5-21 microns. .Me/os/ra granulata
83b. Diameter 3-5 microns
Me/os/ra granulata var. angust/ss/ma
84a. Sulcus (groove) angular at base
Melosira ambigua
84b. Sulcus (groove) not angular at base 85
85a. Semi-cells shorter than wide
Me/os/ra distans var. a/p/gena
85b. Semi-cells about as long as wide 86
86a. With robust short spines.. .Me/os/ra ita//ca
86b. With fine teeth 87
87a. Sulcus distinctly acute-angled
Me/os/ra crenu/ata
87b. Sulcus not distinctly acute-angled
Me/os/ra islandica
88a. Radial markings (striations), in valve view,
extending from center to margin; short mar-
ginal spines sometimes present in valve view 89
88b. Area of prominent markings, in valve view,
limited to about outer half of circle; mar-
ginal spines generally absent ... (Cydotella) 90
89a. Radiate hyaline areas on valve view
(Stephanodiscus) 99
89b. No radial hyaline areas on valve view
(Coscinodiscus) 106
90a. Cells with marginal spines
Cydotella pseudostelligera
90b. Cells without marginal spines 91
91a. Central area with 3-4 round, raised spots
Cydotella ocellata
91 b. Central area without such ocelli
92a. Central area with star-shaped lines around
a central dot Cyc/ote//a stelligera
92b. Central area otherwise
93a. Cells small; 4-10 microns diameter
93b. Cells larger; 10-80 microns diameter 95
94a. Cells in chains; single ocellus in central area
Cydotella atomus
94b. Cells all isolated; no ocellus in central area
Cydotella glomerata
95a. Central area clear. .Cydotella meneghiniana
95b. Central area with markings 96
96a. Circular shadow line passes through the
costae Cydotella striata
96b. No circular shadow line 97
97a. Central area with punctae or short lines....
Cydotella kutzingiana
97b. Central area with fine radial striae 98
98a. A puncta at inner end of several shortened
marginal costae Cydotella bodanica
92
93
94
98b. No puncta at inner end of several marginal
costae Cydotella comta
99a. Cell diameter 4-30 microns 100
99b. Cell diameter 30-80 microns 104
100a. Prominent rib-like structures over outer
third of cell Stephanodiscus dubius
100b. No prominent rib-like structures 101
101a. Spine at end of each striation
Stephanodiscus tenuis
101b. Spines not as above 102
102a. Spines alternating with striae
Stephanodiscus hantzschii
102b. Spines not as above 103
103a. Girdle view with two transverse bands... .
Stephanodiscus binderanus
103b. Girdle view without transverse bands
Stephanodiscus astraea var. minutula
104a. Outer punctae of striae 12 in 10 microns...
Stephanodiscus astraea
104b. Outer punctae of striae 16 in 10 microns.. 105
105a. Cell diameter 30-60 microns
Stephanodiscus niagarae
105b. Cell diameter 72-80 microns
.... Stepnanod/'scus niagarae var. magnifies
106a. Surface slightly undulate; markings poly-
gonal Coscinodiscus rothii
106b. Surface flat; markings angular with central
dots Cosc/nod/scus denarius
107a. Cell longitudinally symmetrical in valve view 108
107b. Cell longitudinally unsymmetrical (two sides
unequal in shape), at least in valve view... 188
108a. Raphe at or near the edge of the valve.... 109
108b. Raphe or pseudoraphe median or sub-
median 124
109a. Cells lying side by side in colonies
Badllaria paradoxa
109b. Cells isolated or in twos 110
110a. Valve face transversely undulate
Cymatopleura so/ea
110b. Valve face not transversely undulate 111
111a. Marginal, keeled raphe areas lie opposite
one another on the two valves
Hantzschia amphioxys
111 b. Marginal, keeled raphe areas lie diagonal to
one another on the two valves. .(Nitzschia) 112
112a. Valve long-pointed, spine-like
Nitzschia acicularis
112b. Valve not long-pointed and spine-like .... 113
113a. Valve axis sigmoid 114
113b. Valve axis not sigmoid 116
114a. Cell 20-40 microns long . .Nitzschia parvula
114b. Cell more than 40 microns long 115
115a. Cell 50-70 microns long .. .Nitzschia sigma
115b. Cell 160-500 microns long
Nitzschia sigmoidea
116a. Carinal dots extended far across the valve
Nitzschia denticula
46-4
-------
Key to Fresh Water Algae Common in Water Supplies and in Polluted Water
ALCAE AND WATER POLLUTION
116b. Carinal dots not extended far across the
valve 117
117a. Cells in star-shaped colonies
N/tzsch/a holsatica
117b. Cells not in star-shaped colonies 118
118a. Keel only slightly excentric
Nitzschia dissipata
118b. Keel distinctly excentric 119
119a. Cell distinctly pulled in at the middle
Nitzschia linearis
119b. Cell not distinctly pulled in at the middle. . 120
120a. Cell with longitudinal fold 121
120b. Cell without longitudinal fold 122
121a. Cell 6-9 microns broad. .Nitzschia hungarica
121b. Cell 16-35 microns broad
Nitzschia tryblionella
122a. Striae 15-17 in 10 microns
Nitzschia amphibia
122.b. Striae more than 25 in 10 microns 123
123a. Striae 28-30 in 10 microns; cells elliptical-
lanceolate Nitzschia fonticula
123b. Striae 35-40 in 10 microns; cells linear-lan-
ceolate Nitzschia palea
124a. Cell transversely symmetrical in valve view 125
124b. Cell transversely unsymmetrical (two ends
unequal in shape or size), at least in valve
view 175
125a. Cell round-oval in valve view; not more
than twice as long as wide (Coccone/s) 126
125b. Cell elongate, more than twice as long as
wide 127
126a. Wall markings (striae) 18-20 in 10 microns
Coccone/s pediculus
I26b. Wall markings (striae) 23-25 in 10 microns
Coccone/s placentula
127a. Cell flat; girdle face wide, valve face narrow
(Tabellaria) 128
127b. Girdle and valve faces about equal in width 129
128a. Girdle face less than one-fourth as wide as
long Jabellaria fenestrata
128b. Girdle face more than one-half as wide as
long Tabellaria flocculosa
129a. Cell with several markings (septa) extending
without interruption across the valve face;
no marginal line of pores present (Diatoma) 130
129b. Cross-markings (striations or costae) on
valve surface, either interrupted by longi-
tudinal space (pseudoraphe), line (raphe), or
line of pores (carinal dots) 132
13Da. Cells 2-4 microns wide. Diatoma elongatum
130b. Cells 4-13 microns wide 131
131a. Cells 4-8 microns wide . .. .Diatoma anceps
131b. Cells 10-13 microns wide. .D/atoma vulgare
132a. Cells attached side by side to form a ribbon
of several-to-many cells (Fragilaria) 133
132b. Cells isolated or in pairs 138
133a.
133b.
134a.
134b.
135a.
135b.
136a.
136b.
137a.
137b.
138a.
138b.
139a.
139b.
140a.
140b.
14la.
141b.
142a.
142b.
143a.
143b.
144a.
144b.
145a.
145b.
146a.
146b.
147a.
147b.
148a.
148b.
149a.
149b.
Cells attached at middle portion only
Fragilaria crotonensis
Cells attached along entire length 134
Central area clear Fragilaria capucina
Central area not clear; has striations 135
Striae coarse 136
Striae fine 137
Valves much inflated at center
Fragilaria leptostauron
Valves not inflated at center
Fragilaria pinnata
Striae very short; cells 3-5 microns wide..
Fragilaria brevistriata
Striae long; cells 5-12 microns wide
Fragilaria construens
Cell narrow, linear, often narrowed to both
ends; true raphe absent (Synedra) 139
Cell commonly "boat" shaped in valve
view; true raphe present 147
Cell width 1-2 microns Synedra nana
Cell width 2-10 microns 140
Cell width 2-5 microns 141
Cell width 5-10 microns 144
Central clear area on one side of valve only
Synedra vaucheriae
No clear area on one side of center of valve
only 142
Central clear area present; striae almost
continuous 143
Central clear area absent; striae short
Synedra tabulata
Cell length about 500 microns
. Synedra acus var. angust/ss/ma
Cell length 40-200 microns
Synedra acus var. radians
Valves linear Synedra capitata
Valves lanceolate to linear-lanceolate 145
Valves narrow lanceolate; striae 12-14 in 10
microns Synedra acus
Valves linear-lanceolate; striae not 12-14 in
10 microns 146
Large clear refractive central area; ends
generally capitate Synedra pulchella
Large clear non-refractive central area; ends
non-capitate Synedra ulna
Cell longitudinally unsymmetrical in girdle
view; sometimes with attachment stalk . . .
(Achnanthes; 148
Cell symmetrical in girdle as well as valve
view; generally not attached 150
Valves constricted toward poles
Achnanthes microcephala
Valves gradually tapering toward the poles
Striations pronounced
Achnanthes lanceolata
Striations fine ... Achnanthes minutissima
149
46-5
-------
Key to Fresh Water Algae Common in Water Supplies and in Polluted Water
Key
150a. Area without striations extending as a trans-
verse belt around middle of cell
Staurone/s phoenicenteron
150b. No continuous clear belt around middle of
cell 151
151a. Cell with coarse transverse markings (costae),
which appear as solid lines even under high
magnification (Pinnularia) 152
151b. Cell with fine transverse markings (striae),
which appear as lines of dots under high
magnification 153
152a. Cell 5-6 microns broad
Pinnularia subcapitata
152b. Cell 34-50 microns broad ,
Pinnularia nobilis
153a. Girdle view hour-glass shaped; valves with
median longitudinal keel (extension)
Amphiprora alata
153b. Girdle view not hour-glass shaped; valves
without median longitudinal keel 154
154a. Longitudinal black spaces extending across
striations 155
154b. No longitudinal black spaces extending
across striations 157
155a. Longitudinal black spaces wavy
/4nomoeone/'s ex/'//s
155b. Longitudinal black spaces straight 156
156a. Longitudinal black spaces near margin ....
Ca/one/s
156b. Longitudinal black spaces near raphe: cen-
tral nodules with pair of extensions along
each side of raphe Diploneis smithii
157a. Raphe and valve sigmoid 158
157b. Raphe and valve not sigmoid 160
158a. Valve striae forming transverse and longi-
tudinal rows (Cyrosigma) 159
158b. Valve striae forming transverse and oblique
rows Pleurosigma delicatulum
159a. Cell length 150-240 microns
Cyrosigma attenuatum
159b. Cell length 80-120 microns
Gyros/gma kutzingii
160a. Pair of longitudinal extensions of central
nodule along sides of raphe
Frustulia ovu/gar/s
160b. Central nodule without longitudinal exten-
sions (Navicula) 161
161a. Striae irregularly shortened in central area
Navicula mutica
161 b. Striae not irregularly shortened in central
area 162
162a. Broad clear lanceolate area over much of
valve Navicula confervacea
162b. No broad clear area over much of valve .. 163
163a. Central area long, rectangular
Navicula accomoda
163b. Central area not long and rectangular .... 164
164a. Margin of valve undulate
Navilcula contenta
164b. Margin of valve not undulate 165
165a. Short septum at apices of valve
Navicula incomposita
165b. No short septum at apices of valve 166
166a. Central area large, irregularly rectangular ..
Navicula exigua var. cap/fata
166b. Central area not irregularly rectangular ... 167
167a. Central area strongly widened transversely 168
167b. Central area round, rhombic, lanceolate, or
small 169
168a. Valve length less than 25 microns
Navicula canalis
168b. Valve length more than 25 microns
Navicula graciloides
169a. Valve ends distinctly narrowed 170
169b. Valve ends truncate, rounded, or acute ... 172
170a. Valve broadly lanceolate; 5-7 microns ... 171
170b. Valve narrowly lanceolate; width 4-5 mi-
crons Navicula notha
171a. Central area large, rounded; ends not capi-
tate Navicula viridula
171b. Central area medium sized, irregular; ends
capitate Navicula cryptocephala
172a. Terminal striae more strongly marked than
elsewhere Navicula hungarica
172b. Terminal striae not more strongly marked
than elsewhere 173
173a. Valves almost linear
. Navicula tripunctata
173b. Valves lanceolate 174
174a. Central area large; valve lanceolate
Navicula lanceolata
174b. Central area small; valve linear-lanceolate
Navicula radiosa
175a. Cells attached together at one end only to
form radiating colony (Asterionella) 176
175b. Cells not forming a loose radiating colony 177
176a. Larger terminal swelling 1Vz to 2 times
wider than the other . .Asterionella formosa
176b. Larger terminal swelling less than 11/z times
wider than the other
Asterionella gracillima
177a. Cells in fan-shaped colonies
Meridion circulars
177b. Cells isolated or in pairs 178
178a. Prominent wall markings in addition to
striations present just below lateral margins
on valve (Surirella) 179
178b. Wall markings along sides of valve limited
to striations 183
179a. Cell width 40-160 microns 180
179b. Cell width 8-30 microns 181
180a. Cell transversely symmetrical
Surirella striatula
180b. Cell transversely unsymmetrical
Surirella splendida
46-6
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Key to Fresh Water Algae Common in Water Supplies and in Polluted Water
ALCAE AND WATER POLLUTION
181a. Cell linear, symmetrical
Surirella angustata
181b. Cell wider at one end 182
182a, Longitudinal folds marginal
Surirella brightwellii
182b. Longitudinal folds extend to the center ...
Surirella ovata
183a. Cell elongate; sides of valve almost parallel
except for terminal knobs ... (Asterionella) 176
183b. Sides of valve converging toward one end 184
184a. Cells bent in girdle view
Rhoicosphenia curvata
184b. Cells straight in girdle view 185
185a. Longitudinal line crossing striae near both
sides of valve Gomphoneis
185b. No longitudinal line crossing striae near
both sides of valve (Gomp/ionema) 186
186a. Narrow end enlarged in valve view
Gomphonema geminatum
186b. Narrow end not enlarged in valve view . .. 187
187a. Tip of broad end about as wide as tip of
narrow end in valve view
Gomphonema parvulum
187b. Tip of broad end much wider than tip of
narrow end in valve view
Comphonema olivaceum
188a. Valve with transverse septa or costae 189
188b. Valve with no transverse septa or costae .. 191
189a. Central portion of raphe "V" shaped
(Epithemia) 190
189b. Central portion of raphe straight
Rhopalodia gibba
190ai. Cells 8-15 microns wide; constricted below
the recurved capitate poles
Epithemia sorex
190b. Cells 15-18 microns wide; only slightly con-
stricted below the recurved somewhat capi-
tate poles Epithemia turgida
191 a. Convex margin of valve undulate at least
near the ends (Eunotia) 192
191b. Convex margin of valve not undulate 193
192a. Valve arcuate Eunotia lunaris
192b. Valve linear, only slightly curved
Eunotia pectinalis
193a. Raphe located almost through center of
valve (Cymbella) 194
193b. Raphe excentric; near concave edge of valve
Amphora ovalis
194a. Cell only slightly unsymmetrical
Cymbella cesati
194b. Cell distinctly unsymmetrical 195
195a. Central area with a puncta
Cymbella tumida
195b. Central area without puncta 196
196a. Striations distinctly cross-lined
Cymbe//a prostrata
196b. Striations not distinctly cross-lined 197
197a. Striae 7-9 in 10 microns; cells 30-100 mi-
crons long Cymbella turgida
197b. Striae 12-18 in 10 microns; cells 10-40 mi-
crons long Cymbella ventricosa
Flagellate Algae
198a. Cell in a loose, rigid, conical sac {lorica);
isolated or in a branching colony
(Dinobryon) 199
198b. Case or sac, if present, not conical; colony,
if present, not branching 202
199a. Branches diverging, often almost at a right
angle Dinobryon divergens
199b. Branches compact, often almost parallel .. 200
200a. Narrow end of lorica sharp pointed 201
200b. Narrow end of lorica blunt pointed
Dinobryon sertularia
201 a. Narrow end drawn out into a stalk
Dinobryon stipitatum
201 b. Narrow end diverging at the base
Dinobryon sociale
202a. Cells isolated or in pairs 203
202b. Cells in a colony of four or more cells ... 252
203a. Prominent transverse groove encircles the
cell 209
203b. Cell without transverse groove 204
204a. Plastid golden-brown 205
204b. Plastid green, yellow-green, red, or blue-
green 215
205a. Anterior end of cell rounded; one flagellum
(Chromulina) 206
205b. Anterior end of cell oblique; two flagella .. 207
206a. Plastid in anterior half of cell; posterior por-
tion of cell attenuate
Chromulina rosanoffii
206b. Plastid almost full length of cell; Posterior
portion of cell wide, rounded
Chromulina vagans
207a. Flagella extending from gullet; flagella al-
most equal in length (Cryptomonas.) 208
207b. No gullet; flagella very unequal in length . .
Oc/iromonas
208a. Cell narrowed to posterior end
Cryptomonas cylindrica
208b. Cell not narrowed to posterior end
Cryptomonas erosa
209a. Cell with prominent projections, rigid, one
forward and two or three on posterior end
Ceratium hirundinella
209b. Cell without several rigid, polar projections 210
21 Oa. Portions above and below transverse groove
about equal 211
210b. Front portion distinctly larger than posterior
portion 214
211 a. Cells naked, with no cell wall Cymnodinium
211b. Cells with cell wall composed of several
plates 212
46-7
-------
Key to Fresh Water Algae Common in Water Supplies and in Polluted Water
Key
212a. Cell wall thin but composed of plates
Glenodinium palustre
212b. Cell wall thick with clearly evident plates
(Peridinium) 213
213a. Ends of cells pointed
Peridinium wisconsinense
213b. Ends of cell rounded ..Peridinium cinctum
214a. Transverse furrow extends about half way
around cell Hemidinium
214b. Transverse furrow extends all way around
cell Massartia vorticella
215a. Cell with long bristles extending from sur-
face plates Mallomonas caudata
215b. Cells without bristles and surface plates .. 216
216a. Plastids blue-green Cyanomonas
216b. Plastids green, yellow-green, or red 217
217a. Cell naked, not covered by wall or lorica or
rigid membrane Dunaliella
217b. Cell covered by wall or loose rigid covering
or rigid membrane 218
218a. Space between protoplast and wall with
radial strands of protoplasm Haematococcus
218b. No radial strands of cytoplasm between
protoplast and wall or lorica 219
219a. Cell protoplast enclosed in loose rigid cov-
ering (lorica) 220
219b. Cell with membrane or wall but no loose
rigid covering 225
220a. Cell with four flagella Pedinopera
220b. Cell with one or two flagella 221
221 a. Lorica flattened; cell with two flagella
Phacotus lenticularis
221 b. Lorica not flattened; cell with one flagellum 222
222a. Lorica often opaque, generally dark brown
to red; plastid green Trache/omonas crebea
222b. Lorica often transparent, colorless to light
brown; plastid light brown (Chrysococcus) 223
223a. Outer membrane (lorica) oval
Chrysococcus ova//s
223b. Outer membrane (lorica) rounded 224
224a. Lorica thickened around opening
Chrysococcus rubescens
224b. Lorica not thickened around opening ....
Chrysococcus major
225a. Plastids brown to red to olive- or blue-green 226
225b. Plastids grass green 229
226a. Plastid blue-green to blue .. (Chroomonas) 227
226b. Plastids brown to red to olive-green
Rhodomonas lacustris
227a. Cell not pointed at one end
Chroomonas setoniensis
227b. Cell pointed at posterior end 228
228a. Plastid one per cell .. . Chroomonas caudata
228b. Plastids two per cell Chroomonas nordstetii
229a. Cell with colorless, rectangular wing
Pteromonas angulosa
229b. No wing extending from cell 230
230a. Cells with two chloroplasts, one on each
side Cryptoglena n/'gra
230b. Cells with more than two chloroplasts 231
231a. Cells flattened; margin rigid (Phacus) 232
231 b. Cell not flattened; margin rigid or flexible 233
232a. Posterior spine short, bent
Phacus p/euronectes
232b. Posterior spine long, straight
Phacus longicauda
233a. Pyrenoid present in the single plastid; no
paramylon; margin not flexible; two or
more flagella per cell 234
233b. Pyrenoid absent; paramylon present; several
plastids per cell; margin flexible or rigid;
one flagellum per cell 240
234a. Cells long fusiform (tapering at each end)
(Chlorogonium) 397
234b. Cells not fusiform, generally almost spher-
ical , 235
235a. Plastids numerous Vacuo/ar/a novo-munda
235b. Plastids few, commonly one 236
236a. Two flagella per cell 237
236b. Four flagella per cell ... .Carter/a multifilis
237a. Cell with sheath of different shape from pro-
toplast Sphaerellopsis
237b. Cell not as above (Ch/amydomonas) 238
238a. Distinct clear area across middle of cell ....
Ch/amydomonas pertusa
238b. • No distinct clear area across middle of cell 239
239a. Pyrenoid angular; eyspot in front third of
. cell Ch/amydomonas reinhardi
239b. Pyrenoid circular; eyespot in middle third of
cell Ch/amydomonas g/obosa
240a. Cell flexible in form; paramylon a capsule or
disc; cell elongate (Euglena) 241
240b. Cell rigid in form; paramylon ring-shaped;
cell almost spherical 250
241a. Green plastids hidden by a red pigment ...
Euglena sanguinea
241 b. No red pigment except for the eyespot . . . 242
242a. Plastids at least one-fourth the length of the
cell 243
242b. Plastids discoid or at least shorter than one-
fourth the length of the cell 244
243a. Plastids two per cell Euglena agilis
243b. Plastids several per cell, often extending
radiately from the center . .Euglena viridis
244a. Posterior end extending as a colorless spine 245
244b. Posterior end rounded or at least with no
colorless spine 247
245a. Posterior end gradually narrowed to a spine
Euglena acus
245b. Posterior end with an abrupt spine 246
246a. Spiral markings very prominent and granular
Euglena spirogyra
246b. Spiral markings fairly prominent, not granu-
lar Euglena oxyuris
46-8
-------
Key to Fresh Water Algae Common in Water Supplies and in Polluted Water
ALCAE AND WATER POLLUTION
247a. Small; length 35-55 microns Euglena gracilis
247b. Medium to large; length 65 microns or more 248
248a. Medium in size; length 65-200 microns 249
248b. Large in size; length 250-290 microns
Euglena ehrenbergii
249a. Plastids with irregular edge; flagellum two
times as long as cell .. Euglena polymorpha
249b. Plastids with smooth edge; flagellum about
one-half as long as the cell ... Euglena deses
250a. Cell almost spherical or with abrupt poste-
rior tip; paramylon ring-shaped
(Lepocinclis) 251
250b. Posterior end of cell gradually pointed; cell
margin with spiral ridges . .. .Phacus pyrum
25>1a. Posterior end with an abrupt, spine-like tip
Lepocinclis ovum
251 b. Posterior end rounded ...Lepocinclis texta
252a. Plastids brown 253
2S2b. Plastids green 254
253a. Cells in contact with one another
Synura uve//a
253b. Cells separated from one another by a space
Uroglenopsis americana
254a. Colony flat; one cell thick Gonium pectorale
254b. Colony rounded; more than one cell thick . 255
2.55a. A long straight rod extending from each cell
Chrysosphaerella longispina
255b. No long straight rod extending from each
cell 256
256a. Cells in contact with one another 257
256b. Cells separated from one another by a
space 260
257a. Cells radially arranged . . Pandorina morum
257b. Cells all facing one direction 258
258a. Cells each with two flagella . .(Pyrobotrys) 259
258b. Cells each with four flagella
Spondylomorum quaternarium
259a. Eyespot in the wider (anterior) end of the
cell Pyrobotrys stellata
259b. Eyespot in the narrower (posterior) end of
the cell Pyrobotrys gracilis
260a. Cells more than 400 per colony
Volvox aureus
260b. Cells less than 150 per colony 261
261 a. Cells of two distinct sizes in colony
Pleodorina
261 b. Cells all of one size in colony
Eudorina elegans
Green Algae and Associated Forms
262a. Cells joined together to form a net
Hydrodictyon reticulatum
262b. Cells not forming a net 263
263a. Cells attached side by side to form a plate
or ribbon one cell thick and one (or two)
cells wide; Number of cells commonly 2, 4,
or 8 (Sceneries™ us.) 264
263b. Cells not attached side by side 268 279b.
264a.
264b.
265a.
265b.
266a.
266b.
267a.
267b.
268a.
268b.
269a.
269b.
270a.
270b.
271a.
271 b.
272a.
272b.
273a.
273b.
274a.
274b.
275a.
275b.
276a.
276b.
277a.
277b.
278a.
278b.
279a.
Middle cells without spines but with
pointed ends 265
Middle cells with rounded ends 266
All cells in colony erect
Scenedesmus obliquus
Median cells erect, terminal cells lunate ...
Scenedesmus dimorphus
Terminal cells with spines 267
Terminal cells without spines
Scenedesmus bijuga
Terminal cells with two spines each
Scenedesmus quadricauda
Terminal cells with three or more spines
each Scenedesmus abundans
Cells isolated or in nonfilamentous or non-
tubular thalli 269
Cells in filaments or other tubular or thread-
like thalli 335
Cells isolated and narrowest at the center
due to incomplete fissure (desmids) 270
Cells isolated or in clusters but without cen-
tral fissure 276
Each half of cell with three spine-like or
pointed knobular extensions . .(Staurastrum) 271
Cell margin with no such extensions 273
Margin of cell with long spikes
Staurastrum paradoxum
Margin of cell without long spikes 272
Ends of lobes with short spines
Staurastrum polymorphum
Ends of lobes without spines
Staurastrum punctulatum
Semi-cells with no median incision or de-
pression (Cosmarium) 274
Semi-cells with a median incision or de-
pression 275
Median incision narrow linear
Cosmarium botrytis
Median incision wide, "U" shaped
Cosmarium portianum
Margin with rounded lobes
Euastrum oblongum
Margin with sharp-pointed teeth
Micrasterias truncata
Lunate or otherwise bent cells in a wide
gelatinous matrix (Kirchneriella) 277
Cells otherwise 278
Cells sharply pointed
Kirchneriella lunaris
Cells bluntly pointed
Kirchneriella subsolitaria
Cells elongate 279
Cells round to oval to angular 297
Cells quadrately arranged in fours
Tetradesmus
Cells not quadrately arranged 280
46-9
-------
Key to Fresh Water Algae Common in Water Supplies and in Polluted Water
Key
280a. Cells radiating from a central point
(Act/'nastrum; 281
280b. Cells isolated or in irregular clusters 282
281a. Cells cylindric ..../\ct/nastrum gradllimum
281 b. Cells distinctly bulging
/\ct/nastrum hantzschii
282a. One or both cell ends gradually narrowed
to an acute spine-like point
Ourococcus bicaudatus
282b. Cells either with true spines or without
spine-like points 283
283a. Cells with terminal spines 284
283b. Cells without terminal spines 285
284a. Cell ends blunt .. . Ophiocytium capitatum
284b. Cell ends tapering .. . .Schroederia setigera
285a. Cells with colorless attachment area at one
end Characium
285b. No attachment area at one end of cell... . 286
286a. Plastids two per cell; unpigmented area
across center of cell (Closterium) 287
286b. Cell with plastid that continues longitudi-
nally across the center of the cell 290
287a. Cell small; length up to 177 microns
Closterium acutum
287b. Cell larger; length more than 240 microns 288
288a. Cell long and narrow; width up to 5 mi-
crons Closterium aciculare
288b. Cell wide; minimum width 19 microns. .. . 289
289a. Inner margin of cell straight
Closterium acerosum
289b. Inner margin of cell tumid and curved ...
Closterium moniliferum
290a. Two, four, or many cells surrounded by
homogenous envelope
Elakatothrix getatinosa
290b. No gelatinous envelope 291
291a. Cell five to ten times as long as broad .... 292
291 b. Cell two to four times as long as broad .. . 294
292a. Pyrenoid absent or one per cell
(Ankistrodesmus) 293
292b. Pyrenoids several per cell
Closteriopsis brevicula
293a. Cells bent Ankistrodesmus falcatus
293b. Cells straight
.... Ankistrodesmus falcatus var. acicularis
294a. Plastid pale yellow-green; reddish oil drop-
lets present Pleurogaster
294b. Plastid grass-green; storage food is starch 295
295a. Cells semi-circular; cell ends pointed but
with no terminal spines fSe/enastrum) 296
295b. Cells arcuate but less than semi-circular;
cell ends pointed and each with a short
spine Closteridium lunula
296a. Cells with rounded ends
Selenastrum capricornutum
296b. Cells with pointed ends
Selenastrum gracile
297a. Plastids green 298
297b. Plastids golden-brown; cells with pseudo-
podia 306
298a. Numerous gelatinous setae extending from
surface of colony Chaetopeltis megalocystis
298b. No gelatinous setae extending from surface
of colony 299
299a. Cells arranged in a flat regular colony 300
299b. Cells not in a tight, flat, regular colony ... 307
300a. Marginal cells with one or two or more
spines or spine-like extensions 301
300b. Marginal cells otherwise 304
301 a. Colonies limited to four cells with true
spines Tetrastrum
301 b. Colonies generally of eight or more cells, if
limited to four cells, without true spines
(Pediastrum) 302
302a. Numerous spaces between cells
Pediastrum duplex
302b. Cells fitted tightly together 303
303a. Cell incisions deep and narrow
Pediastrum tetras
303b. Cell incisions deep and wide
Pediastrum boryanum
304a. All cells in contact with neighboring cells.. 305
304b. At least some cells lie free from one an-
other Dispora
305a. Quadrangular space in center of each group
of four cells Crucigenia quadrata
305b. No quadrangular space in center of each
group of four cells .... Pras/'o/a nevadense
306a. Cells isolated C/irysamoeba
306b. Cells in colonies Chrysidiastrum
307a. Plastid distinctly central Apiococcus
307b. Plastid parietal 308
308a. Cells angular 309
308b. Cells round to oval 311
309a. Two or more spines at each angle
Polyedriopsis spinulosa
309b. Spines none or less than two at each angle
(Tetraedron) 310
31 Oa. Corners produced into processes
Tetraedron limneticum
310b. Corners not produced into processes ....
Tetraedron muticum
311a. Cells with long sharp spines 312
311b. Long sharp spines absent 315
312a. Cells round 313
312b. Cells oval 314
313a. Cells isolated Colenkinia radiata
313b. Cells in colonies ... Micractinium pusillum
314a. Each cell end with one spine
Diacanthos belenophoris
314b. Each cell end with more than one spine ...
Chodatella quadriseta
315a. Each cell with a sheath which is not con-
fluent with sheaths of adjacent cells
(Cloeocystis) 316
315b. Cells or sheaths otherwise 317
46-10
-------
Key to Fresh Water Algae Common in Water Supplies and in Polluted Water
ALGAE AND WATER POLLUTION
316a. Colonies angular .. .Gloeocystis planctonica
316b. Colonies rounded Gloeocystis gigas
317a. Each cell group with two shapes of cells ..
Dimorphococcus lunatus
317b. All cells of essentially the same shape ... 318
318a. Colony of definite, regular form, round to
oval 319
318b. Colony, if present, not a definite oval or
sphere; or cells may be isolated 325
319a. Colony a tight sphere of cells 320
319b. Colony a loose sphere of cells enclosed by
a membrane 321
320a. Sphere solid, slightly irregular; no connect-
ing processes between cells
Planktosphaeria gelatinosa
320b. Sphere hollow, regular; short connecting
processes between cells
Coelastrum microporum
321a. Cells round 323
321b. Cells oval (Oocystis) 322
322a. Cells with polar nodules .Oocystis lacustris
322b. Cells without polar nodules Oocystis borgei
323a. Cells connected to center of colony by
• branching stalk (Dictyosphaerium) 324
323b. No stalk connecting the cells
Sphaerocystis schroeteri
324a. Cells rounded D/ctyospnaerium pulchellum
324b. Cells straight, oval
Dictyosphaerium ehrenbergianum
325a. Oval cells enclosed in a somewhat spherical,
often orange-colored matrix
Bofryococcus braunii
325b. Cells round, isolated or in colorless matrix 326
326a. Adjoining cells with straight, flat walls be-
tween their protoplasts 327
326b. Adjoining cells with rounded walls between
their protoplasts 328
327a. Cells embedded in a common gelatinous
matrix Palmella mucosa
327b. No matrix or sheath outside of cell walls
Phytoconis botryoides
328a. Cells loosely arranged in a large gelatinous
matrix Tetraspora gelatinosa
328b. Cells isolated or tightly grouped in a small
colony 329
329a. Cells located inside of protozoa
Zoochlorella
329b. Cells not inside of protozoa 330
330a. Cells with two or more plastids
Palmellococcus
330b. Each cell with a single plastid 331
331a. Plastid filling two-thirds or less of the cell.. 332
331 b. Plastid filling three-fourths or more of the
cell Chlorococcum humicola
332a. Cell diameter 2 microns or less; reproduc-
tion by cell division Nannochloris
332b. Cell diameter 2.5 microns or more; repro-
duction by internal spores (Chlorella) 333
333a. Cells rounded 334
333b. Cells ellipsoidal to ovoid
Chlorella ellipsoidea
334a. Cell 5-10 microns in diameter; pyrenoid
indistinct Chlorella vulgaris
334b. Cell 3-5 microns in diameter; pyrenoid
distinct Chlorella pyrenoidosa
335a. Cells attached end to end in an unbranched
filament 336
335b. Thallus branched or more than one cell
wide 362
336a. Plastids in form of one or more marginal,
spiral ribbons; spirals may be incomplete.. 337
336b. Plastids not in form of spiral ribbons 342
337a. Spiral turn of plastic incomplete Sirogonium
337b. Plastid forming one or more spiral turns .. .
(Spirogyra) 338
338a. One plastid per cell 339
338b. Two or more plastids per cell 341
339a. Threads 18-26 microns wide
Spirogyra communis
339b. Threads 28-50 microns wide 340
340a. Threads 28-40 microns wide
Spirogyra varians
340b. Threads 40-50 microns wide
Sp;>ogyra porticalis
341a. Threads 30-45 microns wide; 3-4 plastids
per cell Spirogyra fluviatilis
341 b. Threads 50-80 microns wide; 5-8 plastids
per cell Spirogyra majuscula
342a. Filaments when breaking, separating
through middle of cells 343
342b. Filaments, when breaking, separating irregu-
larly or at ends of cells 346
343a. Starch test positive; cell margin straight; one
plastid, granular (Microspora) 344
343b. Starch test negative; cell margin slightly
bulging; several plastids (Tribonema) 345
344a. Cells 22-33 microns broad
Microspora amoena
344b. Cells 11-20 microns broad
Microspora wittrockii
345a. Plastids two to four per cell
Tribonema minus
345b. Plastids more than four per cell
Tribonema bombycinum
346a. Filaments short; generally 2-3 cells long ...
St/chococcus bacillaris
346b. Filaments longer than 2-3 cells 347
347a. Marginal indentations between cells 348
347b. No marginal indentations between cells . . 349
348a. Cells much shorter than broad
Desmidium grevillii
348b. Cells almost as long as broad
Hyalotheca mucosa
349a. Plastids two per cell (Zygnema) 350
46-11
-------
Key to Fresh Water Algae Common in Water Supplies and in Polluted Water
Key
349b. Plastid one per cell (sometimes appearing
numerous) 352 365b.
350a. Cell dense green, each plastid reaching to 366a.
the wall Zygnema sterile 366b.
350b. Cells light green; plastids not completely 367a.
filling the cell 351
351 a. Width of thread 26-32 microns; maximum 367b.
cell length 60 microns ... Zygnema insigne 368a.
351 b. Width of thread 30-36 microns; maximum
cell length 120 microns
Zygnema pectinatum 368b.
352a. Some cells with walls having transverse
wrinkles near one end; plastid an irregular 369a.
net (Oedogonium) 353
352b. No apical wrinkles in wall; plastid not 369b.
porous 356
353a. Thread diameter less than 25 microns .... 354 370a.
353b. Thread diameter 25 microns or more .... 355
354a. Thread diameter 9-14 microns
Oedogonium suedcum 370b.
354b. Thread diameter 14-23 microns 371a.
Oedogonium boscii
355a. Dwarf male plants attached to normal thread 371 b.
when reproducing 372a.
Oedogonium idioandrosporum 372b.
355b. No dwarf male plants produced 373a.
Oedogonium grande
356a. Plastid a flat or twisted axial ribbon 373b.
(Mougeotia) 357 374a.
356b. Plastid an arcuate marginal band (Ulothrix) 359
357a. Threads with occasional "knee-joint" bends 374b.
Mougeot/'a genurVexa
357b. Threads straight 358
358a. Threads 19-24 microns wide; pyrenoids 4-16 375a.
per cell Mougeotia sphaerocarpa 375b.
358b. Threads 20-34 microns wide; pyrenoids 4-10 376a.
per cell Mougeot/'a sca/ar/s
359a. Threads 10 microns or less in diameter ... 360 376b.
359b. Threads more than 10 microns in diameter 361
360a. Threads 5-6 microns in diameter 377a.
Ulothrix variabilis
360b. Threads 6-10 microns in diameter 377b.
Ulothrlx tenerrima
361a. Threads 11-17 microns in diameter 378a.
Ulothrix aequalis
361 b. Threads 20-60 microns in diameter 378b.
Ulothrix zonata
362a. Thallus a tangled tubular mass of filaments 379a.
Thorea ramosissima
362b. Thallus otherwise 363 379(3.
363a. Thallus a gelatinous tube in which cells are
embedded Hydrurus 380a.
363b. Thallus otherwise 364 380b.
364a. Thallus a flat plate of cells
Hildenbrandia rivularis 381 a
364b. Thallus otherwise 365
365a. Thallus a tubular layer of cells
Enteromorpha intestinalis
Thallus otherwise 366
Thallus a long tube without cross-walls ... 367
Thallus otherwise 370
Tube with constrictions especially at base of
branches — D/chotomos/'phon tuberosus
Tube with no constrictions ... .(Vaucheria) 368
Egg sac attached directly, without a stalk,
to the main vegetative tube
Vaucheria sessilis
Egg sac attached to an abrupt, short, side
branch 369
One egg sac per branch
Vaucheria terrestris
Two or more egg sacs per branch
Vaucheria geminata
Thallus a leathery strand with regularly
spaced swellings and a continuous mem-
brane of cells 396
Thallus otherwise 371
Filament unbranched
Schizomeris leibleinii
Filament branched 372
Branches in whorls (clusters) 373
Branches single or in pairs 378
Thallus embedded in gelatinous matrix ...
(Batrachospermum) 374
Thallus not embedded in gelatinous matrix 375
Nodal masses of branches touching one an-
other Batrachospermum vagum
' Nodal masses of branches separated from
one another by a narrow space
Batrachospermum moniliforme
Main filament one cell thick (Nitella) 376
Main filament three cells thick ... .(Chara) 377
Short branches on the main thread re-
branched once Nitella flexilis
Short branches on the main thread re-
branched two to four times Nitella gracilis
Short branches with 2 naked cells at the
tip Chara globularis
Short branches with 3-4 naked cells at the
tip Chara vu/gar/s
Most of filament surrounded by a layer of
cells Compsopogon coeruleus
Filament not surrounded by a layer of cells
379
End cell of branches with a rounded or
blunt-pointed tip 380
End cell of branches with a sharp-pointed
tip 387
Plastid green; starch test positive 381
Plastids red; starch test negative
Audouinella violacea
Some cells dense, swollen, dark green
(spores); others light green, cylindric
Pithophora oedogonia
46-12
-------
Key to Fresh Water Algae Common in Water Supplies and in Polluted Water
ALGAE AND WATER POLLUTION
382
383
381 b. All cells essentially alike, being light to me-
dium green, cylindric (Cladophora)
382a. Branches arising from below apices of cells
Cladophora profunda var. nordstedt/ana
382b. Branches arising from apices of cells
383a. Branches often appearing forked or in threes
Cladophora aegagropila
383b. Branches distinctly lateral 384
384a. Branches forming acute angles with main
thread, thus forming clusters
Cladophora glomerata
384b. Branches forming wide angles with the main
thread 385
385a. Threads crooked and bent
Cladophora Iracta
385b. Threads straight 386
386a. Branches few, seldom rebranching
Cladophora insignis
386b. Branching numerous, often rebranching ...
Cladophora crispata
387a. Filaments embedded in gelatinous matrix .
387b. Filaments not embedded in gelatinous ...
matrix
388a. Cells of main filament much wider than
even the basal cells of the branches
(Draparnaldia)
388b. No abrupt change in width of cells from
main filament to branches .. (Chaetophora)
389a. Branches (from the main thread) with a cen-
tral main axis Draparnaldia plumosa
3fl9b. Branches diverging and with no central
main axis Draparnaldia glomerata
388
391
389
390
390a. End cells long-pointed with colorless tips
Chaetophora attenuata
390b. End cells abruptly pointed, mostly without
long colorless tips ... Chaetophora e/egans
391 a. Branches very short, with no cross-walls
Rhizodonium hieroglyphicum
391 b. Branches long, with cross-walls 392
392a. Branches ending in an abrupt spine having
a bulbous base (Bulbochaete) 393
392b. Branches gradually reduced in width, end-
ing in a long pointed cell, with or without
color (Stigeodonium) 394
393a. Vegetative cells 20-48 microns long
Bulbochaete mirabilis
393b. Vegetative cells 48-88 microns long
Bulbochaete insignis
394a. Branches frequently in pairs 395
394b. Branches mostly single
Stigeodonium stagnatile
395a. Cells in main thread 1-2 times as long as
wide Stigeodonium lubricum
395b. Cells in main thread 2-3 times as long as
wide Stigeodonium tenue
396a. Nodes covered by a ring of antheridial tis-
sue Lemanea annulata
396b. Nodes covered by wart-like outgrowths of
antheridial tissue Sacheria
397a. Pyrenoids two per cell
Chlorogonium elongatum
397b. Pyrenoids several per cell
Chlorogonium euchlorum
This outline was prepared by C. M. Palmer
former Aquatic Biologist, (from Algae
and Water Pollution , MERL, ORD,
U.S. EPA, Cincinnati, Ohio 45268.)
Descriptors: Algae, Plankton,
Identification Keys
46-13
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A KEY FOR THE INITIAL SEPARATION OF SOME COMMON
PLANKTON ORGANISMS
1. No chlorophyll present, unless through ingestion 8
1. At least some chlorophyll present 2
2. Pigments not in plastids Cyanophyta
2. Pigments in one or more plastids 3
3. Cell wall of over-lapping halves and distinctly sculptured Bacillariophyta
3. Cell wall not of over-lapping halves, or if so, then not sculptured 4
4. Pyrenoids present; color usually bright green Chlorophyta
4. Pyrenoids absent; color green, yellow-green or yellow-brown . 5
5. Bright green, motile, usually with one anterior flagellum Euglenophyta
5. Yellowish to brownish, motile or not 6
6. With a distinct lateral groove, motile Pyrrophyta
6. Without a lateral groove 7
7. Seldom motile; unicellular, colonial or filamentous Xanthophyta
7. Motile, unicellular or colonial Chrysophyta
8. Unicellular; naked or enclosed in a smooth or sculptured shell 9
8. Multicellular; body usually with a distinct exoskeleton 11
9. Amoeboid; sometimes with shell, no cilia or flagella Ameoboid Protozoa
9. Actively motile; never with shell; cilia or flagella obvious 10
10. Body more or less covered by short cilia;
movement "darting" Ciliate Protozoa
10. Body with one or more flexible whip-like falgella;
movement "continous" Flagellate Protozoa
11. Shell bivalved (clam-like) 12
11. Shell not composed of two halves 13
12. With distinct head anterior to valves Cladocera
12. No head anterior to valves Ostracoda
13, Usually microscopic; body extended into a tail or foot with one
or more toes Rotifera
13,, Usually macroscopic if mature 14
14. Appendages bilateral; head not prominent Copepoda
14. Appendages unilateral; head prominent Phyllopoda
BI.AQ. 33. 6.16 47-1
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CHLOROPHYTA
A Key to Some of the Common Filamentous Genera
1. Filaments unbranched 2
1. Filaments branched (sometimes parenchymatous) 12
2. Chloroplast single, parietal band 3
2. Chloroplast one or more, if parietal not a band 5
3. Chloroplast encircling more than half the cell (Napkin-ring like) Ulothrix
3. Chloroplast encircling less than half the cell 4
4. Filaments of indefinite length; cells with square ends Hormidium
4. Filaments usually short, of 3-8 cells, with ends round Stichococcus
5. Cell .wall of H pieces; pyrenoids lacking Microspora
5. Cell wall not of H pieces 6
6. Some cells with apical caps Oedogonium
6. Cells without apical caps 7
7. Chloroplast (s) parietal 8
7. Chloroplast (s) axial 9
8. Chloroplast one or more, spiral bands Spirogyra
8. Chloroplast several, longitudinal bands Sirogonium
9. Cell walls without a median constriction 10
9. Cell walls with a median constriction 11
10. Chloroplast stellate Zygnema
10. Chloroplast an axial band Mougeotia
11. Filaments cylindrical Hyalotheca
11. Filaments triangular, twisted Desmidium
12. Coenocytic dichotomously branched, with constrictions Dichotomosiphon
12. Filaments with regular cross walls 13
13. Parenchymatous, discoid, epiphytic Coleochaete
13. Not parenchymatous 14
14. Main axis cells much broader than branch cells Draparnaldia
14. Main axis and branch cells approximately the same breadth 16
15. Main axis and lateral branches attenuated into long multicellualr hairs 16
15. Axis and branches not attenuated into long multicellular hairs 17
16. Sparsely or loosely branched Stigeoclonium
16. Densely and compactly branched Chaetophora
47-2
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17. Cells bearing swollen or bulbous-based setae 18
17. Cells without setae 19
18. Swollen-based setae on dorsal surface of cells; prostrate
epiphytes; little or not al all branched Aphanochaete
18. Bulbous-based setae terminal on branches; not
prostrate epiphytes Bulbochaete
19. With terminal and/or intercalary akinites Pithophora
19. Without distinctive akinites 20
20. Cells of erect filaments becoming shorter and broader toward
filament apex; usually growing on back of turtles; branching only
from base Basicladia
20. Thallus not as above . 21
21. Filaments irregularly branched; branches short 1 - or few celled . . . Rhizoclonium
21. Filaments repeatedly branched; branches narrowed toward tips Cladophora
47-3
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CHLOROPHYTA
A Key to Some Common Non-Filamentous Genera
1. Unicellular "..... 2
1. Colonial 27
2. Motile in vegetative state, flagella 2-4 3
2. Non-motile in vegetative state 5
3. Cells with 2 flagella 4
3. Cells with 4 flagella Carteria
4. Cell enclosed by bicovex shell Phacotus
4. Cell not enclosed by a shell Chlamy domonas
5. Cells with median constriction (often slight), or of chloroplast only 6
5. Cells without a median constriction '. . 15
6. Cells lunate Closterium
6. Cells not lunate in any degree 7
7. Cells cylindrical, noticeably longer than broad 8
7. Cells almost never cylindrical; flattened or triangular in apical view 9
8. Length 2-3 times the breadth, contriction nearly lacking Cylindrocystis
8. Length much greater than breadth, nodulose at constriction Pleurotaenium
9. Cells triangular in end view Staurastrum
9. Cells not triangular in end view 10
10. Semicells with lateral incisions, appearing lobed 11
10. Semicells without lateral incisions 12
11. Lateral incisions few, shallow, lobes rounded Euastrum
11. Lateral incisions many, deep, lobes angular Micrasterias
12. Semicells with radiating arms Staurastrum
12. Semicells without arms; spines, granules, or teeth may be present 13
13. Semicells without spines Cosmarium
13. Semicells with spines 14
14. Spines few, usually at the apical corners Arthrode smus
14. Spines numerous, scattered Xanthidium
15. Cells elongate, sometimes needle-like 16
15. Cells spherical, ovid, angular; not needle-like 18
16. Cells with terminal setae Schroederia
16. Cells without terminal setae 17
47-4
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17. Cells acicular, without a row of pyrenoids Ankistrodesmus
17. Cells acicular, very long, with a row of 10-12 pyrenoids Closteropsis
18. Cells without spines or processes . 19
18. Cells with spines or processes 23
19. Cells embedded in a gelatinous matrix 20
19. Cells without a gelatinous matrix 21
20. Gelatin obvious, lamellate; chloroplast cup-shaped Gloeocystis
20. Gelatin sometimes obvious, chloroplast, star-like .Asterococcus
21. Cells spherical 22
21. Cells angular Tetraedron
22. Cell wall smooth Chlorella
22. Cell wall sculptured Trochiscia
23. Cells angular 24
23. Cells spherical or oval, with spines 23
24. Angles with furcated processes Tetraedron
24. Angles with spines Polyedriopsis
25. Cells spherical, spines delicate Golenkinia
25. Cells oval, spines evident 26
26. Spines localized at ends of cell Lagerheimii
26. Spines distributed over cell Franceia
27. Motile, each cell with 2 equal-length flagella 28
27. Non-motile invegetative state 33
28. Colony a "flat" plate 29
28. Colony spherical or ovid 30
29. Colony "horse-shoe" shaped Platydorina
29. Colony quadriangular or circular Gonium
30. Cells 8-16, crowded-pyriform Pandorina
30. Cells more than 16, not crowded, spherical or nearly so 31
31. Cells more than 300 in number Volvox
31. Cells less than 300 in number ~~, T~32
32. Cells (16) - 32 in number Eudorina
32. Cells 64-128 - (256) in number Pleodorina
33. Cells of colony lying in one plane 34
33. Cells not in a conspicuous single plane 37
34. Colony circular (rarely cruciate) Pediastrum
34. Colony not circular ~ '. ', ", 735
47-5
-------
35. Colony a flat strip; cells side by side Scenedesmus
35. Colony quadriangular 36
36. Colony usually large, cells in 4's, no spines Crucigenia
36. Colony of 4 cells, each with 1 or 2 marginal spines Tetrastrum
37. Cells acicular (needle-like) Ankistrodesmus
37. Cells not acicular 38
38. Colony without a gelatinous envelope 39
38. Colony with a more or less conspicuous gelatinous envelope 47
39. 2-8 oval enclosed by a distinct sheath Oocystis
39. Cells not enclosed by a sheath 40
40. Cells with long spines or setae 41
40. Cells without spines or setae 42
41. Colony pyramidate, cell spherical, long spines Errerella
41. Colony quadrate, or a tetrahedron, long setae Micractinium
42. Cells linear, radiating from a common center Actinastrum
42. Cells no linear 43
43. Cells strongly lunate, often "back-to-back" Selena strum
43. Cells not lunate ". . ~ . . . 44
44. Cells arranged in a hallow sphere 45
44. Cells not arranged in a hallow sphere 46
45. Cells spherical, sometimes joined by processes Coelastrum
45. Cells not spherical, outer angles extended into stout, blunt
teeth or spines Sorastrum
46. Cells uniform, spherical, in groups of 4 - 8 Westella
46. Cells not uniform, ellipsoid (oblong) or reniform Dimorphococcus
47. Cells curved to strongly lunate 48
47. Cells not curved or lunate 49
48. Cells lunate, loosely arranged in colony Kirchneriella
48. Cells curved or reniform, colony compact, distinct Nephrocytium
49. Cells connected by branching central strands Dictyosphaerium
49. Cells not connected by stands 50
50. Cells cylindrical or fusiform 51
50. Cells spherical or slightly ovoid 52
51. Cells in parallel "bundles" of 2 - 8 Quadrigula
51. Cells longitudinally arranged, not grouped laterally Elakatothrix
-------
52. Cells ellipsoid or ovoid, envelope lamellated Gloeocystis
52. Cells spherical, or nearly so 53
53. Chloroplast axial, star-shaped Asterococcus
53. Chloroplast parietal, not star-shaped ~'. '. '. . 54
54. Cells enclosed by lamellated sheaths Gloeocystis
54. Cells in homogenous envelopes Sphaerocystis
47-7
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EUGLENOPHYTA
1. Vegetative cells sessile Colacium
1. Vegetative cells motile 2
2. Cells with chlorophyll 3
2. Cells without chlorophyll 8
3. Protoplast within a lorica or test Trachelomonas
3. Protoplast naked, no lorica 4
4, Body strongly metabolic Euglena
4. Body rigid 5
5. With two laminate, longitudinal chloroplasts Chryptoglena
5. With numerous chloroplasts . 6
6. Body conspicuously flattened, sometimes twisted Phacus
6. Body not compressed, radially symmetrical 6
7. Body broadly ellipsoid to ovoid Lepocinclis
7. Body elongate, narrow Euglena
8. Cells with one flagellum Astasia
8. Cells with two flagella Peranema
47-8
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KEY TO SOME COMMON DIATOM GENERA (BACTLLARIOPHYTA) OF
MICHIGAN
Diatoms in Valve View
1. Valves without a dividing line or cleft; markings of valve radiate about a central
point, (centric diatom genera) 2
2. Frustules usually in filaments or zig-zag chains; rectangular in girdle
view; valve round, oblong, triangular or elongate 3
3. Frustules cylindrical; markings prominent on girdle; sulcus
present; seldom seen in valve view Melosira
3. Frustule not cylindrical 4
4. Valve ovate to oblong; two horns or processes present on valve face,
scatter small spines often present Biddulphia
4. Valve not ovate to oblong, horns or processes absent 5
5. Valve face appearing as two; three sided pieces giving the
appearance of six processes Hydrosira
5. Valve face three to several times longer than broads; margins
undulate: "costae" evident Terpsinoe
2. Frustules usually solitary (sometimes forming short chains) 6
6. Frustules usually elongated; many intercalary bands, frustules
cylindrical 7
7. Each valve with a single long spine Rhizosolenia
7. Each valve with two long spines Attheya
6. Valves discoid; cylindrical; or spherical; somtimes with spines or
processes 8
8. Ornamentation of valves in two concentric parts of unlike
pattern Cyclotella
8. Ornamentation of valves radiate; continuous from center to
margin of valves 9
9. Ornamentation of valves distinctly radiate; rows of punctae
single at center becoming multiseriate at the margin; margin
of valve with recurved spines Stephanodiscus
9. Ornamentation of valves not distinctly radiate or becoming
multiseriate at margin 10
47-9
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10. Isolated large punctum evident at the margin spines
not evident Thalassiosira
10. Isolated punctum not evident at the margin, short
spines present Cascinodiscus
1. Valve with a dividing line or cleft; marking of wall bilaterally
disposed to an axial or excentric line (pennate diatom genera) 11
11. Both valves with a pseudoraphe 12
12. Valves asymetrical to one axis 13
13. Valve asmetrical to longitudinal axis, striae present . . Ceratoneis
13. Valve asymetrical to transverse axis 14
14. Valves clavate 15
14. Valves not clavate; striae present; valves with unequal
capitate ends; often forming star like colonies . . Asterionella
15. "Costae" present, frustules may be joined face
to face to form fan like filaments Meridion
15. "Costae: present, frustules single (appears
as asymetrical Fragilaria) Opephora
12. Valves symetrical to both axes 16
16. Frustules septate or "costate"; often appearing in
zig-zag chains 17
17. Septae present; usually many partially septate
intercalary bands; valves triundulate Tabellaria
17. Septae absent; prominant "costae" on valve . . . Diatoma
16. Frustules occuring free or attached in filaments;
sometimes forming fascicles 18
18. Frustules typically forming long filaments; usually
not more than 5 or 6 times longer than broads;
often appearing costate Fragilaria
18. Frustules usually solitary or forming fascicles;
usually many times longer than broad Synedra
(note: the above two genera are actually seperated
only on the basis of growth habit)
11. At least one valve with a pseudoraphe 19
47-10
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19. One valve with a true raphe the other valve with a pseudoraphe 20
20. Valve asymetrical to the transverse axis; partial terminal septae;
bent about the transverse axis Rhoicosphenia
20. Valves symetrical to both axes 21
21. Valve elliptical; valves with a marginal and/or submarginal
hyaline ring; often loculiferous; bent about the longitudinal
axis Cocconeis
21. Valves usually lanceolate or linera lanceolate; bent
around the transverse axis Achnanthes
(Those with a sigmoid raphe are sometimes put in
Achnanthidium or Eucocconeis)
19. Both valves with a raphe 22
22. Raphe median or nearly so, never completely marginal;
not in a canal .. 23
23. Valves sigmoid in outline 24
24. Raphe sigmoid; punctae in two series; one transverse
and one longitudinal row forming a 90° angle .... Gyrosigma
24. Raphe sigmoid; punctae in three series forming
angles of other than 90° Pleurosigma
23. Valve not sigmoid in outline 25
25. Valves symetrical to both axes 26
26. Frustules with septate intercalary bands 27
27. Intercalary bands with marginal loculi, punctae
distinct Mastagloia
27. Intercalary bands with two large faramen along
apical axis, punctae indistinct Diatomella
26. Frustules without septate intercalary bands 28
28. Valve face with a sigmoid saggital keel;
"hourglass" shape outline in girdle view . . . Amphiprora
28. Valve face without a sigmoid saggital keel 29
29. Valve with undulate or zig-zag irregular logitudinal lines or
blank spaces Anomoeneis
29. Valve without undulate or zig-zag irregular logitudinal lines or
blank spaces 30
47-11
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30. Valve with thickened, non-punctate central area; (stauros)
pseudoseptae sometimes present, longitudinal lines and blank
spaces lacking Stauroneis
30. Valve with or without stauros, septal absent 31
31. Valve with longitudinal lines or blank spaces 32
32. Proximal ends of raphe usually curved in opposite
directions; "defaut regularier" toward valve apices;
longitudinal blank spaces Neidium
32. Proximal ends of raphe straight; valves with fine
striae that appear as costae; longitudinal line
near margin Caloneis
31. Valves without longitudinal lines or blank spaces 33
33. Valves with siliceous ribs along each side of the raphe 34
34. Raphe bisects siliceous ribs on valve; central
area small and orbicular; striae and punctae
very distinct ' Diploneis
34. Raphe short; less than 1/2 length of valve; central
area long and narrow; terminal nodules evident,
elongate 35
35. Raphe short; 1/4 or less the length of the valve;
striae not evident Amphipleura
35. Raphe longer; usually about 1/3 the length of
the valve; striae usually fine but evident . . . Frustulia
33. Valve without siliceous ribs 36
36. Valves with smooth transverse costae; raphe
often ribbon like; Pinnularia
36. Valves with transverse striae 37
37. Raphe sigmoid Scoliopleura
37. Raphe straight 38
38. Raphe in straight and raised keel Tropodoneis
38. Raphe straight and not in a keel 39
39. Striae daubly punctate, central area long and narrow . . . Brebessonia
39. Striae single to lineate, central area variable .... Navicula
47-12
-------
25. Valves symetical to one axis only . ' 40
40. Valves symetrical to the longitudinal axis 41
41. Punctae in one series; longitudinal line absent Gomphonema
41. Punctae in two series; longitudinal line present Gomphoneis
40. Valves symetrical to transverse axis 42
42. Raphe short; vestigial terminal; with evident terminal nodules,
central nodule lacking 43
43. Colonial; forming tree like colonies; valves usually with
evident spines Desmogonium
43. Usually not in colonies or if colonial, forming only
short chains or stellate clumps 44
44. Cells shaped like the femur of a chicken . . . . Actinella
44. Valves various shaped; lunate to nearly straight;
valve often with undulate dorsal and/or ventral
margin; raphe prominant in girdle view 45
45. Dorsal margin convex, ventral margin slightly
concave, both margins sinvate-dentate . . . Amphicampa
45. Dorsal margin convex, ventral margin straight
to concave, one, both or neither margin wavy,
pseudoraphe often present on ventral margin . . . Eunotia
42. Raphe not vestigial; usually as nearly as long as the valve;
valves usually cymbiform 46
46. Valves convex; central nodule usually lies very close to the
ventral margin; both raphe visible in girdle view .... Amphora
46. Valves flat or nearly so; raphe a smooth curve with the same
curvature as the axial field; raphe not visible in girdle
view Cymbella
22. Raphe marginal and in a canal 47
47. Valves with a single canal that is usually marginal but may appear
to be somewhat central 48
48. Valves symetrical to both axes 49
49. Transverse internal septae that appear as "costae"; canal
nearly median Denticula
49. Transverse "costae" lacking; carnial dots present . . . Nitzschia
47-13
-------
48. Valves asymetrical to longitudinal axis 50
50. "Costae" quite evident 51
51. Axial field forming an acute angle at the central nodule;
raphe along the ventral margin of valve Ephithemia
51. Axial field forming a less acute angle at the central
nodule; raphe along the dorsal margin of the valve . . Rhopalodia
50. "Costae" not evident; carnial dots along the raphe 52
52. Raphe of one valve diagonally opposite the raphe on
the other valve Nitzschia
52. Raphe of one valve directly opposite the raphe on the
other valve Hantzschia
47. Valves with a canal next to both lateral margins 53
53. Valve face transversely undulate; band of short costae along each
lateral margin appearing like a row of beads Cymatopleura
53. Valve face not transversely undulate 54
54. Valve shaped like a saddle Campylodiscus
54. Valve face flat; either isopolar or heteropolar; sometimes
the frustule is slightly spiral in shape Surirella
47-14
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CHRYSOPHYTA
A Key to Some More or Less Common Genera
1. Filamentous, branched Phaeothamnion
1. Not filamentous 2
2. Unicellular 3
2. Colonial 7
3. Protoplast enclosed by a lorica 4
3. Protoplast not enclosed by a lorica 6
4. Epiphytic or epizooic 5
4. Motile; cells with siliceous scales many of which have long,
siliceous spines Mallomonas
5. Epiphytic; lorica flask-shaped Lagynion
5. Epiphytic or epizooic; lorica cylindrical .Epipyxis(= Hyalobryon)
6. Motile; protoplast naked Ochromonas (and assoc.)
6. Non-motile; protoplast with long delicate, pseudopodia Rhizochrysis
7. Sessile; each cell in a long, cylindrical lorica Epipyxis (Hyalobryon)
7. Motile .8
8. Each cell within a companulate, basally pointed lorica Dinobryon
8. Lorica absent 9
9. Colony bracelet-shaped Cyclonexis
9. Colony spherical 10
10. Colony bristling with long siliceous rods Chrysosphaerella
1.0. Colony without siliceous rods from each cell 11
11. Colonies not enclosed by a gelatinous sheath Synura
11. Colonies enclosed by a distinct gelatinous sheath 12
12. Shorter flagellum more than 1/2 length of longer flagellum Uroglenopsis
12. Shorter flagellum less than 1/2 length of longer flagellum Uroglena
47-15
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CYANOPHYTA
A Key to Some of the Common Genera
1. Cells not in trichomes; unicellular or colonial 2
1. Cells in trichomes 10
2. Colony with some regular arrangement of cells 3
2. Colony amorphous, no definite form 6
3. Colony a flat plate 4
3. Colony spherical, cells peripheral 5
4. Cells regularly arranged Merismopedia
4. Cells irregularly arranged .Holopedium
5. Colony with a central branching system Gomphosphaeria
5. Colony without a central branching system Coelosphaerium
6. Colony many celled .7
6. Colony mostly few celled 9
7. Cells elongate Aphanothece
7. Cells spherical 8
8. Cells close together Microcystis
8. Cells more than 2-3 diameters apart Aphanocapsa
9. Cells usually hemispherical, with or without definite gelatinous sheaths . . Chroococcus
9. Cells spherical or ovaod, gelatinous sheaths very distinct Gloeocapsa
10. Trichomes without sheath (not filamentous) 11
10. Trichomes in a sheath (filamentous) 20
11. Heterocysts absent 12
11. Heterocysts present 14
12. Trichomes straight . . Oscillatoria
12. Trichomes regulary spiraled 13
13. Cross walls distinct Arthrospira
13. Cross walls lacking Spirulina
14. Heterocysts terminal 15
14. Heterocysts intercalary 18
15. Trichomes cylindrical Cylindrospremum
15. Trichomes attenuate 16
16. Trichomes solitary Calothrix
16. Trichomes in masses '. '.\ T?
47-16
-------
17. Trichomes without akinetes Rivularia
17. Trichomes with akinetes Gloeotrichia
18. Trichomes straight, parallel in bundles Aphanizomenon
18. Trichomes solitary, or if in masses, not parallel 19
19. Trichomes solitary, or if numerous, then not in a firm gelatinous
matrix Anabaena
19. Trichomes entangled in a firm gelatinous matrix Nostoc
20. Many parallel trichomes in a sheath Microcoleus
20. A single trichome or row of trichomes in a sheath 21
21. Filaments not branched 22
21. Filaments branched 23
22. Sheath obvious firm Lyngbya
22. Sheath indistinct, delicate Phormidium
23. Filaments with false branching .24
23. Filaments with true branching 26
24. Without heterocysts Plectonema
24. With heterocysts 25
25. False branches arising single Tolypothrix
25. False branches in pairs Scytonema
26. Trichomes always uniseriate Haplosiphon
26. Trichomes wholly or in part nultiseriate Stigonema
47-17
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XANTHOPHYCEAE
A Key to Some Common Genera
1. Filamentous 2
1. Not filamentous ' 4
2. Filaments branched, siphonaceaous Vaucheria
2. Filaments not branched .' 3
3. Cell wall of stout H pieces, cells sometimes barrel-shaped Tribonema
3. Cell wall of delicate H pieces, cells short and cylindrical Bumilleria
4. Cells embedded in a gelatinous matrix 5
4. Cells not embedded in a gelatinous matrix 7
5. Colonial gelatinous envelope dichotomously branched Mischococcus
5. Colonial gelatinous envelope not branched . . .6
6. Colonial envelope, tough "heavy" cartilaginous Botryococcus
6. Colonial envelope watery; colonies small, free floating Chlorobotrys
7. Cells epiphytic 8
7. Cells not epiphytic 11
8. Stipe long, seta-like Stipitococcus
8. Stipe short; or cell-sessile Peroniella
9. Cell vase-like, apex flattened Stipitococcus
9. Cell oval or spherical Peroniella
10. Cells cylindrical, ends broadly rounded Ophiocytium
10. Cells not cylindrical Characiopsis
11. Cells cylindrical, straight or contorted Ophiocytium
11. Cells globose, with rhyzoids, on soil Botrydium
47-18
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Acicular: needle-like in shape. (Ankistrodesmus)
Aerial: algal habitat on moist soil, rocks, trees, etc.; involving a thin film of water;
sometimes only somewhat aerial.
Akinete: A type of spore formed by the transformation of a vegetative cell into a thick-
walled resting cell, containing a concentration of food material. (Pithophora)
Amoeboid: like an amoeba; creeping by extensions of highly plastic protoplasm
(pseudopodia). (Chrysamoeba)
Amorphous: without definite shape; without regular form.
Anastomose: to separate and come together again; a meshwork.
Antapical: the posterior or rear pole or region of an organism, or of a colony of cells.
Anterior: the forward end; toward the top.
Antheridiurn: a single cell or a series of cells in which male gametes are produced; a
multicellular, globular male organ in the Characeae, more properly called
a globule (a complicated and specialized branch in which antheridial cells
are produced.
Antherozoid: male sex cell; sperm.
Apex: the summit, the terminus, end of a projection, of an incision, or of a filament
of cells.
Apical: Forward tip.
Aplanospore: non-motile, thick-walled spore formed many within an unspecialized
vegetative cell; a small resting spore.
Arbuscular: branched or growing like a tree or bush.
Armored: See theca.
Attenuate: narrowing to a point or becoming reduced in diameter. (Gloeotrichia)
Autospores: spore-like bodies cut out of the contents of a cell which are small replicas
of the parent cell and which only enlarge to become mature plants. (Coelastrum)
Axial: along a median line bisecting an object either transversely or longitudinally
(especially the later, e.g. an axial chloroplast).
Bacilliform: rod-shaped.
Bilobed: with two lobes or extensions.
47-19
-------
Bipapillate: with two small protrusions; nipples.
Biscuit-shaped: a thickened pad; Pillow-shaped.
Bivalve (wall): wall of cell which is in two sections, one usually slightly larger
than the others.
Blepharoplast: a granular body in a swimming organism from which a flagellum arises.
Bristle: a stiff hair; a needle-like spine. (Mallomonas)
Capitate: with an enlargement or a head at one end. (as in some species of Oscillatoria)
Carotene: Orange-yellow plant pigment of which there are four kinds in algae; a
hydrocarbon, C, H.
Chlorophyll: a green pigment of which there are five kinds in the algae chlorophyll-a
occurring in all of the algal divisions.
Chloroplast: a body of various shapes within the cell containing the pigments of which
chlorophyll is the predominating one.
Chromatophore: body within a cell contining the pigments of which some other tan
chlorophyll is the predominating one; may be red, yellow, yellow-green
or brown.
Chrysolaminarin: See leucosin.
Coenobium; a colony with 2^ number of cells. (Scenedesmus)
Coenocytic: with multinucleate cells, or cell-like units; a multinucleate, non-cellular
plant. (Vaucheria)
Collar: A thickened ring or neck surrounding, the opening in a shell or lorica through
which a flagellum projects from the inclosed organism. (Trachelomonas)
Colony: a group or closely associated cluster of cells, adjoined or merely inclosed by a
a common investing mucilage or sheath; cells not arranged in a linear series to
form a filament; either aggregate or coenobium.
Constricted: cut in or incised, usually form two opposite points on a cell so that an
isthmus is formed between two parts or cell halves; indented as at the
joints between cells of a filament. (Cosmarium)
Contractile vacuole: a small vacuole (cavity) which is bounded by a membrane that
pulsates, expanding and contracting.
Crenulate: wavy with small scallops; with small crenations.
Crescent: an arc of a circle; a curved figure tapering to horn-like points from a wider,
cylindrical midregion.
Cross wall: a cross partition.
47-20
-------
Cup-shaped: a more or less complete plate (as a chloroplast) which lies just within
the cell wall, open at one side to form a cup.
Cylindrical: a figure, round in cross section, elongate with parallel lateral margins
when seen from the side, the ends square or truncate. (Hyalotheca)
Daughter cells: cells produced directly from the division of a primary or parent cell;
cells produced from the same mother cell.
Dichotomous: dividing or branched by repeated forkings, usually into two equal portions
or segments.
Disc; Disc-shaped: a flat (usually circular) figure: a circular plate.
Distal: the forwar or anterior end or region as opposed to the basal end.
Ellipsoid: an ellipse, a plane figure with curved margins, the poles more sharply
rounded than the lateral margins of an elongate figure.
Epiphyte: living upon a plant, sometimes living internally also.
Euplankton: true or openwater plankton (floating) organisms.
Eye-spot: a granular or complex of granules (red or brown) sensitive to light and
related to responses to light by swimming organisms of spores. (Pandorina)
False Branch: a branch formed by lateral growth of one or both ends of a broken
filament; a branch not formed by lateral division of cells in an unbroken
filament, (Tolypothrix)
Filament: a thread of cells; one or more rows of cells; in the blue-green algae the
thread of cells together with a sheath that may be present, the thread of
cells alone referred to as a trichome.
Flagellum (flagella): a relatively coarse, whip-like organ of locomotion, arising from
a special granule, the blepharoplast, within a cell. (Euglena)
Fucoxanthin: a brown pigment predominant in the Phaeophyta and Chrysophyta. (Synura)
Fusiform: a figure broadest in the midregion and gradually tapering to both poles which
may be acute or bluntly rounded; shaped like a spindle. (Closterium)
Gamete: a sex cell; cells which unite to produce a fertilized egg or zygospore.
Gas vacuole: See pseudovacuole.
Gelatin (gelatinous): a mucilage-like substance.
Glycogen: a starch-like storage product questionably identified in food granules of the
Cyanopjyta. (Chroococcus)
Gregarious: an association; groupings of individuals not necessarily joined together but
closely associated.
47-21
-------
Gullet: a canal leading from the opening of flagellated cells into the reservoir in the
anterior end. (Euglena)
Gypsum: granules of calcium sulphate which occur in the vacuoles of some
desmids. (Closterium)
Haematochrome: a red or orange pigment, especially in some Chlorophyta and
Euglenophyta, which masks the green chlorophyll.
Heterocyst: an enlarged cell in some of the filamentous blue-green algae, usually
empty and different in shape from the vegetative cells, (Anabeana)
Hold-fast cell: a basal cell of a filament or thallus, differentiated to form an
an attaching organ. (Oedogonium)
H-pieces: wall of overlapping H-shaped structures. (Tribonema)
Intercalary: arranged in the same series, as spores or heterocysts which occur in
series with the vegetative cells rather than being terminal or lateral.
(heterocyst of Anabeana)
Laminate: plate-like; layered.
Lateral groove: a groove in Dinoflagellates encircling the cell. (Ceratium)
Leucosin: a whitish food reserve characteristic of many of the Chrysophytam especially
the Heterokontae; gives a metallic lustre to cell contents. (Dinobryon)
Lorica: a shell-like structure of varying shapes which houses an organism, has an
opening through which organs of locomotion are extended. (Dinobryon)
Lunate: crescent-shaped; as of the new moon in shape. (Selenastrum)
Median construction: See constricted.
Metabolic: plastic, changing shape in motion as in many Euglena.
Micron: a unit of microscopical measurement; one 1/1000 of a millimeter, determined
by using a micrometer in the eyepiece of the microscope which has been
calibrated with a standard stage micrometer; expressed the symbol.
Moniliform: arranged like a string of beads; beadlike; lemon-shaped. (Anabeana)
Mother Cell: the cell which by mitosis or by internal cleavage gives rise to
other cells (usually spores).
Multinucleate: with many nuclei.
Multiseriate: cells arranged in more than one row; a filament two or more cells in
diameter. (Stigeonema)
Motile: motion caused by cilia or flagella. (Volvox)
Oblong: a curved figure, elongate with the ends broadly rounded but more sharply curved
than the lateral margins.
47-22
-------
Obovate: an ovate figure, broader at the anterior end than at the posterior.
Oogonium: a female sex organ, usually an enlarged cell; an egg case.
Oval; an elongate, curved figure with convex margins and with ends broadly and
symmetrically curved but more sharply so than the lateral margin.
Ovoid: shaped like an egg; a curved figure broader at one end than at the other.
Paramylum: a solid, starch-like storage product in the Euglenophyta. (Euglena)
Parietal: along the wall; arranged at the circumference; marginal as opposed to
central or azial in location.
Pellicle: a thin membrane. (Euglena)
Peridinin: a brown pigment characteristic of the Dinoflagellata. (Ceratium)
Periplast: bounding membrane of cells in Euglenoids and Chrysophytes.
Phycocyanin: a blue pigment found in the Cyanophyta, and in some Rhodophyta.
Phycoerythrin: a red pigment found in the Rhodophta, and in some Cyanophyta.
Plcinkton: organisms srifting in the water, or if swimming, not able to move
against currents.
Plastid: a body or organelle of the cell, either containing pigments or in some
instances colorless.
Plate: sections, polygonal in shape, composing the cell wall of some Dinoflagellata
(the thecate or armored dinoflagellates).
Posterior: toward the rear; the end opposite the forward (anterior) end of a cell
or of an organism.
Protoplast: the living part of the cell; the cell membrane and its contents usually
enclosed by a cell wall of dead material.
Pseudocilia: meaning false cilia; flagella-like structures not used for locomotion as
in Apiocystis and Tetraspora.
Pseudoparenchymatious: a false cushion; a pillow like mound of cells (usually attached)
which actually is a compact series of short, often branched
filaments. (Coleochaete)
Pseudovacuole: meaning a false vacuole; a pocket in the cytoplasm of many blue-green
algae which contains gas or mucilage; is light refractive. (Microcystis)
Pyrenoid: a protein body around which starch or paramylum collects in a cell, usually
buried in a chloroplast but sometimes free within the cytoplasm. (Oedogonium)
Pylform: pear-shaped. (Pandorina)
47-23
-------
Reniform: kidney-shaped; bean-shaped. (Dimorphocacus)
Replicate: infolded; folded back as in the cross walls of some species of Spirogyra; not
a plane or straight wall.
Reticulate: netted, arranged to form a network; with openings.
Scale: siliceous or inorganic material covering the cell. (Mallomonas)
Semicell: a cell-half, as in the Placoderm desmids in which the cell has two parts
that are mirror images of one another, the two parts often connected by a
narrow isthmus. (Staurastrum)
Septum; a cross-partition, cross wall or a membrane complete or incomplete through
the short diameter of a cell, sometimes parallel with the long axis.
Setae: a hair, usually arising from within a cell wall; or a hair-like extension
formed by tapering of a filament of cells to a fine point.
Sheath; a covering, usually of mucilage, soft or firm; the covering of a colony
of cells, or an envelope about one or more filaments of cells.
Siphonous: a tube; a thallus without cross partitions. (Vaucheria)
Solitary: unicellular; solitary. (Chlamydomonas)
Spine: a sharply-pointed projection from the cell wall. (Mallomonas)
Sproangium: a cell (sometimes an unspecialized vegetative cell) which gives rise to
spores; the case which forms abcut the zygospores in the Zygnematales.
Star-shaped: See stellate
Stellate: with radiating projections from a common center; star-like. (Zygnema)
Stigma: see eyespot.
Suture: a groove between plates, as in some Dinoflagellata; a cleft-like crack or line
in some zygospores of the Zygnemataceae. (Ceratium)
Thallus: a plant body which is not differentiated into root, stem and leal organs; a
frond; the algal plant.
Theca; Thecate: a firm outer wall; a shell, sometimes with plates as in the
Dinoflagellata. (Peridinium)
Test: a shell or covering external to the cell itself. See Lorica.
Transverse furrow (groove): a groove extending around the cell as in the
Dinoflagellata. (Ceratium)
Trichrome: in blue-greens, a series of cells joined end to end. (Oscillatoria)
47-24
-------
True Branch: a branch formed by means of lateral division of cells in a main filament.
Includes all branched algae except those blue- green algae with false
branching.
Tychoplankton: the plankton of waters near shore; organisms floating and entangled
among weeds and in algal mats, not in the open water of a lake
or stream.
Undulate: regularly wavy.
Unicellular: See solitary.
Vegetative: referring to a non- reproductive stage, activity, or cell as opposed to
activities and stages involved in reproduction, especially sexual reproduction.
Xanthophyll: a yellow pigment of several kinds associated with chlorphyll,
Zoospore: an animal- like spore equipped with flagella and usually with an eye- spot.
This key was prepared by Dr. Matthew H. Hohn,
Professor of Biology, Central Michigan
University, Mt. Pleasant, Michigan.
Descriptors: Plankton, Identification Keys
47-25
-------
CLASSIFICATION - FINDER
for
NAMES OF AQUATIC ORGANISMS
in
WATER SUPPLIES AND POLLUTED WATERS
Part I. The System of Classification
I INTRODUCTION
A Every type of living creature
has a favorite place to live.
There are few major groups that
are either exclusively terres-
trial or aquatic. The following
remarks will therefore apply in
large measure to both, but pri-
mary attention will be directed
to aquatic types.
B One of the first questions usu-
ally posed about an organism is:
"What is it?", usually meaning
"What is it's name?". The nam-
ing or classification of bio-
logical organisms is a science
in itself (taxonomy). Some of
the principles involved need to
be understood by anyone working
with organisms however.
1 Names are the "key number",
"code designation", or "file
references" which we must
have to find information
about an unknown organism.
2 Why are they so long and why
must they be in Latin and
Greek? File references in
large systems have to be long
in order to designate the
many divisions and subdivi-
sions. There are over a
million and a half items (or
species) included in the
system of biological nomen-
clature (very few libraries
have a million books).
3 The system of biological no-
menclature is regulated by
international congresses.
a It is based on a system of
groups and super groups,
of which the foundation
(which actually exists in
nature) is the species.
Everything else has been
devised by man and is sub-
ject to change and revision
as man's knowledge and
understanding increase.
b The basic categories em-
ployed are as follows:
(1) Similar species are
grouped into genera
(genus)
(2) Similar genera are
grouped into families
(3) Similar familes are
grouped into orders
(4) Similar orders are
grouped into classes
(5) Similar classes are
grouped into phyla
(phylum)
(6) Similar phyla are
grouped into kingdoms
4 The scientific name of an or-
gan isin~Ts~~ITs~genus" name plus
its species name. This is ana-
logous to our system of sur-
names (family names) and given
names (Christian names).
a The generic (genus) name
is always capitalized and
the species name written
with a small letter. They
should also be underlined
or printed in italics when
used in a technical sense.
For example:
Homo sapiens - modern man
Homo neanderthalis -
neanderthal man
Esox niger - Chain pickerel
Esox lucius - northern pike
Esox masquinongy -
muskellunge
b Common names do not exist
for most of the smaller and
less familiar organisms.
For example, if We wish to
refer to members of the
BI.AQ. 24.6.76
48-i
-------
RELATIONSHIPS BL1WEEN LIVING ORGANISMS
ENERGY FLOWS FROM LEFT TO RIGHT, GENERAL EVOLUTIONARY
SEQUENCE IS UPWARD
PLANTS 5
ORGANIC MATERIAL
PRODUCED, USUALLY
BY PHOTOSYNTHESIS
ENERGY STORED
FLOWERING PLANTS
AND GYHNOSPERHS 76
CLUB MOSSES, FERNS 76
LIVERWORTS, MOSSES 73
ALGAE 12
M_MM_aMI_^^^^_^^^_^M_MMHMMI^^_^B_MMi_^^^_Hi_M
ANIMALS 81
ORGANIC MATERIAL INGESTED OR
CONSUMED
DIGESTED INTERNALLY
ENERGY RELEASED
243
ARACHNIDS 167 MAMMALS
INSECTS 154 BIRDS 242
CRUSTACEANS 129 REPTILES 241
SEGMENTED WORMS 121 AMPHIBIANS 240
MOLLUSCS 172 FISHES 195
MOSS ANIMALS 120,181 PROCHORDATES 191
WHEEL ANIMALS 116 STARFISH GROUPS 185
ROUNDWORMS 113
FLATWORMS 108
JELLYFISH - CORAL GROUP 103
SPONGES 99
^— — — — — ^— ^— — —
FUNGI 250
ORGANIC MATERIAL
REDUCED
BY EXTRACELLULAR
DIGESTION AND IN-
TRACELLULAR META-
BOLISM TO MINERAL
CONDITION
ENERGY RELEASED
BASIDIOMYCETES 266
ASCOMYCETES 265
HIGHER PHYCOMYCETES
261
*>
\
: DEVELOPMENT OF MULTICEUU^AROR COENOCYTICORGANISMS
DIATOMS 38
PIGMENTED FLAGELLATES
12
BLUE GREEN ALGAE 7
PHOTOTROPIC
BACTERIA 252
CHEMOTROPIC BACTERIA
252
HIGHER PROTISTA
PROTOZOA 82
AMOEBOID PROTOZOA 86 CILLIATED PROTOZOA 92
FLAGELLATED PROTOZOA 85 SPOROZOA 98
(COLORLESS FLAGELLATES 85 SUCTORIA 97
DEVELOPMENT OF A NUCLEAR MEMBRANE
LOWER PROTISTA (ORMONERA)
LOWER PHYCOMYCETES
261
NOTE: NUMERALS REFER TO PARAGRAPHS IN PARTS 2 AND 3.
W. B. COOKE AND H. W. JACKSON, AFTER WHITTAKER
BI.ECO.pl.2b.4.66
ACTINOMYCETES 253
SPIROCHAETES 255
MYXOBACTERIA 254
PARASITIC
BACTERIA 251
AND VIRUSES
SAPROBIC BACTERIA 251
4S-2
-------
Classification - Finder
genus Anabaena (an alga),
we must simply use the
generic name, and:
Anabaena planctonica,
Anabaena constricta, and
Anabaena flos-aquae
are three distinct species
which have different signi-
ficances to water treatment
plant operations.
A complete list of the various
categories to which an organism
belongs is known as its "classi-
fication". For example, the
classification of a type of
frog spittle, a common fila-
mentous alga, and a crayfish
or crawdad are shown side by
side below. Their scientific
names are Spirogyra crassa and
Cambarus sciotensis.
a Examples of the classifica-
tion of an animal and a
plant:
(Frog Spittle)
Plantae
Chlorophyta
Chlorophyceae
Zygnematales
Zygnemataceae
Spirogyra
crassa
Kingdom
Phylum
Class
Order
Family
Genus
Species
(Crayfish)
Animalia
Arthropoda
Crustacea
Decapoda
Palaemonidae
Cambarus
sciotensis
These seven basic levels of
organization are often not
enough for the complete de-
signation of one species
among thousands; however,
and so additional echelons
of terms are provided by
grouping the various cate-
gories into "super..."
groups and subdividing them
into "sub..." groups as:
Superorder, Order, Suborder,
etc. Still other category
names such as "tribe", "di-
vision", "variety", "race",
"section", etc. are used on
occasion.
II
c Additional accuracy is gained
by citing the name of the
authority who first described
a species (and the date) im-
mediately following the spe-
cies name. Authors are also
often cited for genera or
other groups.
d A more complete classification
of the above crayfish is as
follows:
Kingdom A.nimalia
Phylum Arthropoda
Class Crustacea
Subclass Malacostraca
Order Decapoda
Section Nephropsidea
Family Astacidae
Subfamily Cambarinae
Genus Cambarus
Species sciotensis Rhoades
1944
e It should be emphasized that
since all categories above
the species level are essen-
tially human concepts,- there
is often divergence of opin-
ion in regard to how certain
organisms should be grouped.
Changes result as knowledge
grows.
f The most appropriate or cor-
rect name for a given species
is also sometimes disputed,
and so species names too are
changed. The species itself,
as an entity in nature, how-
ever, is relatively timeless
and so does not change to
man's eye.
THE GENERAL RELATIONSHIPS OF
LIVING ORGANISMS •;
Living organisms (as contrasted to
fossil types) have long been group-
ed into two kingdoms: Plant King-
doms and Animal Kingdoms. Modern
developments however have made this
48-3
-------
Classification - Finder
simple pattern technically unten-
able. It has become evident that
there are as great and fundamental
differences between certain other
groups and these (two), as there
are between the traditional "plant"
and "animal". The accompanying
chart consequently shows the
Fungi as a third kingdom.
B The three groups are essentially
defined as follows on the basis
of their nutritional mechanisms:
1 Plantae: photosynthetic;
synthesizing their own organic
substance from inorganic min-
erals. Ecologically known as
PRODUCERS.
2 Animalia: ingest and digest
solid particles of organic food
material. Ecologically known
as CONSUMERS.
3 Fungi: extracellular digestion
(enzymes secreted externally).
Food material then taken in
through cell membrane where it
is metabolized and reduced to
the mineral condition. Ecolo-
gically known as REDUCERS.
C Each of these groups includes
simple, single celled representa-
tives, persisting at lower levels
on the evolutionary stems of the
higher organisms.
1 These groups span the gaps be-
tween the higher kingdoms with
a multitude of transitional
forms. They are collectively
called PROTISTA.,
2 Within the protista, two prin-
ciple sub-groups can be defined
on the basis of relative com-
plexity of structure:
a The bacteria and blue algae,
lacking a nuclear membrane,
may be considered as the
lower protista or MONERA.
b The single celled algae and
protozoa having a nuclear
membrane, are best referred
to simply as the higher
protista.
48-4
-------
Classification - Finder
Part II. Biological Classification
I INTRODUCTION
A What is it?
B Policies
C Procedures
II PLANT KINGDOM
A "Algae" defined
1
2
3
4
5
6
B PHYLUM CYANOPHYTA - blue-green 7
algae
CLASS Myxophyceae 8
Order Chroococcales 9
Order Hormogonales 10
Suborder Hetercystineae 11
C PHYLUM CHLOROPHYTA - green 12
algae
CLASS Chlorophyceae 13
Order Volvocales 14
Order Ulotrichales 15
Order Chaetophorales 16
Order Chlorococcales 17
Order Siphonales 18
Order Zygnematales 19
Order Tetrasporales 20
Order Ulvales 21
Order Schizogoniales 22
Order Oedogoniales 23
Order Cladophorales 24
CLASS Charophyceae 25
Order Charales 26
D PHYLUM CHRYSOPHYTA - yellow- 27
green algae or yellow-brown
algae
CLASS Xanthophyceae 28
Order Heterocapsales 30
Order Heterococcales 31
CLASS Chrysophyceae - 32
yellow-green algae
Order Chrysomondales 33
Order Rhizochrysidales 34
Order Chrysosphaerales 35
Order Chrysocapsales 36
Order Chrysotrichales 37
CLASS Bacillariophyceae - 38
Diatoms
Order Pennales - pennate 39
diatoms
Order Centrales - centric 40
diatoms
E PHYLUM EUGLENOPHYTA - eugle- 41
noid algae
F PHYLUM PYRRHOPHYTA - yellow 42
brown algae
CLASS Desmokontae
Order Desmomonadales
CLASS Dinophyceae -
dinoflage Hates
Order Gymnodiniales
Order Peridiniales
Order Dinocapsales
Order Chloromonadales
CLASS Cryptophyceae
43
44
45
46
47
48
49
50
Order Rhizochloridales
29
G PHYLUM CHLOROMONADOPHYTA 51
H PHYLUM RHODOPHYTA - red algae 52
CLASS Rhodophyceae 53
Order Bangiales 54
Order Nemalionales 55
Order Gelidiales 56
4S-5
-------
Classification - Finder
Order Cryptonemiales
Order Gigartinales
Order Rhodymeniales
Order Ceramiales
57
58
59
60
I PHYLUM PHAEOPHYTA - brown algae 61
CLASS Phaeophyceae 62
Order Ectocarpales 63
Order Sphacelariales 64
Order Tilopteridales 65
Order Chordiales 66
Order Desmarestiales 67
Order Punctariales 68
Order Dictyosiphonales 69
Order Laminariales 70
Order Fucales 71
Order Dictyotales 72
J PHYLUM BRYOPHYTA 73
CLASS Hepaticae - liverworts 74
CLASS Musci - mosses 75
K VASCULAR PLANT GROUP 76
Emergent vegetation 77
Rooted plants - floating leaves 78
Submerged vegetation 79
Free floating plants 80
III ANIMAL KINGDOM 81
A PHYLUM PROTOZOA - protozoa 82
CLASS Mastigophora 83
Subclass phytomastigina 84
Subclass zoomastigina 85
CLASS Sarcodina - amoeboid 86
protozoa
Order Amoebina
Order Foraminifera
Order Radiolaria
Order Heliozoa
87
88
89
90
Order Mycetozoa (Myxomycetes) 91
CLASS Ciliophora - ciliates 92
Order Holotricha 93
Order Spirotricha 94
Order Peritricha 95
Order Chonotricha 96
CLASS Suctoria - suctoria 97
CLASS Sporozoa 98
B PHYLUM PORIFERA - sponges 99
CLASS Calcispongea 100
CLASS Hyalospongea 101
CLASS Demospongea 102
C PHYLUM COELENTERATA 103
CLASS Hydrozoa - hydroids 104
CLASS Scyphozoa - jellyfish 105
CLASS Actinozoa (Anthozoa) - 106
corals
D PHYLUM CTENOPHORA - comb 107
jellies
E PHYLUM PLATYHELMINTHES - 108
flatworms
CLASS Turbellaria - turbella- 109
rians
CLASS Trematoda - fluke 110
CLASS Cestoidea - tapeworms 111
F PHYLUM NEMERTEA - proboscis 112
worms
G PHYLUM NEMATODA - threadworms,113
roundworms
48-6
-------
Classification - Finder
H PHYLUM NEMATOMORPHA -
Horsehair worms
114
I PHYLUM ACANTHOCEPHALA - thorny 115
headed worms
J PHYLUM ROTIFERA - rotifer, 116
wheel animalcules
K PHYLUM GASTROTRICHA - gastro- 117
trichs
L PHYLUM KINORHYNCHIA
M PHYLUM PRIAPULIDA
N PHYLUM ENDOPROCTA
118
119
120
0 PHYLUM ANNELIDA - segmented 121
worms
CLASS Polychaeta - polychaet 122
worms
CLASS Oligochaeta - bristle 123
worms
CLASS Hirudinea - leeches 124
CLASS Archiannelida 125
CLASS Echiuroidea 126
CLASS Sipunculoidea - peanut 127
worms
P PHYLUM ARTHROPODA -jointed 128
legged animals
CLASS Crustacea - crustaceans 129
Subclass Branchiopoda 130
Order Anostraca - fairy 131
shrimps
Order Notostraca - tadpole 132
shrimps
Order Conchostraca - clam 133
shrimps
Order Cladocera - water fleas!34
Subclass Ostracoda - seed 135
shrimps, ostracodes
Subclass Copepoda - copepods 136
Subclass Branchiura - fish 137
lice
Subclass Cirripedia -
barnacles
Subclass Malacostraca
Order Leptostraca
138
139
140
Order Hoplocardia 141
(Stomatopoda) - mantis shrimps
Order Syncarida
Order Peracarida
Suborder Mysidacea
Suborder Cumacea
Suborder Tanaidacea
142
143
144
145
146
Suborder Isopoda - sowbugs,147
pillbugs
Suborder Amphipoda - scuds 148
Order Eucarida 149
Suborder Euphausiacea - 150
krill
Suborder Decapoda - shrimp,151
lobster, crab
Macrurous group (4 tribes) 152
shrimps, prawns, lobsters,
crayfish
Brachyurous group 153
(2 tribes) - crabs and hermit
crabs
CLASS Insecta - the insects 154
Orders represented by imma- 155
ture stages only.
Order Plecoptera - stone- 156
flies
Order Ephemeroptera -
mayflies
157
Order Odonata - dragon and 158
damselflies
Order Megaloptera - alder- 159
flies, dobsonflies, fishflies
Order Neuroptera - spongilla-160
flies
-------
Classification - Finder
Order Trichoptera - caddis- 161
flies
Order Lepidoptera - aquatic 162
caterpillars
Order Diptera - two winged 163
flies
Orders including aquatic 164
adults
Order Coleoptera - beetles 165
Order Hemiptera - true bugs 166
CLASS Arachnoidea - spiders, 167
scorpions, mites
Order Xiphosoura - horse- 168
shoe or king crabs
Order Hydracarina - aquatic 169
mites
Order Pantopoda (Pycnogonida)-170
pycnogonids
Order Tardigrada 171
Q PHYLUM MOLLUSCA 172
CLASS Amphineura - chitons 173
CLASS Gasteropoda - snails 174
Order Prosobranchiata 175
Order Opisthobranchiata 176
Order Pulmonata - air breath- 177
ing snails
U PHYLUM PHORONIDEA - tufted 184
worms
CLASS Scaphopoda - tusk
shells
CLASS Bivalvia
(Pelecypoda)
178
179
CLASS Cephalopoda - squid, 180
octipus, nautilus
R PHYLUM BRYOZOA (Ectoprocta) - 181
Moss animals
S PHYLUM BRACHIOPODA - lamp
shells
182
T PHYLUM CHAETOGNATHA - arrow 183
worms
V PHYLUM ECHINODERMATA -
echinoderms
185
CLASS Asteroidea - starfishes 186
CLASS Ophiuroidea - brittle 187
stars
CLASS Echinoidea - sea urchins 188
CLASS Holothuroidea - sea 189
cucumbers
CLASS Crinoidea - sea lilies 190
W PHYLUM CHORDATA - chordates 191
192
Subphylum Hemichordata -
Acorn worms
Subphylum Urochordata -
tunicates, sea squirts
193
Subphylum Cephalochordata - 194
lancelets
Subphylum Vertebrata 195
(Craniata) - vertebrates
CLASS Agnatha - jawless 196
fishes
Order Myxiniformes - 197
hagfishes
Order Petromyzontiformes - 198
lampreys
CLASS Chrondrichthys -
cartilage fishes
199
Order Squaliformes - sharks 200
Order Rajiformes - skates, 201
rays
Order Chimaeriformes - 202
chimaeras
CLASS Osteichthys (Pisces) - 203
bony fishes
Order Acipenseriformes - 204
sturgeons
Order Polyodontidae -
paddle fishes
205
48-8
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Classification - Finder
Order Semionoteformes - gars 206
Order Amiiformes - bowfins 207
Order Clupeiformes - soft 208
rayed fishes
Family Clupeidae - herrings 209
Family Salmonidae - trouts, 210
salmon
Family Esocidae - pikes, 211
pickerels
Family Serranidae - sea 228
basses
Order Myctophiformes -
lizard fishes
Order Cypriniformes -
212
213
Family Cyprinidae - minnows, 214
carps
Family Catostomidae - suckers215
Family Ictaluridae - fresh- 216
water catfishes
Order Anguilliformes ~ eel- 217
like fishes
Order Notacanthiformes -
spiny eels
218
Order Beloniformes - needle- 219
fishes, flying fishes
Order Cyprinodontiformes - 220
killifishes, livebearers
Order Gadiformes - cods and 221
hakes
Order Gasterosteiformes - 222
stickelbacks
Order Lampridiformes - Opahs, 223
ribbon fishes
Order Beryciformes - beard- 224
fishes
Order Percopsiformes - trout 225
and pirate perches
Order Zeiformes - dory
226
Order Perciformes - spiny- 227
rayed fishes
Family Centrarchidae -
sunfishes, freshwater
basses
229
Family Percidae - perch 230
Family Sciaenidae - drum 231
Family Cottidae - sculpins 232
Family Magilidae - mullets 233
Order Pleuronectiformes - 234
flounders
Order Echeneiformes - remoras235
Order Gobiesociformes - 236
clingfishes
Order Tetraodontiformes - 237
spikefishes
Order Batrachoidiformes - 238
toadfishes
Order Lophiiformes -
goosefishes
239
CLASS Amphibia - frogs, toads,240
salamanders
CLASS Reptilia - turtles, 241
snakes, lizards
CLASS Aves - birds 242
CLASS Mammalia - whales, 243
seals, walrusses
IV FUNGUS KINGDOM 250
A Bacteria 251
Eubacteria 252
Actinomycetes 253
Myxobacteria 254
Spirochaetes 255
Other bacterial types 256
B FUNGI 260
"Phycomycete" group 261
48-9
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Classification - Finder
CLASS Chytridiomycetes
CLASS Oomycetes
CLASS Zygomycetes
CLASS Ascomycetes
CLASS Basidiomycetes
CLASS Fungi Imperfecti
262
263
264
265
266
267
This outline was prepared by H. W.
Jackson, former Chief Biologist,
National Training Center, and revised by
R. M. Sinclair, Aquatic Biologist, National
Training Center, MOTD, OWPO, USEPA,
Cincinnati, Ohio 45268.
Descriptors: Aquatic Organisms,
Classification
48-10
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