United States
Environmental Protection
Agency
Environmental Research
Laboratory
Corvallis OR 97330
3-
EPA-600(78-088
September 1978
Research and Development
xvEPA
NUTRIENT CHEMISTRY
OF A LARGE, DEEP LAKE
IN SUBARCTIC ALASKA
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REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1 Environmental Health Effects Research
2 Environmental Protection Technology
3 Ecological Research
4 Environmental Monitoring
5, Socioeconomic Environmental Studies
6 Scientific and Technical Assessment Reports (STAR)
7 Interagency Energy-Environment Research and Development
8 "Special" Reports
9 Miscellaneous Reports
This report has been assigned to the ECOLOGICAL RESEARCH series This series
describes research on the effects of pollution on humans, plant and animal spe-
cies, and materials. Problems are assessed for their long- and short-term influ-
ences. Investigations include formation, transport, and pathway studies to deter-
mine the fate of pollutants and their effects. This work provides the technical basis
for setting standards to minimize undesirable changes in living organisms in the
aquatic, terrestrial, and atmospheric environments.
This ciocumenL is available io the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161
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EPA-600/3-78-088
September 1978
NUTRIENT CHEMISTRY OF A LARGE,
DEEP LAKE IN SUBARCTIC ALASKA
J. D. LaPerriere, T. Tilsworth, and L. A. Casper
Institute of Water Resources
University of Alaska
Fairbanks, Alaska 99701
R800276
Project Officer
Eldor W. Schallock
Assessment and Criteria Development Division
Corvallis Environmental Research Laboratory
Corvallis, Oregon 97330
CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U. S. ENVIRONMENTAL PROTECTION AGENCY
CORVALLIS, OREGON 97330
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DISCLAIMER
This report has been reviewed by the Arctic Environmental Research
Station, U. S. Environmental Protection Agency, and approved for publication.
Approval does not signify that the contents necessarily reflect the views
and policies of the U. S. Environmental Protection Agency, nor does mention
of trade names or commercial products constitute endorsement or recommendation
for use.
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ABSTRACT
The primary objective of this project was to assess the state of the
water quality of Harding Lake, and to attempt to predict the effects of
future development within its watershed. Since the major effect of degrada-
tion of water quality due to human activity is the promotion of nuisance
growths of plants, the major emphasis was placed on measurements of plant
growth and concentrations of the major nutrients they require. Planktonic
algal growth was found to be low, below 95.6 gm/m2/year, and the growth of
submerged rooted plants was found to be relatively less important at approxi-
2
mately 1.35 gm/m /year. Measurements of the growth of attached algae were
not conducted, therefore the relative importance of their growth is currently
unknown.
A model for predicting the effect of future real estate development in
the watershed was modified and applied to this lake. This model adequately
describes current water quality conditions, and is assumed to have some
predictive ability, but several cautions concerning application of this
model to Harding Lake are discussed.
A secondary objective was to study the thermal regime of a deep sub-
arctic lake. Intensive water temperature measurements were made throughout
one year and less intensive measurements were conducted during two additional
years. The possibility that this lake may occasionally stratify thermally
under the ice and not mix completely in the spring was discovered. The
implications of this possibility are discussed for management of subarctic
lakes. Hydrologic and energy budgets of this lake are attempted; the annual
4 32
heat budget is estimated at 1.96 x 10 ± 1.7 x 10 cal/cm .
The results of a study of domestic water supply and waste disposal
alternatives in the watershed, and the potential for enteric bacterial con-
tamination of the lake water are presented. Limited work on the zooplankton,
fishes, and benthic macroinvertebrates of this lake is also presented.
iii
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CONTENTS
Abstract iii
Figures vi
Tables vii
Acknowledgements x
1. Introduction 1
2. Conclusions 4
3. Recommendations 6
4. Description of Study Area 8
5. Materials and Methods 15
General 15
Climatology 15
Physical Limnology 16
Depth, Temperature, Electroconductivity, pH, Dissolved Oxygen. 16
Light Penetration 17
Chemical Limnology 18
Sampling 18
Ammonia 18
Organic Nitrogen and Ammonia „ 19
Nitrite/Nitrate 19
Phosphorus 20
Inorganic Carbon 21
Total Organic Carbon 21
Biological Limnology 21
Algae 21
Vascular Aquatic Plants 24
Zooplankton. 24
Benthic Macroinvertebrates . 25
Enteric Bacteria 25
6. Results and Discussion 27
Climatology 27
Heat Budget 27
Hydrology. 28
Physical Limnology 29
Thermal Regime 29
Dissolved Oxygen ..... ..... 34
Light Penetration 38
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CONTENTS (continued)
Chemical Limnology 38
Ionic Composition ..... 38
Hydrogen Ion Concentration 46
Nutrient Chemistry 46
Biological Limnology 57
Algae 57
Vascular Aquatic Plants 83
Zooplankton 88
Fishes 89
Benthic Macroinvertebrates 90
Enteric Bacteria 90
References 109
Appendix 115
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FIGURES
Number Page
1 Morphometric map of Harding Lake (after Blackwell,
1965) with sampling stations indicated 9
2 Hypsometric curve for Harding Lake (after
Blackwell, 1965) 10
3 Watershed map for Harding Lake 12
4 Isotherms—Harding Lake, with ice thickness indicated 30
5 Temperatures observed under ice at Harding Lake,
May 1975 32
6 Temperature profiles for selected dates. Spring 1975,
Harding Lake 33
7 Isopleths of electrical conductivity.
Harding Lake 35
8 Isopleths of dissolved oxygen. Harding Lake 36
9 Isopleths of percent saturation of dissolved
oxygen. Harding Lake 37
10 Light penetration. Harding Lake 39
11 Isopleths of hydrogen ion concentration as the negative
logarithm, pH. Harding Lake 47
12 Isobaths--nitrate and nitrite nitrogen.
Harding Lake 49
13 Isopleths of nitrate and nitrite concentration.
Harding Lake 50
14 Total phosphorus isopleths. Harding Lake 56
15 Algal count. September 28, 1974. Harding Lake 61
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FIGURES (continued)
Number Page
16 Algal pigment concentration, Harding Lake. ... 63
17 Algal primary production. Station Deep I,
Harding Lake, Alaska. Ice thickness and Secchi
depth indicated 66
18 Algal primary production, Harding Lake .... 68
19 Annual algal primary production. Harding Lake . . 71
20 Diurnal primary productivity. Harding Lake.
Deep Station I. June 25-26, 1975 76
21 Diurnal primary productivity. Harding Lake.
Deep Station I. September 12-13, 1975 77
22 Heterotrophic production. Harding Lake. November 14, 1975. . . 80
23 Plant distribution map. Harding Lake, 1975 . 85
24 Dry weight of zooplankton captures. Harding Lake 87
25 Morphometric map of Harding Lake with sampling
stations for benthos and bacteriological sampling
indicated 103
vn
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TABLES
Number Page
1 Heat Budget Estimates, Harding Lake--1973-1975 27
2 Water Quality and Cation and Anion Balance,
Harding Lake—June 3, 1975 40
3 Limnological Properties, Harding Lake--1966 41
4 Chemistry of Snow, Ice, and Water, Harding Lake—April 30, 1966 . . 43
5 Cation Composition of World Rivers vs. Harding Lake 45
6 Organic and Ammonia Nitrogen, Harding Lake--1975,
Deep Station I 51
7 Organic and Ammonia Nitrogen, Harding Lake--1975,
Shallow Stations 53
8 Nutrient Values for Selected Oligotrophic Lakes 57
9 Plankton Counts, Harding Lake—September 28, 1974,
Deep Station 1 58
10 Algae Identified from Harding Lake 62
11 Integral Values of Algal Growth Parameters and Incident
Radiation, Harding Lake, Deep Station I 70
12 Annual Algal Primary Production, High-Latitude Lakes 73
13 Rodhe's Index: Selected Oligotrophic Lakes 74
14 Time-of-Day Effects on Carbon-14 Experiments, Harding Lake 78
15 Predicted Total Phosphorus and Resultant Chlorophyll a
Concentrations and Secchi Depths for Selected Development
Possibilities at Harding Lake 82
16 Submersed Hydrophyte Species, Harding Lake--1974 84
vm
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TABLES (continued)
Number Page
17 Plant Biomass Estimates for Samples Representing 100%
Cover of a Single Species, Harding Lake—1974 86
18 Zooplankton Counts, Harding Lake—August 5, 1974 88
19 Zooplankton Identified from Harding Lake 89
20 Fish Stocking History, Harding Lake ..... 91
21 Netting Records, Harding Lake . .92
22 Benthic Macroinvertebrates, Profundal and Sublittoral
Stations, Harding Lake—July 24, 1973 95
23 Benthic Macroinvertebrates, Littoral Stations, Harding Lake--
August 17, 1973 98
24 Chironomids Reared from Harding Lake—1974 102
25 Statistical Summary of Fecal Coliform Results, Harding Lake—
1973 105
26 Statistical Summary of Total Coliform Results, Harding Lake--
1973 106
IX
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ACKNOWLEDGEMENTS
The many local, state, and federal agencies that participated in this
project both directly and indirectly include the following: Fairbanks North
Star Borough; Alaska Department of Fish and Game; and Alaska Department of
Natural Resources, Division of Parks; Alaska Department of Health and Social
Services, Environmental Health Division; Alaska State Troopers; the Girl
Scouts of America; the United States Army, Fort Wainwright; and the U. S.
Environmental Protection Agency, Arctic Environmental Research Laboratory.
Many individuals assisted with these research studies. A special
acknowledgement is directed to Dr. David Nyquist who was instrumental in the
early development of the project proposal. The late congressman Nick Begich
is acknowledged for his assistance in achieving funding, and a note of thanks
is extended to U. S. Senator Mike Gravel for his interest in the project.
Field and laboratory assistance as well as administrative and clerical
help was provided by Institute of Water Resources personnel, especially
Martha Kandelin, Donald Woodruff, Larry Dietrich, Thomas Weingartner, Wolfgang
Hebel, Paul Larson, Lucy McCarthy, and Timothy Cordis.
Technical assistance with fish surveys was provided by the Alaska Depart-
ment of Fish and Game. The Environmental Health Division, Alaska Department
of Health and Social Services, was very helpful in conducting the sanitary
survey for the lake and its developed area. Additionally, laboratory per-
sonnel of the Environmental Health Division gave valuable assistance in the
coliform analyses. The work on the vascular hydrophytes was conducted by
Frederick Payne of Michigan State University with funding assistance from the
Foundation for Environmental Education. Mounting of the dissected chironomid
adults and associated ecdyses was conducted by Margaret P. McLean of the
Freshwater Institute of Environment Canada and these were identified by Dr.
Ole A. Saether of that institute. Assistance with the application of current
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water quality models to Harding Lake was provided by Dr. Roger W. Bachmann
and Daniel E. Can-field, Jr. of Iowa State University.
Several units of the University of Alaska deserve special mention,
including the Institute of Marine Science, Institute of Arctic Biology,
Virology-Rabies Unit of the State of Alaska Department of Health and Social
Services, and the Forest Soils Laboratory.
Others who deserve special mention for the roles they played in comple-
tion of this project include the Hollinrake family, Tryphena Taylor, and the
many other residents surrounding Harding Lake who graciously provided help
when needed.
Environmental Protection Agency personnel were very helpful and patient;
especially noted are the services of Ernst Mueller, the original project
officer, and Eldor Schallock, the project officer, for his sincere interest
and assistance with the project.
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SECTION 1
INTRODUCTION
Harding Lake is centrally located in Interior Alaska at 64°25' N,
146°50' W, adjacent to the Tanana River and abutting the Tanana-Yukon uplands.
Fairbanks, the second largest urban area in the state with a population of
approximately 65,000, is 73 km to the northwest and access to the lake is
afforded by one of the primary highways of the state. Paralleling the high-
way in this area and passing within a few kilometers to the north of the lake
is the Trans-Alaska Pipeline and its right-of-way. This lake is the closest
lake to Fairbanks having sufficient size (988 hectares) and depth (43 m
maximum, 16 m mean) for recreation in the Tanana Valley.
Lakeside development began very early in the history of the region when
the present highway was a trail. The relatively early importance of the lake
in the Fairbanks area is indicated by the renaming of the lake in 1923 for
President Warren G. Harding. The aboriginal name for the lake had been
Salchaket Lake. Building of first-tier lakeside dwellings has been intense
with occupancy of private lots on nearly 75% of the lakeshore (Larson,
1974). Development is now proceeding in second-tier lots in many sections.
This development has created concern for the water quality of the lake.
In 1966, Alaska State Division of Public Health scientists discovered possible
coliform bacteria contamination of the lake. Ecologists (Weeden, 1971;
Nyquist, 1971), noting the density of near-shore development and aware of the
bacterial contamination of the lake, became concerned that the lake might
lose its recreational potential. Lakeshore residents also expressed concern
over deterioration of the aesthetic qualities of the lake and its environs,
with some reports of "blooms" of floating algae and many complaints about
waste disposal practices. These signs all pointed to cultural (accelerated)
eutrophication of the lake from nonpoint discharges suspected to be emanating
from septic infiltration and surface run-off along the developed shoreline.
1
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Although there had been infrequent, short-term studies of the lake by
various investigators, especially students of the University of Alaska at
Fairbanks, there were no comprehensive data on the nutrient status and
trophic state of the lake. Attendant to the specific problem of assessing
cultural eutrophication of the lake, there was the general need to develop
fundamental limnological knowledge about the physical, chemical, and biolog-
ical regimes of deep subarctic lakes. Recent studies of a deep lake in the
Canadian arctic have been reported (Schindler et al.3 1974; Welch and Kalff,
1974; Rigler et al.3 1974), but with few exceptions (Hobbie, 1964), there is
not even rudimentary data on most deep lakes in the Alaskan arctic and
subarctic and references have been made to the scarcity of information on
arctic lakes (Livingstone, 1963; Hobbie, 1973). The extensive efforts of
the Tundra Biome Program were largely confined to tundra ponds and only
recently, in post-Biome studies, have large lakes come into the forefront of
this effort.
This fundamental knowledge is particularly important with regard to the
thermal mechanics of such lakes. The extreme annual temperature variation
in areas such as the Alaskan intermontaine plateau produces thick ice cover
over a large part of the year in a cycle broken by nearly temperate summer
conditions. An equally eccentric light regime in concert with this seasonal
temperature cycle may produce unusual hydromechanical situations at times of
seasonal changeover. Thus, a study of the thermal regime of Harding Lake
was seen to be a significant contribution to knowledge of large arctic and
subarctic lakes.
The limited scale of Phase I work provided an important conclusion,
namely, that concentration values of nearly all plant nutrient parameters
studied were near the detection limits of standard methods. This necessi-
tated selecting more sensitive methods or looking to collective parameters
to obtain information on the nutrient status of the lake. It also became
apparent that the low levels of plant nutrients in the water column probably
meant that the nutrient status of the sediments and the rooted vascular macro-
phytes were important parameters to be considered.
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The establishment of a permanent field station at the onset of Phase II
marked the beginning of intensive biological studies, especially measurement
of algal production and ancillary work on vascular hydrophyte populations.
Studies of the higher trophic levels were begun or advanced, with some
attention given to zooplankton dynamics, benthic macroinvertebrates, and
certain aspects of the fish community of the lake.
During Phase III, completion of the chemical nutrient work focused on
potential loading of the lake system from its watershed. A theoretical
approach to questions of cultural eutrophication has often concerned measure-
ments of the macronutrients necessary for algal growth and the algal response
to their presence. More recently Vollenweider (1971) and others have devel-
oped sophisticated models to predict the effects of specific nutrient loading
of lakes de-emphasizing the role of plant nutrients dissolved in the lake
water in favor of emphasizing the role of their potential supply by the
contributing watershed. Ancillary to the focus on the role of the watershed,
a limited amount of work was addressed to the phenomenon of the dropping
water level which was of great concern to the lakeshore land owners. More
detailed studies of the vernal thermal characteristics of this lake were also
carried out during this phase. An ancillary study which concerned benthic
invertebrates as trophic indicators in Alaska was also completed during this
phase and that study treated information concerning this lake (LaPerriere,
1975).
When our analyses showed an apparent under-ice dormancy of the phyto-
plankton, as indicated by very low productivity but relatively high standing
crop (inferred from chlorophyll a measurements), the importance of algal
heterotrophy was considered. Rodhe (1955) discusses this phenomenon con-
cerning lakes in high latitudes. Thus, an experiment to measure an aspect of
algal heterotrophy was chosen to conclude the field work on November 14,
1975.
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SECTION 2
CONCLUSIONS
1. The falling water level of Harding Lake, which is a serious concern
of the lakeshore residents, is most probably due to the natural cycle of the
amount of precipitation.
2. Harding Lake may be classified as dimictic, but on rare occasions it
may not reach complete saturation with oxygen in the spring when thermal
stratification, initiated at the end of the ice-cover period, is not broken
because of absence of wind.
3. Concentrations of plant nutrients C, N, and P are currently moderate
in Harding Lake, but future management decisions should protect the lake from
additions of these nutrients.
4. Harding Lake supports low algal production comparable to other
oligotrophic lakes of high latitudes. Reports of visible algal blooms on
Harding Lake can most likely be attributed to tree pollen that covers the
surface in the spring.
5. The growth of vascular aquatic plants is relatively less important
than the algal growth of Harding Lake.
6. Application of a lake management model for the effects of nutrient
loading on algal growth adequately describes peak growth, which occurs under
the ice in spring. Should increased loading change algal succession patterns
so that peak growth occurred in summer, visable deterioration of water
quality would occur.
7. Heterotrophic algal growth may be important in this lake during
winter when light penetration is low due to heavy ice and snow cover and to
the short daylight period.
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8. Zooplankton biomass appears to be highest in late summer at about
ten times winter values.
9. The community of benthic chironomids found in this lake helps to
classify it as oligotrophic.
10. Bacterial contamination detected between 1966 and 1971 was most
likely due to improper sewage disposal methods at the state and the U. S.
Army recreational areas. At both areas pit privies were replaced by vault
toilets between 1970 and 1972, and during 1973 no excessive counts were
detected near either recreation area.
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SECTION 3
RECOMMENDATIONS
1. Further research should be conducted on the potential for monomixis
in deep subarctic lakes. Lakes more productive than Harding could suffer
summer oxygen content problems following a spring during which mixing was
not complete and the deep waters were not reoxygenated.
2. The hydrology of Harding Lake should be studied in some detail,
both to allow measurement of the water retention time and to provide those
who would manage the lake level with predictions of the results of certain
actions. Japanese scientists from the Institute of Low Temperature Science
of Hokkaido University are attempting to obtain funds from the Japanese
government to study the hydrology of Harding Lake and to take and examine a
20-m core of its sediments.
3. Research should be conducted on the relative importance of the
benthic algae as primary producers in subarctic lakes. This production has
been found to be relatively more important than that of phytoplankton in
certain lake studies.
4. The sediments of Harding Lake should be studied to ascertain their
role in the cycling of nutrients into the dissolved phase.
5. Further research should be conducted on heterotrophic algal production
in subarctic lakes.
6. Research should continue concerning the use of chironomids as
trophic state indicators for lakes of subarctic Alaska. This research
should be of both a taxonomic and ecological nature.
7. Food-habit and production studies should be conducted on the fishes
of Harding Lake. Research should also be carried out on production of
zooplankton in this lake.
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8. As the real estate surrounding Harding Lake continues to be
developed, the state agencies responsible should recommend pumped vault or
incinerating toilets prior to the time when a system of central treatment
becomes economical. This action would protect the lake from one source of
increased nutrient loading as well as from bacterial contamination. The
use of pit privies or septic tanks should be prohibited in areas where
the soil is unsuitable for proper operation.
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SECTION 4
DESCRIPTION OF STUDY AREA
The geomorphological setting and the surface geology of the Harding
Lake area have been described in a thesis by J. Michael Blackwell (1965),
who also, in the course of his study, mapped the morphology of Harding and
Little Lakes (Figure 1) as well as that of Quartz, Birch, and Chisholm Lakes
of the same formation group. His major conclusion was that these lakes were
most probably formed during the Delta (111Indian) glaciation when aggradation
of the Tanana River drowned tributary valleys. His work gives good evidence
that the reasons that Harding Lake is so much deeper than its sister lakes,
Birch and Quartz, the major lakes of nearby valleys, are because of more
recent tectonic activity and reduced infilling. He found strong evidence of
a linear fault along the deep axis of the lake and some evidence in the silt
on terraces north of the lake of an ancient sudden rush of water from the
lake. He speculates that the lake has filled in with sediments to a far
lesser degree than the sister lakes due to the small size of the contributing
watershed and perhaps to a lesser deposition of eolian silt on its hills.
Morphometrically, Harding Lake (elevation 217 m) is very close to
being conical in shape. The hypsometric curve is presented in Figure 2.
The ratio of mean to maximum depth (z/z ) is 16/43 = 0.37; the volume is
83 ^
1.59 x 10 m ; the volume development is 1.12; and the relative depth is
2.4%. The surface, 988 hectares in area, has a shoreline development index
of 1.08 indicating how nearly circular it is in shape. The average slope
for the lake is 2.4% or 24 m/km, but the lake contains extensive shallows
with 33% of the surface area underlain by water of 5 m or shallower. The
drainage basin of the lake covers slightly more than 2,000 hectares giving
an extremely low potential watershed input. It should also be noted that in
this area the mean annual precipitation is only 30.5 cm, with a mean annual
snowfall of 127 cm, accounting for about a third of the annual volume. Of
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N
11
KM
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0
0
50-
100
1
200
~r
AREA, hectares
300 400 500
600
700
800
900
1000
FIGURE 2
HYPSOMETRIC CURVE FOR HARDING LAKE (after Blackwell, 1965)
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the snowpack, an estimated 20-30% is measurable as runoff, the difference
being intercepted or evaporated (Guymon, G. L., 1973, personal communication)
Continuous flow into the lake is limited to a fractional cubic meter
per second provided by the undefined, swampy drainage of Little Lake and
another small stream draining the northeast area of the basin. All other
drainages exhibit flow only during snowmelt or infrequent heavy rainfall.
A limited study of the hydrology of the inlet on the northeast by our
group has shown that at one time the drainage basin included a section we
have named the potential watershed (Figure 3). This was seen to be a possi-
bility upon examination of all available USGS maps of the area, some of
which showed the stream at the northeast entering the lake and others which
showed the stream diverging with one branch flowing out to the Salcha River.
Tracing that stream on foot our hydrologists have found the branch to the
Salcha River to contain standing dead trees indicating that it is somewhat
recent in development. Attempts to age these trees and nearby controls by
increment boring, however, have not proved possible because of interpreta-
tion difficulties.
Information on the soil types in the Harding Lake watershed are avail-
able in Schoephorster (1973). Very limited information concerning the shore
sequence of plant cover is presented by LaPerriere and Robertson (1973).
The temperature regime of the area may be characterized as extreme with
a mean minimum January temperature of -27°C, with extreme lows of -53°C; a
mean maximum July temperature of 22°C, and extreme highs of 32°C; and a mean
annual temperature of -5°C (Johnson and Hartman, 1969).
Snowfall is generally concentrated in the period after freeze-up (Watson
et al,, 1971), diminishing with the onset of winter conditions. Winters are
characteristically clear with little wind. Occasionally, however, lake ice
may be blown free of snow during the fall period. This was the case in
1973, resulting in large wind-swept areas on Harding Lake. The snowfall
during that winter was below the 127-cm annual average, therefore the possi-
bility of occasional light penetration into the ice covered lake in fall and
winter was demonstrated but observations through the winters of the study
did not confirm this possibility.
11
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WATERSHED
POTENTIAL WATERSHED \
FIGURE 3
WATERSHED MAP FOR HARDING LAKE
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As a part of the study by Larson (1974), the shorelands around Harding
Lake were studied to determine the extent of development and the types and
conditions of sanitation facilities existing. This survey included identifi-
cation of sewage disposal practices, water supply practices and the gathering
of descriptive information relative to characterization of development.
The development area of Harding Lake contains some 400 individual land
parcels of which 262 are lake-front lots. Nonetheless, some 38% of the
shoreline of the lake is undeveloped and most of this is in some form of
public ownership. In general, the shoreline of Harding Lake is considered
to be highly developed when compared with recreation areas in the conter-
minous United States. Land parcels at Harding Lake are small with a mean
2
size of 2,216 m . Eighty percent of the lots at Harding Lake have lake
frontage of less than 30 m, and 77% of the cottages on lots at Harding Lake
have setbacks of less than 23 m from the shoreline. Usage of private
cabins at the lake occurs primarily during the summer months. The average
usage rate is about 46 days which is substantially less than the average
reported for second homes in the United States. Total cabin usage is approxi-
mately 23,000 people-days for a one-year period.
Five larger recreational facilities are located on the shores of Harding
Lake and they occupy a total of 1,900 m of the shoreline. Primary use of
these facilities occurs during the summer months and each has an associated
swimming area. These include the Farthest North Shriners1 Club, Camp Clegg
(Girl Scouts of America), Camp Bingle (Presbyterian Youth), a U. S. Army
recreation area, and a state recreation area. The state recreation area
occupies some 975 m of lake shoreline and consists of the public bathing
beach, 89 campground units, 63 picnic units3 a general store concession and
several sports activity fields. During fiscal year 1973, a total of 50,636
people visited the Harding Lake recreation area which makes it the second
most visited site in the Alaska park system.
Water supplies at Harding Lake are quite varied with the most popular
method being the transport of water to the lake in containers. Additionally,
potable water is supplied by a spring near the lake and through nine indi-
vidual wells. Untreated lake water is commonly used for some purposes,
including cleaning, flushing, and washing.
13
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A large number of sewage disposal methods are used at Harding Lake;
however, no community sewage collection or treatment exists. Disposal
methods include the use of privies (almost 80%), chemical toilets, cesspools,
septic tank systems, holding tanks, and incinerator toilets. Some of the
soil types in the Harding Lake area are considered to be extremely poor
relative to soil treatment of wastewater discharge and pit privies and
septic tank systems should be discouraged in such areas. It is believed
that the best alternative sewage disposal method for the control of waste-
water discharge would be one of collection and central treatment. It is
recognized, however, that such a system may be impractical because of remote-
ness and a relatively small seasonal population. In general a lack of
satisfactory shoreland zoning ordinances, especially with regard to setback
requirements, exists.
14
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SECTION 5
MATERIALS AND METHODS
GENERAL
Field crews were transported to sampling stations by boat during the
ice-free season and by snowmachines when the ice cover had formed. The boat
ordinarily used was a (7.3-m) flat-bottomed boat powered by a 50.7 horse-
power (metric) outboard motor. The bow of the boat was fitted with a crane
and winch for lowering and raising heavy equipment. The snowmachines were
equipped with sleds for hauling equipment, and one sled was a metal facsimile
of a dogsled allowing one rider at the rear.
Trips onto the unstable ice of late spring were made on foot by personnel
wearing neoprene wet suits, hauling equipment in a 2.7-m inflatable rubber
boat. Profiles were run at stations located by sighting to landmarks from
boat or snowmachine and comparing depth, sounded by sonar, to the morpho-
metric map. (Figure 1).
CLIMATOLOGY
Climatological data were collected intensively during the summer season
of 1974. Precipitation data were collected daily using a standard 20.3-cm
(8") diameter rain gauge containing a funnel collector allowing measurement
to the nearest .025 cm (.01").
Daily high and low air temperatures were measured using standard U. S.
Weather Bureau thermometers mounted on stainless steel backs and a Townsend
support. These were housed in an all-wood instrument shelter built to
Weather Bureau standards.
To measure pan evaporation, an evaporation station was set up in an
open area near the permanent field station. The station consisted of a
United States class A pan 25.4 cm (10") in depth and 120.65 cm (47.5")
15
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in diameter mounted on an open framework about 10.2 cm (4") above the ground,
allowing air to circulate under the pan. A hook gauge inside a stilling
well was used to measure evaporation and wind movement over the pan was
measured with a contact anemometer reading in miles of wind movement. Pan
water surface temperatures were measured with a shielded floating maximum-
minimum thermometer. Relative humidity was measured using a standard sling
psychrometer.
All instruments were installed and measurements taken according to
procedures outlined by the World Meteorological Organization (1970).
PHYSICAL LIMNOLOGY
Depth, Temperature, Electroconductivity, pH, and Dissolved Oxygen
Depth profiles of the lake for temperature, dissolved oxygen, hydrogen
ion and conductivity were determined in situ with a Martek Mark II Water
Quality Monitoring System. Temperature is determined both separately and in
conjunction with the oxygen subunit of this system. Depth is measured by a
diffused silicon diaphragm pressure transducer.
The system includes a transducer array on a 46-m electrical cable and a
control/display unit. Power is provided by a battery pack in the control/
display unit, with outputs read on 8.4-cm (3.25") taut-band meters with
mirrored scales which give maximum stability under pitch and roll. Range
switches on depth, oxygen, pH, and conductivity allowed fairly accurate
determination of these values, but the lack of a range switch for either tem-
perature scale was found to be a serious deficiency.
The hydrogen ion concentration as its negative logarithm, pH, is
determined by a sealed glass Ag-AgCl cell with pressure equalization and
temperature compensation and a reference electrode. The sensor unit also
includes a preamplifier to convert the high impedance output of the glass
electrode to a low impedance signal for transmission through the cable. The
calibration functions include zero, asymmetry, and slope which allow the
calibration and span to be set accurately. The calibration procedure is
conducted in the laboratory prior to field work. The pH unit is extremely
stable and may be used for long periods without recalibration as was
16
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confirmed by frequent checks with buffer standards. As the cell output is
temperature compensated, measurements through the thermocline were possible
without extensive equilibration time.
Dissolved oxygen is determined by a pressure-equalized polarographic
oxygen electrode. The electrode is equipped with a vibrating-wand stirring
mechanism to create a constant flow across the electrode face to prevent
depletion of oxygen at the electrode. This stirring unit malfunctioned
several times and, until repaired, necessitated manual movement of the
electrode with the cable until a constant output was obtained. Results from
summer of the third year are in error and will not be reported since the
pressure-equalizing diaphragm failed, resulting in dilution of the support-
ing electrolyte upon immersion.
Where necessitated by sensor failure and for calibration purposes,
oxygen was determined by Winkler titration according to standard methods
(APHA, et al., 1971). A stainless steel sewage sampler was utilized to
obtain samples. Since the oxygen was at or near saturation, displacement of
air from the sampler was not believed to be a significant source of error,
particularly since the scale of the oxygen sensor only allows estimation to
0.1 mg/1 and is accurate to no more than 0.2 mg/1. Calibration of the
sensor was usually conducted by the temperature-saturation method.
Electrical conductivity is not temperature-compensated in this unit. A
calibration curve was established and conductivity values corrected with the
use of simultaneous temperature data.
Light Penetration
Light penetration was routinely measured during the ice-free season
with a Secchi disk. The disk used during the summer of 1973 was a 20-cm
limnological style disk painted in alternating quadrants of black and white.
During the remainder of the project, a 50-cm oceanographic style white disk
was used.
Occasionally, light penetration was measured with a GM submarine photo-
meter consisting of a matched set of Weston photocells encased under opal
glass filters in a gimballed deck cell and a finned sea cell. The penetration
17
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of red, blue, and green light was measured by attaching the appropriate
filters under the opal glass filter on the sea cell.
CHEMICAL LIMNOLOGY
Sampling
Samples for nutrient analysis were collected with a 4- or 6-liter Van
Dorn sampler and, in a few cases, with a portable peristaltic sampling pump.
Samples to be analyzed immediately, such as alkalinity, were placed in
collapsible plastic cube-shaped containers while samples to be stored were
placed in acid-washed plastic bottles and frozen.
Ammonia
Ammonia was determined by the automated phenol-hypochlorite method as
outlined in the USEPA Methods for Chem.'loal Analysis of Water and Wastes
(1971). Reagent flow rates were reduced relative to sample flow to minimize
dilution of the extremely low ammonia levels encountered in Harding Lake.
At concentrations around the detection limit of 5 pg/1 as nitrogen we en-
countered problems similar to those of scientists studying Lake Tahoe
(Goldman, 1974). Contamination of the samples in the laboratory atmosphere
was a serious problem demonstrated by the appearance of large spikes between
samples. Efforts to eliminate this interference were largely unsuccessful.
Clasby, R. C., (1974, personal communication) indicated that this problem
was a persistent one in ammonia determinations at such low levels.
During the second year of the project, an attempt was made to determine
ammonia at the new field station using a manual phenol-hypochlorite method
(Environment Canada, date unknown). Ammonia analysis was terminated shortly
thereafter as consistent values at or below the detection limit throughout an
annual cycle were indicative of a low concentration situation in the lake and
more detailed data did not warrant the time required for careful analysis
(Alexander, V. A., 1974, personal communication).
The data which were obtained must be regarded as estimates, particularly
where concentrations are reported at or below the detection limit of 5 ug/1.
At such low levels, there is also the possibility of error from storage
losses, even though these were minimized by analysis of fresh samples.
18
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Reeburgh, W. S., (1974, personal communication) indicated the feasibility of
trace ammonia analysis by stripping ammonia from a sample with an inert gas,
after making the sample sufficiently basic to drive the equilibrium to free
ammonia. The ammonia could then be trapped in a boric acid solution and
concentration determined by a conductometric method using a differential
conductivity cell. Such a method had not been standardized, however, and
could not be developed by this project.
Organic Nitrogen and Ammonia
It had been intended to determine total Kjeldahl nitrogen and total
phosphorus simultaneously, utilizing a Technicon Auto-Analyzer with a
continuous digestion unit. Difficulties with the operation of the unit and
especially poor results with total phosphorus resulted in termination of
attempts to run the analyses by Kjeldahl digestion. Gales and Booth (1974)
report excellent recoveries of both phosphorus and nitrogen by a vanadium
pentoxide catalized digestion procedure. Personal communication with Gales,
M. E. (1975) revealed problems in pH control of the phosphorus side of the
determination which is highly dependent on acidity. The recommendation was
to use a manual phosphorus digestion, using a Technicon continuous digestor
if possible, and independent nitrogen determination.
Because of scheduling problems with the Technicon continuous digestion
unit, it was decided that a manual organic nitrogen method would be used.
The method for organic and ammonia nitrogen was taken from the USEPA methods
manual (1971). In this procedure, organic nitrogen is manually digested
with sulfuric acid and potassium persulfate, with subsequent determination
of the resulting ammonium sulfate by the phenol-hypochlorite procedure
utilizing the automated colorimeter.
Nitrite/Nitrate
Nitrate and nitrite were initially determined by the automated hydrazine
reduction method (USEPA, 1971) which reduces nitrate to nitrite. The nitrite
is then determined by diazotization with sulfanilamide and coupling with N-
(l-napthyl)-ethylenediamine dihydrochloride to form a highly colored
absorbing species. An alternate method, using a copper cadmium amalgam
reduction column, was not initially used as prior experience with the system
19
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allowed us to be aware of the tendency of the column to plug and channelize.
However, in 1975 the improved cadmium reduction method of Stainton (1974)
was incorporated.
This method utilizes a 1-m length of cadmium wire jacketed in a length
of Teflon tubing. This column is coiled and attached to the Auto-Analyzer
manifold. The nitrite produced by the column is determined as in the hydra-
zine method.
The amalgamation and regeneration procedure for this column followed
the recommendations of Clasby, R. C. (1975, personal communication). Ten ml
of distilled/deionized water was alternated with 10 ml of 10% HC1, 10 ml of
2% HgCU, and 10 ml of EDTA, beginning and ending with a water rinse.
Phosphorus
Total phosphorus was determined by manual digestion according to the
ammonium persulfate method and subsequent quantitation by the single reagent
method (USEPA, 1971).
The digestion procedure followed the method published in Methods for
Chemical Analysis of Water and Wastes (USEPA, 1971) with the addition of
the neutralization step with phenolphthalein indicator. This procedure is
similar to the more recent procedure (USEPA, 1974) which differs only in
strength of the strong acid solution and utilizes a potentiometric (pH)
neutralization. The single reagent method is unchanged in the 1974 mannual.
Some orthophosphate analyses were attempted initially in the project by
the single reagent method (USEPA, 1971) and also by the extraction procedure
of Shapiro (1973). As with many of the analyses, low levels resulted in
difficulties in attaining reproducible results. It also became apparent
from the literature (Rigler, 1964; Schindler, D. W., 1975, persnnal commu-
nication) that orthophosphate is difficult to determine and the results
are often in question as to reliability and interpretation. As Vollenweider
(1971) and others are utilizing total phosphorus in interpreting lake
nutrient status, it was eventually decided to determine total phosphorus
only.
20
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Inorganic Carbon
Harding Lake itself contains negligible quantitites of humic material
and other species contributing to alkalinity apart from the carbonate
system. Alkalinity values were then taken to be representative of the
inorganic carbon in the lake.
Alkalinity was initially determined by potentiometric (pH) titration
with 0.02 N Sulfuric acid as outlined in Standard Methods for the Examination
of Water (APHA, et al. 3 1971) and graphical analysis of the end point. This
procedure was later run at the same time as conductometric determination of
the end point according to the method of the International Biological
Programme (Golterman, 1969). The conductometric method was found to give a
sharply defined equivalence point and was adopted.
Total Organic Carbon
At the outset of the project, total organic carbon was determined on a
Beckman Carbonaceous Analyzer. Concentrations in Harding Lake were found to
be near the detection limit of the instrument. Since the variability of the
analysis was greater than that likely to occur in the lake, the analysis was
discontinued.
BIOLOGICAL LIMNOLOGY
Direct Counts--
Samples for direct counts of plankton population were taken with a non-
metallic Van Dorn sampler and each 100-ml sample was placed into a glass
bottle containing 10 ml of Lugol's iodine. Upon reaching the laboratory,
the sample bottles were thoroughly shaken and 5 ml from each sample was
placed in a settling chamber and allowed to settle for approximately 24
hours.
Transects across the area of the counting chamber were examined using
400x magnification on an inverted microscope. Usually 1/4 of the chamber
was examined, but 1/2 chamber was counted when low numbers were encountered,
21
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Chlorophyll a and Phaeophytin—
Chlorophyll a content of the algae was determined according to the
method delineated by Strickland and Parsons (1965). Approximately two
liters of water were filtered through a glass-fiber filter under reduced
light conditions and with the vacuum controlled at 15-20 cm of mercury. The
filters were frozen until the extraction could be carried out. Phaeophytin
was determined on acidified extracts according to the method presented in
the IBP manual, Chemloal Analysis of Fresh Water (Golterman, 1969).
Autotrophic Primary Productivity-
Algal primary productivity was measured in a light- and dark-bottle
test following Goldman (1963) with the following modifications. The samples
were taken with a nonmetallic Van Dorn sampler and distributed to two light
bottles and one dark bottle for each depth. The dark bottles were prepared
by dipping the typical borosilicate reagent bottles of approximately 125-ml
size in black latex and taping with two layers of black electrical tape.
The top of the ground glass stopper was treated in the same way and the cap
and neck were covered with aluminum foil during incubation to exclude all
light.
The bottles were each innoculated with 5 microcuries (yCi) of radio-
active sodium bicarbonate NaH*CO~ and secured on their sides in plexiglass
holders along a buoyed and anchored cord. In the winter the cord was
suspended from a wooden dowel placed across the access hole and the hole was
covered with materials opaque to light, usually snow. The incubation
period was routinely 24 hours as had been recommended by Hobbie (1962). At
the end of the incubation period each bottle was placed in an insulated
light-tight box and filtration of either the whole bottle or a 50-ml aliquot
was conducted as quickly as possible through a 2.5-cm diameter1 0.45-um
membrane filter.
Filtration vacuum was controlled at 15-20 cm of mercury to prevent
lysis of cells. All manipulation of the samples was carried out under
reduced light conditions to prevent damage to light-sensitive cells. The
filters were not dried but were immediately dropped into 10 ml of Aquasol,
a liquid scintillation cocktail which dissolves the filter and is miscible
with water. Drying of the filters was avoided in order to prevent
22
-------
autorespiration of labeled cell material which is a problem associated with
slow death of labeled cells (Law, A. T., 1974, personal communication).
Counting was conducted in an ambient temperature liquid scintillation
counter for three 10-minute periods for each vial. Corrections were made
for quench and background. Calculations were performed based on those
presented in the IBP manual on primary production (Vollenweider, 1969a).
Alkalinity, a measurement of the nonradioactive carbon (C-12) available
to plants in the natural aquatic system, was measured for each depth at
which productivity was measured.
During the first phase of the project, an attempt was made to measure
algal productivity using the acidification-bubbling technique of Schindler,
Schmidt, and Reid (1972). At the same time an attempt was made to modify
the technique to allow the use of miniature scintillation vials to reduce
the use of the expensive liquid scintillation cocktail. These two modifica-
tions were abandoned as being incompatible with the low productivity situ-
ation encountered.
Heterotrophic Production—
Heterotrophic production of the algae and bacteria was measured follow-
ing the methods outlined in the paper by Maeda and Ichimura (1973). Numbered
borosilicate bottles were filled with lake water taken from 3 m, and carbon-
14 labeled glucose was added in triplicate at concentrations of 0.018, 0.036,
0.072, 0.144, and 0.288 mg/1. Other bottles were filled and triplicate
treatments of carbon-14 labeled sodium acetate at concentrations of 0.00024,
0.00047, 0.00094, 0.00188, and 0.00376 mg/1 were set up. One set of concen-
trations of each treatment was immediately killed with Lugol's iodine. A
different set of all concentrations of each treatment was dosed with strepto-
mycin at 3 mg/1. The bottles were incubated in situ for 21 hours well away
from the access hole in the ice. A slit was cut with a 1.5-m ice saw and
the rope suspending the incubation rack was moved from the access hole to
the end of the slit and anchored. The hole and slit were covered with
enough snow to exclude light. Filtration and counting were conducted in the
same manner as for the algal primary productivity experiments.
23
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Vascular Aquatic Plants
The beds of vascular aquatic plants were mapped by a skin diver who
delineated the extent of the bed with a marked line. The water depth was
measured at equally spaced intervals with a weighted, marked line by a
person in a boat who was recording data.
At the height of the growing season stands that were noted to be pure
-1 2
(of only a single species) were sampled with either a 3.57 x 10 m
-2 2
quadrat or a 5.29 x 10 m Ponar dredge. The above-ground biomass was
separated, dried and weighed, providing a biomass estimate for 100% cover of
that species.
Transects were then laid out in the plant beds perpendicular to the
shoreline and percent cover of each species was estimated by a diver for a
-1 2
3.57 x 10 m quadrat sample placed every 5 m from shore to the outer edge
of the plant bed.
Zooplankton
Net Hauls—
Zooplankton were routinely sampled by 20-m vertical hauls with a small
(76 cm long x 13 cm mouth diameter) Wisconsin net with a mesh size of 76
microns. The samples were washed into 20-ml glass vials with either dis-
tilled water or 90% ethanol (in winter). Upon return to the laboratory
these vials were emptied into tared weighing pans and dried in a 60°C oven
for 24 hours to a constant weight.
Traps--
Zooplankton were occasionally sampled with a clear plexiglass rectangu-
q
lar trap (0.074 m ) lowered and raised by means of a winch. The trap has
hinged doors at the top and bottom that swing open as the trap falls through
the water column and close as the trap begins its return to the surface. A
plankton bucket (158-micron mesh) is attached near the bottom of the trap so
that the entire contents of the trap are filtered. The contents of the
plankton bucket were washed into 300-ml polyethylene bottles with filtered
lake water and 10 ml of Lugol's iodine solution were added. In the labora-
tory, ten 1-ml subsamples were taken with a Hensen-Stempfle pipette and all
fields were counted in a Sedgewick-Rafter counting cell.
24
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Benthic Macroinvertebrates
Sampling was accomplished with a standard 15.24-cm square Ekman dredge.
Each sample was immediately washed free of sediments in a #30 mesh (590
micron) screen-bottomed bucket, and the remaining contents were washed into
a 1.14-liter jar. Alcohol was added to bring the concentration to approxi-
mately 25% by volume and the samples were returned to the laboratory where
they were refrigerated at 5°C until the organisms were picked.
Picking was accomplished on the entire sample by diluting subsamples in
white enamel pans and separating the organisms from the debris with forceps.
The organisms were separated to order and stored in 90% ethanol until identi-
fied.
Chironomid larvae from the 1973 samples were prepared for identification
by preparing head capsule mounts on glass slides. Each chironomid so pre-
pared was heated in 5% KOH for fifteen minutes (or immersed overnight in
cold KOH) and rinsed in distilled water, then the head was dissected onto a
glass slide and covered with a water-miscible mounting medium. After
checking that the head was in position with teeth uppermost, a cover slip
and label were affixed. The body was left on the slide if it were suffi-
ciently small and flattened.
The samples for the rearing effort were taken with a standard Ponar
dredge or by hand and treated as above except that ethanol was not added to
the quart jars. Picking was accomplished almost immediately at the field
laboratory located at the lake. Each chironomid larva or pupa was placed in
a separate 10-ml vial with clean lake water and the vial was plugged with
cotton.
Daily checks were conducted on all vials so that the adults and associ-
ated ecdyses could be preserved. As soon as an adult was observed in a
vial, the vial was placed in an ethyl acetate killing jar, when the cotton
could be removed 90% ethanol was added, and a screw cap affixed. The dis-
sected adults and associated ecdyses were later mounted and identified.
Enteric Bacteria
All bacteriological analyses (standard plate counts, total coliform,
and fecal coliform) were performed by the Fairbanks laboratory of the Alaska
25
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Departmen
-------
SECTION 6
RESULTS AND DISCUSSION
CLIMATOLOGY
Heat Budget
From the thermal data taken, it was possible to estimate the heat
budgets of Harding Lake for three years (1973, 1974 and 1975). The calcu-
lated heat budgets include the energy required to heat the water in the
lake from the minimum temperature to the maximum temperature, and the
amount of energy needed to melt all ice on the lake. The energy required
to heat the ice from its minimum temperature to the melting point is compara-
tively small and was not calculated.
TABLE 1. HEAT BUDGET ESTIMATES FOR HARDING LAKE—1973-1975
Year
1973
1974
1975
Ice
thickness
(cm)
81
100
77
Heat needed
to melt ice
(cal/cm2)
5,941
7,309
5,612
Winter heat*
income
(cal/cm2)
8,991
10,819
9,292
Summer heat**
income
(cal/cm2)
8,700
10,196
10,770
Annual
heat budget
2
(cal/cm )
17,691
21,015
20,062
*winter heat income is that amount of heat necessary to melt the ice and
heat all lake water to 4°C.
**summer heat income is that amount of heat necessary to raise the water
temperature from 4°C to its maximum.
27
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In the heat budget calculations, the total area of the lake was taken to
in 9
be 9.9 x 10 cm ; this, of course, varied slightly with the water level
during a given year.
A thermal regime of a shallow (3m) arctic lake (Imikpuk Lake, 70°N) at
Barrow, Alaska, reported by Brewer (1958) gives an approximate annual heat
budget of around 14,000 cal/cm2 of which 90% is accounted for by ice cover.
This occurs in an area having a thawing index of about 500 degree days
compared with 3000 degree days for Harding Lake.
A deep arctic lake (Schrader Lake 69°N) has a summer heat budget of
p
approximately 9000 cal/cm (Hobbie, 1973). No winter heat budgets are
reported but ice thicknesses are somewhat greater than Harding which would
put its annual heat budget somewhat above Harding. Since the thermocline
of Schrader is deeper, the maximum summer temperature generally runs half
that of Harding and in some years remains near 4°C when statification is not
set up. Thus Schrader Lake cannot be considered temperate, while Harding
Lake fits Hutchinson's (1957) definition of a temperate lake.
Hydrology
In order to obtain a rough water balance for Harding Lake, climatolog-
ical data was collected throughout the study and intensively during the
summer of 1974. As a result of these measurements, the following estimates
of water input to the lake were made for June 1974 to June 1975 (given in
terms of change in lake level):
1. Direct rainfall on lake = 16.5 cm (6.5")
2. Rainfall runoff to lake from immediate drainage area = 1.5 cm (0.6")
3. Snowmelt on lake = 13.0 cm (5.1")
4. Snowmelt runoff to lake from immediate drainage area = 6.6 cm (2.6")
5. Input from stream at northeast end = 2.8 cm (1.1")
From the above, it is estimated that the annual total lake input is
about 41 cm. Evaporation was calculated from pan measurements to be about
18 cm, and since the lake level did not change appreciably, there must be a
net groundwater loss of about 23 cm.
28
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An adjoining drainage basin east of Harding Lake of about 2600 hectares
provides some input to the lake (Figure 3). However, this stream is diver-
gent and splits into two streams about 3 km from the lake. From stream-
gaging measurements, it appears that during times of high streamflow such as
the snowmen period, about 30% of the flow goes to Harding Lake and 70% to
the Salcha River. During periods of low flow only approximately 10% flows
into the lake.
o
Base flow of the stream during the summer seemed to be about .07 m /sec
while the peak measured during the snowmelt period was slightly over
.6 m /sec. The stream has apparently been divergent for some time, since
channel formation is fairly mature for both the divergent branches. The
older channel is probably the one to the lake, but this is by no means
certain.
It appears that it would be possible to control the lake level somewhat
by diverting more of the flow of the stream toward the lake during natural
periods of low lake level, but further studies would certainly be needed to
assess the total amount of available streamflow, the type of diversion
apparatus needed, and most importantly, the ideal lake level. From stream-
flow measurements, it was estimated that if all available water had gone to
Harding Lake during 1975, the lake level would have been raised by over 10 cm.
However, the water available in the stream probably is highly variable from
year to year.
PHYSICAL LIMNOLOGY
Thermal Regime
Figure 4 illustrates slightly more than two annual cycles of the
temperature regime of Harding Lake. From this graph it could be inferred
that Harding Lake is dimictic, undergoing a complete mix top to bottom in
both autumn and spring. While this is undoubtedly true for most years,
much evidence was seen for the possibility of an incomplete turnover in the
spring of occasional years. During the late spring of 1974 while the lake
was still almost completely ice covered the field crew noted water consider-
ably warmer than 4°C close to the lower surface of the ice, though this
seemed to consist of a very thin layer easily disturbed by the probe assembly
29
-------
OJ
o
TEMPERATURE, °C
Os—~iirrr\—r ,
Surface-
35
MAY JULY SEPT NOV.
1973
'JAN.
MAR. MAY JULY SEPT.
1974
NOV. 'JAN.
MAR. MAY JULY SEPT
1975
FIGURE 4
ISOTHERMS-HARDING LAKE, WITH ICE THICKNESS INDICATED
-------
of the Martek Mark II. The existence of warm layers beneath melting ice was
attributed to flow of meltwater under the ice by Hutchinson (1957). This
water is less dense even at 4°C than the water below because of low salt
content.
The ice at that time was noted to be candled, that is, with long vertical
holes throughout the structure. A good discussion of ice-melting phenomena
for arctic lakes, which describes thoroughly the process at Harding Lake, is
contained in a review paper by Hobbie (1973). On May 31 the ice was observed
to cover approximately 67% of the lake surface; a wind arose that night and
the lake was essentially ice free on June 1. This is a frequently observed
phenomenon attributable to ice candling, a condition wherein the ice cover is
composed of loosely packed ice candles. These may be tipped easily by the
wind and then are rapidly melted by the warmer water. The weather remained
windy through June 2 when our field crew observed..."heavy waves, fetching
towards the NE shore, approximately 6 m long and up to .6 m in height." On
that day, measurements of various parameters showed the lake to be in full
wind-driven overturn.
During the next winter a set of thermistors was attached to a wooden
post and frozen into the ice in such a position that the thermistors were
spaced every 0.15 m throughout the ice and water column to 1.8 m. Heavy
snowfall caused depression of the ice allowing water to seep up within the
snow and when the latter froze, the thermistor cords, though bagged together
and tied high on the pole, froze into the ice. On May 9, 1976, the entire
pole had melted free of the surrounding ice and was removed. It was observed
that anything of different albedo than the ice, even a piece of white card-
board box lying on the ice, would melt down into the ice as radiation was
absorbed.
On May 9 and May 21, a thermistor was lowered gently down a 0.15 m hole
which had been drilled with a power ice auger and left undisturbed for at
least a day. Figure 5 illustrates the results found. In both cases the
water was being warmed by solar radiation, and by May 21, this heating was
dramatic. The ice was entirely gone by May 27, and, on May 29, measurements
showed the lake to be weakly stratified. The reappearance of the 4°C iso-
therm while the ice was still on the lake followed by slowly strengthening
31
-------
TEMPERATURE, °C
2.5L
FIGURE 5
TEMPERATURES OBSERVED UNDER ICE AT HARDING LAKE, MAY 1975
32
-------
DEGREES,(°C.)
5 10 15 20 25
DEGREES, (°C.)
5 10 15 20 25
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DEGREES, (°C.) DEGREES, (°C.)
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FIGURE 6
TEMPERATURE PROFILES FOR SELECTED DATES. SPRING 1975,
HARDING LAKE
33
-------
stratification (Figure 6) shows an under-ice overturn that may or may not
have involved the deep water that spring. Further evidence of the lack of
wind-driven reoxygenating circulation that spring is seen in Figure 7 where
it can be seen that water of low conductivity, probably meltwater, stayed
near the surface unmixed with the rest of the water column through ice-off
and until summer stratification was completely formed. Unfortunately, the
necessity of repairs to the Martek system in early summer did not allow us to
get data to complete this conductivity plot to the end of the field work.
If Harding Lake should miss a spring turnover and the resultant uptake
of dissolved oxygen the hypolimnion is expected to remain sufficiently well
oxygenated to support aquatic life. This is due to the great volume of the
hypolimnion and the low productivity of this lake. However, for subarctic
lakes in general, this potential has important management implications,
especially for lakes more productive than Harding Lake, where the decomposi-
tion of dead plant and animal materials settling into the hypolimnion could
use up the dissolved oxygen.
Dissolved Oxygen
While it is recognized that biological activity has much to do with
dissolved oxygen in a lake, the primary influence on dissolved oxygen content
in Harding Lake was found to be physical, that is, explainable through the
inverse relationship between temperature and concentration.
Failure of the oxygen probe of the Martek system occurred during the
winter of 1973-1974 and again in June of 1975. However, enough data was
obtained to provide some knowledge of the oxygen conditions in the lake.
Figure 8 illustrates the actual dissolved oxygen content of the water column
and Figure 9 illustrates the relationship with temperature by showing how
close to complete saturation with oxygen the water was at various depths at
various times. Supersaturation is seen at about 6-8 m during the summers.
This is attributable to photosynthetic activity of the algae at depths suffi-
cient for the water to be isolated from mixing except by the strongest
winds.
34
-------
OJ
en
CONDUCTIVITY, [i mho/cm at 20°C
35
MAY
JULY SEPT.
1973
JAN. MAR.
MAY JULY SEPT.
1975
FIGURE 7
ISOPLETHS OF ELECTRICAL CONDUCTIVITY. HARDING LAKE
-------
CO
CTl
DISSOLVED OXYGEN, mg/l
Oi ,-
SURFACE-
35
MAY JULY SEPT. NOV.
1973
JAN. MAR.
MAY JULY
1974
SEPT NOV.
JAN. MAR.
MAY JULY
1975
SEPT
FIGURE 8
ISOPLETHS OF DISSOLVED OXYGEN. HARDING LAKE
-------
DISSOLVED OXYGEN, % saturation
SURFACE-
5 -
10
S. 15
-------
Light Penetration
The characteristics of light penetration of the water column on June 26
1975, are illustrated in Figure 10. This measurement was conducted on other
occasions during the ice-free seasons of the project and no significant
differences were noted. The particular pattern shown, with green light
penetrating to greatest depth, is characteristic of waters with a small
amount of dissolved organic matter (Hutchinson, 1957).
Secchi depths were taken at frequent intervals during the ice-free
season, and these measurements are illustrated in Figure 17. A commonly used
"rule of thumb" states that doubling the Secchi depth gives the compensation
depth for algal productivity, that is, the depth at which photosynthesis
equals respiration and net productivity is zero (Cole, 1974). Examination of
Figure 17 shows this rule to be applicable to Harding Lake with some occasions
when net productivity stopped either above or below double the Secchi depth.
CHEMICAL LIMNOLOGY
Ionic Composition
The water quality parameters and a cation/anion balance for Harding Lake
have been determined by the U. S. Geological Survey, Table 2. Other analyses
have been reported by Barsdate (1966, 1967), and selected data is presented
in Tables 3 and 4.
Of significance to the ionic composition of the lake is the small area
of the drainage basin, which is about equal to the surface of the lake
itself. The lake is in a transition zone between muskeg to the north and
steep hills covered with deciduous (aspen and birch) and coniferous (spruce)
forest on the other compass points. Since most of the drainage is rapid from
the slopes, the residence time of liquid precipitation on the ground is
short. Also reducing potential weathering of minerals are the extended
period of frozen ground and the high proportion of snowfall which is rapidly
lost through sublimation or evaporation before the ground is thawed.
Data of Barsdate (1966) show the electrical conductivity of Birch Lake,
a lake of the same formation group as Harding to be about 50% greater than
that of Harding. Relative abundance of Mg, Ca, and K are approximately
38
-------
100
10
z
UJ
UJ
o
IT
ID
C/5
HARDING LAKE
June 1975
RED
GREEN
\
_L
0
8 12 16
DEPTH, meters
20
24
FIGURE 10
LIGHT PENETRATION. HARDING LAKE
39
-------
TABLE 2A. WATER QUALITY, HARDING LAKE,
JUNE 3, 1975 (PROVISIONAL) (USGS)
Parameter
Alk, T (as CaC03)
Aluminum T
Bicarbonate
Boron T
Calcium dis
Carbon T org
Chloride dis
Cobalt T
Color
Copper T
Fluoride dis
Hardness, noncarb.
Hardness, T
Iron dis
Magnesium dis
Manganese dis
Molybdenum T
TABLE 2B. CATION
Concentration
30
50
36
40
6.9
3.7
0.7
<50
7
30
0.1
0
27
10
2.3
0
0
AND ANION
mg/1
yg/1
mg/1
yg/1
mg/1
mg/1
mg/1
yg/1
yg/1
mg/1
mg/1
mg/1
yg/1
mg/1
yg/1
yg/1
inDLt
-------
TABLE 3. LIFINOLOGICAL PROPERTIES OF HARDING LAKE, 1966. (BARSDATE, 1967)
OJ
(U Q.
+s E
fO rd
Q OO
31 Mar 149
150
151
152
30 Apr 164
165
166
167
168
2 Jun 189
190
191
192
193
194
10 Jul 225
226
227
228
E
CL
Ol
Q
0.8
5
10
25
0.8
5
10
25
42
0
1
5
10
25
29
0
5
10
25
o
Q.
QJ
0.4
2.8
3.1
3.5
0.0
2.8
3.1
3.4
3.7
4.8
4.4
4.1
3.7
3.4
17.3
16.4
5.9
3.7
o
4-> CVI
•i —
•r- E
4-> O
O --v.
3 O
"O -C
C E
O 3.
75
69
69
70
81
99
80
60
96
48
53
69
74
70
71
62
64
67
66
en
E
0
Q
11.6
10.6
10.3
8.7
12.5
10.4
10.2
8.3
0.2
10.8
10.2
10.2
9.6
7.4
8.6
8.8
10.4
8.4
(13
OO
0
80
78
76
65
86
77
76
62
2
84
78
77
72
56
89
89
85
64
Q.
7.31
7.26
7.27
7.14
7.45
7.10
6.63
6.88
6.89
7.53
7.53
7.45
6.82
7.35
7.28
7.50
7.35
7.00
7.10
00 S_
• O Cc—
^. CJ r— (/]
i — n3 O -*->
0 E (00-
33 15
31 21
30 18
31 18
36 30
27 23
19 23
26 23
37 50
19 21
21 29
26 30
20
28
27 31
26 33
24 32
18 31
24 35
o> -^
+-> en
(13 E
0 i-
•r- O)
I^J | ^
S- 4->
tO ro
Q- 5!
0.0
0.1
0.0
0.1
2.4
0.3
0.6
0.3
0.1
0.3
0.2
1.1
0.3
i
en
•r—
00
•=;)-
O
00
23
5
16
21
55
13
23
10
23
14
11
16
24
i
en
D-
1
o
D-
0.00
0.00
0.00
0.13
0.10
0.00
0.10
0.10
0.00
0.00
0.00
et
1
cn
00
0
2.6
2.6
2.0
2.9
1.1
0.2
0.0
1.2
2.6
0.3
0.2
0.3
2.9
(continued)
-------
TABLE 3 (continued)
01
-,un
•*-> (XI
•i- E
4-> O
O ~^
^ O
E E
O -1
O -— -
62
66
61
66
74
69
69
cn
E
O
Q
9.1
9.0
10.6
8.8
3.3
10.2
10.3
(13
GO
.
0
96
95
92
67
25
82
83
—r~
0-
7.68
7.68
7.36
7.11
6.96
7.18
7.18
oo
• 0
-^ O
i — re
cn
0 E
h- — -
25
25
26
29
31
26
26
S-
O '—•
i — CO
o +->
O •!-
i- 13
O>
_l_j [ ^
to CL
3 "-^
31
32
32
33
185
31
30
cu -\
-i-> cn
0 S-
•<- CD
±j +j
S- +->
(T3 rd
D- S
0.4
0.3
0.5
0.1
1.0
0.5
0.3
i
cn
•r—
GO
1
O
•1 —
00
14
15
14
26
44
-------
TABLE 4. CHEMISTRY OF SNOH. ICE, AND HATER. HARDING LAKE. (BARSDATE, 1967)
CM >,O
•^ E" CO
4-> U T-
O ^-, i— r—
3 O «O -».
x> -c -v cn
c: E •— E
O -—'
5.2
118 44
11 11
81 36
9.8 4.8
o— -
i — (/)
O -4-*
0 ••-
C
S- D
OJ
-M •!->
03 d.
3
0
0
33
0
0
30
9
QJ \
•4-> en
n3 E
3
0 S-
•^ O)
4-i 4_>
s- -»->
(O (T3
D- S
10.3
3.8
0.0
0.7
0.2
0.0
1.7
,s
1 ^£
c^~ I
o o>
•r— ^3.
COx —
0
3
20
>1
0
23
27
^ ^
0.
-------
TABLE 4. (continued)
Concentration (yg/1 )
Date
April 30, 1966
II
II
June 2, 1966
Sample
No.
169
170
163
172
173
164
195
Copper
Filtered
1.5
2.0
2.3
3.1
4.7
1.7
1.7
Total
1.9
3.2
1.4
3.5
5.3
2.4
2.0
Manganese
Filtered Total
1.8
1.9
3.9
7.8
2.0
1.4
5.2
6.9
4.4
3.7
3.6
2.1
1.8
5.9
Iron
Filtered
11
16
19
27
7.4
12
4.8
Total
365
115
25
69
22
27
36
Zinc
Total
4.1
11
1.7
7.1
17
3.8
4.3
-------
equal. This might be expected from the common geologic settings of the
lakes, but actual concentrations are 2 to 3 times greater for these elements
in Birch which has a substantially larger, flatter drainage. This is sig-
nificant to the relative oligotrophy of Harding as it applies to nutrient
loading in a comparable manner.
The ionic composition of the lake is bicarbonate type of moderate
hardness. A comparison of the cationic composition to the average composi-
tion of the world rivers (Clark, 1924) shows the Mg/Ca ratio to be somewhat
higher but not unusually so. Hutchinson (1957) points out that the
composition of open lakes approximates the average river composition due to
source materials and exchange reactions.
TABLE 5. CATION COMPOSITION OF WORLD RIVERS VS. HARDING LAKE
Ca
Mg
K
Na
Mean river
concentration (%)
63.5
17.4
3.4
15.7
Harding Lake
concentration (%)
55.5
30.5
3.8
10.6
The reported compositions are consistent with the geology of the Yukon-
Tanana Upland. These low-lying hills are covered with wind-blown loess
composed of quartz, feldspar, and mica, particularly on slopes with a
southern aspect. The bedrock, exposed in some areas, consists of granitic
material and Birch Creek Schist, a quartz-mica schist. These silicaceous
materials are relatively inert to weathering and dissolution, contributing
relatively small amounts of calcium and bicarbonate to the lake compared to
the potential contributions of limestone and other carbonate formations
found in other areas of Alaska.
45
-------
Hydrogen Ion Concentration
The results of our measurements of hydrogen ion concentration, as the
negative logarithm, pH, are shown in Figure 11. Failure of the reference
electrode during two periods of the field work of this project cause the
patterns of fall and early winter to remain unknown. The 6.6 and 6.8 lines
which appear only at the beginning of the project may be an artifact due to
the initial use of a pH meter which is not thermally compensated on samples
taken from a Van Dorn sampler. This was necessary while the Martek multi-
probe system was being refitted for the work on this lake with a longer cord
and a more sensitive electroconductivity transducer.
The patterns shown are typical for a lake of moderate alkalinity where
the carbonate system buffers against any major changes. Slightly increased
pH is seen near the surface during the height of the plant-growing season,
as expected.
Nutrient Chemistry
Carbon—
Inorganic carbon was routinely measured as bicarbonate alkalinity as
part of the procedure of measuring algal primary productivity. Alkalinity
values ranged between 11.8 and 42.3 mg/1 as CaCO.-., averaging 31.0 ± 3.5
mg/1. Bicarbonate alkalinity values were converted to the concentration of
carbon present by means of the table of Saunders, Trama, and Bachmann (1962)
which corrects for In situ temperature and pH differences. On at least two
occasions, paired samples were both titrated for alkalinity and analyzed for
dissolved inorganic carbon in a Fisher-Hamilton gas partitioner (chromato-
graph) according to the method of Stainton (1973) and the results were
identical. Thus it was concluded that alkalinity provided an adequate
measure of inorganic carbon. As was mentioned in the Methods section,
organic carbon was measured on initial samples and then this measurement was
abandoned as the Harding Lake samples varied little, remaining near 5 mg/1
the detection limit of the instrument.
46
-------
MAY
JULY SEPT
1973
NOV.
JAN. MAR. MAY
JULY
1974
SEPT. NOV.
JAN. MAR.
MAY JULY
1975
SEPT.
FIGURE 11
ISOPLETHS OF HYDROGEN ION CONCENTRATION AS THE NEGATIVE LOGARITHM, pH . HARDING LAKE
-------
Nitrogen--
Niirate/nitrite measurements for Deep Station I for most of the first
year of the project are shown in Figure 12. The same information for most
of 1975 is illustrated in a slightly different way in Figure 13. The
remaining species of nitrogen, ammonia and organic nitrogen were measured
together during 1975 and these data are presented in Tables 6 and 7 since
there was little variation in this composite measurement rendering graphical
illustration unnecessary. As was mentioned in Methods, ammonia was measured
by itself during the first year of the project, but problems with contami-
nation caused us to abandon this effort. The small amount of ammonia data
obtained is presented in Appendix Table A-l. It should again be noted that
the stated detection limit of the method used was 5 yg/1 as N.
The nutrient cycles of ammonia and nitrate for Harding Lake display a
vernal decline to below detectability which continues throughout the summer.
Onset of autumnal circulation and corresponding physical conditions restores
these nutrients to their predepletion levels. Observation of this type of
cycle are common and are reported extensively in the literature for both
marine and limnological systems (Steele and Baird, 1961; Stewart and Markello
1974; Lueschow et al.„ 1970; Gruending and Malanchuk, 1974; and Schindler
and Nighswander, 1970). This phenomenon is attributed to assimilation by
bacteria and phytoplankton at the onset of the vernal production and subse-
quent mineralization of cellular nitrogen during autumnal die-off and decline
in production.
In terms of concentration of nitrate and ammonia, Harding Lake is very
similar in both cycling and concentration to Lake Tahoe (Lake Tahoe Area
Council, 1971), considered to be a hyperoligotrophic lake. Unfortunately,
most of the work on other Alaskan lakes is such that the results do not lend
well to comparison since many are reconnaissance-type studies (Barsdate and
Alexander, 1971; LaPerriere and Casper, 1976) or are obviously not morphologi-
cally comparable (Alexander and Barsdate, 1971). Some reports on lakes in the
arctic, such as Char Lake, (72°42'N, 94°50'W) (Schindler et al., 1974) or
Lake Peters (69°19'N, 145°03'W) (Hobbie, 1962) which are clearly oligotrophic,
show inorganic nitrogen levels comparable to those of Harding Lake.
48
-------
40 m
20
LU
CD
O
OC.
LJ
h
i
LU
5
OC
10
5
HARDING LAKE
APRIL MAY JUNE JULY
AUG.
SEPT.
1973
OCT. NOV.
DEC.
FIGURE 12
ISOBATHS-NITRATE AND NITRITE NITROGEN. HARDING LAKE
-------
N03+N02-N, pg/l.
Surface*
CO
o>
"cu
£
Q_
LU
Q
30-
FEB.
OCT.
FIGURE 13
ISOPLETHS OF NITRATE AND NITRITE CONCENTRATION. HARDING LAKE
50
-------
TABLE 6. ORGANIC AND AMMONIA NITROGEN (mg/1 as N)
HARDING LAKE. 1975. DEEP STATION I
Depth
(m)
1
2
3
4
6
8
10
12
14
16
18
20
25
30
35
40
Jan 16
.13±.02
.22±.00
.16±.02
.12
.18±.01
.21±.04
.16±.03
Feb 22 Mar 21
.18±.02 .15±.05
.19±.04 .22±.04
.14±.01
.20±.02
.12±.02 .16±.04
.17±.06 .13±.04
.20±.10
.14±.02 .16±.04
.19±.10
.23±.02
.20±.00
Apr 11
.15
.25±.09
.17±.05
.17±.03
.16±.01
.32±.06
.43
.25±.08
.20
.32±.06
May 2 May 7 May 20
.23 .15±.04 .29
.23±.06
.22±.12 .15±.02 .24+. 04
.24±.06 .38
.18 .42
.29±.13 .15
.34
.10±,02
.20
.2U.07
.15
.20
May 28 Jim 3
.15
.08
.34
.18
.11 .16±.04
.12
.20
.16
.16
.16
.20
.14
.12
(continued)
-------
TABLE 6 (continued)
en
ro
Depth
(m)
1
2
3
4
6
8
10
12
14
16
18
20
25
30
35
40
Jun 9
.22
.24±.00
.12±.02
.16±.03
.26
.18
,15±.04
.18
.11
.19
,09±.03
.23±.04
.14±.04
.1U.06
Jun 18
.23
.22
.18
.12
.14
.10
.25
.14
.15
.19
.06
.24
Jun 25
.21±.10
.28±.ll
.21+. 08
.24±.09
.15±.05
.10±.05
.16±.03
.18±.01
.27
.16±.04
Jul 16
.26
.10
.22
.14
.29
.12
.09
.11
.21±.14
.10
.09
.10
.27
.14
Jul 30
.19±.08
.22±.01
,20±.05
.15±.05
.22±.01
.20
.19±.10
.20±.04
.29±.04
.18±.02
.20±.02
.18±.05
.17±.07
.20±.04
.21
Aug 13
.19±.08
.15±.04
.19±.06
.16±.08
.13±.04
.19±.07
.17±.06
.18
.17±.06
.15±.06
.27±.03
.20±.06
.22±.10
.11±.03
Aug 25
.12
.19±.06
.10
.11±.02
.14±.06
.17±.05
.22
.18
.12±.04
.17±.01
.30±.02
.14±.02
.18
.12±.00
Sep 12
.23±.00
.14±.01
.14±.01
.17±.07
.26±.ll
.16±.02
.17±.05
.10±.05
.23±.08
.18±.06
.19±.07
.2i±.n
.12±.04
.68
Oct 13
.27±.17
.14±.01
.16±.00
.17±.02
.18+. 07
.21
.25±.10
.17±.ll
.16±.04
.18
.28
.20±.06
,15±.07
.20±.02
-------
TABLE 7. ORGANIC AND AMMONIA NITROGEN (mg/1 as N)
HARDING LAKE. 1975. SHALLOW STATIONS
Depth February 22 March 21
(m) S-I S-II S-IV S-V S-I S-II S-IV S-V
1 .10 .28±.05
2 .14
3 .10
4 .12
5
6 .14±.00
7
8 .18
9
10 .13±.03
11
12 .13±.01
April 11 May 3
1 .25±.06 .21 .20±.03
2 .16±.03 .2U.04
3 .14±.01
4 .19±.08
5
6 .13±.03
7
8 .14±.02
9
10 .17±.02
11
12
(continued)
53
-------
TABLE 7 (continued)
Depth
(m)
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
May 28
S-I S-II S-IV S-V S-I
.30 .13 .14
.52 .15
.23 .18 .30±.05
.03
July 16
.24 .11 .llt.Ol
.20 .16 .21±.05
.14 .18+. 08
.11 .12±.04
August 13
.30±.08 .37 .28±.12
.33±.16 .10 .10
.25±.12 .13+.00 .22±.02
.37+.06
October 13
.20±.06 .16±.01
.19±.13 .12±.02
.18±.03 .36±.20
.22±.12
June 18
S-II S-IV S-V
.15±.06
.13 .19±.00
.22
July 30
.2U.01
.09±.02
.18±.09
August 25
.18±.04
.17±.03
.12
54
-------
Phosphorus—
For reasons cited in the Methods section, the most successful phosphorus
measurements were of total phosphorus made during part of 1975. Analysis of
samples taken after August 13, 1975, was not completed before the end of the
project due to potential contamination of the ammonia and organic nitrogen
measurements that would be caused by use of the total phosphorus digestion
agent, ammonium persulfate, in the laboratory. The total phosphorus data is
illustrated in Figure 14.
The seasonal cycle of total phosphorus is undramatic and shows little
change except for shifts in the depth of the peak concentration. It would
be unexpected that the total phosphorus would exhibit a seasonal change in
terms of average concentration in a well oxygenated lake with a minimum
number of point and nonpoint nutrient inputs. The features of the seasonal
cycle are similar to those reported by Stewart and Markello (1974) which
also exhibit a fairly constant average with peak concentrations found at
discrete depths.
Total nitrogen and total phosphorus, being collective parameters,
clearly indicate the comparative nutrient status of the lake. The concen-
tration of individual species of nutrients, especially dissolved inorganic
forms, depend largely on relative rates of biological uptake and release
whereas total forms indicate the active pool of nutrients in the water
column. These parameters are also more frequently reported in the literature
and may be more reliable analytically for the class of oligotrophic lakes
where analysis problems are frequent at levels commonly close to the detection
limit.
To illustrate the relative status of Harding Lake, Table 8 has been
compiled to tabulate some of the nutrient values for oligotrophic lakes.
In general, the total nutrient status of Harding is in the range of
other lakes identified as oligotrophic. The upper limits of these ranges
appear high in some cases but relatively high peaks commonly occur in the
nutrient profiles. It is known that plankton tend to stratify at discrete
depths (Baker and Brook, 1971) and sampling such strata would tend to give
high total nutrient values. The peak total phosphorus values in Harding lie
55
-------
0
TOTAL P, jug/I
Surface^
10
w 15
0)
CD
E
of
H
0.
UJ 20
25
30
*- I
FEB.
I
JUN. AUG.
APR.
1975
FIGURE 14
TOTAL PHOSPHORUS ISOPLETHS. HARDING LAKE
56
-------
during summer at depths in the range of 15-20 m, the same depth range at
which the peak photosynthetic pigment concentrations lie, indicating
phytoplankton stratification at those depths.
TABLE 8. NUTRIENT VALUES FOR OLIGOTROPHIC LAKES
Lake
Mowich
Nordford
Vorderer
Finstertaler
Tahoe
Superior
Char
Harding
Total P(yg/L)
2-4
5
See 1-14
2-20
8-15
8
6-20
Total N(pg/L)
15-135
0-180
40-270
100-150
70-300
Source
Larson, 1973
Str0m, 1932
Pechlaner, 1966
Lake Tahoe Area Council,
1971
Gruending & Malanchuk, 1974
Schindler, et aZ.3 1974
BIOLOGICAL LIMNOLOGY
Algae
Autotrophic Primary Production--
Actual counts of the plankton, with emphasis on the algae present in the
water column, were only conducted once, for samples of September 28, 1974,
at Deep Station I. The results of these counts are presented in Table 9 and
Figure 15. Other observations were occasionally made concerning the algal
composition and Table 10 contains a list of all algae identified to April
1975.
During the three years of this project, algal growth dynamics were
studied in two major ways. Chlorophyll a measurements, which have often
been used to estimate biomass and to evaluate growth were taken; and, algal
primary production was assessed using a method of measuring the uptake of
radioactive 14C-labeled bicarbonate (Steemann-Nielsen, 1952).
57
-------
TABLE 9. PLANKTON COUNTS (CELLS/LITER) HARDING LAKE. SEPTEMBER 28, 1974. DEEP STATION I
Depth in meters of sample
Species 2 4 6 8 10 16 20 24 30
Asterionella foimosa 8 xlO2 2 xlO3 3 xlO3 2 xlO3 4 xlO2 9 xlO3 5 xlO3 2 xlO3 1 xlO4
Cocaoneis sp. 4 xlO
Cyclotella sp. 3 xlO3 8 xlO2 2 xlO3 4 xlO3 2 xlO3 2 xlO3 3 xlO3 5 xlO3
Cymbella sp. 8 xlO2 8 xlO
2
Di-atoma elongatum 8 xlO
MeZos-ira italica 9 xlO3 8 xlO3 1.5x10 1.8x10
N-itzsehia sp. 8 xlO 2 xlO3
01 Synedra nana 8 xlO2 3 xlO3 2 xlO3
Chlorophyceae
Ankistrodesmus ? •? •? -5 -3
setigerus 2 xlO^ 5 xlOJ 2 x!0J 6 xlO^ 2 xlOJ
Cosmari-TMn _
sub-tian-id-iwri 8 xl 0
Crueigenia 2
teticaped-ia 8 xlO
2
Staurastrum eurvatum 8 xlO
Chrysophyceae
Diceras phaesolus 2 xlO3 8 xlO2 3 xlO3 2 xlO3 2 xlO3
2 3
D-inobryon borge-i 8 xlO 2 xlO
D. crennulatum 2 xlO3 6 xlO3 6 xlO3 6 xlO3 4 xlO3
(continued)
-------
TABLE 9 (continued)
Depth in meters of sample
Species
D. cvennulatum,
"loricas
D. soo-iale
D. soeiale, loricas
Dinobryon sp.
unidentified
2468
4.0xl04 5.4xl04 3.4xl04 B.OxlO4
8 xlO2
8 xlO2
10
2.8xl04
4 xlO2
3 xlO3
16 20 24 30
4 xlO3 8 xlO2
2 xlO2
3 xlO3 8 xlO2 2 xlO3
Dinobryon sp. uniden- ,
tified, loricas 4 xlO
Mallomonas globosa 4 xlO3 8 xlO2 2 xlO3 4 xlO3
Ciliates
unidentified 4 xlO3 5 xlO3 8 xlO2 3 xlO3 2 xlO3 6 xlO3 7 xlO3 2 xlO3
Cladocera
2
Daphnia sp. 8 XlO
Cryptophyceae
Cryptomonaa sp. 2 xlO3 2 xlO3 2 xlO3 8 xlO2 8 xlO2 8 xlO2 8 xlO2 2 xlO3
3
C. marssonii 2 xlO
Rhodomanar, minuta 3.3xl04 4.6xl04 6.2xl04 4.1xl04 1.9xl04 3.0xl04 3.1xl04 3.6xl04 2.0xl04
Cyanophyceae
Oscillatoria bormeti 2 xlO 3 xlO3 l.lxlO4
Dinophyceae
unidentified 4 xlO2
(continued)
-------
TABLE 9 (continued)
Species
Depth in meters of sample
10
12
20
24
30
en
o
Flagellates
unidentified
Protozoa
Di-dini-wn sp.
unidentified
Rotatoria
Kellioottia
long-isp-ina lorica
Kevatella sp.
Polyavtha major
2.3xl04 9 xlO3 2.2xl04 1.4xl04 1.6xl04 3.8xl04 1.7xl04 2.7xl04 l.SxlO4
2 xlO3 4 xlO3 2 xlO3 7 xlO3 5 xlO3 5 xlO3 8 xlO2
2 xlO3
4 xlO2 8 xlO2
xlO2 8 xlO2
-------
5o
48
o>
O
"b 40
c/
O
O
32
24
CD
< 16
8
O1-
2m
4m
n
m
6m
HARDING LAKE .Station DEEP I-Sept. 1974
& Bacillariophyceae
H3 Chrysophyceae
ED Cryptophyceae
S3 Chlorophyceae
C3 Cyanophyceae
D Unidentified flagellates and ciliates
F
fy
•4-'
•'1%;
$
I'1
*fc.
$••*
llr'
r~r
/ X1
•/'
^
^
:^
/ /
^
TT
:
;
.
:
w
'ri
8m 10m !6m
SAMPLE DEPTH
20m
24m
30m
FIGURE 15
ALGAL COUNT. SEPTEMBER 28,1974. HARDING LAKE
-------
TABLE 10. ALGAE IDENTIFIED FROM HARDING LAKE
Bacillariophyceae
Asterionella formosa
Cocconeis sp.
Cyclotella sp.
Cymbella sp.
Diatoma elongatum
Melosira italioa
Nitzschia sp.
Synedra nana
Charophyceae
Chara Sp.
Chlorophyceae
Anikistrodesmus setlgevus
Cosmarium subtimidiwn
Crucigenia tetrapedia
Staurastrum curvatwn
Chrysophyceae
Diceras phaseolus
DlnobTyan sp.
D. borgei
D. orenulatwn
D. soci-ale
Mallomonas globosa
Cryptophyceae
Cryptomonoas S p.
C. marssonii
Rhodomonas minuta
Cyanophyceae
Anabaena sp.
Coccochloris sp.
Desmonema sp.
Gloeotrichia sp.
Nost-oc sp.
Scytonema sp.
Osdilatori-a bornet'L
Dinophyceae
Cerat-ium sp.
The results of the chlorophyll a measurements during the last year of
the project are presented in Figure 16 and other data are contained in
Tables A-2 and A-3 of the Appendix. Early in the project difficulties were
encountered with chlorophyll a measurement. These difficulties were elimi-
nated by increasing the amount of water filtered to nearly two liters and
utilizing a low-volume 4-cm spectrophotometric cell, and the first reliable
data were obtained on August 6, 1973. Routine measurement of phaeopigments,
the breakdown products of chlorophyll, began on August 10, 1974. Before
that date, some chlorophyll measurements are falsely high due to the measure-
ment of phaeopigments as true chlorophyll. It appears that phaeopigments
found here are only significant relative to chlorophyll a when snow-covered
ice is present and light is reduced to very low levels throughout the water
62
-------
DEEP I
PIGMENT CONCENTRATION, mg/m3
en
co
0
10/6/74
0 2
10
15
O)
.20
I
H
Q_
LLJ oc
s^ tO
30
35
L
12/6/74 12/7/74 1/15/75 2/21/75 3/21/75 4/11/75 5/3/75 5/8/75
0202020202020202
\
5/20/75
0 2
"1 1 I
CHLOROPHYLL a
PHAEOPHYTIN
FIGURE 16
ALGAL PIGMENT CONCENTRATION, HARDING LAKE
-------
DEEP I
PIGMENT CONCENTRATION, mg/m3
CTl
-p.
5/29/75
0 2
10
0)
X
I-
Q.
y 25
30
35 L
6/9/75
0 2
n I r
6/19/75
0 2
I I I
7/16/75
0 2
1 I I
7/30/75
0 2
n i i i
8/14/75
0 2
8/26/75
0 2
I 1 I
10/13/75 11/14/75
0 0
-
CHLOROPHYLL a
PHAEOPHYTIN
FIGURE 16 (CONTINUED)
ALGAL PIGMENT CONCENTRATION, HARDING LAKE
-------
column. Unfortunately, the large size of the finned sea cell of the sub-
marine photometer available to this project did not allow measurement of
light extinction under the ice seal so we were unable to quantify this
inverse relationship between light and phaeopigment concentration.
Figures 17 and 18 present the results of the light and dark bottle
experiments utilizing NaH*C03 to measure carbon fixation by the algae. The
experiment was routinely run only to 30 m, considerably below the 1% light
level during strong summer sunlight (See Figure 10), but this is seen to be
somewhat inadequate for certain dates when measurable fixation was still
occurring at 30 m.
Table 11 presents the results of integration over depth of the chloro-
phyll a, carbon fixation measurements, and light radiation received at the
surface. The data of January 15, February 21, and November 14, 1975, are
questionable because the Sign Rank test showed no significant difference
between the mean distribution of the light and dark bottles for these dates.
March 21, 1976, data are also not considered accurate as the light and dark
bottles were incubated in an incorrect sequence relative to the depths at
which the water was taken.
No relationship was found between these measurements. Attempts were
also made to relate chlorophyll a concentration and fixed carbon (mg/m ) at
each depth, on each day when both were measured, and no pattern was found.
Figure 19 presents a means of estimating the annual primary production
assignable to the planktonic algae. This figure shows that estimates from
our data for 1974 and 1975 are significantly different, at least between
June 20 and September 28. This difference most probably occurs because of
difficulties with the quality of the purchased radioactive tracer. All
experiments up to that of June 19, 1975, (and additionally, those of
October 14 and November 14, 1975) were run with a batch of tracer of good
6 4
quality and the calibration value is acceptable, 6.68 X 10 + 4.71 X 10
cpm/ml. All other experiments were run using a different batch of higher
variability 3.73 X 106 ± 1.40 X 105 cpm/ml. The above calibrations are
specific to our standards and counting situation, but the fact that this
batch is highly variable has been verified by others using this batch
65
-------
CARBON FIXED,mg/m3/doy
5/7/74 6/20/74 7/2/74
0 20
Y////Y////V,
0 20
20
Q>
-------
CARBON FIXED, mg/m3/day
5/20/75
0 20 40 60
28 -
12:30-
14 = 00
5/28/75
0 20 40
16:50-
16:50
6/10/75
0 20 40
16:10-
16:10
6/18/75
0 20 40
10:05
10:05
6/25/75
0 20 40
7/16/75
0 20
28 -
20=20-
20:20
7/30/75
0 20
8/13/75 8/25/75
0 20 40 0 20
11 = 15-
11=15
19=15-
19:27
9/12/75
0 20
07:26-
07M5
10/14/75 11/14/75
0 20 0 10
15=28-
15:50
20=30-
16:30
FIGURE 17 (CONTINUED)
ALGAL PRIMARY PRODUCTION. STATION DEEP I, HARDING LAKE, ALASKA.
ICE THICKNESS AND SECCHI DEPTH INDICATED. INNER LINES FOR MAY 20
AND 28, 1975 INDICATE VALUES CORRECTED FOR LAKE MORPHOMETRY.
67
-------
CARBON FIXED, mg/m3/day
STATION-SHALLOW I
6
oc
5
10
d
0
5
in
/20/74 7/2/74 7/16/74 7/31/74 8/27/74 9/28/74 5/28/75
?0 0 20 0 20 0 20 0 20 0 20 0 20
1 1 1
\
-
5/19/75 7
5 20 C
1 1
-
1 1
-
! 1 1
\
-
III III I i 1 .
L- —
/16/75 7/30/75 8/26/75 10/14/75
20 0 20 0 20 0 20
\' ' '
1. 1 1
1 1 1
i i
STATION-SHALLOW m
6/20/74 7/16/74
^0 20 0 20
~
10 L
STATION- SHALLOW BT
6/20/74 7/2/74 7/16/74 7/31/74 5/28/75
^0 20 0 20 0 20 0 20 40 60 80 0 20 40
5
n
1 |
/
I \
/
1 I
1 \
1 1 1 1 1 1 1 1 I
ll.ll
I \
FIGURE 18
ALGAL PRIMARY PRODUCTION, HARDING LAKE
68
-------
CARBON FIXED, mg/m3/doy
STATION-SHALLOW Y
8/15/74 8/27/74 9/14/74 9/28/74 6/19/75
^0 20 40 60 0 20 0 20 0 20 0 20
0
5
10
1 1 1 1 1 1
"
-
1 1 1
_ /
-
1 |
1
-
1 1 1 I
/ \
"
-
7/16/75 7/31/75 8/26/75 10/14/75
0 20 40 0 20 0 20 0 20
5
in
i l 1 1
1 I 1
)l
l I 1
>
FIGURE 18 (CONTINUED)
ALGAL PRIMARY PRODUCTION, HARDING LAKE
69
-------
TABLE 11. INTEGRAL VALUES OF ALGAL GROWTH PARAMETERS AND
INCIDENT RADIATION. HARDING LAKE. DEEP STATION I
Date
8/06/73
8/27/73
10/18/73
12/04/73
3/14/74
4/06/74
5/07/74
6/20/74
7/02/74
7/16/74
7/31/74
8/15/74
8/27/74
9/14/74
9/28/74*
10/06/74
12/03/74
1/05/75
2/21/75
3/21/75
4/11/75
5/02/75
5/08/75
5/20/75
5/28/75
6/10/75
6/18/75
6/25/75
7/16/75
7/30/75
8/13/75
8/25/75
9/12/75
10/14/75
11/14/75
8.
7.
3.
15.
14.
20.
8.
2.
2.
6.
13.
12.
21.
31.
44.
45.
50.
47.
63.
53.
41.
44.
30.
3.
7
8
9
0
3
7
5
4
4
5
4
9
4
6
6
4
0
6
6
6
9
0
3
1
Chlorophyll a
2
(mg/m )
(to
(to
(to
(to
(to
(to
(to
(to
(to
(to
(5/5/75)
(to
(to
(5/29/75)(to
(6/09/75)(to
(to
(to
(to
(8/14/75)(to
(8/26/75) (to
(to
(to
C-14 production
2
(mg/m /day)
10m)
10m)
4m)
30m)
35m)
35m)
15m)
30m)
12m)
30m)
20m)
20m)
25m)
30m)
30m)
30m)
30m)
30m)
30m)
30m)
4m)
118
98
94
156
154
138
124
141
88
1
10
7
11
118
188
401
447
194
398
297
232
215
309
325
128
203
1
.8
.0
.4
.8
.8
.0
.4
.6
.8
.0
.0
.6
.3
.9
.7
.9
.2
.3
.1
.2
.0
.2
.6
.1
.3
.8
.8
radiation
2
(gm-cal/cm /day)
618.
273.
316.
385.
473.
377.
564.
301.
408.
566.
371.
419.
203.
6
0
5
9
6
1
8
7
7
6
9
2
5
*A11 chlorophyll a measurements prior to this date were calculated by the
Strickland and Parsons formula, after this date by the IBP formula.
70
-------
500i~
CVJ
E
\
o>
E
Q
UJ
X
O
03
o
400
300
200
100
JAN.
FEB.
MAR.
APR.
MAY
JUN.
JUL. AUG. ' SEPT. ' OCT. ' NOV. ' DEC.
FIGURE 19
ANNUAL ALGAL PRIMARY PRODUCTION. HARDING LAKE
-------
(Williams, S., 1976 personal communication; Alexander, V., 1976, personal
communication). This latter batch contained two populations of unknown size
of different specific activities one of which is approximately double the
other. Because ampules for standard preparation were not drawn at random
from the entire batch, there is no way to assign ampules used to anything
more accurate than a value somewhere between the two specific activities
according to the particular ampules drawn for standard preparation by each
user. This problem was not found before much work had been accomplished by
all groups and individuals using this batch of tracer due to the stockpiling
of sample filters, which was necessitated by the remote location of field
sites.
Figure 19 indicates that the activity estimated by our standards for the
second batch is probably too low, allowing overestimation of productivity and
production. Note the closeness in daily fixation on May 7, 1974, and two
dates in early May, 1975, when the same, more reliable first batch of tracer
was being used. In any case, our estimate of annual production, at 47.8 gm
2
C/m /year is most undoubtedly high due also to the fact that the daily pro-
ductivity was not corrected for lake morphometry. Some estimate of the
effect of these corrections can be made by reference to Figure 17 where
productivity at all depth at Deep Station I for May 20, 1975, is plotted both
corrected and uncorrected for the amount of lake surface area underlain by
water of the depth of the measurement.
On the whole, there was no significant added variance component between
shallow stations as compared to within the stations when Bartlet's test for
homogeneity of variance and a Model II one-way analysis of variance was
performed on the shallow-station data. Thus it is valid to compare any one
shallow station to the comparable section of the Deep Station I In a com-
parison of this type, the first 4 m of the data for May 28, 1975, at Deep
Station I is plotted both corrected and uncorrected for lake morphometry in
Figure 17, and the corrected inner line can be compared to that representing
production measured at Shallow Stations I or IV (Figure 18) on that date.
The areal production obtained by integration of the inner corrected line is
not significantly different from that of either of the shallow stations. Nor
is it significantly different from that of the uncorrected line for the first
72
-------
4 m of Deep Station I. Thus, with few exceptions, littoral area production
is adequately represented by the measurements in the upper 4 m of Deep
Station I. It can be noticed from Figures 17 and 18 that the shallow stations
were often run a day later or earlier than the deep station, and variations
due to weather changes show effect. These variations however, are not large
enough to warrant further consideration in estimating annual algal production.
The two high values near the bottom of Shallow Station IV on July 31, 1974,
and at Shallow Station V on August 15, 1974, may be artifacts due to copre-
cipitation of the bicarbonate with oxidizing iron, since deposits of red iron
precipitates have been noted in the littoral of this lake, or it may be a
true effect of optimum light as these are both gravel-bottomed stations, or
the effect may be of optimum local nutrient availability.
Comparison of the algal primary productivity and production of Harding
Lake to other well-studied lakes is informative (Table 12). Unfortunately,
the best-studied high-latitude lakes are found in the arctic and may not be
strictly comparable to subarctic Harding Lake.
TABLE 12. ANNUAL ALGAL PRIMARY PRODUCTION. HIGH-LATITUDE LAKES
Lake and
Char Lake
Latitude
72°42'N
Meretta 72°42'N
Schrader
Peters 69
69°22'N
°19'N
Harding 64°25'N
Annual
1969
1970
1971
1969
1970
1971
1959
1961
1969
1975
2
gm C/m
5.8
6.3
7.2
31.2
16.5
31.7
7.5
6.5
0.9
47.8
(Kalff and
1971)
(Kalff and
1971)
(Hobbie, 1
(Hobbie, 1
Holmgren,
Holmgren,
964)
964)
73
-------
It should be noted that Peters and Schrader Lakes are both somewhat
turbid due to glacial water sources, and that Char Lake is ice covered
except for a very short period in late summer, at times remaining ice covered
throughout some years. Therefore, the growth of the planktonic algae of
these lakes would be expected to be somewhat light limited. Merretta Lake
receives sewage from the village of Resolute and is thought to be more
productive than nearby Char Lake because of the increased nutrient loading.
Considering Rodhe's (1965) index which considers the shape of the daily
productivity curve as well as its integral as summer averages, Harding Lake
can be compared to other clear, deep, oligotrophic lakes (Table 13). Rodhe's
index is the quotient of a (maximum production in mg C/m /day) divided by
« fflaX
za (mg C/m /day).
TABLE 13. RODHE'S INDEX. SELECTED OLIGOTROPHIC LAKES
Lake
Byglandsfjorden ^59°N
Char 72°42'N
Tahoe 39°09'N
Harding 64°25'N
a
max
za
0.14
0.12
0.002
0.11
Reference
Lande (1973)
Kalff and Welch
Goldman (1974)
(1974)
The peculiarities of the algal productivity of Lake Tahoe illustrated
here are due to the extreme depths at which algal growth occurs as compared
to the low maximum production at each particular depth. From the above
figures it can be seen that algal primary productivity values would help to
classify Harding Lake as oligotrophic. Reports of visable algal blooms on
this lake have been attributed by our field crew to probably stem from high
amounts of floating tree pollen occurring each spring.
The light regime peculiar to the latitude at which this lake is located
presents a different setting than that of temperate lakes (Johnson and
Hartman, 1969). This latitude enjoys more sunlight and twilight as a percent
of the time in a year: about 62% as compared to 56% for 50°N latitude in the
middle of the conterminous states. Proportionally more of the total year's
74
-------
sunlight is experienced here in summer and less in winter. Indeed, from late
May to late July, continuous sunlight and twilight occur and no darkness is
experienced. Thus the question arises as to whether this extended summer
sunlight and reduced winter sunlight influences algal primary production.
The need to conduct carbon-14 algal primary production experiments for
24 hours, because of the low productivity expected in northern waters, is
documented (Hobbie, 1964). It has been noted by marine researchers that 24-
hour incubations tend to underestimate productivity in comparison to shorter
experiments that are summed. This has been attributed to respiration losses
of previously fixed labeled carbon during the night period of darkness
(Eppley and Sharp, 1975). Due to our particular work regime, coupled with
our need to travel 89.6 km (56 miles) to reach the lake, the great majority
of our experiments, Figures 17 and 18, were begun late in the day and thus
the dark respiration in the light bottles did not involve previously labeled
fixed material, but instead, the experiments were usually terminated fol-
lowing the height of the light period.
Diurnal experiments were conducted on June 25-26, 1975, and again on
September 12-13, 1975, to assess the 24-hour incubation period by comparing
it to the sum of four 6-hour periods. On June 25-26, close to the summer
solstice, the lake basin enjoys approximately 21.5 hours of sunlight and 2.5
hours of civil twilight, and no period of darkness. In late September, near
the autumnal equinox, the daylight lasts 12.5 hours and twilight lengthens
the light period to a total of slightly more than 14 hours.
The results of these experiments are shown in Figures 20 and 21 and
Table 14. While this type of experiment would have to be repeated many times
to yield results that could be statistically analyzed, and error separated,
many interesting results are noted. In June while the pyrheliometer measured
early-morning incident radiation almost half that of the evening, fixation
was almost immeasurable for the early morning period, A, while that of the
evening, D, was sizable. The midday depression of photosynthesis noted in
comparing periods A and B of approximately equal light intensity is commonly
found in experiments of this type (Wetzel, 1975). It can also be noted that
in September the sum of the four 6-hour incubations gives approximately the
75
-------
CTl
Q.
UJ
Q
Oi—
16
10
12
14
24
32 0
22:30
6/25/75-
22:30
6/26/75
TOTAL
CARBON FIXED, mg/m3/time interval
8 16 0 8 16 0 8 16 0
16
T
1
22:30
6/25/75-
4:30
6/26/75
A
\
4:30-10:30
6/26/75
B
10:30-16:30
- 6/26/75
c
16:30-22:30
6/26/75
D
FIGURE 20
DIURNAL PRIMARY PRODUCTIVITY. HARDING LAKE. DEEP STATION I. JUNE 25-26/75
-------
to
n£
h-
Q_
Lul
Q
0
CARBON FIXED, mg/m3/time interval
16 0 8 16 0 8
16 0
16
7:15
9/12/75-
7:15
9/13/75
TOTAL
I
7:15-13:15
9/12/75
T
13:15-19:15
9/12/75
1
B
19:15
9/12/75-
1:15
9/13/75
c
1:15-7:15
9/13/75
D
FIGURE 21
DIURNAL PRIMARY PRODUCTIVITY. HARDING LAKE. DEEP STATION I. SEPT. 12-13, 1975
-------
same fixation as the 24-hour incubation, while in Oune the 24-hour fixation
seems to be an underestimate.
TABLE 14. TIME-OF-DAY EFFECTS ON CARBQN-14 EXPERIMENTS. HARDING LAKE.
June 25-26, 1975
Integral Production Incident Radiation
2 2
Time Period* mg/m /time interval gm-cal/cm /time interval
22:30 -
22:30 -
4:30 -
10:30 -
16:30 -
7:15 -
7:15 -
13:15 -
19:15 -
1:15 -
22:30 (24 hours)
4:30 (6 hours)
10:30 (6 hours)
16:30 (6 hours)
22:30 (6 hours)
7:15 (24 hours)
13:15 (6 hours)
19:15 (6 hours)
1:15 (6 hours)
7:16 (6 hours)
72.8
0.7
43.4
42.6
23.8
September 12-13, 1975
113.6
66.0
18.5
19.6
6.8
580.5
43.8
171.9
266.6
98.2
283.4
98.2
86.0
54.5**
43.9**
* All times noted are Alaska Standard Time
** Moisture condensed on dome of pyrheliometer
Heterotrophic Algal Production--
Measurements of heterotrophic algal production were attempted twice
during this study. Rodhe (1955) has speculated on the possibility of higher
relative importance of heterotrophic compared to autotrophic algal production
during winter in lentic aquatic ecosystems at high latitudes when sunlight is
very reduced.
The first attempt of February 21, 1975, was not successful. Radioactive
carbon labeled galactose was the only substrate tested on natural populations
sampled at 20 m and incubated for 6 hours. Fixation of the radiocarbon was
so slight as to be insignificantly higher than background. The second experi-
ment followed the work of Maeda and Ichimura (1973) and the substrates pre-
sented were glucose and acetate. It is assumed, in this type of experiment,
78
-------
that heterotrophic bacteria are the main glucose-fixing organisms, while
acetate fixation can also be carried out by small flaggelated green algae as
a dark reaction. To separate out the algal fixation, streptomycin, at 3
mg/1, is added to kill the bacteria that might also find the acetate an
acceptable substrate.
While this technique can be questioned because of several inherent
weaknesses, some information was gained. Regarding Figure 22, it is seen
that streptomycin was only slightly more effective in depressing the fixation
of glucose (to 73% at the highest concentration) than the fixation of acetate
(to 87%). This could be attributed to a weakness of the technique as
explained by the fact that the activity of streptomycin is somewhat specific
to gram-negative rod-shaped bacteria. The use of a broad-spectrum antibiotic
that does not affect algal cells or an algastat that does not affect bacteria
would improve the technique. In this particular experiment glucose fixation
was not significantly reduced by the added bactericide most probably because
the amount of glucose added was inadvertently large enough to promote algal
fixation. The work of Wright and Hobbie (1965) has shown that heterotrophic
primary production likely is carried out under two separate mechanisms. With
low concentrations of simple organic substrates, bacteria are able to utilize
them for growth by an active transport process explainable by Michaelis -
Menten kinetics equations. When higher concentrations of substrates are
available, the algae probably become able to utilize them through a passive
transport process, wherein the substrate diffuses through the cell wall when
the surrounding concentration becomes higher than the internal concentration.
Thus, our experimentation, while not being intensive enough to allow
calculation of uptake velocities or upper limits of in-lake concentrations of
simple organic substances, has shown that heterotrophic primary production by
algae as well as bacteria may be an important wintertime activity in Harding
Lake.
Management Implications of the Algal Studies--
The relationship between lakeside development and degradation of lake
water quality has been recognized for some time and the phenomenon has been
termed "cultural eutrophication." This recognition has generated public
79
-------
oo
o
7.0r-
6.0-
5.0
C\J
\
E
10
CM
E 4.0
Q.
O
o
r
Z
O
X
UJ
3.0
2.0
i.o
0
• ACETATE
• ACETATE,with streptomycin
A ACETATE.with Lugol's iodine
o GLUCOSE
n GLUCOSE, with streptomycin
& GLUCOSE, with Lugol's iodine
...•••'a
.3.5
3.0
2.5
A—A
0
0.04 0.08
0.12
0.16
0.2
0.24
0.28
0.32
SUBSTRATE CONCENTRATION, acetate- mg/l X I02, glucose-mg/l
FIGURE 22
HETEROTROPHIC PRODUCTION. HARDING LAKE. NOV. 14/75
2.0
E
LO
C\J
\
E
CL
o
10
O
1.5
X
1.0 F7
0.5
co
o
o
0
0.36 0.4
-------
concern that lakes be protected from development that would prove to have a
detrimental effect on water quality. Predicting the allowable level of
development for a particular lake, however, has proved difficult.
The most visible evidence of water quality degradation consists of
nuisance growths of algae with a resulting decrease in water clarity.
Limnologists have recently developed empirical models based on the relation-
ship between the phosphorus input and the resultant algal growth (Vollen-
weider, 1969b, 1971; Bachmann and Jones, 1974; Dillon and Rigler, 1975; Jones
and Bachmann, 1976; and Schindler, 1977).
Dillon and Rigler (1975) have applied their model to determining the
extent to which development of recreational dwellings can be permitted while
still maintaining the peak level of summer algal biomass (as chlorophyll a)
below that selected by agencies managing a particular lake. We will attempt
to utilize this model to assess the effects of future real estate development
on Harding Lake. The phosphorus concentration is predicted using an equation
derived from Vollenweider's (1969b) model
where
[P] = predicted total phosphorus concentration
L = loading
z = mean depth
a = sedimentation rate
p = flushing rate
The limited amount of nutrient analyses performed on aspects other than
the water column at Harding Lake do not allow an accurate estimation of the
phosphorus loading to the lake. Thus, the equation must be modified to
separate the known present total phosphorus concentration from that which
would be added by further cottage development. The equation becomes
rpi = - rp -,
LFJ z(a+l/R) L oj
where
[P] = predicted concentration of total phosphorus
K - annual total phosphorus output per cottage
81
-------
C = number of additional cottage units
A = surface area of the lake
z = mean depth
a = sedimentation rate
R = retention time
[P ]= present average total phosphorus concentration
For this study K is calculated as 0.3 x 10 mg/cottage-year using the value
of 0.8 kg/capita-year of Dillon and Rigler (1975), and the 0.3 capita-year/
cottage-year obtained from Larson's (1974) study of cottage use at Harding
Lake during 1973. A sedimentation rate of 0.65 was chosen, and the retention
time of the lake has been estimated as approximately 70 years from the water
budget calculations. The present average total phosphorus concentration is
taken as 14 mg/m .
Using Equation 2, the effects on total phosphorus concentration of some
future development possibilities at Harding Lake were calculated. Chlorophyll
a values were then predicted from these total phosphorus concentrations
(Dillon and Rigler, 1974). Finally, water clarity as Secchi depth values
were predicted (Jones, J., and Bachmann, R., 1977, personal communication).
These predictions are presented in Table 15.
TABLE 15: PREDICTED TOTAL PHOSPHORUS AND RESULTANT CHLOROPHYLL a
CONCENTRATIONS AND SECCHI DEPTHS FOR SELECTED
DEVELOPMENT POSSIBILITIES AT HARDING LAKE
Development
1975
a cottage on
Additional
Cottage
Equivalents
0
130
Predicted
total P
o
(mg/m )
14.0
14.4
Predicted
Chlorophyll a
(mg/m3)
3.3
3.5
Predicted
Secchi depth
(m)
3.3
3.2
every parcel
all cottages
converted to
year-round
homes
1,119
22.2
6.5
2.2
82
-------
Application of these models to Harding Lake may be questionable. With
the nitrogen-to-phosphorus ratio at roughly 10:1, phosphorus may not be the
limiting nutrient in Harding Lake as is assumed for these models. In addi-
tion, the fact that inorganic nitrogen forms are nearly undetectable during
the growing season provides evidence that the lake may be nitrogen limited,
in which case the models may lose their predictive ability.
It can be noted that the predicted chlorophyll a concentration of 3.3
3 3
mg/m for the measured total phosphorus concentration of 14 mg/m of 1975 was
3
approximated by the values actually measured at about 2 mg/m in early
spring 1975 (Figure 16). During this under-ice chlorophyll a peak, a Secchi
depth of 5 m was measured (Figure 17) which is close to the 3.3 m predicted.
The fact that Harding Lake has its peak algal biomass and productivity
under the spring ice rather than in the summer may also make these models
inapplicable. As pointed out above, however, these models seem to predict
adequately the peak chlorophyll a concentration and resultant Secchi depths.
The reduction in water clarity at peak algal biomass is not currently noticed
by the general public because of the ice cover. Perhaps the greatest danger
in future development on Harding Lake would be that nutrient additions might
promote a shift in algal succession so that the peak growth would occur in
summer. The resultant loss of water clarity (below the current summer Secchi
depth of approximately 11 m) could be very noticeable and undesirable.
Vascular Aquatic Plants
A list of the submerged hydrophyte species found in Harding Lake during
the summer of 1974 is presented in Table 16. One macroalga (Chara sp.) and
one pteridophyte (isoetes muvicata var. Braunii) were found as well as a
variety of angiosperms. Figure 23 presents a map of the plant beds and
locates the starting points of the transects samples. Table 17 presents the
biomass estimates for the samples that represented 100% cover of a single
species. The transect data is included in Appendix Table A-4.
Using the transect percent cover data and the biomass estimates for 100%
cover for each species, the biomass produced above the sediments was esti-
mated for each of the major plant beds. The bed containing transect #1,
c •->
which is 2 x 10 m in extent, produced approximately 6400 kg of plant tissue
83
-------
TABLE 16. THE SUBMERSED HYDROPHYTE
SPECIES OF HARDING LAKE, ALASKA 1974
Chava sp.
Isoetes murioata var. Brauni-i
Spargani-um angust'lfoli-um
Potamogeton fili-form-is
Potamogeton Fre-isii
Potamogeton grcartineus
Potamogeton perfoliatus subsp. Richardsoni-i
Potamogeton praelongus
GlyoeT-ia boreal-is
Eleochar-is aei,au1ax"is
Ranunculus confervo-ides
Subulari-a aquat-ica
Myriophy11wn s p.
Minor species:
Potamogeton natans
Junous alp-inus
EteoGhajcis palustris
Polygonum amphi-bium
84
-------
SMALL COLONY OF Polygonum amphibium
co
un
4m
ISOLATED INDIVIDUALS OF
Potamogeton filiformis -
SMALL COLONY OF
Eleocharis oalustris
SCATTERED COLONIES OF
Chara sp., Potamogeton perfollatus
SUBSP Richardson// AND
P. praelongus
SMALL ZONE OF Eleocharis acicularls,
Subularia aquatica AND SHALLOW-WATER
FORMS OF Potamogeton perfoliatus SUBSP
Richardsonii AND P.gramineus
A INDICATES TRANSECT STARTING
POINT
AREAS OF MAJOR SUBMERSED
HYDROPHYTE COLONIZATION,
CHARACTERIZED BY TRANSECT
DATA SUMMARIES.
5
N
0.5
Km
FIGURE 23
PLANT DISTRIBUTION MAP. HARDING LAKE, 1975
-------
(at 31.7 ± 37.6 g/m2). The bed which included transects #2-#6, which has an
n r\
area of 3 x 10 m, produced approximately 6900 kg of plant tissue (at 23.1 ±
30.6 g/m2). Thus, over the entire lake surface, the vascular plant produc-
tion equaled approximately 1.35 g/m dry weight submerged hydrophytes for the
growing season of 1974. This can be compared to the algal production for
1975 estimated at 47.8 gm C/m2/year which can be converted to 95.6 g/m /year
dry weight algae (Lind, 1974). The relatively greater importance of the
planktonic algal production in Harding Lake is demonstrated. However one
aspect of primary production remains unknown since no measurements of benthic
algal production were conducted during this project. In 1974 no benthic
algae were observed to be growing on the surfaces of the vascular aquatic
lants. During 1975, however, epiphytic growth appeared to be heavy.
TABLE 17- PLANT BIOMASS ESTIMATES FOR SAMPLES
REPRESENTING 100% COVER OF A SINGLE SPECIES, HARDING LAKE, 1974
2
Species g/m
Chara sp. 36.7 ± 19.0
Isoetes mux"iaata var. Braunii 56.9 ± 58.5
Potamogeton filiformis 25.0
P. perfol-iatus subsp. Richardsoni-i, 121.0
(shallow-water form <_ 15cm)
P. perfoliatus subsp. R-Lohardsoni-i 28.4 ± 14.8
(deep-water form >_ 15cm)
P. praelongus 91.5 ± 2.8
Clyeeria borealis 92.6
Eleoohari-s ao'Loulax-'ls 185 ±93
Myriophyllum sp. 17.2 ± 6.9
Work on the vascular plants of this lake was also conducted during the
summer of 1966 (LaPerriere and Robertson, 1973). Unfortunately, the plant
beds were unmapped, thus it is not possible to calculate the annual production
for that year.
86
-------
Zooplankton
Very limited sampling of the zooplankton was conducted during this
project. The major effort in this regard consisted of dry-weight measure-
ments presented in Figure 24. The biomass present from season to season
throughout a year is seen to vary by roughly a factor of ten and is probably
concentrated in the upper 10 m of water. Limited data for May and June of
1973, not plotted because of lack of sufficient replicates, helps to indicate
that the peak concentration is found in early August and the lowest concen-
tration is found in March.
Counts of zooplankton taken with a large plexiglass trap near midnight
and noon on August 5, 1974, (Table 18) show as is usually found that the
zooplankton are distributed differently at different times of day. Of
special note is the capture of Leptodova kintii at 10 m at night, a predator
known to be phototactic and nocturnal.
TABLE 18. ZOOPLANKTON COUNTS. HARDING LAKE. AUGUST 5, 1974
3
Individuals per m
Sample Time:
Sample Depth:
Bosmi-na ooTegni
CeTati-wn sp.
Daphn-ia long-irerms
Ho loped'lwn s p .
Kelliootti-a longispina
Keratella sp.
LeptodoTa 'k'indt'L-i
Polyphemus pediculus
copepods
nauplii
unknowns
0:00-2:00
2m
2.2xl03
B.lxlO4
2.8xl03
5.7xl02
1.4xl03
2.4xl02
1.2xl04
4.1xl02
2.4xl02
0:00-2:00
10m
3.3xl03
8.7xl04
3.8xl03
2.4xl02
2.6xl03
S.lxlO2
8.1x10
8.1x10
1.4xl04
3.2xl02
S.lxlO2
12:00-14:00
2m
2.1xl03
l.lxlO5
3.2xl02
2.4xl02
2.5xl03
1.6xl02
1.4xl03
3.2xl02
4.0xl03
12:00-14:00
10m
l.SxlO3
l.SxlO5
2.8xl03
8.1x10
2.5xl03
l.SxlO3
1.6xl02
3.9xl03
l.SxlO3
9.0xl03
87
-------
CO
CO
0
20 meter haul
— DEEP I, 1973-4
— DEEP H, -
10 meter haul
SHALLOW IE, 1973-4
SHALLOW I , 1975
JULY
AUG.
SEPT. ' OCT.
NOV.
DEC
JAN.
FEB. ' MAR. ' APR. 'MAY
FIGURE 24
DRY WEIGHT OF ZOOPLANKTON CAPTURED. HARDING LAKE
-------
Table 19 presents the zooplankters identified from Harding Lake during
this project. An interesting phenomenon occurred several times when zoo-
plankters were noted in high concentrations crawling over the plexiglass
holders for the light and dark bottles of the algae experiments. The
plankter involved was Sida cristallina. It is especially interesting to note
that this occurred in deep water (at Deep Station I) since Brooks (1959) has
reported "...they are never present in large numbers in the open water, nor
are they likely to be found far out from the weedy margin."
TABLE 19. ZOOPLANKTON IDENTIFIED FROM HARDING LAKE
Cladocera
Bosmina coregoni
Daphnia longiremus
Eupyoevous glacial-Is
Holopedium gibber>um
Leptodora kindtii
Polyphemus pediculosis
Sida crystalina
Copepoda
Cyclops capitallatus
Cyclops sp.
Diaptomus pvibilofensis
MoTaria mvazeki
Rotifera
Kellicottia longispina
Kevatella cocJilearis
Fishes
While this project did not work with the fishes of the lake the follow-
ing information has been provided us by the Alaska Department of Fish and
Game.
Fish species contained in Harding Lake as of 11 February 1975:
Native:
Coregonus sardinella (Valenciennes) least cisco
Cottus cognatus (Richardson) slimy sculpin
Esox lucius (Linneaus) northern pike
Lota lota (Linneaus) burbot
Successfully Introduced:
Oncorhynchus kisutch (Walbaum) coho or silver salmon
Salvelinus namaycush (Walbaum) lake trout
89
-------
Stocking and netting records are presented in Tables 20 and 21. The
1939 stocking of rainbow trout was unsuccessful. Recaptures of lake trout
indicate that a breeding population has not been established.
Benthic Macroinvertebrates
Concurrent with the first two years of this project were two years of
work on Alaskan lake benthos (LaPerriere, 1975) that treated samples from
Harding Lake as well as other lakes in the state. Samples were taken by
dredge the first summer and all organisms identified as far as possible
(Tables 22 and 23). Sampling stations not identified in Figure 1 can be seen
in Figure 25. During the second summer samples were taken both by dredge and
by hand (by a diver) and the chironomids were separated and reared (Table
24).
The emphasis of the benthos work was on chironomids (nonbiting midges
of the order Diptera), which have been relied upon in Europe as good indi-
cators of the trophic state of lakes. Unfortunately the necessary taxonomic
and ecological studies necessary to designate indicator chironomids in the
Nearctic are not nearly complete. The first major paper on this subject has
just been published (Saether, 1975) tabulating chironomid species and their
distribution across the trophic spectrum. Of the chironomids of Harding Lake
which have been identified to species, only one, Monodiamesa bathyphila
(Kieff.), appears in Saether1s tables. He believes it to be restricted to
the oligotrophic situation in the Nearctic; however, it is also found in
mesotrophic lakes in the Palearctic.
Enteric Bacteria
During the summer of 1973 (May-September) a thesis study was conducted
relative to the water quality and pollution control at Harding Lake (Larson,
1974). This study, in the form of a graduate student thesis, included an
evaluation of the lake water sanitary bacteriology in addition to a survey of
sanitary facilities located at the lake. The objectives of the study were to
characterize the shore land development at Harding Lake, to investigate the
water supply and solid waste and sewage disposal practices, and to determine
if Harding Lake was being contaminated to an extent that might limit recrea-
tional activities.
90
-------
TABLE 20. FISH-STOCKING HISTORY. HARDING LAKE
Date
Stocked
1939
1956-1965
1963
1965
December 1965
July 1967
July 1968
July 1969
July 1971
Species
RTi
LT*
RT
LT
LT
LT
LT
SS3
ss
SS
Total
Number
No good records
No good records
125,000
252 adult
235 adult
88,000 eyed eggs
(75,000 hatched)
31,200 fingerling
375,800 fingerling
338,500 fingerling
232,800 fingerling
Per Kg Per Hectare Source
Forest Service
Forest Service
ADF&G
ADF&G
ADF&G
ADF&G
ADF&G
ADF&G
ADF&G
640 217 ADF&G
= rainbow trout, Salmo ga-irdnevi
2LT = lake trout, Salvelinus namaycush
3SS = silver salmon, Onehorhynchus kisuteh
(Information from Alaska Department of Fish and Game [ADF&G], 1974).
-------
TABLE 21. NETTING RECORDS. HARDING LAKE
UD
ro
Date
Sep-Oct 1959**
Sep 1960
Jun 1961
Oct 7-8, 1962
1963
1964**
Sep 1, 1964
Oct 13, 1964
Sep 10, 1965
Oct 6, 1965
Sep 13, 1966
Species
NP1
LCi2
LT3
NP
NP
LCi
No test
NP
LCi
NP
LT
NP
LCi
NP
LCi
LT
NP
LCi
LT
NP
LCi
BB4
Fish
Netted
35
40
1
24
2
2
netting
4
6
10
5
4
6
6
5
3
2
70
6
16
23
2
Length
Range
* -965
* -305
done
490-750
185-290
356-813
478-767
498-838
188-295
254-617
191-218
559-597
506-597
127-279
432-635
318-615
185-216
480-559
(mm)
Mean
533
201
991
465
650
592
218
480
206
574
551
203
523
465
201
518
Net Age Percent
Hours Frequency Class Composition
566 .06
.07
.002
18.5 1.3
31 .06
.06
.08
.04
.08
.12
.06
.05
.03
.02
.73
.03
.08
.12
.01
(continued)
-------
TABLE 21 (continued)
•JO
CO
Date
1967
Sep 1968
Jun 5, 1969
Jun 6, 1969
Jun 26, 1969
Aug 1970**
Aug 13, 1971
Jun 8-21,1972
Sep 8, 1972
Species
No test
LT
NP
LCi
BB
NP
NP
NP
LCi
LT
NP
BB
LCi
SS5
LT
NP
LCi
BB
NP
LCi
LT
NP
LT
SS
Fish
Netted
netting
4
20
119
2
6
9
8
5
6
12
9
392
2
1
1
6
9
11
22
1
31
1
8
Length
Range
done
533-685
440-705
390-715
371-621
152-175
393-821
485-690
375-695
120-235
95-117
540
675
118-235
509-670
511-634
129-246
561
173-707
588
201-250
(mm)
Mean
633
562
530
480
164
691
591
462
580
584
157
541
228
Net Age Percent
Hours Frequency Class Composition
290 .014
.07
.41
.006
.13
.18
.07
.05
352 .02
.04
.03
1.11
24 .08
.04
.04
.25
.04
.05
.10
.01 V
.55
.02 V
.13 I
(continued)"
-------
TABLE 21 (continued)
Date
May 22- Aug 10, 1973
Aug 6-9,1974
Nov 22-Dec 6, 1974
Species
LT
NP
LCi
SS
BB
NP
LT
LCi
BB
SS
NP
LT
BB
SS
Fish
Netted
8
148
76
25
2
45
2
28
10
3
7
2
17
8
Length
Range
630-730
255-830
145-155
580-665
140-635
570-730
120-200
380-655
335-395
140-580
495-680
380-670
285-410
(mm) Net
Mean Hours
696.8 419.5
515.9
150
662.5
449.5 576
650
155.9
474
361.7
395.7 552
587.5
580.9
359.4
Age
Frequency Class
.02
.35
.18
.06
.005
.08
.003
.05
.02
.005
.01
.004
.03
.01
Percent
Composition
3
57
29
10
1
51
2
32
11
4
21
6
50
23
:NP - northern pike, Esox luoius
2LCi- least Cisco, Coregonus sardinella
3LT - lake trout, Salvelinus namayoush
4BB - burbot, Lota lota
5SS - silver salmon, Onoor'hyna'hus kisuteh
indicates data not provided
**date unknown
(Information from Alaska Department of Fish and Game, 1974.)
-------
TABLE 22. BENTHIC MACROINVERTEBRATES. HARDING LAKE
PROFUNDAL AND SUBLITTORAL STATIONS. JULY 24. 1973
Station Depth
DEEP STATION I
Sample 1 42 m
Sample 2 42 m
Sample 3 42 m
DEEP STATION II
Sample 1 20 m
Sample 2 20 m
Sample 3 20 m
SHALLOW STATION II
Sample 1 18 m
Sample 2 18m
Group
cl.1
w.2
c.3
cl.
c.
w.
c.
cl
w.
c.
w.
c.
w.
w.
c.
cl.
Organism
Identification
P-isi-dium sp.
Peloscolex sp.
Phaenopsectra sp.
Pisiditm sp.
Phaenopsectra sp.
Peloscolex sp.
unidentified tubificid
Phaenopsectra sp.
Pis-idiwn sp.
Peloscolex sp.
Phaenopsectra sp.
Peloscolex kurankov-i
Phaenopsectra sp.
Phaenopsectra sp.
Peloscolex kurankovi.
Peloscolex sp.
unidentified tubificid
Monodiamesa bathyph-il-ia
Procladius sp.
Protanypus sp.
Pis -id-turn sp.
Number
3
1
1
1
1 ecdysis
2
4
4
6
5
4
5
1 ecdysis
1
1
1
1 ecdysis
2
1
5
1cl.-clams, 2w.-worms, 3c.-chironomids
(continued)
95
-------
TABLE 22 (continued)
Organism
Station
Depth Group
Identification
Number
Sample 3 18 m
SHALLOW STATION III
Sample 1 16m
Sample 2
Sample 3
16 m
16 m
cl. Pisidiwn sp. 3
c. ChiTonorms sp. (pupa) 1
Monodicmesa bathyphilia 3 ecdyses
Phaenopseetra sp. 1
Procladius sp. 3
Prooladius sp. 2 ecdyses
Protanypus sp. 2
Pvotanypus sp. 3 ecdyses
Stiotochivonomus rosensch'dldi 1 ecdysis
w. Pelosoolex sp. 1
C. Protanypus 2
c. Monodicmesa bathyphilia 1 ecdysis
Protanypus sp. 2
Protanypus sp. 6 ecdyses
cl. Pisidiwn sp. 8
S.^ Lymnaea sp. 1
w. unidentified tubificid 1
SHALLOW STATION IV
Sample 1 11 m
s.
w.
Monodicmesa bathyphilia
Monodicmesa bathyphilia
Procladius sp.
Protanypus sp.
Phaenopseotra sp.
Lymnaea sp.
Pelosoolex sp.
1
6 ecdyses
1
2 ecdyses
1 ecdysis
9
1
.-snails,,
(continued)
96
-------
TABLE 22 (continued)
Station Depth
SHALLOW STATION IV
Sample 2 llm
Sample 3 llm
Group
c.
cl.
cd.5
m.6
s.
w.
c.
cl.
w.
Organism
Identification
Pvooladius sp.
Protanypus sp.
Pisidium sp.
unidentified calanoid
unidentified
Lymnaea s p .
Peloscolex sp.
Phaenopsectra sp.
Pi-s-id-ium sp.
Peloscolex sp.
unidentified tubificid
Number
3
1
2
4
1
5
1
1
1
3
1
5cd.-copepods, 6m.-mites
97
-------
TABLE 23. BENTHIC MACROINVERTEBRATES. HARDING LAKE
LITTORAL STATIONS. AUGUST 17, J973
ORGANISM
Depth
Station (m) Group
7 0.75 a.1
ce.2
cl.3
e.4
I.5
n.6
s.7
t.8
11
(Sample 1) 1.0 a.
c.9
cl.
1.
s.
n
(Sample 2) 1.0 a.
ne.10
s.
w.11
Identification
Eyalella azteca
Palpomyia sp.
unidentified adult
Pisidiim sp.
unidentified larva
Dina sp.
unidentified
Lymnaea
Gyrallus sp. (type 2)
unidentified Beraeidae
unidentified Limnephilidae
Mystaoides sp.
Eyalella azteoa
Cl-inotanypus sp.
Pis-idiwn sp.
Dina sp.
Lymnaea S p .
Gyrallus (type 1 )
Gyrallus (type 2)
Eyalella azteoa
unidentified
Gyrallus sp.
Pelosoolex sp.
Number
1
7
1
15
1
1
1
2
1
1
1
1
22
1
16
1
1
3
2
15
1
1
13
ia.-amphipods, 2ce.-ceratopogonids (flies), 3cl.-clams, 4e.-empidids (flies),
51.-leeches, 6n.-nematomorphs, 7s.-snails, 8t.-trichopterans, 9c.-chironomids
\
(flies), 10ne.-nematodes, nw.-worms
(continued)
98
-------
TABLE 23 (continued)
ORGANISM
Depth
Station (m) Group Identification
16 6.0 c. Monodiamesa bathyphilia
Procladius sp.
Stempellina sp.
cl . Pisidium sp.
t. Mystaaldes sp.
W. Pelosoolex sp.
unidentified tubificid
18 1.0 a. Eyalella azteca
C. Denrichryptoah-ironomus sp.
Tony tar sus sp.
ce. unidentified
cl . Pis-idlum sp.
cd.12 unidentified
ta,13 Chryspos sp.
w. Pelosoolex sp.
unidentified tubificid
21 *1.5 a. Hyalella azteca
ce. Leptooonops (adult)
Palpomyia sp.
c. Dicrotendipes sp.
M-iorotendlpes sp.
Potthastia sp.
Procladius sp.
Parachironomus sp.
Stempellina sp.
Tony tarsus sp.
Number
1 ecdysis
3
1
5
1
15
3
7
1
1
15
1
1
5
10
53
1
2
8
1
1
1
2
28
1
*this is a composite of two dredge samples
12cd.-copepods, 13ta.-tabanids (flies)
99
(continued)
-------
TABLE 23 (continued)
ORGANISM
Depth
Station (m) Group
cl.
1.
m.14
s.
t.
w.
23 1.3 a.
c.
cl.
1.
ma.15
m.
t.
w.
25 1.0 a.
s.
t.
w.
Identification
Pisidiwn sp.
Dina dub-La
unidentified
Gyrallus (type 1)
Gyrallus (type 2)
Lynmaea sp.
Mystaoides sp.
unidentified pupa
Peloscolex sp.
unidentified tubificids
Ryalella azteoa
Harnisch-ia sp.
P-is-idi-um sp.
Dina s p .
Parao loedes s p .
unidentified
unidentified Beraeidae
Peloscolex sp.
unidentified Lubriculidae
incomplete
unidentified tubificids
Hyalella azteca
Lymnaea S p .
Gyrallus (type 1 )
Gyrallus (type 2)
unidentified Beraeidae
Trianodes sp.
unidentified Lumbriculidae
Number
36
1
1
2
4
1
2
1
15
20
49
1
5
4
2
1
1
32
6
6
18
1
1
3
1
2
2
ll+m.-mites, 15ma.-mayfl ies
(continued)
TOO
-------
TABLE
23 (continued)
ORGANISM
Depth
Station (m) Group
27 1.0 a.
c.
m.
n
s.
t.
w.
30 0.5 a.
ce.
c.
cl.
ma.
s.
t.
w.
35 1.3 a.
ce.
c.
cl.
1.
m.
Identification
Eyalella azteoa
Ablabesmyia
Papaoloedes
unidentified
Gyrallus (type 2)
Lymnaea sp.
unidentified Beraeidae
Peloscolex sp.
Hyalella azteoa
Palpomyia sp.
Cryptochironomus dig-itatus
Stictoch'ironomus rosenscholdi
Pisidium sp.
Paraoloeodes sp.
Physa sp.
Gyrallus (type 1 )
unidentified Beraeidae
Tnanodes sp.
unidentified Lumbriculidae
unidentified tubificid
Hyalella azteoa
PalpomyLa sp.
Polyped-iwn sp.
Stempell'ina sp.
P-is-id'lwn sp.
Dina sp.
unidentified
Number
12
1
2
1
3
1
1
1
10
1
4
6
2
2
1
5
1
1
1
2
6
3
1
1
1
1
1
(continued)
101
-------
TABLE 23 (continued)
ORGANISM
Depth
Station (m) Group
s.
ta.
t.
w.
Identification
Lyrrmaea
Gyrallus (type 2)
Chrysops sp.
unidentified Beraeidae
Pelosaolex sp.
unidentified tubificid
Number
2
5
1
1
7
4
TABLE 24. CHIRONOMIDS REARED FROM HARDING LAKE, 1974
Tanypodinae
Clinotanypus pinguis (Loew)
Proaladius (Psilotanypos) bellus (Loew)
Procladius (Pr>ocad-ius) freemani (Subl.)
Chironominae
E-infeldia pagana (Meig.)
Pca>achi.Tonomus sp. n. near swamrnei'dami
Chironomus cf. hyperboreus (Staeg.)
Chironomus s p. n.
Chironomus sp. (female) probably different from the two above.
102
-------
o
OJ
N
o
KM
0.5
CONTOUR INTERVAL
4 meters
FIGURE 25
MORPHOMETRIC MAP OF HARDING LAKE WITH SAMPLING STATIONS FOR BENTHOS AND
BACTERIOLOGICAL SAMPLING INDICATED.
-------
Justification for the study was based on two reasons: (1) Coliform
bacteria studies conducted by the State of Alaska from the period 1966
through 1971 indicated that serious contamination of the lake may have been
occurring. Coliform data ranged up to 4,500 per 100 ml recorded on August
30, 1966. Additionally, during July of 1971, total coliform analyses indi-
cated a high value of 1,200 coliforms per 100 ml and the Department of
Health and Social Services, State of Alaska, considered closing the lakefront
to recreational use. (2) During the early 1970s, Harding Lake property
owners expressed concern about the possible pollution and/or contamination of
Harding Lake. Some of this concern was based on deterioration of aesthetic
values, which stemmed from improper disposal of solid waste and unsubstan-
tiated reports of sewage pollution of the lake.
This investigation was considered of high priority in the study of the
lake because of the high degree of recreational use of the waters. In the
Fairbanks area, only two moderate size lakes are easily accessible by the
road system and within 80 km of the community - Harding and Birch Lakes.
Harding Lake is the larger of the two and closer to the population center of
Fairbanks, therefore it receives a higher utilization.
The bacteriological investigation included the collection and analyses
of samples for standard plate counts, total coliform counts, and fecal coli-
form counts. Sample stations were established on the lake waters and included
near-shore stations, some lying over bottom muds and others over gravel,
pelagic stations, and stations located along inlet streams. Additionally,
vertical profile samples were taken within the lake for a determination of
mixing patterns and potential subsurface contamination. Intensified sampling
occurred during July and August for the purpose of monitoring water quality
during period of high recreational use.
A summary of data from the bacteriological investigation is included in
Tables 25 and 26. Data from standard plate counts were found to be of
little value in detection of pollution or contamination and are, therefore,
not included with this summary. Table 25 is a summary of the fecal coliform
information collected for Harding Lake. All of the fecal coliform tests were
within the recommended limit (below 200 organisms per 100 ml) suggested by
104
-------
TABLE 25. STATISTICAL SUMMARY OF FECAL COLIFORM RESULTS.1 HARDING LAKE. 1973
Date
May 30
June 25
July 17
August 7
August 28
September 3
September 5
May 30
June 25
July 17
August 7
August 28
September 3
September 5
May 30
June 25
July 17
August 7
August 28
September 3
September 5
Number of
Samples
29
48
49
44
49
49
49
25
38
39
39
39
39
39
4
10
10
5
10
10
10
Mean
All Lake Stations
0
0.2
0.2
1.0
0.3
0.4
0.1
Near-Shore Stations
0
0.2
0.2
1.1
0.4
0.5
0.2
Pelagic Stations
0
0.2
0
0
0
0
0
Standard
Deviation
0.9
0.6
2.1
1.0
2.6
0.9
0.9
0.6
2.2
1.1
2.9
1.0
0.6
Range
0- 5
0- 2
0- 8
0- 6
0-18
0- 6
0- 5
0- 2
0- 8
0- 6
0-18
0- 6
0- 2
iFecal Coliforms/100 ml.
105
-------
TABLE 26. STATISTICAL SUMMARY OF TOTAL COLIFORM RESULTS.1 HARDING LAKE. 1973
Date
Number of
Samples Mean
Standard
Deviation
Range
All Lake Stations
May 30
June 25
July 17
August 7
August 28
September 3
September 5
29
48
49
44
49
49
49
3
6
9
6
318
297
166
.6
.1
.3
.5
.2
.5
.5
7.4
4.8
9.8
9.1
225.7
248.6
93.7
0-
0-
0-
0-
2-
30-1
20-
39
21
32
38
776
,480
390
Pelagic Stations
May 30
June 25
July 17
August 7
August 28
September 3
September 5
May 30
June 25
July 17
August 7
August 28
September 3
September 5
5
10
10
5
10
10
10
24
38
39
39
39
39
39
1
6
3
2
535
304
223
Near -Shore
4
6
10
7
262
295
152
.2
.2
.8
.0
.6
.0
.0
Stations
.1
.1
.8
.0
.5
.9
.0
1.6
3.4
9.4
2.8
102.4
84.9
66.8
8.1
5.1
9.5
9.5
215.0
276.3
94.8
0-
2-
0-
0-
444-
190-
130-
0-
2-
0-
0-
0-
30-1
20-
3
13
30
6
766
460
330
39
21
32
38
754
,480
390
iTotal Coliforms/100 ml
(continued)
106
-------
TABLE 26 (continued)
Date
May 30
June 25
July 17
August 7
August 28
September 3
September 5
May 30
June 25
July 17
August 7
August 28
September 3
September 5
Number of
Samples Mean
16
23
24
24
24
24
24
8
15
15
15
15
15
15
Mud Bottom
5.
8.
14.
5.
369.
397.
185.
Gravel Bottom
2.
2.
4.
9.
90.
135.
99.
Standard
Deviation
Stations
1
3
6
7
8
5
0
Stations
1
6
7
2
8
7
2
9.7
5.3
9.7
8.9
196.8
292.7
83.8
1.9
1.9
5.2
10.3
102.3
150.2
89.4
Range
0-
0-
0-
0-
8-
102-1
54-
0-
0-
0-
0-
2-
30-
20-
39
21
32
36
754
,480
390
5
7
14
38
348
536
320
107
-------
the National Technical Advisory Committee (1968) as a standard for recrea-
tional water. There was no single sample location or area where fecal
coliforms were consistently detected and thus it is felt that fecal contami-
nation was sporadic and of a local nature. Due to the relatively low fecal
coliform values, it is suggested that little, if any, domestic sewage was
entering Harding Lake from the developed area.
Total coliform data is presented in Table 26 as a summary. Total
coliform analyses showed that Harding Lake complied with State of Alaska
criteria for recreational waters during the study period. Only one of over
300 total coliform analyses exceeded the criterion of 1,000 total coliforms
per 100 ml of sample. Total coliform results were widely variable but again
it was concluded that little or no domestic sewage was contaminating the lake
from its developed area. Based on lack of correlation with the recreational
usage data, it was apparent that the human-use level at Harding Lake had no
adverse effect on total coliform number. Although the results of the vertical
distribution study were inconclusive, it appeared that no significant increase
in bacterial numbers occurred with depth.
108
-------
REFERENCES
Alexander, V., and R. J. Barsdate. 1971. Physical Limnology, Chemistry and
Plant Productivity of a Taiga Lake. Int. Revue ges. Hydrobiol.,
56:825-872.
American Public Health Association, American Water Works Association, Water
Pollution Control Federation. 1971. Standard Methods for the Examina-
tion of Water and Wastewater, 13th ed. New York, New York. 874 pp.
Bachmann, R. W., and J. R. Jones. 1974. Phosphorus Inputs and Algal Blooms
in Lakes. Iowa State Journal of Research, 49:155-160.
Baker, A. L., and A. J. Brook. 1971. Optical Density Profiles as an Aid to
the Study of Microstratified Phytoplankton Populations in Lakes. Arch.
Hydrobiol., 69:214-233.
Barsdate, R. J. 1966. Pathways of Trace Elements in Arctic Lake Ecosystem.
Progress Report to the Atomic Energy Commission (for the period 15
April 1965 through 14 April 1966) AEC Contract AT(04-3)-310 PA No. 4.
86 pp.
Barsdate, R. J. 1967. Pathways of Trace Elements in Arctic Lake Ecosystems.
Progress Report to the Atomic Energy Commission (for the period
15 April 1966 through 14 April 1967) AEC Contract AT(04-3)-310 PA
No. 4. 58 pp.
Barsdate, R. J., and V. Alexander. 1971. Geochemistry and Primary
Productivity of the Tangle Lake Systems, an Alaskan Alpine Watershed.
Arctic and Alpine Research, 3:27-41.
Blackwell, J. M. 1965. Surficial Geology and Geomorphology of the Harding
Lake Area, Big Delta Quadrangle, Alaska. M.S. Thesis, University of
Alaska, Fairbanks, Alaska. 91 pp.
Brewer, M. C. 1958. The Thermal Regime of an Arctic Lake. Transactions,
American Geophysical Union, 39:278-284.
Brooks, J. L. 1959. Cladocera. In: Freshwater Biology, W. T. Edmondson,
Ed., Second Edition. John Wiley & Sons, Inc. New York. London.
1248 pp.
Clark, F. W. 1924. The Data of Geochemistry. Fifth Ed. Bull. U. S. Geol.
Surv. 770. 841 pp.
109
-------
Cole, G. A. 1975. Textbook of Limnology. C. V. Mosby Co., St. Louis,
Missouri. 283 pp.
Dillon, P. J., and F. H. Rigler. 1974. The Phosphorus-Chlorophyll Relation-
ship in Lakes. Limnol. and Oceanog., 19:767-773.
Dillon, P. J., and F. H. Rigler. 1975. A Simple Method for Predicting the
Capacity of a Lake for Development Based on Lake Trophic Status. J. Fish.
Res. Board Can., 32:1519-1531.
Environment Canada, (undated) Manual of Methods for Chemical Analysis.
Environment Canada, Freshwater Institute, Winnipeg, Manitoba, Canada.
92 pp.
Eppley, R. W., and J. H. Sharp. 1975. Photosynthetic Measurements in the
Central North Pacific: the Dark Loss of Carbon in 24-hr. Incubations.
Limnol. Oceanog., 20:981-987.
Gales, M. E., and R. L. Booth. 1974. Simultaneous and Automated Determi-
nation of Total Phosphorus and Total Kjeldahl Nitrogen. EPA-670/4-74-002.
U. S. Environmental Monitoring Agency, Cincinnati, Ohio. 21 pp.
Goldman, C. R. 1963. The Measurement of Primary Productivity and Limiting
Factors in Freshwater with Carbon-14. In: Primary Productivity
Measurement, Marine and Freshwater, M.S. Doty, ed. U. S. Atomic
Energy Commission TID-7633. pp. 103-113.
Goldman, C. R. 1974. Eutrophication of Lake Tahoe Emphasizing Water Quality.
EPA-660/3-74-034, USEPA Ecological Research Series, Con/all is, Oregon.
408 pp.
Golterman, H. L. ed. 1969. Methods for Chemical Analysis of Fresh Waters.
IBP Handbook No. 8, Blackwell Scientific Publications, Oxford and
Edinburg. 166 pp.
Gruendling, G. K., and J. L. Malanchuk. 1974. Seasonal and Spatial
Distribution of Phosphates, Nitrates, and Silicates in Lake Champlain,
USA. Hydrobiologia, 45:405-421.
Hobbie, J. E. 1962. Limnological Cycles and Primary Productivity of Two
Lakes in the Alaskan Arctic. Ph.D. Thesis, Indiana University.
Bloomington. 124 pp.
Hobbie, J. E. 1964. Carbon 14 Measurements of Primary Production in Two
Arctic Alaskan Lakes. Verh. Internat. Verein. Limnol. 15:360-364.
Hobbie, J. E. 1973. Arctic Limnology, a Review. In: Alaska Arctic Tundra,
M. E. Britton, ed., Technical Paper No. 25, Arctic Institute of North
America, Washington, D.C. pp. 127-168.
110
-------
Hutchinson, G. E. 1957. A Treatise on Limnology. Vol 1. Geography, Physics
and Chemistry. Wiley, New York. 1015 pp.
Johnson, P. R., and C. W. Hartman. 1969. Environmental Atlas of Alaska.
Institute of Arctic Environmental Engineering, Institute of Water
Resources, University of Alaska, Fairbanks. 109 pp.
Jones, J. R., and R. W. Bachmann. 1976. Prediction of Phosphorus and
Chlorophyll Levels in Lakes. Journal Water Pollution Control Federation,
48:2176-2182.
Kalff, J., and S. Holmgren. 1971. Phytoplankton. In: International
Biological Program Annual Report on Char Lake Project. University of
Toronto, Department of Zoology, pp. 8-9.
Kalff, J., and H. E. Welch. 1974. Phytoplankton Production in Char Lake, a
Natural Polar Lake, and in Meretta Lake, a Polluted Polar Lake,
Cornwallis Island, Northwest Territories. J. Fish. Res. Board Can.,
31:621-636.
Lake Tahoe Area Council. 1971. Eutrophication of Surface Waters-Lake Tahoe.
EPA 16010 DWS 05/71, USEPA, Washington, D.C. 154 pp.
Lande, A. 1973. Byglandsfjorden. Primary Production and Other Limnological
Features in an Oligotrophic Norwegian Lake. Hydrobiologia, 42:335-344.
LaPerriere, J. D. 1975. Evaluation of the Trophic Types of Several Alaskan
Lakes by Assessment of the Benthic Fauna. IWR-63, Institute of Water
Resources, University of Alaska, Fairbanks. 49 pp.
LaPerriere, J. D., and L. A. Casper. 1976. Biogeochemistry of Deep Lakes
in the Central Alaska Range. IWR-68, Institute of Water Resources,
University of Alaska, Fairbanks. 35 pp.
LaPerriere, J. D., and B. R. Robertson (compilers). 1973. The Distribution
and Succession of Aquatic Vascular Plant Communities in Relation to
Physical-Chemical Characteristics of Various Lakes and Ponds of the
Tanana Valley, Central Alaska. Institute of Water Resources, University
of Alaska, Fairbanks. 17 pp.
Larson, G. L. 1973. A Limnology Study of a High Mountain Lake in Mount
Rainier National Park, Washington State, USA. Arch. Hydrobiol.,
72(l):10-48.
Larson, P. R. 1974. Evaluation of Water Quality and Pollution Control at
Harding Lake, Alaska. M.S. Thesis, University of Alaska, Fairbanks,
Alaska. 159 pp.
Lind, 0. T. 1974. Handbook of Common Methods in Limnology. The C. V. Mosby
'company, Saint Louis. 154 pp.
Ill
-------
Livingstone, D. A. 1963. Alaska, Yukon, Northwest Territories, and Greenland.
In: Limnology in North America, D. G. Frey, ed. University of Wisconsin,
Madison, pp. 559-574.
Lueschow, L. A., J. M. Helm, I. R. Witner, and G. W. Karl. 1970. Trophic
Nature of Selected Wisconsin Lakes. Trans. Wise. Acad. Sci. Arts and
Letters, 58:237-264.
Maeda, 0., and S. Ichimura. 1973. On the High Density of a Phytoplankton
Population Found in a Lake under Ice. Int. Revue ges. Hydrobiol.,
58:673-685.
National Technical Advisory Committee. 1969. Water Quality Criteria.
Federal Water Pollution Control Administration, Washington, D. C. 234 pp.
Nyquist, D. 1971. Limnology of Harding Lake with Implications of Resource
Development. Paper read at 22nd Alaska Science Conference, August 1971,
at University of Aalska, Fairbanks, Alaska.
Pechlaner, R. 1966. Die Finstertaler Seen (Kutai, Osterreich). I.
Morphometrie, Hydrographie, Limnophysik and Limnochemie. Arch.
Hydrobiol., 62:165-230.
Rigler, F. H. 1964. The Phosphorus Fractions and the Turnover Time of
Inorganic Phosphorus in Different Types of Lakes. Limnol. Oceanog.,
9:511-518.
Rigler, F. H., M. E. MacCallum, and J. C. Roff. 1974. Production of
Zooplankton in Char Lake. J. Fish. Res. Board Can., 31:637-646.
Rodhe, W. 1955. Can Plankton Production Proceed during Winter Darkness in
Subarctic Lakes? Verh. Internat. Verein. Limnol., 12:117-122.
Rodhe, W. 1965. Standard Correlations between Pelagic Photosynthesis and
Light. Mem. 1st. Hal. Idrobiol., (supplement), 18:365-381.
Saether, 0. A. 1975. Nearctic Chironomids as Indicators of Lake Typology.
Verh. Internat. Verein. Limnol., 19:3127-3133.
Saunders, G. W., F. B. Trama, and R. W. Bachmann. 1962. Evaluation of a
Modified C-14 Technique for Shipboard Estimation of Photosynthesis in
a Large Lake. Great Lakes Div., Univ. of Michigan, Ann Arbor.
Publication #8:1-61.
Schindler, D. W. 1977. Evolution of Phosphorus Limitation in Lakes.
Science, 195:260-262.
Schindler, D. W., and J. E. Nighswander. 1970. Nutrient Supply and Primary
Production in Clear Lake, Eastern Ontario. J. Fish. Res. Board Can.,
27:2009-2036.
12
-------
Schindler, D. W., R. V. Schmidt, and R. A. Reid. 1972. Acidification and
Bubbling as an Alternative to Filtration in Determining Phytoplankton
Production by the C Method. 0. Fish. Res. Board Can., 29:1627-1631.
Schindler, D. W., H. E. Welch, J. Kalff, G. J. Burnskill, and N. Kritsch.
1974. Physical and Chemical Limnology of Char Lake, Cornwall is Island
(75°N lat.). J. Fish. Res. Board Can., 31:585-607.
Schoephorster, D. B. 1973. Soil Survey of Salcha—Big Delta Area, Alaska.
United States Department of Agriculture, Soil Conservation Service, in
cooperation with University of Alaska, Institute of Agricultural
Sciences. U. S. Government Printing Office, Washington, D.C.
Shapiro, J. 1973. A Field Fixation Technique for Dissolved Phosphate in
Lake Water. Limnol. Oceanog., 18:143-145.
Stainton, M. P. 1973. A Syringe Gas-Stripping Procedure for Gas-Chromato-
graphic Determination of Dissolved Inorganic and Organic Carbon in Fresh
Water and Carbonates in Sediments. J. Fish. Res. Board Can., 30:1441-
1445.
Stainton, M. P. 1974. Simple Efficient Reduction Column for Use in the
Automated Determination of Nitrate in Water. Anal. Chem., 46:1616.
Steemann-Nielsen, E. 1952. The Use of Radio-active (sic) Carbon (C ) for
Measuring Organic Production in the Sea. J. du Conseil., 18:117-140.
Steele, J. H., and I. E. Baird. 1961. Relations between Primary Production,
Chlorophyll and Particulate Carbon. Limnol. Oceanog., 6:68-78.
Stewart, K. M., and S. J. Markello. 1974. Seasonal Variations in Concentra-
tions of Nitrate and Total Phosphorus, and Calculated Nutrient Loading
for Six Lakes in Western New York. Hydrobiologia, 44:61-89.
Strickland, J. D. H., and T. R. Parsons. 1965. A Manual of Sea Water
Analysis. Bulletin No. 125, Fisheries Research Board of Canada, Ottawa.
203 pp.
Str0m, K. M. 1932. Nordfjord Lakes, A Limnology Survey. Skrifter Det
Norske Viden. Akad. I. Oslo No. 8. 56 pp.
U. S, Environmental Protection Agency. 1971. Methods for Chemical Analysis
of Water and Wastes. Analytical Quality Control Laboratory, USEPA.
Cincinnati, Ohio. 312 pp.
U. S. Environmental Protection Agency. 1974. Methods for Chemical Analysis
of Water and Wastes. Methods Development and Quality Assurance
Research Laboratory, USEPA. Cincinnati, Ohio. 298 pp.
113
-------
Vollenweider, R. A., ed. 1969a. A Manual on Methods for Measuring Production
in Aquatic Environments. IBP Handbook No. 12. F. A. Davis Company,
Philadelphia, Pa. 213 pp.
Vollenweider, R. A. 1969b. Mbglichkeiten und Grenzen elementarer Modelle der
Stoffbilanz von Seen. Arch. Hydrobiol., 65:1-136.
Vollenweider, R. A. 1971. Scientific Fundamentals of the Eutrophication of
Lakes and Flowing Waters, with Particular Reference to Nitrogen and
Phosphorus as Factors in Eutrophication. Organization for Economic
Cooperation and Development, Paris. 159 pp.
Vollenweider, R. A. 1975. Input-Output Models, with Special Reference to
the Phosphorus-Loading Concept in Limnology. Schweiz. Zeit. Hydrol.,
37:53-84.
Watson, C., C. Branton, and J. Newman. 1971. Climatic Characteristics of
Selected Alaskan Locations. Technical Bulletin #2, Institute of
Agricultural Sciences, University of Alaska, Fairbanks, Alaska. 56 pp.
Weeden, R. B. 1971. Problems in Public Management of Accessible Lakes in
Interior Alaska. Paper read at 22nd Alaska Science Conference, August
1971, at University of Alaska, Fairbanks, Alaska.
Welch, H. E., and J. Kalff. 1974. Benthic Photosynthesis and Respiration in
Char Lake. J. Fish. Res. Board Can., 31:609-620.
Wetzel, R. G. 1975. Limnology. W. B. Saunders Company. Philadelphia,
London, Toronto. 743 pp.
World Meteorological Organization. 1970. The Guide to Hydrometeorological
Practices. Second Edition. Secretariat of the World Meteorological
Organization. Geneva, Switzerland.
Wright, R. T., and J. E. Hobbie. 1965. The Uptake of Organic Solutes in
Lake Water. Limnol. Oceanog., 10:22-28.
114
-------
APPENDIX
Page
A-l Ammonia Nitrogen Concentration (ug/1 as N), Harding Lake--1973 . . 116
A-2 Chlorophyll a Concentrations, Deep and Shallow Stations,
Harding Lake—1973-1974 118
A-3 Chlorophyll a and Phaeopigment Concentrations, Shallow
Stations, Harding Lake--1975 „ 120
A-4 Plant Transect Data Summary, Harding Lake--1974 123
115
-------
TABLE A-1. AMMONIA NITROGEN CONCENTRATION (vg/1 as N). HARDING LAKE. 1973
Deep Station I
Depth (m) Apr 26
1
2
4
5 20
10 5
15
20 5
25
30
40 5
Deep Station
Depth (m) Apr 26
1
2
3 3
4
5 2
10 2
20 2
Jun 17 Jul 16 Aug 6 Oct 23 Dec 4
5 15 10 11
<2 10 14
<2 11 10
<2 9
<2 116
<2 6
<2 6
6
3
II Shallow Station II
Jun 17 Depth (m) Apr 26 Jun 17 Jul 16
<2 1 4 21
<2 <2
4 <2
<2 5 10
6 <2
<2 8 4
3 10 6
(continued)
116
-------
TABLE A-l (continued)
Shallow Station III Shallow Station IV
Depth (m) Apr 26 Jun 17 Jul 16 Depth (m) Apr 26 Jun 17
1
2
4
5
6
8
10
15
2 25
3
3
5
2
<2
8 4
5 <2
1 <2
2
4
5 12
6
8 <2
10 62
117
-------
TABLE A-2. CHLOROPHYLL a CONCENTRATIONS*
HARDING LAKE. DEEP AND SHALLOW STATIONS. 1973-1974
DEEP STATION
August 6,
Depth
(m)
0
2
4
6
8
10
1973
Concentration
(mg/m )
0.68
0.84
1.00
0.77
1.12
0.84
December 4
Depth
(m)
0
2
4
6
8
10
15
20
25
30
± 0.
± 0.
± 0.
± 0.
04
07
24
06
, 1973
Concentration
(mg/m3)
0.41
0.50
0.53
0.55
0.75
0.73
0.54
0.39
0.39
0.34
± 0.
± 0.
± 0.
± 0.
± 0.
± 0.
± 0.
± 0.
04
07
00
04
01
08
01
01
August
I
27, 1973
Depth Concentration
2
(m) (mg/m )
0
2
4
6
8
10
March
Depth
(m)
2
4
6
8
10
12
14
16
20
25
30
35
0.67
0.72
0.74
0.74
0.88
0.98
15,
± 0.
± 0.
+ 0.
± 0.
± 0.
± 0.
1974
06
04
02
01
06
10
Concentration
(mg/m )
1.92
0.88
0.61
0.45
0.42
0.35
0.28
0.27
0.29
0.29
0.32
0.25
± 0.
± 0.
± 0.
± 0.
± 0.
± 0.
± 0.
± 0.
± 0.
± 0.
± 0.
15
03
11
00
01
03
01
04
04
05
04
October 18,
Depth
(m)
0
2
4
Depth
(m)
2
4
6
8
10
12
14
16
20
25
30
35
1973
Concentration
(mg/m )
0
1
1
April
.97
.00
.07
16,
± 0.04
± 0.03
± 0.08
1974
Concentration
(mg/m )
1
2
1
0
0
0
0
0
0
0
0
0
.92
.27
.35
.79
.56
.45
.42
.32
.24
.30
.39
.30
± 0.15
± 0.02
± 0.03
± 0.02
± 0.00
± 0.04
± 0.00
± 0.02
± 0.01
^calculated according to Strickland and Parsons (1965)
(continued)
118
-------
TABLE A-2 (continued)
SHALLOW STATION II
August
Depth
(m)
0
2
4
6
8
10
27, 1973
Concentration
0
(mg/m )
0.66
0.86 ± 0.15
0.91
0.74 ± 0.01
0.75 ± 0.01
0.66
March 15, 1974
Depth Concentration
(m) (mg/m3)
2 1.88 ± 0.04
SHALLOW STATION III
August 6, 1973
Depth Concentration
q
(m) (mg/m )
0 0.65 ± 0.17
2 0.81 ± 0.13
4 0.74 ± 0.28
6 0.99 ± 0.08
8 0.89 ± 0.09
10 1.15 ± 0.09
SHALLOW STATION IV
March 15, 1974
Depth Concentration
(m) (mg/m )
April 6, 1974
Depth Concentration
(m) (mg/m )
0.39 ± 0.06
2 0.83
3 2.24 ± 0.24
119
-------
TABLE A-3. CHLOROPHYLL a AND PHAEOPIGMENT CONCENTRATIONS*
HARDING LAKE. SHALLOW STATIONS. 1975
Depth
(m)
1
2
3
4
1
2
3
4
1
2
3
4
Shallow Station
May 29
Chlorophyll a Phaeophytin
(mg/m ) (mg/m )
1.49
1.44
1.84
2.09
July 16
Chlorophyll a Phaeophytin
3 3
(mg/m ) (mg/m )
0.65
0.70
0.42
0.68
August 14
Chlorophyll a Phaeophytin
3 3
(mg/m ) (mg/m )
0.79
0.68
0.39 0.71
0.59 0.14
I
June
Chlorophyll a
o
(mg/m )
0.52
0.61
0.67
0.78
July
Chlorophyll a
o
(mg/m )
0.65
0.52
0.56
0.69
August
Chlorophyll a
(mg/m )
0.62
0.43
0.57
0.81
19
Phaeophytin
(mg/m )
30
Phaeophytin
q
(mg/m )
.008
26
Phaeophytin
q
(mg/m )
0.30
0.09
Calculated according to Golterman (1969)
(continued)
120
-------
TABLE A-3 (continued)
Depth
(m)
1
2
3
4
Depth
(m)
1
2
4
6
8
10
12
Depth
(m)
1
2
3
October 13
Chlorophyll a Phaeophytin
3 3
(mg/m ) (mg/m )
0.65 0.53
0.82 0.01
0.57 0.09
0.91
Shallow Station
February 22
Chlorophyll a Phaeophytin
(mg/m3) (mg/m3)
0.79
0.31
0.07 0.18
0.00 0.09
0.53
0.14 0.01
Shallow Station
March 22
Chlorophyll a Phaeophytin
3 3
(mg/m ) (mg/m )
0.65
0.71
0.66
II
April 11
Chlorophyll a Phaeophytin
(mg/m3) (mg/m3)
2.73
2.18
2.22
0.55 0.03
0.34 0.02
0.31 0.03
0.57
IV
May 3
Chlorophyll a Phaeophytin
(mg/m ) (mg/m3)
1.23
1.30
1.43
(continued)
121
-------
TABLE A-3 (continued)
Depth
(m)
1
2
3
1
2
3
1
2
3
Chlorophyl
o
(mg/m )
0.63
0.80
0.75
Chlorophyl
(mg/m )
0.51
0.69
0.81
Chlorophyl
0
(mg/m )
0.24
0.64
0.75
Shallow Station
June 19
1 a Phaeophytin
(mg/m )
July 30
1 a Phaeophytin
(mg/m )
.004
August 26
1 a Phaeophytin
(mg/m )
0.46
0.15
V
July 16
Chlorophyll a
2
(mg/m )
0.64
0.32
0.84
August
Chlorophyll a
(mg/m )
0.76
0.73
0.73
October
Chlorophyll a
(mg/m )
0.79
0.44
0.75
Phaeophytin
(mg/m )
0.33
14
Phaeophytin
(mg/m )
0.08
13
Phaeophytin
0
(mg/m )
0.06
0.45
0.17
122
-------
TABLE A-4. PLANT TRANSECT DATA SUMMARY. HARDING LAKE. 1974
Distance
From Shore
(m)
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
Depth
(cm)
5
25
35
50
60
80
90
100
120
140
160
180
190
200
200
230
250
270
290
310
Species
Transect 1
G. borealis
E. acicularis
G. borealis
P. filiformis
J. muricata
E. acicularis
J. muricata
P. filiformis
E. acicularis
I. muricata
P. filiformis
P. Richardsonii
E. acicularis
I. muricata
I. rrturieata
I. muricata
E. acicularis
J. muricata
I. muri,cata
E. ac'iculap'is
I. murioata
I. mur-ioata
I. murieata
I. mwcTsCat-a
I. mua"leata
I. muT'Loata
P. Riohardsonii
P. Riohardsonii
P. Richards onii
P. Richardson-Li
Chora sp.
Height
(cm)
a, 40
2
•\. 40
6-8
5
6
5
10
2
3
6-8
10
1
3
1
6
2
5
6
2
3
3
4
4
4
2
40
60
60
30
6
Cover
%
20
40
30
20
5
5
80
5
80
20
20
5
10
20
20
70
5
25
50
5
25
40
20
30
20
5
20
50
50
20
50
(continued)
123
-------
TABLE A-4 (continued)
Distance
From Shore
(m)
5
10
15
20
25
30
5
10
15
20
25
30
35
40
45
Depth
(cm)
58
95
120
140
120
130
80
35
45
60
70
80
88
no
130
J.
P.
s.
I.
p.
E.
I.
P.
P.
I.
P.
I.
P.
I.
S.
S.
I.
p.
s.
I.
p.
p.
s.
I.
p.
I.
I.
p.
I.
I.
Species
Transect 2
muriaata
Richards onii
angus tifo 1 iim
murioata
gramineus
aciulavis
rmricata
gpomineus
Riohardsonii
muricata
gpomineus
murioata
gramineus
murioata
Transect 3
angustifoliwn
angus tifo Hum
murioata
filiformis
angus tifo 1 ium
murioata
fi liformis
gvamineus
angus tifo 1 ium
mupicata
gramineus
murieata
muriaata
gramineus
murieata
muricata
Height
(cm)
2
22
9
3
12
3
3
50-120
20
4
20-40
5
50
5
60
•^100
4
10
•^100
5
15
20
MOO
4
20
5
5
40
4
5
Cover
%
60
5
negl .
80
10
40
50
5
negl .
20
15
5
5
5
20
50
20
80
80
50
10
5
10
40
5
100
100
negl.
100
70
(continued)
124
-------
TABLE A-4 (continued)
Distance
From Shore
(m)
50
55
60
65
70
75
80
85
90
95
100
5
10
15
20
Depth
(cm)
150
160
170
195
210
240
250
280
300
320
340
6
18
25
32
Species
I. muricata
P. Richards onii
I. muricata
P. Richards onii
Myriophyllum sp.
P. Richardsonii
I. muricata
Myriophyllum sp.
P. Richardsonii
Ranunculus sp.
Myriophyllum sp.
P. Richardsonii
Myriophyllum sp.
P. Richards onii
Myriophy 1 lum S p .
Myriophyllum sp.
Myriophyllum sp.
P. Richardsonii
Char a sp.
Myriophyllum sp.
Myriophyllum sp.
Transect 4
S. angusti folium
S. aquatica
E. acicularis
P. gramineus
S. fluctuans
S. aquatica
I. muricata
P. gramineus
P, Richardsonii
S. augustifotium
E. acicularis
P. Richardsonii
Height
(cm)
5
100
5
100
50
100
6
60
100
6
30
50
60
150
50
40
20
200
6
20
20
•v 60
3
2
12
-v 60
2
4
15
20
•^100
2
20
Cover
%
40
50
30
50
30
50
20
30
40
10
50
20
80
negl.
60
20
negl .
60
negl .
negl .
negl .
80
40
10
10
50
20
negl .
5
negl .
50
50
50
(continued)
125
-------
TABLE A-4 (continued)
Distance
From Shore
(m)
25
30
35
40
45
50
55
60
65
5
10
15
Depth
(cm)
40
45
55
80
105
125
155
255
345
20
35
42
E.
I.
P.
P.
E.
I.
P.
P.
S.
E.
I.
P.
P.
S.
I.
P.
P.
I.
P.
J.
P.
I.
P.
I.
P.
P.
no
E.
I.
P.
P.
P.
Species
acicularis
muricata
gramineus
Richardsonii
acicularis
muricata
gramineus
Richardsonii
angus tifo lium
acicularis
muricata
gramineus
Richards onii
angus tifo lium
muricata
gramineus
Richardsonii
muricata
Richardsonii
muricata
Richardsonii
muricata
Richardsonii
muricata
Richardsonii
Richardsonii
Transect 5
plants
acicularis
muricata
gramineus
filiformis
gramineus
Height
(cm)
4
5
25
20
2
3
20
25
^110
2
3
30
25
•v 55
4
40
25
5
50
6
90
6
100
10
100
150
2
2
10
10
10
Cover
30
10
10
80
10
20
10
80
40
10
10
20
60
negl.
50
20
30
100
20
80
30
50
20
50
20
10
negl .
negl.
negl .
5
10
(continued)
126
-------
TABLE A-4 (continued)
Distance
From Shore
(m)
20
25
30
35
40
45
50
55
60
65
70
75
5
10
15
20
25
Depth
(cm)
55
85
95
110
120
135
140
150
175
200
240
270
30
40
50
70
90
Species
P. filiformis
P. gramineus
P. Richards onii
I, rmricata
P. filiformis
P. gramineus
P. Richards ami
P. filiformis
P. Richardsonii
E. acicularis
P. filiformis
P. Richardsonii
E. acicularis
P. Richardsonii
P. Richards onii
P. Richardsonii
P. praelongus
P. Richardsonii
P. praelongus
P. Richardsonii
P. praelongus
P, Richardson-Li
Chora sp.
P. praelongus
P. Richardsonii
P. praelongus
P. Richardsonii
Transect 6
no plants
no plants
no plants
P, Richards onii
P. Richards onii
Height
(cm)
10
10
30
3
10
10
30
10
20
4
10
40
4
100
100
100
120
100
130
100
150
80
10
150
30
100
20
25
25
Cover
%
5
10
negl .
negl .
5
10
negl .
negl.
5
80
5
5
40
30
50
50
20
40
10
50
40
40
negl .
20
negl .
negl .
negl .
40
40
(continued)
127
-------
TABLE A-4 (continued)
Distance
From Shore
(m)
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
125
130
Depth
(cm)
110
120
135
150
165
175
180
185
205
230
245
260
275
300
320
330
350
365
380
400
420
Species
no plants
no plants
no plants
Ranunoulus sp.
P. Richardsonii
J. muvicata
P. Richards onii
P. Richardson-Li
P. filiformis
no plants
no plants
no plants
no plants
P. Richardsonii
P. Richardsonii
P. Richardsonii
P. Richards onii
P. Freisii
P. Richardsonii
P. Freisii
P. Freisii
P. Freisii
P. Fveisii
Height
(cm)
2
100
6
100
90
10
100
100
100
50
20
100
20
20
20
20
Cover
°/
h
negl.
5
10
30
15
negl .
30
60
30
5
50
5
50
negl .
negl.
negl .
128
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-600/3-78-088
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Nutrient Chemistry of A Large Deep Lake in
Subarctic Alaska
5. REPORT DATE
September 1978
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
J.D. LaPerriere, Tilsworth, and L.A. Casper
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Institute of Hater Resources
University of Alaska
Fairbanks, Alaska 99501
10. PROGRAM ELEMENT NO.
1BA608
11. CONTRACT/GRANT NO.
R800276
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Research Laboratory-Corvallis
Office of Research and Development
US. Environmental Protection Agency
Corvallis, Oregon 97330
13. TYPE OF REPORT AND PERIOD COVERED
extramural - final
14. SPONSORING AGENCY CODE
EPA/600/02
15. SUPPLEMENTARY NOTES
16. ABSTRACT
The primary objective of this project was to assess the state of the water
quality of Harding Lake, and to attempt to predict the effects of future development
within its watershed. Since the major effect of degradation of water quality due to
human activity is the promotion of nuisance growths of plants, the major emphasis was
placed on measurements of plant growth and concentrations of the major nutrients they
require. Planktonic algal growth was found to be low, below 95.6 gm/nr/year, and the
growth of submerged rooted plants was found to be relatively less important at approx-
imately 1.35 gm/m^/year. Measurements of the growth of attached algae were not con-
ducted, therefore the relative importance of their growth is currently unknown. A
model for predicting the effect of future real estate development in the watershed was
modified and applied to this lake. This model adequately describes current water quali'1
conditions, and is assumed to have some predictive ability, but several cautions con-
cerning application of this model to Harding Lake are discussed. A secondary objective
was to study the thermal regime of a deep subarctic lake. Hydrologic and energy budgets
of this lake are attempted; the annual heat budget is estimated at 1.96x10^ - 1.7x10^
cal/cm . The results of a study of domestic water supply and waste disposal alternative
in the watershed, and the potential for enteric bacterial contamination of the lake
water are presented. Limited work on the zooplankton, fishes and benthic macroinverte-
brates of this lake is also presented.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDEDTERMS
c. COSATl Field/Group
Water Quality
Nutrients
Nutrient Chemistry
Watershed
Zooplankton
Benthic Macroiinvertebrates
Submerged rooted plants
08/H,J
13/B
06/C
18. DISTRIBUTION STATEMENT
Release to public
19. SECURITY CLASS (This Report)
unclassified
21. NO. OF PAGES
20 SECURITY CLASS {This page)
unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77)
*U.S. GOVERNMENT PRINTING OFFICE: 1978—7'i||-'iin v
129
------- |