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PB-260 181
                          ErivironmsTrtal Protectlcoi
                          Region V, Library
                          230 South Dearborn Street
                          Chicago, IlljLBods  6060H

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ENVIRONMENTAL PROTECTION

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                                     LAKE MICHIGAN STUDIES

                                   Special Report Number IM 4
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                                    BIOLOGICAL INVESTIGATIONS

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                                           April 1963
                           U.S. DEPARTMENT OF HEALTH,  EDUCATION AND WELFARE
                                        Public Health Service
                             Division of Water Supply and Pollution Control
                             Great Lakes-Illinois River Basins Project

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                                      TABLE OF CONTENTS

                                                                      Page
             INTRODUCTION                                               1
PARAMETERS:  DEFINITIONS AND SIGNIFICANCE                  2

     Phytoplankton                                         2
     Benthic Fauna                                         h
     Organic Matter                                        6
     Light Penetration                                     6
             METHODS AND PROCEDURES                                     8

9           RESULTS                                                   10

                  Phytoplankton                                        10
                  Benthic Fauna                                        12
                  Organic Matter                                       1^
                Light Penetration                                    14

             CHICAGO BEACH ALGAL PROBLEM                               15

             CONCLUSIONS                                               16

f                  Local Effects of Waste Discharges                    l6
                  General Biological Condition of Lake Michigan        l6

             REFERENCES                                                18

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                    TABLES
1    Phytoplankton, Total Counts, Surface
2    Fhytoplankton, Total Counts, 5 Meters
3    Phytoplankton, Predominant Genera, Surface
k    Phytoplankton, Predominant Genera, 50 Meters
5    Organic Matter
6    Benthic Fauna, Amphipoda
7    Benthic Fauna, Oligochaeta
8    Light Penetration
                                          FIGURES
1    Phytoplankton Densities April 2k - May 7
2    Phytoplankton Densities June 5 - June 18
3    Phytoplankton Densities July 17 - July 30
k    Phytoplankton Densities August 29 ~ September 9
5 '   Phytoplankton Densities October 9 - October 23
6    Phytoplankton Densities October 18 - November 30
7    Phytoplankton Densities October 28 - December k
8    Distribution of Benthic Fauna April 2k - June 18
9    Distribution of Benthic Fauna July 17 - July 30

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                                         INTRODUCTION
                   This report presents infoimation obtained from biological
              studies in Lake Michigan between April 24, 1962 and December 4,
              1962.  Sampling stations were established at intervals of approxi-
              mately ten miles throughout the lake; on 1, 4, 7 and 10 mile
              contours from the shoreline.in the southern basin;  and at intervals
              of two or three hundred y&a-ys in Milwaukee and Chicago harbors.
              The sampling stations on the one to ten mile contours are referred
              to as inshore stations in this report.

                   These biological studies were made for the purpose of:
              (l) evaluating the general biological condition of the lake, (2)
              defining areas adversely affected by wastes frcsn tributary streams
              and sewer outfalls, and (3) supplementing and substantiating
              chemical, bacterial and physical data.

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             PARAMETERS:  DEFINITIONS AND SIGNIFICANCE

Phytoplankton

      The suspended microscopic plant life, called phytoplankton
(or planktonic algae), are only slightly motile and exist at or
near neutral buoyancy.  As such they are subject to lake currents
and represent the microflora of the sampling site only at the
time of sampling.  Favorable conditions of light, temperature,
and water movement produce amounts of phytoplankton that increase
with the availability of nutrients.  Many inorganic elements are
required for algal cell growth, including nitrogen, phosphorus,
potassium, calcium, and iron (2l).  Organic substances are also
required.  Provasoli (2.6) has shown that vitamin B12, thiamine
and certain other organic compounds are necessary for algal growth.
Bogan (l) demonstrated that algae reproduce rapidly when phosphate
phosphorus is added to water, and continue to reproduce as more
phosphorus is added.  However, nitrogen and other nutrients must
also be present if algal production is to continue.  Sawyer (2)
concluded that an inorganic nitrogen concentration of 0.30 mg/1
and a soluble phosphorus concentration of 0.01 mg/1 could produce
nuisance algal blooms.  Since plankton store phosphorus in excess
of their needs,nitrogen may be a more critical Halting factor for
algal production than phosphorus (22).  Mackenthun (2^) suggests
that "the initial stimulus for algal production is supplied by
dissolved phosphorus and that a continued high rate of nitrogen
supply does not appear to be necessary for continued algal
production.  Recycling of nutrients within the lake basin is
sufficient to promote algal blooms for at least a number of years."

      The kinds of algae constituting a standing crop are important.
Several species of the blue-greens and several other algal forms
impart objectionable tastes and odors making water treatment
difficult and expensive (25).  Certain species of the Chlorophyceae
(green algae), the Chrysophyceae (brown algae) and Bacillarieae
(diatoms) are common in oligotrophic lakes(27> 3)  The diatoms
Tabellaria, Asterionella, Synedra, and Fragilaria are usually
the predominant algae in Lakes Michigan and Superior (3), both
oligotrophic.  On the other hand, some of the euglenoids, blue-
greens, and diatoms appear to favor nutrient-enriched waters of
eutrophic lakes.  Species of Anacysbis, Oscillatorij,;Stephanpdiscus,
Cyclotella and Melosira often predominate eutrophic lakes (1^-j.
They are also the predominant forms in many nutrient enriched
midwestern streams (3).

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            Relationship of Algae to Eutrophication

      Historically, nutrient enrichment of lakes has increased
"biological productivity.  This is known as eutrophication, or
lake aging (4).  Eutrophication is primarily manifested in
increasing densities of planktonic algae.  When nutrients for
the growth of aquatic plants "become available the planktonic
algae develop.  As the concentration of nutrients "becomes greater
the density of algal growth also may "become greater.  Algae are
important elements of the food chain and beneficial in moderate
amounts.  They only "become troublesome when they become too
numerous, and particularly troublesome if the blue-greens become
predominant.  An overabundance of planktonic algae results in a
green murky water which sometimes produces unpleasant odors and
unsightly scums.  As the algae become more numerous,, the trans-
parency of the water decreases and sunlight is denied the rooted
aquatic plants on the lake bottom.  Water filtration plants
experience difficulty through tastes and odors and clogging of
sand filters, and industrial water users must combat slime and
corrosion (25) (5).

      The nutrients that support planktonic algae also promote the
development of attached algae which cover all suitable substrata
wherever sufficient light can penetrate.  Lake Erie has exhibited
luxuriant growths of an attached algal form called Cladophora for
many years (29) and more recently these algae have become a
nuisance in certain areas of Lake Ontario (6) and Lake Michigan (8).
They break loose as they mature, or during storms, and litter the
beaches, foul fishing nets, and clog water intake screens.

      In the deeper areas of the eutrophic lake, more particularly
below the thermocline, dissolved oxygen values may be drastically
reduced due to the oxygen demand exerted by the decay of biological
materials (28) (12).  The algae which become dense during the summer
months die off and are succeeded the next year by another crop of
algae.  As the algae die, they settle to the lake bottom and are
attacked by microorganisms that, along with the macro-anitaal forms
in the bottom ooze, exert an oxygen demand.  As the years progress
nutrient levels rise and algal densities increase; the demand and
subsequent diminution of oxygen below the thermocline increases
accordingly.

      Eutrophication may be either natural or induced.  A lake under-
goes natural eutrophication as the nutrients that support algal
growth enter the lake from the watershed.  Algae  in their growth
functions  use the mineral nutrients that have been leached from
the soil.  If the  soil is fertile, nutrients for algae are likely

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to be abundant.  During the warmer months algae populations tend to
increase up to the point where one of the essential nutrients has
been depleted.  Since nitrogen and phosphorus are not abundant in
young glacial-lakes} those nutrients are utilized as they become
available.  As nutrients are continually fed by leaching from the
soils in the drainage area and the concentration of those nutrients
rises, more planktonic algae develop.  The eutrophic lake;  exhibits
periodic algal blooms that may cause the nuisance conditions dis-
cussed previously.

      The eutrophication of a lake is accelerated by the addition
of nutrients other than those from natural sources (U).  Treated
sewage contains high concentrations of the nutrients required
for algal growth and has been responsible for induced eutro-
phication of many lakes throughout the world.  Unfortunately,
the conventional sewage treatment facility removes only part of
the growth nutrients in sewage.  The Zurichsee, a deep,  16,500 acre,
glacial lake in the Swiss Alps, is a classic, much-studied example
of induced eutrophication through the introduction of domestic
wastes (k).  The lake is composed of two basins separated by a
narrow passage.  The upper basin received no sewage and remained
essentially unchanged during the five decades that the lower basin
received sewage from communities with a combined population of about
100,000.  The basin receiving sewage changed from a clear-water lake
to one murky with algae, and finally to advanced aging where the
noxious blue-green algae predominated.  The populations of deepwater
trout and whitefish diminished early in the process and coarse fish
became dominant.

      The Madison, Wisconsin lakes have had a similar history,
as have numerous less-publicized ponds and small lakes throughout
our country (2).  lake Erie has undergone considerable change in
the past 25 years and recent investigations indicate that it is
becoming an eutrophic lake (7).

      Lake Michigan is considered an oligotrophic lake, or one
that is deep, clear, and contains little organic material.

      However, long -term records of plankton populations in Lake
Michigan at Chicago indicate a gradual rise over the past fifty
years (9).

Benthic Fauna

      The kinds and numbers of benthic fauna inhabiting a particular
lake area are determined by the characteristics of the substratum,
the quality of the water, and certain physical features such as
morphometry of the basin, currents, wave action, temperature, light
and depth (12).

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      The habitats suitable for the predominant Lake Michigan
organisms are as follows (lo):

Organic sediment, turbid water:

      Oligochaeta (sludge-worms)
      Tendipedidae (midge larvae)
      Hirudinae (leeches)
      Pulmonata (air-breathing snails)

Sand and gravel, clear water:

      Amphipoda (scuds)
      Prosobranchia (gill-breathing snails)
      Sphaeriidae (fingernail clams)

      There are three major zones of biological productivity on
a lake floor.  The littoral zone extends from the water's edge
to the lakeward limit of rooted aquatic vegetation.  The sub-
littoral zone extends from the littoral zone lakeward to the upper
limit of the hypolimnion.  The profundal zone includes all of the
lake bottom up to the upper limits of the hypolimnion.

      The littoral and sublittoral zones are usually populated
by insects and molluscs which often comprise as much as 70% of
the total number of organisms.  The benthic population of the
profundal 'zone is usually composed of a great variety of species
but only a few representatives of each (12).

      Deleterious compounds such as toxic metals could render
the area unsuitable for many organisms.  The nature of the bottom
would also alter the speciation of the benthic populations.  For
example, organic sediments provide a suitable habitat for
oligochaetes and tendipedids but not for some of the amphipods
and molluscs.

      One genus of the Amphipoda, Pontoporeia, was found in
biological collections from all areas of Lake Michigan, and was
the predominant bottom dwelling organism in areas not greatly
influenced by organic sediments.  The relative scarcities of
.Ainphipoda" ' and concomitant abundance of Oligochaetes are,
therefore, considered reasonable indicators of lake areas
subjected to organic enrichment if other conditions are favorable
to its growth.

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                                                               6

Organic Matter

     The organic matter in lake water is either dissolved or
particulate.  This determination deals with the particulate
organic matter which consists of phytoplankton (minute plants),
zooplankton (minute animals), and non-living organic matter.
The bacteria and smallest algae, and the fishes are not included.

     The amount of organic matter per cubic meter of water is a
gross measure of the biological productivity potential.  When
considered with phytoplankton densities and light penetration,
the measure of organic matter may be useful in the evaluation
of abnormal values for phytoplankton and certain chemical and
bacteriological data.  In 1959 a series of vertical plankton
tows in the middle of Lake Ontario yielded values ranging from
8 mg/m3 to 80 mg/m.3 (13).

     High concentrations of organic matter in harbor areas would
not necessarily indicate high biological productivity.  A study
of phytoplankton densities might reveal low values, in which case
the organic materials would be suspected as being from sewage or
industrial wastes.  Therefore, in interpretation of the data, any
known sources of organic wastes which influence the lake area must
be considered.  Chemical data from samples taken concurrently
should supplement the biological information.

Light Penetration

     Water transparency from the lake surface to a given depth
is directly related to transmission of light energy and the
consequent production of biological materials (12).  If all other
growth factors are present, optimum light remains as the limiting
growth factor.  While the method for determining transparency
has inherent faults due to surface ripple, surface reflection,
angle of the sun, wave action, color, and variations among humans
in ability to see, the fact remains that the light that penetrates
to a submerged object is a light source for photosynthetic plants.

     Measurement of transparency has long been used by limnologists
and the value of these data is therefore enhanced by correlations
of transparencies and other pertinent data, such as phytoplankton
densities, in one situation with the same data revealed in another
situation.  For e'xample, Rawson (l^) in his studies of six
oligotrophic lakes and six eutrophic lakes in Canada found that

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transparencies less than ten feet occurred voider algal "bloom
conditions in the eutrophic lakes.  He also indicated that trans-
parencies of 20 feet or more were common in the oligotrophic lakes.
Investigators at Lake Washington, Seattle also reported that trans-
parencies of the lake water decreased as phytoplankton densities
increased (15).

     Colloidal and suspended matter emanating from the shores
produce high turbidities and reduce the transparency of the water.
This in turn results in a reduced phytoplankton density.  Therefore,
light penetration measurements are more meaningful when phytoplankton
populations are determined for the same waters at the same time.

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                                                               8

                      METHODS AND PROCEDURES

     All samples of "biological materials were collected "by biolo-
gists working cooperatively with other Project scientific personnel.
Samples were taken at the same times and places as the samples taken
for chemical, bacterial,  and physical analyses.  The methods and
equipment were those described in either "Standard Methods for the
Examination of Water and Wastewater," llth Edition (l6), or
"Limnological Methods/1 Welch, 19^8 (17).  Field equipment is described
in Special Report IM-2"Sampling Surveys." That report also indicates
sampling station locations and sampling depths.

     Laboratory methods followed those described in the above publications.

     1.  Phytoplankton samples were preserved in the field by adding
enough formalin to effect a 3% solution in the water sample.  One milli-
liter of the sample in a Sedgwick-Rafter counting cell was examined
microscopically in such a way that one-twentieth or one-tenth of the
cell was observed.  The microscope was fitted with 10X oculars and a
20X objective for counting, and 1<-3X and 97X objectives for identifi-
cation of the organisms.  Each one-celled alga, filament, and colony
was counted as one organism.  Results were tabulated as number of
individual organisms per milliliter of sample.

     2.  Bottom-dwelling animals which had been dredged from the
lake bottom were sifted with a No. 30 U.S. Standard sieve to remove
fine particles.  The organisms were then picked from the sieve and
preserved with formalin.  In the laboratory they were washed with
water, preserved with alcohol, sorted by families, identified and
counted.  Results at each sampling station were recorded as numbers
of organisms per square meter of lake bottom.

     3.  Organic matter at each sampling station was determined
by lowering a 0.5 meter No. 20 plankton net until the weight suspended
below touched the lake bottom, then raising it to the surface.  All
of the material large enough to be retained was washed into containers,
preserved with formalin, and returned to the laboratory.  In the
laboratory the dry weight at 105C and the ashed weight at 600C
were determined.  The loss due to ignition represented the organic
matter (except the smallest plankters called nannoplankton) in a
column of water 0.5 meter in diameter from 1.5 meters off the
bottom to the surface.  The data are reported as milligrams of
organic matter per cubic meter (mg/m3) of water.

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     k.  Light penetration of the water at each sampling station
was determined by an eight inch diameter disc (Secchi disc)
having alternating white and "black quadrants.  The disc was lowered
in the water by a graduated line until it disappeared, raised until
it reappeared, and the average of those two depths recorded.
Measurements are reported in meters and tenths of meters.  When a
rough sea made visibility or reasonably accurate marking of the line
difficult, no measurements were recorded.
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                               RESULTS

     To facilitate analysis the data are tabulated by lake sections
as follows:

     Southeast Quadrant  South and east of Lat. 4330'  Long. 8700f
     Southwest Quadrant  South and west of Lat. 4330'  Long. 8700'
     Northern Basin      North of Lat. 4330'
     (except Green Bay)
     Green Bay
     Milwaukee Harbor
     Chicago Harbor

     The data are summarized by showing the frequency at which
ranges of values occurred at Sampling Stations 1, k, 7, 10, and
beyond 10 miles from shore.  Wo allowance has  been made for
seasonal differences in the tables, but the phytoplankton densities
are presented graphically by lake cruises in chronological order.
Two cruises in October and November were concurrent.  The data
obtained during those months are shown in Figure 7-

     Intensive sampling was carried out in the southern basin and
at widely separated stations in the northern basin.  Therefore,the
results presented and the conclusions that follow will necessarily
specify conditions that exist in the southern basin and generalize
on the biota of the northern basin.  Each of the parameters will
be discussed separately.

Phytoplankton

     Since inorganic nitrogen and dissolved phosphorus are
considered essential for algal growth, the concentrations of these
nutrients in Lake Michigan were compared with phytoplankton data.

     The averages for nitrate nitrogen and total phosphate, as
determined by the Great Lakes-Illinois River Basins Project (and
reported in Special Report LM-3, "Chemical and Physical Investigations")
were 0.12 mg/1 and 0.01 mg/1, respectively; inshore concentrations
as high as 0.36 mg/1 and 0.27 mg/1, respectively, were found.
I

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                                                             11

     The densities of phytoplankton generally followed the same
pattern as nutrient concentrations, except in surface samples
where total phosphate levels were high (0.0*4- mg/l) only during
the summer.  Presumably, uptake "by plankton in inshore areas
effected low concentrations of dissolved phosphorus.  Total counts
of' phytoplankton (Figures 1 through 7) ranged from 1,000-5,000
per ml at many of the stations one, four, seven and 10 miles from
shore with slightly higher counts along the eastern shore.  Beyond
10 miles from shore the densities of phytoplankton diminished
greatly.  Counts in this middle area of the lake were rarely more
than 50 per ml.  Tables 1 and 2 present phytoplankton data by the
number of stations at which ranges of values occurred.  Ranges of
phytoplankton densities in counts per ml for sampling periods
between April and November are as follows:
Sampling Period

April 2k - May 7
June 5 - June 18
July 17 - July 30
August 29 - September 9
October 9 - October 23
October 18 - November 30
October 28 - December k
                                            Inshore ~ 1-10 miles   Beyond 10 miles
165 - 900
 98 - kkO
 28 - 385
No Samples
No Samples
No Samples
 44 - 26k
198 -
352 -
33 -
33 -
42 -
88 -
44 -
4,788
1,067
1,428
1,034
2,086
6,182
1,474
     Although total counts of phytoplankton in the 1,000-5,000
per ml ranges indicate relatively high biological productivity,
the kinds of algae present are equally important.  The diatoms
Melosira, Cyclotella, and Stephanodiscus, which are common
inhabitants of nutrient-enriched waters were the genera that
predominated samples from Milwaukee Harbor and most of the shore-
line stations from Milwaukee to Chicago (Table 2).  Along the
Michigan shoreline, Cyclotella-Stephanodi s cus predominated and
Melosira were numerous in many samples.

     In samples from stations beyond 10 miles, the diatoms
Asterionella, Tabellaria, Fragilaria and Synedra were the pre-
dominant genera (Table 2).  These are the forms that have
typified the planktonic algae of Lake Michigan for many years  (9)
They are also typical of Lake Superior and other oligotrophic
lakes, where they dominate the phytoplankton populations.
In Lake Superior, however, their numbers are less than those

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                                                              12

observed in many Lake Michigan samples.  Lake Superior averages
about 200 per ml in some shoreline areas (3)-  It is also signifi-
cant that Cyclotella sometimes occurred abundantly in Lake Michigan
samples dominated by Asterionella, Fragilaria, Tabellaria and
Synedra.  Table 2 shows that averages of Cyclotella were relatively
high in all sampling zones.

Benthic Fauna

     Only eight different kinds of organisms occurred abundantly,
and the amphipods were abundant in all areas of the lake where
conditions were favorable.  They prefer a habitat of sand or gravel
and are not numerous in lake bottoms covered by organic sediments.
Their occurrence is summarized in Table 6 as percentages of
amphipods to the total number of all benthic fauna.

     Table 6 shows that the southeast quadrant, one-mile stations
were heavily populated by scuds.  Further, nine of the 12 stations
in the 0-25$ occurrence range shown in the table represent one-mile
stations between South Haven and Michigan City where the lake
bottom is subject to wave-induced shifting sands that provide a
poor habitat for bottom-dwelling organisms.  There were no scuds
in Milwaukee Harbor and very few in Green Bay.

     The Oligochaeta are useful in evaluating the effect of organic
influents, on the biota of the lake.  These small worms prefer a
habitat of organic sediment.  Table XTsummarizes the occurrence
of this group of organisms by percentage of organisms to the total
number of bottom-dwelling animals.

     The effect of wastes in Milwaukee Harbor is clearly indicated
by the number of stations where the oligochaetes constituted
75-100$ of the bottom animal populations (Table7).  Values as
high as 170,000 per m.2 were observed.  More noteworthy is the
evidence of large populations of these organisms at the deep-
water stations in both the southern and northern basins of the
lake.  Numbers of oligochaetes ran as high as I,8l6 per m?
of lake bottom at deepwater stations in the northern basin and
2,831 per m2 in the southern basin.  Counts as high as 7,000
per m^ were found at inshore stations near Benton Harbor and
Michigan City.

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                                                             13

     The relative abundance of oligochaetes and amphipods are shown
graphically in Figures 8 and 9 by percentage of each to the total
number of organisms.  The total number of organisms per square
meter of lake bottom is also given.  Generally, benthic populations
were greater in the southern basin (South of Milwaukee and Muskegon)
than in the northern basin.  However, there were individual counts
as high as 19,000 per m2 at inshore stations north of latitude
4330', and as high as 13,000 per m2 south of Latitude 4200'.

     The Tendipedidae were not predominant at any of the stations
but they were found at about two-thirds of the sampling stations.
In some instances they were second to the sludgeworms in abundance
and were otherwise the third most numerous organisms found.  Finger-
nail clams and small snails were comramon at many stations.

     An earlier study of the benthic fauna of Lake Michigan was
made in 1931 and 1937, by Eggleton (l8), (19).  The results of
that study and others in Lake Huron (20) and two Canadian lakes(lU)
provide information that reveals the changing character of Lake
Michigan fauna.  The Canadian lakes are included in the comparisons
because one (Lake Athabasca) is a very oligotrophic lake and the
other (Churchill Lake) is eutrophic.  Both are in a remote area
where effects due to human habitation have been negligible.

     A comparison of percentages of the number of amphipods and
oligochaetes reveal some interesting trophic features of these
lakes, but more important are the comparisons of the fauna of
Lake Michigan in 1931 and 1962.  The percentages of organisms,
the average number of organisms, and the highest number found
in each lake are shown below.

                                                     Ave.   Max.
Lake       Year  % Amphipoda  $ Oligochaeta  % Other Ko/ms  No/m2
Churchill  1957       23'          9

Athabasca  19^7       6l        ' 12

Huron      1952       77           9
       and 1956

Michigan   1931       65          24          11     1,2^3  10,200

Michigan   1962       48          39          13     4,229  26,257

(Harbor stations not included)

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     The 68/0 Other in Churchill Lake and 13$ Other in Lake
Michigan 1962 were mostly midge larvae (Tendipedidae).  The 1931
Lake Michigan study reports that fingernail clams (Sphaeriidae)
were third in dominance.  The change in species dominance and the
increased populations of organisms are probably due to a change
in habitat caused "by organic sedimentation.

Organic Matter

     The organic matter in a half-meter-diameter column of water
at each sampling station is summarized in Table 5-  I*1 "both the
southeast and southwest quadrants the pattern of concentrations
follows very closely those for phytoplankton counts where generally
the plankton was at its highest density near the shoreline and
diminished at stations farther from shore.  In the 0-25 nig/m^
range of Table5$, proportionately more occurrences are recorded
for the southeast quadrant where 37 of 57 were in that range.
In the southwest quadrant 24 out of 111 plankton tows were within
the 0-25 mg/m3 range, and values range from 26-200 mg/m3 at 87
stations.

     The northern basin was not sampled extensively "but results
from 9 of the 10 stations indicated low concentrations of organic
matter.  Only one was in the 76-100 mg/m3 range.

Light Penetration

     Light penetration deeper than 12 meters was observed at
three stations in the southern basin and three stations in the
northern basin.  The deepest light penetration was 18 meters
found at one station centrally located in the northern basin.
The lowest values were less than one meter in Milwaukee Harbor.
In the lake proper the lowest values were^l mile(a^) stations
off Gary, Indiana.  There was considerable difference in light
penetrations at the inshore and mid-lake sampling areas.  This
is clearly indicated by the large number of inshore  stations
where values were less than 6 meters (Table 8).  Penetration
less than 2 meters was observed at 21 stations in the southwest
quadrant.  Most of those low readings were at stations on the
one-mile contour along the Wisconsin and Indiana shores.
Phytoplankton samples taken at the same time produced high
counts along the Wisconsin shore and low counts along the
Indiana shore.  Apparently, waste discharges in the  Indiana
area were responsible for high turbidities and resultant low
biological activity.

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                                                             15

                    CHICAGO BEACH ALGAL PROBLEM
     The Chicago Park District has reported cases of beaches  being
fouled with algae washed in from the lake for several years.   On
August 27, 1961 and on August 16, 1962,  Great Lakes-Illinois  River
Basins Project biologists investigated occurrences at Oak Street
and Montrose beaches.  In 1961 the offending organism was found to
be Dichotomosiphon, a green filamentous alga similar in appearance
to Cladophora.  Rhizoclonium and Cladophora were also present.   In
1962 Cladophora was the principal alga but Oedogonium was also
present intermixed with the Cladophora.   All of these organisms
require a hard substratum, or attachment surface.  The windrows of
algae that completely lined the beaches became foul-smelling  after
a few days exposure to the summer heat.   Flies and other insects
covered the decaying masses.

     Project biologists also examined filamentous algal growths on
boats, breakwaters, buoys, and in harbors from Burns Ditch, Indiana
to Green Bay, Wisconsin.  They found that practically any submerged
solid provides a surface for the growth of algae.  Since the
nutritional requirements of the filamentous algae are similar to
the other algae (12), it is concluded that concentrations of
phosphorus, nitrogen, and other nutrients are ample in the shoreline
areas of the lake between the southern tip of the lake and Green
Bay.

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                                                               16    ^

                             CONCLUSIONS

Local Effects of Waste Discharge^

     The effects of wastes discharged at Milwaukee afford an excellent
opportunity to evaluate the impact on the lake biota in a selected
area.  Inside the Milwaukee Harbor breakwater both the phytoplankton
and benthic fauna were dominated by organisms favoring organic enrich-
ment.  The benthic fe.vna consisted of sludgeworms.  and scuds did not
exist.  Milwaukee Harbor is considered biologically degraded.  At
stations in the vicinity of Milwaukee but outside the breakwater,
sludgeworms also predominated tut pulmonate snails and leeches were
also present.  This lake area is a3.so biologically degraded but to a
lesser degree,

     The dominance of Mj^sira and .Qy_clotella in the Milwaukee area
of the lake was due to the availability of nutrients.  The subsequent
persistence of these organisms at many of the one and four mile
stations south from Milwaukee to near Chicago is attributed to one
or a combination of the following:  (l) a lack of mixing with Lake
Michigan waters, (2) a transport of nutrients coincidental with the
organisms, (3) the addition of nutrients and organisms by waters
emanating from Racina; Kenosha, and Waukegan harbors and waste outfalls.
                                                                       ?
     The relatively high total phytoplankton counts of 1,000-5,000
per ml found at many stations along the shoreline is attributed to
the warmer waters of the littoral zone and nutrient availability.
The slightly greater density on the Michigan shore is probably due to
the prevailing westerly winds that cause the water to be warmer on
the Michigan side of the lake.  The prevailing westerly wind would
also hold the plankton~laden water against the eastern shore.  In
addition, a counterclockwise movement of water in the southern basin
(as is suggested by tracing Melosira and Cjjclotella from Milwaukee
to Chicago) would transport nutrients to the Michigan shoreline.

General Biological Condition of Lake Michigan

     The center of Lake Michigan yielded concentrations of phyto-
plankton in the 0-500 per ml range, and light penetration was generally
more than 6 meters  The flora (predominated by Synedra, Asterionella
and Tabellaria) was similar to the flora of Lake Superior.  The middle
area of the lake :i.s decidely oligotrophic =

     However, the lake waters adjacent to Wisconsin and Michigan
harbors were predominated by Melos3,ra. and Cyclotella.  These genera
of algae are not typical of oligotrophic lakes.  In addition, the total

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phytoplankton counts averaged about 1,500 per ml within the ten mile
contour, and less than 200 per ml at stations beyond the ten mile
contour.  In comparison, Lake Superior averages about 200 per ml at
shoreline stations and much less at the center of the lake.

     The changing character of the benthic fauna is reflected in
increased populations of sludgeworms and decreased populations of
amphipods in the past 30 years.  This has been caused by the continuous
sedimentation of organic matter that has gradually altered the habitat
to one increasingly more favorable to sludgeworms.  As the organic
sedimentation continues the benthic fauna will change, and eventually
become dominated by organisms typical of a eutrophic lake.

     Lake Michigan receives wastes from a number of tributary streams
and waste outfalls.  From the phytoplankton data it appears that some
of those wastes, containing nutrients, do not disperse evenly through-
out the lake, but tend to follow the shorelines where they effect
quantities and kinds of phytoplankton quite different from oligotrophio
lakes.

     Further additions of nutrients to the system will certainly result
in expansion of the inshore areas where high concentrations of phyto-
plankton occur.  Populations of phytoplankton will increase, first in
the lake waters adjacent to the nutrient source, and gradually to other
inshore areas.

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                                                                              18

                                          REFERENCES
              1.   Bogan,  R.H.   The  Use of Algae in Removing Nutrients from
                  Sewage.   Algae  and Metropolitan Wastes,  Transactions of     / -
                  the I960  Seminar.   U.S.  Public Health Service Publication
                  (I960).p.  141.

 f            2.   Sawyer, C.N.  Investigation of the Odor  Nuisance from Madison
                  Lakes.  Reprint.   (1942).

              3.   Williams,  Louis G.    PIankton Population Dynamics.   National
                  Water  Quality Network - Supplement 2. U.S.Department of Health,
 A                Education and Welfare,  Public Health Service, Washington 25, D.C.

              4.   Hasler, A.D.  Eutrophication of Lakes by Domestic Drainage,
                  Ecology,  28  (1947).  pp. 383-395.
              5.   Garnet, M.B.  and  Rademacher,  J.W.   Study of Short Filter Runs
                  with  Lake Michigan Water,  Journal of 
                  Association.  52,  (i960). ppT~I37-152.
                with Lake Michigan Water, Journal of the American Water Works
              6.   Cladophora Investigations.  Ontario Water Resources Commission
                  (1959).   pp.  1-30.

            7.   Beeton,  A.M.  Environmental Changes  in Lake Erie.   Transactions
                 of the American Fisheries Society, 90 (1961). pp. 153-159.

             8.  Quarterly Bulletin.  Michigan Water  Resources Commission
                 Lansing, Mich. (June 1962)7

             9.  Damann, Kenneth E.  Quantitative Study of the Phytoplankton of .  
                 Lake Michigan at Evanston, Illinois.  Butler University Botanical
                 Studies.  Vol. 8 (1941). pp. 27-44.
              10.  Pennak,  R. W.   Fresh-Water Invertebrates of the United States.
                  Ronald Press  Co.,  New York (1953).  pp.  439 and 704.

9            11.  Goodnight, C.F.  and Whitley,  L.S.   Oligochaetes as Indicators
                  of Pollution.   Proceedings of the  Fifteenth Industrial Waste
                  Coriference, Purdue University Engineering Bulletin,  Purdue
                  University, Lafayette, Indiana (i960),   pp. 139-142.

B            12.  Welch,  P.S.   Limnology,.   McGraw-Hill Book Company, Inc.,
9                New York (19527!

              13.  Anderson, D.V.  and Clayton, D.   Plankton in Lake^ Ontario.
                  Physics Research Note #1,  Ontario  Dept. of Lands and Forests,
_                 Maple,  Ontario.   (April 1959).   Table III.
                                                                                            i

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 I
                                                                            19

            t!4.  Rawson, D.S.  A Limnological Comparison of  Twelve  Large  Lakes
                 in Northern Saskatchewan.  Limnology  and Oceanography.
                 Vol. 5, No. 2, (April I960), pp. 195-211.

            15.  Anderson, G.C.  Recent Changes in the Trophic  Nature  of  Lake
                 Washington - A Review.  Transactions,jxF . the_ JL_9_6_0 jeminar.
 g               O.S.Public Health Service Publication (I960),  p. 29.

            16.  Standard Methods, _for the. Examination  of Water  and  Wastewater,
                 Public Health Service, llth Edition (i960).

            17.  Welch, Paul S.  Limnological Methods.  McGraw-Hill, New  York(1948).

 V          18.  Eggleton, F.E.  The Deep-Water Bottom Fauna of Lake Michigan.
                 Papers of the Michigan Academy of Science,  Arts and Letters,
                 Vol. XXI,  (1935). PP. 599-612.
I
            19.  Eggleton, F.E.  Productivity of the  Profundal  Benthic  Zone in
                 Lake Michigan.  Papers of._ the .Michigan Academy of Science,
                 Arts and Letters,. Vol.  XXII, 1936 (1937). pp.  593-611."
            20.  Teter, H.E.  The Bottom Fauna of Lake Huron.   Transactions  of the
                 American Fisheries Society, Vol. 89, No. 2,  (I960),  pp. 193-197.

            21.  Krauss, R.W.  Nutrition.  Fundamental Characteristics of Algal
                 Physiology.  Algae and Metropolitan Wastes .   Trans,  of  the  I960
                 Seminar. U.S. Public Health Service Publication (1961).  pp.  40-46.

            22.  Gerloff, G. and Skocg,F.  Cell Content of  Nitrogen and Phosphorus
                 as a Measure of Their Availability for  Growth of Micro-cyst is
 ft               aeruginosa.  Ecology,, 35. (1954). pp. 348-353.

            23.  Gerloff, G. and Skoog, F. Nitrogen as a Limiting Factor for the
                 Growth of Microcystis agruginos^ in Southern  Wisconsin  Lakes.
                 Ecology., 38. (1957)'. pip.  556-561.

 ft          24.  Mackenthun, K.M.  The Effect of Nutrients on  Photosynthetic
                 Oxygen Production in Lakes and Reservoirs - Preprint. Symposium
                 on Streamflow Regulation  for Quality Control... R.A.  Taft Sanitary
                 Engineering Center, Cincinnati, Ohio.

 ^          25.  Palmer, .C.M. Algae in Wat e r Suppl ie s . Public  Health Service
                 Publication. No. 657"7Tl959). P- "50.
            26.  Provasoli, L. Nutrition  and Ecology of  Protozoa and Algae.  Annual
                 Review of Mic robioloCT .  Vol.  12 (1958).  pp.  279-303.

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                                                                 20

27.  Hynes, H.B.N.  The Biology., of Polluted Waters.  Liverpool  University
     Press. (I960), p. 11.

28.  Odum, E.P. Factors Which Regulate Primary Productivity  and Hetero-
     trophic Utilization in the Ecosystem.  Algae and Metropplitan__Was_t_es.
     Transactions of _the I960 Seminar. U.S.Public Health  Service Publi-
     cation. (1961). pp~. 65-70."""

29.  Langlois, T.H.  The Western End of Lake Erie and Its Ecology.
     J.W, Edwards, Publisher, Inc. Ann Arbor, Michigan. Cl954)P'91.

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-;'>r,<>v..- .*.- -f' v 
                                                                                                                     GlifAT LAKES &  ILLINOIS"
                                                                                                                      RIVtR atSINS  PROOECT
                                                                                                                         LAKE MICHIGAN
                                                                                                               ITOTALPHYTOPLANKTON COUNTS PCRMI
                                                                                                                    CRUinr 3 JULY 17-JULY 50,19G2	
                                                                                                                        Pl'HLtC Hf ALTM SL FWICE
                                                                                                                        v          CHICAGO, ILLINOIS

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          fin0oo'
Surface      50 mewi or deeper
      0-500     O
 Q   500-1000    O
      IOOO-2SOO   ~
                O
                         10       20       30       10
      GREAT  LAKES  5  ILLINOIS
       RIVCR BASINS  PROJfCT
           LAKE MICHIGAN
TOTAL PHYTOPLANKTON COUNTS PER ML
CRUICL" 0 OCTOBER 9-OCTOBER 23,1962
  UE ''*  0'  HI (M ! M, r KJi AT ION, h  V,M I AKf
         (uHi i"  i'f A! TH f,rI-/ rr

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(  )
                                                            GREAT  LAKCC   ILLINOIS

                                                             HIVER BASINS PRO 1FCT
           LAKE MICHIGAN
TOTAL PHYTOPLANKTON COUNTS PfR ML
;,[:lll',[ 0 OCTOBER 18 - NOVEM3ERX),I962

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WISCONSIN  __
 ILLINOIS
                                                                                    	 	 4200
  Surfoc*       50 motari of dpar
   0    0-500      O
GREAT  LAKES  a ILLINOIS
 MIVER BASINS  PROJECT
        500-1000

        I000-2',00
                                                                                    LAKC MICHIGAN
                                                                        TOTAL PHYTOPLANKTON COUNTS PER ML
                                                                                 OCIOBrR 28-DECEMBER 4,196

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