Ecological Assessment of Lake Istokpoga – May 2019
Ecological Assessment of
Lake Istokpoga
Highlands County
Sampled July 2016 to June 2017
Division of Environmental Assessment and Restoration
Florida Department of Environmental Protection
May 2019
DEP Laboratory, Biology Program
2600 Blair Stone Road, MS 6515
Tallahassee, FL 32399-2400
www.floridadep.gov
Ecological Assessment of Lake Istokpoga – May 2019
Page 2 of 96
Contents
Contents ..........................................................................................................................................2
Executive Summary .........................................................................................................................3
Overview ..........................................................................................................................................4
Methods............................................................................................................................................7
Results ..............................................................................................................................................7
Discussion ........................................................................................................................................9
Appendix A. Phytoplankton Wet Taxa ..........................................................................................35
Appendix B. Phytoplankton DiatomTaxa ......................................................................................84
List of Tables
Table 1. Measured field parameters. ............................................................................................. 11
Table 2. Laboratory analytical results. .......................................................................................... 15
Table 3. Dominance of algal species. ........................................................................................... 25
Table 4. Phytoplankton taxonomic variables. ............................................................................... 26
Table 5. Dominant wet and diatom taxa. ...................................................................................... 31
List of Figures
Figure 1 Map of Lake Istokpoga in Highlands County, Florida ..................................................... 6
Figure 2. Graph of water temperature. .......................................................................................... 13
Figure 3. Graph of pH. .................................................................................................................. 13
Figure 4. Graph of dissolved oxygen. ........................................................................................... 14
Figure 5. Graph of specific conductance. ..................................................................................... 14
Figure 6. Graph of color (true). ..................................................................................................... 19
Figure 7. Graph of total organic carbon. ....................................................................................... 19
Figure 8. Graph of total suspended solids. .................................................................................... 20
Figure 9. Graph of turbidity. ......................................................................................................... 20
Figure 10. Graph of ortho-phosphate. ........................................................................................... 21
Figure 11. Graph of total phosphorus. .......................................................................................... 21
Figure 12. Graph of total Kjeldahl nitrogen.................................................................................. 22
Figure 13. Graph of ammonia. ...................................................................................................... 22
Figure 14. Graph of nitrate-nitrite. ................................................................................................ 23
Ecological Assessment of Lake Istokpoga – May 2019
Page 3 of 96
Figure 15. Graph of chlorophyll a, corrected. ............................................................................... 23
Figure 16. Phytoplankton density. ................................................................................................ 24
Figure 17. Comparison of phytoplankton density to chlorophyll a, corrected. ............................ 24
Figure 18. Box and whisker plot of the percent composition by algal group. .............................. 30
Figure 19. Average monthly minimum and maximum precipitation for Highlands County........ 34
Executive Summary
Highlands County Board of County Commissioners (HCBCC), through the Lake Istokpoga
Management Committee (LIMC), requested sampling and analytical assistance from the Florida
Department of Environmental Protection (DEP) for Lake Istokpoga due to reported public
concerns over the health of the waterbody and the potential of harmful algal bloom formation.
Working in collaboration, staff from the DEP’s South Regional Operations Center (SROC) and
Highlands County Parks and Natural Resources (HCPNR) conducted monthly sampling events at
six locations on the lake over the course of one year, July 2016 to June 2017. Field parameters,
water samples, and algal samples were collected at each site and sent for analysis to the DEP
Laboratory in Tallahassee, (DOH Accreditation E31780).
Measured field parameters exhibited similar and/or expected patterns across all 6 locations and
dates. Total suspended solids, turbidity, total Kjeldahl nitrogen, and chlorophyll a tended to
increase over the study period. Lake color decreased over the study however, measurements
were greater than 43 PCU for all sampling dates. For lakes with color greater than 40 PCU, the
annual geometric mean for total phosphorus is to be between the 0.05 and 0.16 mg/L, for total
nitrogen is to be between 1.27 mg/L and 2.23 mg/L, and for chlorophyll a is to be less than 20
µg/L, Chapter 62-302.531(2)(a)(2)(b)1., Florida Administrative Code (F.A.C.). The majority of
single sample nutrient values measured during this study fell within this range however, 67 of the
72 single sample chlorophyll a were greater than 20 µg/L.
Samples were collected to examine whether a bloom condition existed at the time of collection.
Dominant or co-dominant species were present in only 12 of the 72 samples. For those 12
samples, the taxa identified as dominant or co-dominant were Cylindrospermopsis rackiborskii,
Planktolyngbya contorta, Planktolyngbya limnetica, and Microcystis aeruginosa. These are
cyanobacteria species (blue-green algae) that have the potential to produce toxins however,
cyanotoxins were not detected in the 16 samples analyzed. Although potential toxin producing
species may have been present, laboratory results indicate that these species were not producing
toxins at the time of collection.
Additional samples were collected for phytoplankton species identification and enumeration.
With few exceptions, blue-green algae comprised the majority of the phytoplankton samples,
followed by green algae. Algal density varied between the collection dates but generally,
increased over the time, similar to the pattern of increasing chlorophyll a. There was a positive
Ecological Assessment of Lake Istokpoga – May 2019
Page 4 of 96
relationship between increasing phytoplankton density and chlorophyll a. Although algal density
increased over time, the phytoplankton community composition remained fairly consistent
within and among sites, indicating little shift in relative proportions of major groups of algae
over the study period.
The analytical results suggest similar water quality and biological communities among the 6
different locations within the lake, with possibly the exception of the Northeast site. The pattern
of change in both measured field parameters and water quality data reflect the pattern of change
in average monthly rainfall received in Highlands County. This suggests that Lake Istokpoga’s
water quality and algal community is susceptible to, influenced by, and changes in response to
weather-driven patterns.
Overview
DEP Surface Water Quality Standards, Chapter 62-302, Florida Administrative Code (F.A.C.),
are designed to protect the designated uses of waters and exceedances of these standards are
associated with interference with the designated use. DEP uses methods in Chapter 62-303,
F.A.C. to evaluate the condition of a waterbody in relation to the water quality criteria, including
whether adverse impacts to biological communities have occurred. Human stressors that may
negatively impact the condition of a waterbody include increased inputs of nutrients, sediments
and/or pesticides from watershed runoff, undesirable removal of native shoreline and/or upland
buffer vegetation, and introduction of nuisance (generally exotic) plants and animals.
For waterbodies with Class I, II, III and III Limited designations, surface water quality criteria
prohibit the alteration of nutrient concentration “so as to cause an imbalance in natural
populations of aquatic flora and fauna” (62-302.530(48)(b). The criteria also prohibits the
presence of any “substances in concentrations which results in the dominance of nuisance
species” 62-302.530(47) F.A.C.. A variety of field assessment methods and analytical parameters
can be used in conjunction with one another to detect potential stressors and imbalances in the
biological communities. For example, measuring the nutrient concentration in a waterbody may
indicate the potential for excessive plant or algal growth. Measuring the concentration of the
photosynthetic pigment chlorophyll a in a water sample, provides an estimate of algal biomass.
Higher than expected chlorophyll a for a particular waterbody may indicate the presence of algal
bloom conditions which may not only result in unwanted shading of aquatic plants but pose a
human health risk if certain potential toxin producing species are present.
Measuring the concentration of the photosynthetic pigment, chlorophyll a, in a water sample
provides an estimate of algal biomass. For lakes, 62-302.531(2)(a)(2)(b)1., F.A.C. of the
Numeric Interpretations of Narrative Nutrient Criteria describes the applicable interpretation of
the narrative nutrient criteria in paragraph 62-302.530(48)(b), F.A.C. for chlorophyll a. In clear,
low alkalinity lakes (color less than 40 PCU and alkalinity less than 20 mg/L CaCO3), a healthy
system is expected to have a geometric mean chlorophyll a value of less than 6 μg/L. In clear,
high alkalinity lakes (color less than 40 PCU and alkalinity greater than 20 µg/L CaCO3) or in
colored lakes (color greater than 40 PCU), healthy systems are expected to have a geometric
Ecological Assessment of Lake Istokpoga – May 2019
Page 5 of 96
mean chlorophyll a value of less than 20 μg/L. Annual geometric mean chlorophyll a greater
than these values may result in the waterbody being identified as impaired or not meeting water
quality standards. Higher chlorophyll a indicates greater algal biomass and possibly the presence
of bloom conditions.
Lake Istokpoga is located approximately 7 miles northeast of Lake Placid, FL in Highlands
County (Figure 1). Fed by Arbuckle Creek and Josephine Creek in the north, the lake discharges
into the C41 canal to the south. Lake Istokpoga is part of the Kissimmee watershed and
therefore, lies within the Peninsula Nutrient Watershed Region, 62-302.200(13)(e) F.A.C. The
predominate land use surrounding the lake includes pastures, citrus groves, and residential
dwelling. This lake has a Class III designated use defined as fish consumption; recreation,
propagation and maintenance of a healthy, well-balanced population of fish and wildlife, 62-
302.400 F.A.C.
Using the methods of evaluation in Chapter 62-303, F.A.C., Lake Istokpoga is currently verified
impaired for chlorophyll a, total phosphorous, and total nitrogen and was included on the
verified list of impaired waters adopted June 27, 2017, https://floridadep.gov/dear/watershed-
assessment-section/content/lists-impaired-waters-group-4-basins. Currently, a Total Maximum
Daily Loads (TMDLs) is under development for the lake and is anticipated to be completed by
2022. Additional information about this waterbody is available on DEP ArcGIS Online,
http://fdep.maps.arcgis.com/home/index.html.
https://floridadep.gov/dear/watershed-assessment-section/content/lists-impaired-waters-group-4-basinshttps://floridadep.gov/dear/watershed-assessment-section/content/lists-impaired-waters-group-4-basinshttp://fdep.maps.arcgis.com/home/index.html
Ecological Assessment of Lake Istokpoga – May 2019
Page 6 of 96
Figure 1 Map of Lake Istokpoga in Highlands County, Florida
Ecological Assessment of Lake Istokpoga – May 2019
Page 7 of 96
Methods
Working in collaboration, staff from the DEP’s South Regional Operations Center (SROC) and
Highlands County Parks and Natural Resources (HCPNR) conducted monthly sampling events at
six locations on the lake over the course of one year, July 2016 to June 2017. Water quality
readings for temperature, specific conductivity, dissolved oxygen, and pH were conducted at
each site using YSI multi-parameter meters. Direct surface grab samples were collected for
ammonia, chlorophyll a, true color, turbidity, total suspended solids, total organic carbon, nitrate
and nitrite, ortho-phosphate, total phosphorous, algal toxins, and algal species identification.
Water samples were preserved and shipped for analysis to the DEP Laboratory in Tallahassee,
(DOH Accreditation E31780). Due to staff turnover, the October 2016, January 2017, and April
2017 quantitative water samples for algal identification were sent to and analyzed by Greenwater
Labs, Inc..
All field and laboratory methods followed DEP Standard Operating Procedures (see
https://floridadep.gov/dear/quality-assurance/content/dep-sops and
https://floridadep.gov/dear/florida-dep-laboratory/content/dep-laboratory-quality-assurance-
manual-and-sops for details) and met DEP quality assurance/quality control standards (see
https://floridadep.gov/dear/quality-assurance).
All references to 62-302.530, F.A.C. are to the surface water quality criteria table with an
effective date of 02/17/2016 and a notice identification number of 17115667.
Results
Measured field parameters for all 12 sampling dates at the 6 lake locations are presented in Table
1. These parameters exhibited similar patterns across all 6 locations. As expected, water
temperature was highest in the summer months and lowest in the winter months (Figure 2). In
general, measured pH was lowest and less variable across most sites September through
November 2016 (Figure 3). The greatest pH values were measured at most sites March through
June 2017. Dissolved oxygen was recorded as either mg/L or percent saturation. Percent
saturation was calculated to facilitate comparisons across sampling dates. Percent saturation was
higher in the winter and spring months and lower during the summer and fall months (Figure 4).
Specific conductance was only recorded for 6 of the 12 sampling dates. Specific conductance
was slightly lower on the two sampling dates in 2016 than the 4 sampling dates in 2017 (Figure
5).
Analytical chemistry results are presented in Table 2. Graphs for each parameter are included to
help visualize the relationships and patterns in the data. The Northeast site results tended to be
different from other sites for certain sampling dates and parameters. Of note, is that the analytical
results for samples collected at the Northeast site July through September or October 2016 and
especially in June 2017, were greater for ammonia, color, total organic carbon, ortho-phosphate,
and total phosphorus and lower for total suspended solids and turbidity than all the other values
measured at that site and at the other 5 sites during the duration of the study. Also, of note, only
https://floridadep.gov/dear/quality-assurance/content/dep-sopshttp://www.dep.state.fl.us/labs/library/lab_sops.htmhttps://floridadep.gov/dear/florida-dep-laboratory/content/dep-laboratory-quality-assurance-manual-and-sopshttps://floridadep.gov/dear/florida-dep-laboratory/content/dep-laboratory-quality-assurance-manual-and-sopshttps://floridadep.gov/dear/quality-assurance
Ecological Assessment of Lake Istokpoga – May 2019
Page 8 of 96
1 of 72 samples for nitrate-nitrite had a detection greater than the laboratory practical
quantitation limit (PQL). The result for this 1 sample, collected on November 29, 2016 at the
Northwest site, was 10 times greater than the PQL. All laboratory analytical quality control
associated with this sample was re-reviewed and confirmed passing and therefore, it is either an
anomalous result compared to others in the study or there was possible contamination either in
the field or prior to analysis.
Lake color measurements were greater than 43 PCU for all sampling dates (Figure 6). Color and
total organic carbon showed similar patterns (Figures 6 and 7, respectively). Although consistent
in concentration relative to one another, values for color and total organic carbon were more
variable between the 6 locations from July through October 2016. After, values converged and
remained consistent between sites November 2016 through May 2017 and until the exception of
the June 29, 2017 Northeast site sample. Total suspended solids and turbidity values were similar
across sites from July through December 2016 then, steadily increased until May 2017. Both
total suspended solids and turbidity decreased in the June 2017 samples (Figures 8 and 9,
respectively).
Ortho-phosphate and total phosphorus concentrations at the Northeast site were greater in the
first few months and on the final month of the study than for all other samples collected (Figures
10 and 11, respectively). Ortho-phosphate was detected in only 5 samples at the Northeast site
and was either not detected (59 samples) or detected between the laboratory method detection
limit (MDL) and PQL (8 samples) for all other samples collected during the study. Total
phosphorus was detected at all sites and those values increased over time. With the exceptions of
2 samples collected at Northeast site on August 2016 and June 2017, total phosphorus values
ranged between 0.03 and 0.13 mg/L. Total Kjeldahl nitrogen values were lower in 2016 than
2017 and, in 2017 increased over time (Figure 12). Ammonia and nitrate-nitrite values were low
and consistent over the entire study period, with only 2 sample exceptions. Ammonia was
detected below 0.011 mg/L except in the Northeast June 2017 sample and nitrate-nitrite values
were all less than 0.009 mg/L except in the Northwest November 2016 sample (Figure 13 and
14, respectively). Chlorophyll a is an indicator of algal biomass and is considered a potential
response variable to nutrients. Chlorophyll a concentration, in a similar pattern to the total
suspended solids and turbidity data, slowly increased over time (Figure 15). All but 5 of 72
single sample values were greater than 20 µg/L.
DEP taxonomists examined microscopically aliquots of water samples from each location and
sampling date to determine if a dominant taxon or co-dominant taxa of algae were present at the
time of collection. Dominance of one or few species may indicate the presence of an algal bloom
condition in the waterbody. There was a mixed assemblage and no clear dominance of algal
species in 60 of the 72 samples examined (Table 3). Dominance of one or two species in the
samples was observed on only 4 collection dates, July 2016, October 2016, March 2017, and
May 2017. A dominant species was never observed in the samples from the Northeast site. In
July 2016 and October 2016, dominant and co-dominant species occurred in samples at each of
the other 5 sites. For the 12 samples, the taxa identified as dominant or co-dominant were
Cylindrospermopsis rackiborskii, Planktolyngbya contorta, Planktolyngbya limnetica, and
Ecological Assessment of Lake Istokpoga – May 2019
Page 9 of 96
Microcystis aeruginosa. These are cyanobacteria species (blue-green algae) that have the
potential to produce toxins.
Toxin analysis was performed if algal species that have the potential to produce toxins were
observed during the microscopic examination of water samples collected to identify if a
dominant algal species was present. Toxins were analyzed by HPLC/MS/MS for samples
collected at all 6 sites for July and August 2016, the Southeast site for October 2016, and the
South, Southeast, and West sites for June 2017. Microcystins and cylindrospermopsin were not
detected in any of the analyzed samples. Anatoxin-a was analyzed in the June 2017 sample only
and was not detected.
A summary of the water samples collected for quantitative phytoplankton taxonomic analysis is
provided in Table 4. Phytoplankton wet taxa and diatoms are identified separately. In the wet
taxa analysis, soft algae are identified to the lowest practical level, and diatoms are identified
only to order level (diatom). In the diatom analysis, diatoms are identified to the lowest practical
level. Taxa lists are provided for the wet algae and diatoms in appendices A and B, respectively.
Algal density is calculated as number of natural units/mL for phytoplankton samples. Algal
density varied between the collection dates but generally, increased over the time, similar to the
pattern of increasing chlorophyll a (Figure 17). The was a positive relationship between
increasing phytoplankton density and chlorophyll a, corrected analytical results.
Phytoplankton community composition is calculated to examine potential shifts in relative
proportions of major groups of algae. With few exceptions, blue-green algae (cyanobacteria)
comprised the majority of the phytoplankton samples, followed by green algae. Two exceptions
were the Northeast July 2016 sample, which contained 44% diatoms and only 16% blue-greens,
and the September 2016 sample, which contained 43% green and 40% blue-green algae. With
the Northeast July 2016 data point removed, the percent of blue-green algae ranged from 41% to
80% and averaged 63% of the sample community. Green algae comprised the next largest
percent of the samples, ranging from 8% to 43% and averaging 22% of the sample community.
The Northeast July 2016 sample also contained 28% Pyrrophytes, which then decreased to 7% in
the sample collected the following month. In all following samples at this site and in all samples
from the other 5 sites, Pyrrophytes comprised less than 0.7%. In the Northeast July 2016 sample,
the percent of green algae across all sites was approximately half the percent green algae found
in all other samples in the study. The dominant taxa identified in the quantitative samples are
presented in Table 5.
Discussion
Measured field parameters exhibited similar and/or expected patterns across all 6 locations and
dates although specific conductance was greater in 2017 than 2016. The analytical results
suggest similar water quality and biological communities among the 6 different locations within
the lake, with possibly the exception of the Northeast site. Measurements of lake color were
greater than 43 PCU for all sampling dates. The majority of single sample nutrient values
measured during this study fell within the range of annual geometric means identified for lakes
Ecological Assessment of Lake Istokpoga – May 2019
Page 10 of 96
with color greater than 40 PCU however, 67 of the 72 single sample chlorophyll a values were
greater than the 20 µg/L threshold, 62-302.531(2)(a)(2)(b)1., F.A.C.
Dominant or co-dominant species were present in only 12 of the 72 samples taken to examine
whether a bloom condition existed at the time of collection. The cyanobacteria species (blue-
green algae) identified in those samples, Cylindrospermopsis rackiborskii, Planktolyngbya
contorta, Planktolyngbya limnetica, and Microcystis aeruginosa, have the potential to produce
toxins however, cyanotoxins were not detected in the 16 samples analyzed. Although potential
toxin producing species may have been present, laboratory results indicate that these species
were not producing toxins at the time of collection. Although algal density increased over time,
the phytoplankton community composition indicated no shifts in relative proportions of major
groups of algae over the study period.
The pattern of changes in both measured field parameters and water quality data, reflect the
pattern of average monthly rainfall received in Highlands County. Precipitation data was
retrieved for Highlands County from the Community Collaborative Rain, Hail & Snow Network
(CoCoRaHS) Rainy Day’s Report, https://www.cocorahs.org/ViewData/RainyDaysReport.aspx.
Both minimum and maximum precipitation were averaged by month for the period July 1, 2017
to June 30, 2017 (Figure 18). Precipitation data recorded from the station located on the
northeast shore of the lake, Sylvan Shores 8.5NE, # FL-HL-12, reflected the pattern in the
monthly county data. Increases in total suspended solids, turbidity, total Kjeldahl nitrogen, and
chlorophyll a along with decreases in color and total organic carbon coincide with periods of low
precipitation. This suggests that Lake Istokpoga’s water quality and algal community is
susceptible to, influenced by, and changes in response to weather-driven patterns.
https://www.cocorahs.org/ViewData/RainyDaysReport.aspx
Ecological Assessment of Lake Istokpoga – May 2019
Page 11 of 96
Table 1. Measured field parameters.
Field parameters measured at 6 locations on Lake Istokpoga on 12 sampling dates. A dash (-) indicates sample/measurement was not collected. The c indicates a
calculated value.
Site Parameter Unit 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Center Temperature C 29.9 31.1 28.8 25.5 20.3 22.1 16.5 22.2 23.3 21.3 28.1 29.5
Center pH SU 7.9 7.8 7.1 7.4 7.0 7.2 7.6 7.9 8.3 8.8 8.8 8.0
Center Dissolved
Oxygen %Sat 101.7 c 83.4 101.8 103.8 c 113.5 108.8 99.4 c 106.7 108.3 116.3 c 101.1 98.5
Center Dissolved
Oxygen mg/L 7.7 - - 8.5 - - 9.7 - - 10.3 - -
Center Specific
Conductance
µmhos/
cm 101 - - 104 - - 130 138 - 117 - 189.2
Northeast Temperature C 29.8 30.8 29.4 25.4 20.3 22.0 16.6 22.6 24.1 21.3 28.4 29.2
Northeast pH SU 6.5 6.7 6.6 7.2 7.1 7.3 7.5 7.9 8.1 8.1 8.0 6.7
Northeast Dissolved
Oxygen %Sat 75.2 c 66.9 74.2 96.3 c 116.4 110.1 93.4 c 100.3 103.9 110.6 c 83.3 46.1
Northeast Dissolved
Oxygen mg/L 5.7 - - 7.9 - - 9.1 - - 9.8 - -
Northeast Specific
Conductance
µmhos/
cm 110 - - 103 - - 133 140 - 199 - 162.6
Northwest Temperature C 29.9 31.4 29.1 25.6 20.7 22.7 16.9 23.0 23.4 22.9 28.6 30.5
Northwest pH SU 8.2 7.9 7.3 7.3 6.6 7.9 7.9 8.5 7.9 8.8 8.5 8.6
Northwest Dissolved
Oxygen %Sat 111.0 c 115.3 87.4 93.0 c 114.9 100.8 90.9 c 115.8 99.3 117.6 c 89.1 101.3
Northwest Dissolved
Oxygen mg/L 8.4 - - 7.6 - - 8.8 - - 10.1 - -
Northwest Specific
Conductance
µmhos/
cm 107 - - 104 - - 133 139 - 198 - 170.8
South Temperature C 29.9 30.9 30.0 26.0 20.3 22.1 16.7 22.8 24.8 22.2 28.2 30.6
Ecological Assessment of Lake Istokpoga – May 2019
Page 12 of 96
Site Parameter Unit 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
South pH SU 8.2 7.4 7.1 7.7 6.8 7.2 7.6 8.1 8.5 8.7 7.8 8.7
South Dissolved
Oxygen %Sat 100.4 c 94.5 74.8 108.5 c 103.1 106.2 89.5 c 101.8 113.3 114.8 c 70.6 96.3
South Specific
Conductance
µmhos/
cm 116 - - 106 - - 127 134 - 116 - 160.3
Southeast Temperature C 29.6 31.2 29.2 25.4 20.4 22.1 16.5 22.3 24.4 21.2 27.8 30.4
Southeast pH SU 7.8 7.0 6.9 7.6 6.9 7.2 7.7 8.0 8.2 8.6 9.3 8.6
Southeast Dissolved
Oxygen %Sat 95.9 c 81.8 77.6 102.4 c 112.0 106.6 87.1 c 65.7 110.8 105.9 c 102.3 95.7
Southeast Dissolved
Oxygen mg/L 7.3 - - 8.4 - - 8.5 - - 9.4 - -
Southeast Specific
Conductance
µmhos/
cm 107 - - 106 - - 128 136 - 192 - 163.8
West Temperature C 29.5 31.4 28.7 25.4 20.1 21.8 16.5 22.8 23.8 23.3 28.0 29.7
West pH SU 8.4 8.3 7.4 7.4 6.9 7.5 8.6 8.4 9.1 9.3 8.2 9.2
West Dissolved
Oxygen %Sat 102.3 c 116.4 96.7 102.4 c 114.2 104.5 96.3 c 109.7 116.5 124.3 c 89.1 112.5
West Dissolved
Oxygen mg/L 7.8 - - 8.4 - - 9.4 - - 10.6 - -
West Specific
Conductance
µmhos/
cm 108 - - 105 - - 129 135 - 194 - 174.5
Ecological Assessment of Lake Istokpoga – May 2019
Page 13 of 96
Figure 2. Graph of water temperature.
Figure 3. Graph of pH.
14
16
18
20
22
24
26
28
30
32
34
°C
Sample Date
Temperature
Center
Northeast
Northwest
South
Southeast
West
5
6
7
8
9
10
SU
Sample Date
pH
Center
Northeast
Northwest
South
Southeast
West
Ecological Assessment of Lake Istokpoga – May 2019
Page 14 of 96
Figure 4. Graph of dissolved oxygen.
Figure 5. Graph of specific conductance.
40
50
60
70
80
90
100
110
120
130
140
% s
atura
tion
Sample Date
Dissolved Oxygen
Center
Northeast
Northwest
South
Southeast
West
60
80
100
120
140
160
180
200
220
µm
hos/
cm
Sample Date
Specific Conductance
Center
Northeast
Northwes
tSouth
Southeast
Ecological Assessment of Lake Istokpoga – May 2019
Page 15 of 96
Table 2. Laboratory analytical results.
Analytical results for 6 locations on Lake Istokpoga on 12 sampling dates. Data qualifiers are as follows: A - Value reported is the mean of two or more
determinations; I - The reported value is between the laboratory method detection limit and the laboratory practical quantitation limit; J – Estimated value; Q -
Sample held beyond normal holding time; U - Material analyzed for but not detected; value reported is the method detection limit.
Site Analyte Unit 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Center Total Ammonia mg/L 0.009 0.007 0.006 0.004 I 0.006 0.009 0.005 I 0.0078 0.004 I 0.004 I 0.007 0.008
Center Chlorophyll a,
Corrected µg/L 33 30 34 34 48 38 J 56 42 49 51 A 63 48
Center Color (true) PCU 160 120 110 120 Q 130 160 88 75 A 65 67 58 88
Center Total Kjeldahl
Nitrogen mg/L 1.1 J 1.2 1.2 1.2 1.4 1.2 1.3 1.5 1.2 1.7 1.7 1.8
Center Nitrate -Nitrite mg/L 0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
Center Ortho-phosphate mg/L 0.004
U
0.004
U
0.004
U
0.008
IQ
0.004
U
0.004
U 0.004 I
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
Center Total Organic
Carbon mg/L 17 15 15 17 16 16 15 15 15 15 14 16
Center Total
Phosphorus mg/L 0.075 0.059 0.055 0.068 0.059 0.067 0.13 0.083 0.08 0.095 0.097 0.1
Center Total Suspended
Solids mg/L 13 I 9 I 9 I 8 I 12 6 I 24 20 24 I 24 I 42 I 17 I
Center Turbidity NTU 6.9 4.3 A 4.6 5.9 Q 7.1 5.2 14 8.3 9 11 10 8.8
Northeast Total Ammonia mg/L 0.009 0.005 0.006 0.004 I 0.005 0.008 0.005 I 0.006 0.004 I 0.004 I 0.006 0.06
Northeast Chlorophyll a,
Corrected µg/L 26 32 33 A 25 23 19 J 55 A 40 44 44 66 18
Northeast Color (true) PCU 190 130 110 160 Q 190 190 91 74 65 67 57 320
Northeast Total Kjeldahl
Nitrogen mg/L 0.84 1.2 1.2 1.1 0.99 1.1 1.3 1.4 1.3 2.2 2 1.7
Ecological Assessment of Lake Istokpoga – May 2019
Page 16 of 96
Site Analyte Unit 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Northeast Nitrate -Nitrite mg/L 0.004
U
0.004
U
0.004
U
0.004
U 0.009 I
0.004
U 0.007 I
0.004
U
0.004
U
0.004
U
0.004
U 0.009 I
Northeast Ortho-phosphate mg/L 0.016 0.004
U
0.004
U 0.05 Q 0.036 0.037 0.004 I
0.004
U
0.004
U
0.004
U
0.004
U 0.14
Northeast Total Organic
Carbon mg/L 19 15 15 19 19 18 15 14 15 14 14 27
Northeast Total
Phosphorus mg/L 0.07 0.066 0.055 0.1 0.26 0.092 0.12 0.072 0.075 0.092 0.12 0.24
Northeast Total Suspended
Solids mg/L 6 I 12 8 I 10 A 4 I 4 I 26 17 19 20 I 48 I 7 I
Northeast Turbidity NTU 3.7 4.7 4.9 A 2.9 Q 2.6 2.9 15 7.5 7.4 9.4 A 15 3.5
Northwest Total Ammonia mg/L 0.007 0.007 0.006 0.003 I 0.005 I 0.007 0.005 I 0.01 0.004 I 0.004 I 0.006 0.008
Northwest Chlorophyll a,
Corrected µg/L 29 46 49 45 34 34 J 54 26 AQ 63 54 72 6.4
Northwest Color (true) PCU 170 110 100 130 Q 130 130 85 75 Q 65 68 57 51
Northwest Total Kjeldahl
Nitrogen mg/L 0.78 1.3 1.1 1.2 1.2 1.1 1.4 1.6 1.5 2 1.6 1.8
Northwest Nitrate -Nitrite mg/L 0.004
U 0.1
0.004
U
0.004
U 0.004 I 0.008 I
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
Northwest Ortho-phosphate mg/L 0.008 I 0.004 I 0.005 I 0.004
UQ
0.004
U
0.004
U
0.004
U
0.004
UQ
0.004
U
0.004
U
0.004
U
0.004
U
Northwest Total Organic
Carbon mg/L 18 15 15 15 16 16 15 14 15 15 14 13
Northwest Total
Phosphorus mg/L 0.075 0.062 0.058 0.058 0.056 0.05 0.082 0.074 0.086 0.1 0.098 0.078
Northwest Total Suspended
Solids mg/L 9 I 12 17 11 9 I 10 22 24 26 23 I 46 I 40 I
Northwest Turbidity NTU 5.9 5.7 9.1 6.3 Q 5.8 6.4 12 8.8 AQ 10 12 12 9.4
South Total Ammonia mg/L 0.009 0.006 0.006 0.004 I 0.006 0.008 0.004 I 0.007 0.005 I 0.004 I 0.008 0.007
Ecological Assessment of Lake Istokpoga – May 2019
Page 17 of 96
Site Analyte Unit 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
South Chlorophyll a,
Corrected µg/L 42 34 40 38 40 14 J 16 54 43 45 60 51 A
South Color (true) PCU 97 A 110 99 83 80 71 85 74 67 A 66 55 43
South Total Kjeldahl
Nitrogen mg/L 1.6 1.2 1.3 1.4 1.6 1.2 1.3 1.7 1.4 1.9 2.2 2.1
South Nitrate -Nitrite mg/L 0.004
U
0.004
U
0.004
U
0.004
U 0.004 I
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
South Ortho-phosphate mg/L 0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
South Total Organic
Carbon mg/L 14 15 15 15 15 14 16 15 16 15 14 13
South Total
Phosphorus mg/L 0.086 0.059 0.059 0.06 0.03 0.053 0.1 0.079 0.08 0.11 0.11 0.084
South Total Suspended
Solids mg/L 16 11 12 15 I 17 6 I 29 20 21 I 21 I 44 I 40 I
South Turbidity NTU 9.3 4.8 5.8 6.8 6.6 5.8 14 9.3 7.7 A 12 12 9.9
Southeast Total Ammonia mg/L 0.008 0.006 0.005 0.004 I 0.006 0.009 0.005 0.006 0.005 I 0.004 I 0.009 0.008
Southeast Chlorophyll a,
Corrected µg/L 37 33 36 38 42 30 66 53 38 41 54 45
Southeast Color (true) PCU 110 120 100 120 A 110 110 A 86 74 64 67 A 59 44
Southeast Total Kjeldahl
Nitrogen mg/L 1.5 1.2 1.1 1.3 1.4 1.2 1.6 1.7 1.3 1.8 2 1.5
Southeast Nitrate -Nitrite mg/L 0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U 0.004 I
0.004
U
0.004
U
0.004
U
Southeast Ortho-phosphate mg/L 0.004
U
0.004
U
0.004
U
0.004
UQ
0.004
U
0.004
U 0.005 I
0.004
U 0.006 I
0.004
U
0.004
U
0.004
U
Southeast Total Organic
Carbon mg/L 15 15 15 16 16 16 15 15 15 16 16 14
Southeast Total
Phosphorus mg/L 0.083 0.056 0.066 0.073 0.064 0.061 0.13 0.08 0.072 0.099 0.11 0.077
Ecological Assessment of Lake Istokpoga – May 2019
Page 18 of 96
Site Analyte Unit 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Southeast Total Suspended
Solids mg/L 18 12 13 12 12 9 I 25 19 21 I 22 I 46 I 38 I
Southeast Turbidity NTU 7.9 5 5.4 6.5 6.3 5.9 14 9.4 7.1 10 12 8.9 A
West Total Ammonia mg/L 0.007 0.007 0.006 0.005 0.006 0.011 0.005 I 0.009 0.004 I 0.005 I 0.007 0.008
West Chlorophyll a,
Corrected µg/L 25 29 35 46 Q 53 38 AJ 50 60 Q 49 48 62 A 63
West Color (true) PCU 140 120 110 A 100 Q 110 110 85 76 Q 66 69 56 65
West Total Kjeldahl
Nitrogen mg/L 1.2 1.2 1.1 1.6 1.4 1.3 1.3 1.4 1.7 1.8 1.9 1.9
West Nitrate -Nitrite mg/L 0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
0.004
U
West Ortho-phosphate mg/L 0.004
U
0.004
U
0.004
U
0.004
UQ
0.004
U
0.004
U 0.004 I
0.004
UQ
0.004
U
0.004
U
0.004
U
0.004
U
West Total Organic
Carbon mg/L 16 15 15 15 16 14 15 14 16 16 14 14
West Total
Phosphorus mg/L 0.067 0.055 0.061 0.072 0.055 0.055 0.11 0.085 0.083 0.1 0.1 0.096
West Total Suspended
Solids mg/L 12 13 12 13 I 12 10 I 29 35 24 I 22 I 48 I 38 I
West Turbidity NTU 6.6 4.5 5.2 8.1 Q 6.5 A 6.2 13 9.9 Q 9.8 11 12 A 10
Ecological Assessment of Lake Istokpoga – May 2019
Page 19 of 96
Figure 6. Graph of color (true).
Figure 7. Graph of total organic carbon.
0
50
100
150
200
250
300
350
PC
U
Sample Date
Color (true)
Center
Northeast
Northwest
South
Southeast
West
0
5
10
15
20
25
30
mg C
/L
Sample Date
Total Organic Carbon
Center
Northeast
Northwest
South
Southeast
West
Ecological Assessment of Lake Istokpoga – May 2019
Page 20 of 96
Figure 8. Graph of total suspended solids.
Figure 9. Graph of turbidity.
0
10
20
30
40
50
60
mg/L
Sample Date
Total Suspended Solids
Center
Northeast
Northwest
South
Southeast
West
0
2
4
6
8
10
12
14
16
NT
U
Sample Date
Turbidity
Center
Northeast
Northwest
South
Southeast
West
Ecological Assessment of Lake Istokpoga – May 2019
Page 21 of 96
Figure 10. Graph of ortho-phosphate.
Figure 11. Graph of total phosphorus.
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
mg/L
Sample Date
Ortho-phosphate
Center
Northeast
Northwest
South
Southeast
West
0
0.05
0.1
0.15
0.2
0.25
0.3
mg/L
Sample Date
Total Phosphorus
Center
Northeast
Northwest
South
Southeast
West
Ecological Assessment of Lake Istokpoga – May 2019
Page 22 of 96
Figure 12. Graph of total Kjeldahl nitrogen.
Figure 13. Graph of ammonia.
0
0.5
1
1.5
2
2.5
mg/L
Sample Date
Total Kjeldahl Nitrogen
Center
Northeast
Northwest
South
Southeast
West
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
mg/L
Sample Date
Ammonia
Center
Northeast
Northwest
South
Southeast
West
Ecological Assessment of Lake Istokpoga – May 2019
Page 23 of 96
Figure 14. Graph of nitrate-nitrite.
Figure 15. Graph of chlorophyll a, corrected.
0
0.02
0.04
0.06
0.08
0.1
0.12
mg/L
Sample Date
Nitrate-nitrite
Center
Northeast
Northwest
South
Southeast
West
0
10
20
30
40
50
60
70
80
µg/L
Sample Date
Chlorophyll a, corrected
Center
Northeast
Northwest
South
Southeast
West
Ecological Assessment of Lake Istokpoga – May 2019
Page 24 of 96
Figure 16. Phytoplankton density.
Figure 17. Comparison of phytoplankton density to chlorophyll a, corrected.
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000# u
nit
s/m
L
Sample Date
Phytoplankton Density
Center
Northeast
Northwest
South
Southeast
West
0
10
20
30
40
50
60
70
80
0 20,000 40,000 60,000 80,000 100,000 120,000 140,000 160,000
Chlo
rophyll
a, co
rrec
ted (
µg/L
)
Phytoplankton Sample Density (# algal units/mL)
Comparison of Chlorophyll a to Phytoplankton Density
Center
Northeast
Northwest
South
Southeast
West
Ecological Assessment of Lake Istokpoga – May 2019
Page 25 of 96
Table 3. Dominance of algal species.
The presence of dominant or co-dominant algal species in water samples collected at 6 locations on Lake Istokpoga on 12 sampling dates to determine if a bloom
condition was affecting the waterbody at time of collection. The table contains the count of samples and sites for each result. Abbreviations used within the table
are C-Central, NE-Northeast, NW-Northwest, SE-Southeast, S-South, W-West.
Dominant Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-16
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
None; mixed assemblage 1-NE 6 6 1-NE 6 6 6 6 5 6 5 6
Cylindrospermopsis rackiborskii. - - - - - - - - - - 1-W -
Planktolyngbya contorta. 2-C,
NW - - 1-C - - - - - - - -
Planktolyngbya contorta and
Microcystis aeruginosa.
2-SE,
W - - 1-SE - - - - - - - -
Planktolyngbya contorta and
Cylindrospermopsis raciborskii. 1-S - - 1-W - - - - - - - -
Planktolyngbya contorta and
Planktolyngbya limnetica. - - -
2-NW,
S - - - - 1-S - - -
Ecological Assessment of Lake Istokpoga – May 2019
Page 26 of 96
Table 4. Phytoplankton taxonomic variables.
Summary of phytoplankton in quantitative water samples collected at 6 locations on Lake Istokpoga on 12 sampling dates. The table contains the count of
samples and sites for each result.
Site Variable 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Center Number of Wet Taxa 34 37 45 47 39 47 36 33 30 42 30 50
Center Number Wet Algal
Units Identified
303 305 307 366 301 303 336 306 306 319 313 301
Center Algal Density
(# units/mL)
39,214 30,129 21,571 44,229 24,749 56,826 74,351 39,967 48,494 124,670 772,21 74,328
Center Percent Dominant
Wet Taxon
42.74 15.85 10.27 23.4 12.56 21.13 40.72 12.2 12.92 41.28 12.5 13.01
Center % Blue-green 63.37 65.9 48.86 51.9 53.49 66.67 68.75 62.42 71.24 74.92 74.76 68.44
Center % Green 12.86 20.98 22.8 25.4 20.27 20.46 22.02 20.59 17.32 18.18 14.38 20.93
Center % Yellow-green 0 0 0.33 0.8 0 0.33 0 0 0 0 0 0
Center % Cryptophytes 0 0 0.33 0.7 0 0 0.31 0 0 0.31 0 0.33
Center % Euglenophytes 0.33 0 0.65 0.4 0 0 0 0 0 0 0 0
Center % Pyrrophytes 0.66 0 0.33 4.9 0.33 0 0 0 0 0 0.32 0.32
Center % Diatoms 22.78 13.11 27.04 21.9 25.91 12.54 9.23 16.99 11.44 6.58 10.54 10.63
Northeast Number of Wet Taxa 38 50 44 46 76 99 36 35 33 37 34 53
Northeast Number Wet Algal
Units Identified
304 311 302 192 604 534 325 301 303 304 312 301
Northeast Algal Density
(# units/mL)
3,158 4,800 7093 22,178 44,144 88,858 84,072 35,211 33,616 108,272 69,153 22,291
Northeast Percent Dominant
Wet Taxon
47.09 10.89 17.06 22.75 7.47 11.28 38.54 11.6 12.69 36.39 14.29 11.31
Northeast % Blue-green 15.77 43.09 51.66 55.2 41.39 67.42 62.15 55.81 68.65 78.29 60.26 62.79
Northeast % Green 13.33 29.9 27.48 30.2 22.85 20.22 26.15 27.24 19.8 17.76 18.27 27.91
Ecological Assessment of Lake Istokpoga – May 2019
Page 27 of 96
Site Variable 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Northeast % Yellow-green 0.32 0 0.33 0.1 0 0.33 0 0 0 0.33 0 0
Northeast % Cryptophytes 0 0.32 0.33 0.0 0.99 0.67 0.31 0 0 0.31 0 0.33
Northeast % Euglenophytes 0.32 2.25 0.33 0.2 0 0 0 0 0 0 0 0
Northeast % Pyrrophytes 26.73 7.07 3.31 1.0 0.33 0 0 0 0 0 0 0.32
Northeast % Diatoms 43.54 17.36 16.56 13.5 35.76 11.99 11.38 16.94 11.55 3.62 21.47 8.97
Northwest Number of Wet Taxa 25 40 45 47 38 47 41 41 40 39 32 44
Northwest Number Wet Algal
Units Identified
303 305 304 262 303 314 308 302 310 355 318 304
Northwest Algal Density
(# units/mL)
37,737 29,822 23,004 32,151 21,547 67,403 73,296 41,088 56,423 149,873 77,531 91,489
Northwest Percent Dominant
Wet Taxon
50 15.13 8.43 22.27 14.15 19.09 38.14 15.51 10.75 44.38 16.8 15.07
Northwest % Blue-green 52.14 65.9 53.62 52.3 50.17 52.87 70.13 55.63 63.23 77.18 58.49 71.71
Northwest % Green 8.59 22.62 31.58 40.5 18.81 17.2 24.03 25.5 26.77 17.75 20.13 17.43
Northwest % Yellow-green 0 0 0.33 0.4 0 0 0 0 0 0.33 0 0
Northwest % Cryptophytes 0 0 0.33 0.0 0.99 0 0.31 0 0 0.31 0 0.33
Northwest % Euglenophytes 0 0.33 0.33 0.4 0 0 0 0 0 0 0 0
Northwest % Pyrrophytes 0 0 0.33 0.3 0.33 0 0 0 0 0 0.32 0.32
Northwest % Diatoms 39.27 11.15 14.14 6.1 30.03 29.94 5.84 18.87 10 4.79 21.38 10.53
South Number of Wet Taxa 32 39 48 44 40 51 40 38 37 40 32 38
South Number Wet Algal
Units Identified
303 306 301 344 308 300 342 312 301 332 305 298
South Algal Density
(# units/mL)
37,308 53,752 20,385 70,356 28,699 63,603 131,672 40,339 33,975 140,199 55,130 73,286
South Percent Dominant
Wet Taxon
42.74 16.41 11.37 25.84 12.35 23.26 39.61 17.18 10.8 43.25 14.23 12.45
Ecological Assessment of Lake Istokpoga – May 2019
Page 28 of 96
Site Variable 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
South % Blue-green 64.03 54.9 40.86 62.5 57.47 63 68.13 62.18 70.1 74.7 69.51 72.82
South % Green 12.87 28.43 43.19 32.3 21.43 22 21.35 21.79 25.25 23.49 18.03 18.79
South % Yellow-green 0 0 0 0.1 0 0.33 0 0 0 0 0 0
South % Cryptophytes 0 0.33 0 0.0 0.99 0.67 0.31 0 0 0 0 0.33
South % Euglenophytes 0 0 0 0.0 0 0 0 0 0 0 0 0
South % Pyrrophytes 0.33 0 0.66 0.3 0.33 0 0 0 0 0 0.32 0.32
South % Diatoms 22.77 16.34 15.28 4.4 21.1 14 9.94 16.03 4.65 1.81 12.46 8.39
Southeast Number of Wet Taxa 21 40 48 47 45 39 31 33 40 39 37 37
Southeast Number Wet Algal
Units Identified
303 311 309 377 312 301 315 305 309 317 303 304
Southeast Algal Density
(# units/mL)
37,516 41,399 22,889 74,761 26,693 60,391 112,026 41,134 43,246 122,058 44,119 90,331
Southeast Percent Dominant
Wet Taxon
48.39 13.72 10.91 24.36 12.39 37.32 40.82 18.11 12.5 40.06 16.93 15.5
Southeast % Blue-green 79.53 60.13 53.72 63.4 51.92 77.41 68.57 61.97 65.37 77.92 51.82 64.47
Southeast % Green 12.22 28.94 34.95 30.2 19.55 14.29 24.76 24.92 20.06 20.5 32.01 20.39
Southeast % Yellow-green 0 0 0 0.2 0 0.33 0 0 0 0 0 0
Southeast % Cryptophytes 0 0 0 0.0 0.32 0.67 0.31 0 0 0 0 0.33
Southeast % Euglenophytes 0.33 0 0 0.4 0.32 0 0 0 0 0 0 0
Southeast % Pyrrophytes 0 0 0.32 3.9 0.32 0 0 0 0 0 0.32 0.32
Southeast % Diatoms 7.92 10.93 11 6.4 27.56 8.31 6.67 13.11 14.56 1.58 16.17 15.13
West Number of Wet Taxa 25 39 45 53 37 36 30 34 69 38 31 41
West Number Wet Algal
Units Identified
303 312 301 339 303 307 322 308 611 315 306 300
Ecological Assessment of Lake Istokpoga – May 2019
Page 29 of 96
Site Variable 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
West Algal Density
(# units/mL)
43,688 35,887 31,508 49,683 24,750 95,641 88,437 49,340 108,481 130,930 54,573 109,613
West Percent Dominant
Wet Taxon
53.66 16.31 10.61 22.22 14.4 25.56 39.87 16 7.13 49.18 20.15 24.71
West % Blue-green 73.27 68.91 55.48 53.1 58.75 74.59 71.74 50.97 78.23 80.32 68.3 69
West % Green 7.92 21.47 25.58 36.9 23.76 11.73 22.98 21.75 18.17 16.19 17.65 18.67
West % Yellow-green 0 0 0.33 0.1 0 0.33 0 0 0 0.33 0 0
West % Cryptophytes 0 0 0.33 0.1 0 0 0.31 0 0 0.31 0 0.33
West % Euglenophytes 0 0 0.33 0.0 0 0 0 0.32 0 0 0 0
West % Pyrrophytes 0 0 0.33 0.2 0.33 0 0 0 0 0 0.32 0.32
West % Diatoms 18.81 9.62 18.6 10.0 17.49 13.36 5.28 26.95 3.6 3.49 14.05 12.33
Ecological Assessment of Lake Istokpoga – May 2019
Page 30 of 96
Figure 18. Box and whisker plot of the percent composition by algal group.
Ecological Assessment of Lake Istokpoga – May 2019
Page 31 of 96
Table 5. Dominant wet and diatom taxa.
Dominant wet and diatom taxa in quantitative phytoplankton samples for 6 locations on Lake Istokpoga on 12 sampling dates.
Date Variable Center Northeast Northwest Southeast South West
2016-
7-25
Dominant Wet
Taxon Name
Planktolyngbya
contorta
Glenodinium sp. Planktolyngbya
contorta
Planktolyngbya
contorta
Planktolyngbya
contorta
Planktolyngbya
contorta
2016-
7-25
Class Cyanophyceae Dinophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae
2016-
8-23
Dominant Wet
Taxon Name
Planktolyngbya
contorta
Dolichospermum
circinale
Planktolyngbya
contorta
Snowella sp. Snowella sp. Planktolyngbya
contorta
2016-
8-23
Class Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae
2016-
9-27
Dominant Wet
Taxon Name
Planktolyngbya
contorta
Aphanizomenon
flosaquae
Planktolyngbya
contorta
Dictyosphaerium
pulchellum
Dictyosphaerium
pulchellum
Snowella sp.
2016-
9-27
Class Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae
2016-
10-19
Dominant Wet
Taxon Name
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
2016-
10-19
Class Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae
2016-
11-29
Dominant Wet
Taxon Name
Aphanocapsa incerta Planktolyngbya
limnetica
Aphanocapsa
delicatissima
Snowella sp. Aphanocapsa
delicatissima
Aphanocapsa
delicatissima
2016-
11-29
Class Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae
2016-
12-27
Dominant Wet
Taxon Name
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon sp.
2016-
12-27
Class Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae
2017-
1-30
Dominant Wet
Taxon Name
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
2017-
1-30
Class Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae
Ecological Assessment of Lake Istokpoga – May 2019
Page 32 of 96
Date Variable Center Northeast Northwest Southeast South West
2017-
2-28
Dominant Wet
Taxon Name
Cylindrospermopsis
raciborskii
Aphanocapsa
delicatissima
Cylindrospermopsis
raciborskii
Cylindrospermopsis
raciborskii
Cylindrospermopsis
raciborskii
Cylindrospermopsis
raciborskii
2017-
2-28
Class Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae
2017-
3-29
Dominant Wet
Taxon Name
Snowella sp. Aphanocapsa
delicatissima
Cyanodictyon sp. Cyanodictyon sp. Planktolyngbya
contorta
Planktolyngbya
contorta
2017-
3-29
Class Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae
2017-
4-11
Dominant Wet
Taxon Name
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
2017-
4-11
Class Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae
2017-
5-23
Dominant Wet
Taxon Name
Cylindrospermopsis
raciborskii
Merismopedia
warmingiana
Cylindrospermopsis
raciborskii
Dictyosphaerium
pulchellum
Snowella sp. Cylindrospermopsis
raciborskii
2017-
5-23
Class Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae
2017-
6-29
Dominant Wet
Taxon Name
Cyanodictyon
imperfectum
Cyanodictyon
imperfectum
Aphanothece sp. Planktolyngbya
contorta
Cyanodictyon
imperfectum
Cylindrospermopsis
raciborskii
2017-
6-29
Class Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae Cyanophyceae
2016-
7-25
Dominant
Diatom Taxon
Name
Aulacoseira
granulata
Staurosirella pinnata Staurosira
construens
Staurosira
construens
Staurosira
construens
Staurosira
construens
2016-
8-23
Dominant
Diatom Taxon
Name
Staurosira
construens
Aulacoseira sp. Staurosira
construens
Aulacoseira
granulata
Staurosira
construens
Staurosira
construens
2016-
9-27
Dominant
Diatom Taxon
Name
Aulacoseira
granulata
Aulacoseira sp. Staurosira
construens
Aulacoseira sp. Staurosira
construens
Staurosira
construens
2016-
10-19
Dominant
Diatom Taxon
Name
Aulacoseira
granulata
Aulacoseira
granulata
Aulacoseira
granulata
Aulacoseira
granulata
Staurosira
construens
Aulacoseira
granulata
Ecological Assessment of Lake Istokpoga – May 2019
Page 33 of 96
Date Variable Center Northeast Northwest Southeast South West
2016-
12-27
Dominant
Diatom Taxon
Name
Aulacoseira
granulata
Aulacoseira
granulata
Aulacoseira
granulata
Staurosira
construens
Aulacoseira
granulata
Aulacoseira
granulata
2017-
1-30
Dominant
Diatom Taxon
Name
Aulacoseira
granulata
Aulacoseira
granulata
Aulacoseira
granulata
Aulacoseira
granulata
Aulacoseira
granulata
Staurosira
construens
2016-
11-29
Dominant
Diatom Taxon
Name
Aulacoseira
granulata
Aulacoseira
granulata
Aulacoseira
granulata
Aulacoseira
granulata
Aulacoseira
granulata
Aulacoseira
granulata
2017-
2-28
Dominant
Diatom Taxon
Name
Staurosira
construens
Staurosirella pinnata Aulacoseira
granulata
Staurosira
construens
Staurosira
construens
Staurosira
construens
2017-
3-29
Dominant
Diatom Taxon
Name
Fragilaria
berolinensis
Staurosira
construens
Staurosira
construens
Staurosira
construens
Staurosira
construens
Staurosirella pinnata
2017-
4-11
Dominant
Diatom Taxon
Name
Staurosirella pinnata Staurosirella pinnata Fragilaria
berolinensis
Staurosira
construens
Staurosira
construens
Fragilaria
berolinensis
2017-
5-23
Dominant
Diatom Taxon
Name
Fragilaria
berolinensis
Staurosira
construens
Staurosirella pinnata Fragilaria
berolinensis
Fragilaria
berolinensis
Staurosira
construens
2017-
6-29
Dominant
Diatom Taxon
Name
Staurosira
construens
Staurosira
construens
Staurosira
construens
Staurosira
construens
Fragilaria
berolinensis
Staurosira
construens
Ecological Assessment of Lake Istokpoga – May 2019
Page 34 of 96
Figure 19. Average monthly minimum and maximum precipitation for Highlands County.
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Aver
age
(inch
es)
Year-Month
Monthly Precipitation
Average of Min Average of Max
Ecological Assessment of Lake Istokpoga – May 2019
Page 35 of 96
Appendix A. Phytoplankton Wet Taxa
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Center Actinastrum hantzschii - - - - 1 1 - - - - - -
Center Ankistrodesmus - - - - - 8 - - - 1 - -
Center Ankistrodesmus falcatus 3 - 3 - 2 3 - - - - - -
Center Ankistrodesmus
fusiformis
- - - - 2 - - - 3 - - -
Center Aphanizomenon
flosaquae
2 6 5 - 4 1 - - 4 - - 1
Center Aphanocapsa 54 - - - - 8 2 - - 14 - 6
Center Aphanocapsa conferta - - - 7 - - 5 - - 5 - -
Center Aphanocapsa
delicatissima
1 14 10 7 23 8 21 19 25 2 25 15
Center Aphanocapsa elachista - - - - - - - - - 1 - -
Center Aphanocapsa incerta - 10 1 - 28 11 - 18 18 - 11 4
Center Aphanocapsa
planctonica
- - - 5 10 7 1 4 - 1 - -
Center Aphanothece - 12 - 1 - 10 1 9 10 2 25 20
Center Aphanothece clathrata - - - 12 4 - 14 - - 29 - 6
Center Aphanothece smithii - - - - - - - - - 1 - -
Center Bacillariophyta 69 40 83 80 78 38 29 52 35 21 33 32
Center Centritractus
belanophorus
- - - - - 1 - - - - - -
Ecological Assessment of Lake Istokpoga – May 2019
Page 36 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Center Chlamydomonas 1 2 3 - 4 3 - - - - 1 2
Center Chlorella - - - - - - - - - - - 1
Center Chlorophyceae - - - 30 - - 15 - - 20 - 5
Center Chodatella subsalsa - - - - - - 2 - - - - 1
Center Chroococcales - - - 31 - - - - - - - 4
Center Chroococcus - - - 1 - 7 - - - - - 17
Center Chroococcus dispersus - - 3 - 11 - 1 - - - - 7
Center Chroococcus minimus - - - - - - 6 - - 3 - -
Center Chroococcus minutus - - - - - - 1 - - - - -
Center Chroomonas - - 1 - - - - - - - - -
Center Closterium - 1 - - 1 - - - - - - -
Center Closterium acutum linea - - - - - - - - - 1 - -
Center Closterium acutum
variabile
- - - 1 - - - - - 1 - -
Center Closterium gracile - - - - - - - - - - 1 -
Center Coelastrum microporum - - - - - - - - - - - 1
Center Coelastrum
proboscideum
- - - - - 1 - - - - 1 -
Center Coenochloris fottii - - - 1 - - - - - - - -
Center Cosmarium - 1 - - - - - - - 1 - 1
Center Crucigenia apiculata - - - 1 2 - - - - - - -
Ecological Assessment of Lake Istokpoga – May 2019
Page 37 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Center Crucigenia crucifera - - - - - 1 - - - - - -
Center Crucigenia irregularis - - - - - - - 2 - - - -
Center Crucigenia rectangularis - 1 4 - - - - 1 - - - 2
Center Crucigenia tetrapedia - - 1 - - - - 1 - - - -
Center Cryptophyceae - - - - - - - - - 1 - -
Center Cyanodictyon - 8 7 - 9 - - 7 18 - 17 -
Center Cyanodictyon
imperfectum
- - - 67 - 56 125 - - 123 - 35
Center Cyanophyceae - - - 14 - 3 10 - - 10 - 1
Center Cylindrospermopsis
gangetica
- 3 2 - - - - - - - - 7
Center Cylindrospermopsis
raciborskii
2 11 8 6 - 14 12 31 25 8 35 17
Center Cylindrospermum - - 1 - - - - - - - - -
Center Dactylococcopsis
acicularis
- - - 16 - - - - - - - -
Center Dictyosphaerium - - - - - - 4 - - - - -
Center Dictyosphaerium
ehrenbergianum
3 - 5 - - - 1 - 7 - - -
Center Dictyosphaerium
pulchellum
- 19 13 2 4 4 - 8 3 - 23 4
Center Dictyosphaerium
tetrachotomum
- - - 1 - - - - - - - -
Ecological Assessment of Lake Istokpoga – May 2019
Page 38 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Center Dolichospermum - - - - 1 - - - - - - -
Center Dolichospermum
circinale
5 14 18 - 2 3 - 2 - - - 1
Center Dolichospermum
helicoideum
- - 1 - - - - - - - - -
Center Dolichospermum
planctonicum
2 1 - - - - - - - - - -
Center Dolichospermum
spiroides
- 2 - - - - - - - - - -
Center Elakatothrix gelatinosa 2 - 1 - - 2 - - - - - -
Center Elakatothrix viridis - - - 1 - - - - - - - -
Center Euastrum - 2 - - - - - - - - - -
Center Glaucospira - - - - - 1 - - - - - -
Center Glenodinium - - 1 - - - - - - - 1 -
Center Gloeocystis - - - - - - - - - - - 4
Center Goniochloris - - - 2 - - - - - - - -
Center Kirchneriella - 1 6 - 4 1 - 6 4 1 - 3
Center Kirchneriella contorta - - - - - 2 - - - - - -
Center Kirchneriella lunaris
irregularis
- - - - - - 1 - - - - -
Center Kirchneriella obesa - - - - - - - 1 - - - -
Center Koliella - - - - 6 - - 8 - - - 1
Ecological Assessment of Lake Istokpoga – May 2019
Page 39 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Center Koliella longiseta
f.variabilis
- - - 1 - - - - - - - -
Center Lagerheimia - - - 1 - - - - - - - -
Center Lepocinclis 1 - - - - - - - - - - -
Center Merismopedia punctata - - - 1 - - - - - - - 1
Center Merismopedia
tenuissima
1 5 5 1 - 4 5 2 10 10 4 -
Center Merismopedia
warmingiana
2 15 19 - 7 15 - 7 24 - 27 10
Center Micractinium pusillum - - - 1 - - - - - - - -
Center Microcystis - - - 2 - - - - - 1 - 1
Center Microcystis aeruginosa 1 - 2 - 2 - - 2 - - 2 -
Center Microcystis wesenbergii 5 5 3 - - 1 - - 2 - 3 1
Center Monoraphidium - 6 6 - 6 1 - 9 2 1 2 -
Center Monoraphidium
arcuatum
- - - 3 1 4 1 - - 1 - 5
Center Monoraphidium
circinale
- - - 4 - - 2 - - 1 - -
Center Monoraphidium
contortum
- - - 1 - - - - - 2 - -
Center Monoraphidium
griffithii
- - - - - - 10 - - 5 - -
Center Monoraphidium
irregulare
- - - 8 - - 15 - - 3 - -
Ecological Assessment of Lake Istokpoga – May 2019
Page 40 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Center Nephrochlamys rostrata - - - - - - - - - 1 - -
Center Nostocales - - - 3 - - 1 - - 1 - -
Center Oocystis - 4 2 - 3 2 - 3 3 1 2 7
Center Oocystis parva - - - 1 - - - - - - - -
Center Oocystis pusilla - - - 1 - - - - - - - -
Center Pandorina morum - - 1 - - - - - - - - -
Center Pediastrum - - - - - - - - - - - 1
Center Pediastrum duplex 1 1 - - - - - 2 - - - -
Center Pediastrum tetras - - 3 - 3 - 2 1 - - - 1
Center Peridinium 2 - - - 1 - - - - - - -
Center Phacus - - 2 - - - - - - - - -
Center Planktolyngbya - - - - - - - - - 1 - -
Center Planktolyngbya contorta 100 42 23 20 16 18 14 18 24 8 28 18
Center Planktolyngbya lacustris 1 - 2 - - - - - - - - -
Center Planktolyngbya
limnetica
6 18 12 4 16 23 5 30 19 18 28 12
Center Pseudanabaena 2 - - - 1 3 4 2 1 - - 2
Center Pseudanabaena
acicularis
1 - - - - - - - - - - -
Center Pseudodidymocystis - - - - - - 1 - - - - -
Center Pseudodidymocystis
fina
- - - 2 - - 3 - - 2 - -
Ecological Assessment of Lake Istokpoga – May 2019
Page 41 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Center Quadrigula chodati - - - - 2 - - 1 2 - - -
Center Quadrigula closteroides - - - 1 - - 1 - - 1 - -
Center Rhabdogloea 7 4 9 - 14 5 - 17 3 - 9 3
Center Romeria - 2 2 - - 3 - 2 - - 2 6
Center Romeria leopoliensis - - - 4 3 - 2 - - - - -
Center Scenedesmus - - - 9 - 7 15 - - 9 - 8
Center Scenedesmus abundans 4 7 6 2 - 2 1 - 5 1 2 4
Center Scenedesmus
acuminatus
1 - - - - - - - 2 - 2 -
Center Scenedesmus
acutiformis
- 5 - - - - - - 8 - 4 -
Center Scenedesmus bicaudatus 1 - 1 - - 2 - 3 - - 1 1
Center Scenedesmus bijuga 1 2 4 - 2 - - 1 - - - 1
Center Scenedesmus brevispina - - - - - 1 - - - - - -
Center Scenedesmus communis - - - - - - - - - 1 - -
Center Scenedesmus dimorphus 5 - - - - 2 - - - - - 1
Center Scenedesmus obliquus - - 4 - - - - - - - - -
Center Scenedesmus opoliensis - - - - 4 - - - - - - -
Center Scenedesmus perforatus - - 1 1 - 2 - - 1 - 1 -
Center Scenedesmus
quadricauda
9 10 1 2 10 9 - 15 10 - 2 5
Center Scenedesmus verrucosus - - - - - - - - 1 - - -
Ecological Assessment of Lake Istokpoga – May 2019
Page 42 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Center Schroederia judayi 3 - - - - - - - - - - -
Center Schroederia setigera - - - - - - - - - - - 2
Center Selenastrum - - - - - - - - 1 - - -
Center Snowella - 22 16 - 10 1 - 21 35 - 17 -
Center Snowella lacustris - - - 3 - - - - - 1 - 10
Center Snowella litoralis - - - 1 - - 1 - - - - 1
Center Spirulina - 1 1 - - - - - - - 1 -
Center Staurastrum 3 1 - - 1 1 - - 1 - 3 1
Center Staurodesmus - - - 1 - - - - - - - -
Center Stichococcus - - - - - 1 - - - - - -
Center Synechocystis - 6 - - - - - - - - - -
Center Tetraedron - - - - - 1 - - - 2 - 1
Center Tetraedron caudatum - - - - - - - 1 - 2 - -
Center Tetraedron gracile 1 - - - - - - - - - - -
Center Tetraedron minimum - - - - - 1 - - - - - -
Center Tetraedron muticum - 1 - - - - - - - - - -
Center Tetraedron trigonum
gracile
- - 2 - 2 - - - - - - -
Center Tetrastrum
heterocanthum
1 - 3 - 1 - - - - - - -
Center Treubaria
triappendiculata
- - - 1 - - - - - - - -
Ecological Assessment of Lake Istokpoga – May 2019
Page 43 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Center Xanthophyceae - - - 1 - - - - - - - -
Northeast Actinastrum hantzschii - - - 1 3 1 - - - - - -
Northeast Anabaena - - - - - - - - - - - 1
Northeast Ankistrodesmus falcatus 2 - 2 - 1 3 - - - - - 4
Northeast Ankistrodesmus
fusiformis
- 1 - - - 1 - - - - 1 3
Northeast Aphanizomenon - - - - - - - - - - - 1
Northeast Aphanizomenon
flosaquae
- 15 43 - 1 2 - 2 2 - - -
Northeast Aphanocapsa - - - - - 2 3 - - 24 - 7
Northeast Aphanocapsa conferta - - - 5 - - 3 - - 5 - -
Northeast Aphanocapsa
delicatissima
- 10 3 1 20 9 2 29 34 1 13 13
Northeast Aphanocapsa elachista - - - - - - - - - 1 - -
Northeast Aphanocapsa incerta - 7 10 - 7 - - 11 22 - 7 2
Northeast Aphanocapsa
planctonica
- - - 2 - 1 3 4 - 4 - -
Northeast Aphanothece - 3 1 - - 7 - 3 10 1 10 15
Northeast Aphanothece clathrata - - - 4 - 6 12 - - 35 - 12
Northeast Aphanothece smithii - - - - - 1 3 - - - - -
Northeast Bacillariophyta 132 54 50 25 108 64 37 51 35 10 67 27
Northeast Botryococcus braunii 1 - - - - - - - - - 2 -
Ecological Assessment of Lake Istokpoga – May 2019
Page 44 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Northeast Centritractus
belanophorus
1 - - 1 - - - - - - - -
Northeast Chlamydomonas 1 7 11 - - - - - - - 1 1
Northeast Chlorella - - 5 - - - - - - - - 5
Northeast Chlorophyceae - - - 21 - - 27 - - 25 - 9
Northeast Chodatella subsalsa - - - - - - - - - 1 - -
Northeast Chroococcales - - - 27 - - - - - - - -
Northeast Chroococcus - - - 1 - 11 - - - - - 7
Northeast Chroococcus dispersus - - - 1 3 - - - - - - -
Northeast Chroococcus minimus - - - - - - 2 - - 2 - -
Northeast Closterium 1 4 4 - - 1 - 1 - - - 1
Northeast Closterium acutum linea - - - 1 - - - - - - - -
Northeast Closterium gracile - - - - - - - 2 - - - -
Northeast Coccomonas - - 7 - - - - - - - - -
Northeast Coccomonas orbicularis 1 - - - - - - - - - - -
Northeast Coelastrum microporum - 3 - - - - - - - - - -
Northeast Coelastrum
proboscideum
- - - - 2 - - - - - - -
Northeast Coelastrum sphaericum - - - - - - 1 - - - - -
Northeast Coelosphaerium - - - 1 - - - - - - - -
Northeast Coenochloris fottii - - - 1 - - - - - 1 - -
Ecological Assessment of Lake Istokpoga – May 2019
Page 45 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Northeast Cosmarium - - - - - - - - - 3 - 3
Northeast Crucigenia apiculata - - - - 2 1 - - - - - -
Northeast Crucigenia irregularis - - - - 1 - - - 2 - - -
Northeast Crucigenia rectangularis - - 1 - - - - - 5 - - 1
Northeast Crucigenia tetrapedia - 7 - - - - - 3 - - - -
Northeast Cryptomonas - 1 1 - - - - - - - - 1
Northeast Cryptophyceae - - - - - - 1 - - - - -
Northeast Cuspidothrix
issatschenkoi
- 1 - - 1 - - - - - - -
Northeast Cyanodictyon - 8 2 - 5 - - 10 33 - 3 -
Northeast Cyanodictyon
imperfectum
- - - 38 - 53 111 - - 107 - 31
Northeast Cyanophyceae - - - 1 - 8 16 - - 17 - 4
Northeast Cylindrospermopsis
gangetica
- - 2 - 1 - - - - - - 3
Northeast Cylindrospermopsis
raciborskii
27 2 1 3 1 11 4 22 17 2 31 14
Northeast Dactylococcopsis
acicularis
- - - 5 - - - - - - - -
Northeast Desmatractum indutum - - - 1 - - - - - - - -
Northeast Diacanthos
belenophorus
2 - - - - - - - - - - -
Northeast Dichotomococcus - - - 1 - - - - - - - -
Ecological Assessment of Lake Istokpoga – May 2019
Page 46 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Northeast Dictyosphaerium - - - - - - 7 - - - - 2
Northeast Dictyosphaerium
ehrenbergianum
2 - - - 2 1 - - 8 - 3 -
Northeast Dictyosphaerium
pulchellum
- 15 10 1 9 6 2 11 7 - 23 2
Northeast Dictyosphaerium
tetrachotomum
- - - 2 - - - - - 1 - -
Northeast Dolichospermum - - - 1 - - - - - - - 1
Northeast Dolichospermum
circinale
4 28 34 - - - - 2 - - - -
Northeast Dolichospermum
perturbatum
- 1 - - - - - - - - - -
Northeast Dolichospermum
planctonicum
1 2 - - - - - - - - - -
Northeast Dolichospermum
spiroides
- 1 - - - - - - - - - -
Northeast Elakatothrix gelatinosa - 1 - - - - - - - - 1 -
Northeast Elakatothrix viridis - - - - - - - - - 1 - -
Northeast Euastrum - - - - - - - - 1 - - 2
Northeast Eudorina elegans 1 1 - - - 1 - - - - - -
Northeast Glenodinium 81 18 8 - - - - - - - - -
Northeast Gloeocapsa - - - - - - - - - - - 2
Northeast Gloeocystis - 2 - - - - - - - - - -
Ecological Assessment of Lake Istokpoga – May 2019
Page 47 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Northeast Goniochloris - - - 1 - - - - - - - -
Northeast Kirchneriella - 5 10 - 1 - 1 - 1 - 2 1
Northeast Kirchneriella lunaris - - - - - 1 - - - - - -
Northeast Kirchneriella lunaris
irregularis
- - - 1 - - - - - - - -
Northeast Kirchneriella obesa - 3 - - - - - - 1 - - 1
Northeast Koliella - 1 - - 7 1 - 14 - - - 1
Northeast Koliella longiseta - - - - - 2 - - - - - -
Northeast Lagerheimia - - - 1 - 1 - - - - - -
Northeast Lagerheimia
wratislaviensis
- - - 1 - - - - - - - -
Northeast Lepocinclis ovum 1 - - - - - - - - - - -
Northeast Mallomonas - - - - - 1 - - - - - -
Northeast Merismopedia punctata - - - - 2 1 - - - 1 - -
Northeast Merismopedia
tenuissima
1 1 2 3 13 1 6 2 6 11 9 -
Northeast Merismopedia
warmingiana
- 12 21 - 8 9 - 10 22 - 35 3
Northeast Micractinium - - - - - 1 - - - - - -
Northeast Micractinium pusillum - - - - - 1 - - - - - -
Northeast Microcystis - - - - - - 2 - - 1 - 15
Northeast Microcystis aeruginosa 1 8 3 - - - - 2 - - 5 -
Ecological Assessment of Lake Istokpoga – May 2019
Page 48 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Northeast Microcystis wesenbergii 1 - 2 - - 1 - - 5 - 3 3
Northeast Monoraphidium - 7 6 - 3 4 - 3 2 1 3 -
Northeast Monoraphidium
arcuatum
- - - 1 - - 3 - - - - 8
Northeast Monoraphidium
circinale
- - - 5 - - - - - - - -
Northeast Monoraphidium
contortum
- - - 1 - - - - - 3 - -
Northeast Monoraphidium
griffithii
- - - - - - 4 - - 2 - -
Northeast Monoraphidium
irregulare
- - - 2 - - 9 - - 2 - -
Northeast Monoraphidium
komarkovae
- - - - - - - - - - - 1
Northeast Nephrocytium - - - - - - - - - 1 - 1
Northeast Nostocales - - - 1 - - 2 - - - - -
Northeast Oedogonium - - - - - - - - - 1 - -
Northeast Oocystis - 10 1 - - - - 4 1 1 4 3
Northeast Oocystis parva - - - - - - - - - 1 - -
Northeast Ophiocytium capitatum
longispinum
- - 1 - - - - - - - - -
Northeast Oscillatoriales - - - - - - 2 - - - - -
Northeast Pediastrum - - - - - - - - - - - 1
Ecological Assessment of Lake Istokpoga – May 2019
Page 49 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Northeast Pediastrum boryanum - - - - - 2 - - - - - -
Northeast Pediastrum duplex 1 - - - - 1 - - - - - -
Northeast Pediastrum tetras 1 - 1 - - - - 1 - - - -
Northeast Peridinium - 4 2 - - - - - - - - -
Northeast Phacus - 6 1 - - - - - - - - -
Northeast Planctonema
lauterbornii
- - - 1 - - - - - - - -
Northeast Planktolyngbya contorta 2 9 6 12 9 14 17 12 29 12 30 17
Northeast Planktolyngbya
limnetica
1 2 2 2 29 22 8 29 12 14 18 11
Northeast Planktothrix agardhii 3 - - - - - - - - - - -
Northeast Pseudanabaena 3 - 6 - 5 5 4 - - - - -
Northeast Pseudanabaena
mucicola
- - - - - - - - - - - 10
Northeast Pseudodidymocystis
fina
- - - - - - 2 - - - - -
Northeast Quadrigula chodati - 3 - - 3 - - 5 1 - 1 -
Northeast Quadrigula closteroides - - - - - - 1 - - - - -
Northeast Radiocystis geminata - - - - 7 - - - - - - -
Northeast Rhabdoderma - 2 - - - - - - - - - -
Northeast Rhabdogloea 4 4 1 - 5 8 - 11 1 - 2 7
Northeast Romeria - 2 3 - 2 2 - 3 - - 1 2
Ecological Assessment of Lake Istokpoga – May 2019
Page 50 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Northeast Romeria leopoliensis - - - 1 - - 2 - - - - -
Northeast Scenedesmus - - - 6 - 5 14 - - 7 - 14
Northeast Scenedesmus abundans - 6 3 1 7 2 7 2 2 1 3 4
Northeast Scenedesmus
acuminatus
2 1 - 1 - 1 - 1 1 - - -
Northeast Scenedesmus
acutiformis
- 2 - - - - - 6 7 - 1 -
Northeast Scenedesmus bicaudatus 3 - 1 - - 2 - 4 2 - 1 1
Northeast Scenedesmus bijuga 1 2 7 - 2 1 - 3 - - - 1
Northeast Scenedesmus
brasiliensis
1 - - - - 1 - - - - - -
Northeast Scenedesmus dimorphus - - - - - 2 - 1 - - - -
Northeast Scenedesmus obtusus - - - 1 - - - - - - - -
Northeast Scenedesmus opoliensis - - - - 2 - - - - - - -
Northeast Scenedesmus perforatus 3 - 1 1 5 - 4 - 3 - 1 -
Northeast Scenedesmus
quadricauda
9 2 4 - 12 9 - 15 13 - 5 5
Northeast Scenedesmus verrucosus - - - - - - - - 1 - 2 -
Northeast Schroederia judayi 1 6 4 - 4 - - - - - - -
Northeast Schroederia setigera - - - 1 1 - - - - - - -
Northeast Selenastrum - - - - - 1 - - - - 1 -
Northeast Selenastrum westii 1 - - - - - - - - - - -
Ecological Assessment of Lake Istokpoga – May 2019
Page 51 of 96
Site Taxon 2016-
7-25
2016-
8-23
2016-
9-27
2016-
10-19
2016-
11-29
2016-
12-27
2017-
1-30
2017-
2-28
2017-
3-29
2017-
4-11
2017-
5-23
2017-
6-29
Northeast Snowella - 9 14 - 6 - - 16 15 - 17 8
Northeast Snowella
Top Related