00605-
273-P
CLEAR TECHNICAL REPORT NO. 773-P
905R83102
DRAFT
Cladophora Surveillance Program -
Western Basin of Lake Erie, 1982 Season
Preliminary Report
Prepared by
Mark E. Monaco
and
Charles E. Herdendorf
Prepared for
U.S. Environmental Protection Agency
Great Lakes National Program Office
Region V - Chicago, Illinois
Grant No. R005555-02
Project Officer: Clifford Risley, Jr.
THE OHIO STATE UNIVERSITY
CENTER FOR LAKE ERIE AREA RESEARCH
COLUMBUS, OHIO
April 1983
U.S. Environmental Protection Agency
GLNPO Library Collection (PL-12J) J_
77 West Jackson Boulevard,
Chicago, IL 60604-3590
-------
LIST OF TABLES
Table 1. Cladophora sampling dates, South Bass Island, Ohio, 1982
Table 2. Sample analysis breakdown as of April 1983
Table 3. Cladophora standing crop data, South Bass Island, Ohio,
1982
Table 4. Cladophora tissue nutrients, South Bass Island, Ohio,
1982
Table 5. Cladophora water nutrient data, South Bass Island, Ohio,
1982
Table 6. Cladophora physical and meteorology data, South Bass
Island, Ohio, 1982
Table 7. Comparison of observed western Lake Erie depth of
Cladophora growth £m) wjth predicted growth depths,
based on a 50 juEnf sec limiting light regime,
1982
LIST OF FIGURES
Fig. 1. Locations of Cladophora survey stations, western Lake
Erie, 1980 to 1982
-------
INTRODUCTION
In response to the increasing concern for Great Lakes water quality, the
Lake Erie Cladophora Surveillance Program was initiated in 1979 by the
InternationalJoint Commission as a component of the Great Lakes
International Surveillance Program. The Cladophora surveillance program was
established as a means of assessing management strategies. For the past four
years the Center for Lake Erie Area Research (CLEAR), under sponsorship of the
U.S. Environmental Protection Agency, has investigated the growth dynamics,
ecology, and the light and nutritional requirements of Cladophora to
determine the utility of this algae to evaluate management tactics.
This report contains the preliminary 1982 results; a final report will be
submitted in June, 1983. The results presented are from the routinely
monitored site located on the southeast side of East Point, South Bass Island,
Ohio, 41°39' latitude, 82°48' longitude (Figure 1). Substrate at this site is
gently sloping dolomite bedrock. South Bass Island is approximately 10 km
north of the Ohio mainland and is representative of mid-western basin
conditions.
The results for the 1982 Cladophora survey of the western basin are
reported. This survey has been conducted during peak biomass in late June of
1980, 1981 and 1982 to determine the areal and vertical distribution of
Cladophora. A manuscript discussing this component of the Cladophora study
will be submitted to Ecology for publication soon.
Refer to Lorenz and Herdendorf (1981), and Monaco and Herdendorf (1982),
for detailed methods and discussions about the Cladophora study and western
basin surveys. Results of the first two years of this study, Growth Dynamics
of Cladophora glomerata in Western Lake Erie In Relation to Some Environmental
Factors, have been published in the Journal of Great Lakes Research.A
reprint of this paper is included as an appendix.
RESULTS
The preliminary results of the 1982 study are presented here as a series
of data tables. These tables include: Cladophora sampling dates (Table 1),
analysis breakdown (Table 2), standing crop data (Table 3), tissue nutrient
percentages (Table 4), water nutrient concentrations (Table 5), physical
parameters and meteorology data (Table 6), and a comparison of observed depth
of Cladophora growth with predicted growth depths from our model. Discussion
and conclusions from the above data will be presented in the final report.
-------
LITERATURE CITED
Lorenz, R.C., and C.E. Herdendorf. 1981. Lake Erie intensive study:
Cladophora surveillance program, western basin. Prepared for the U.S.
Environmental Protection Agency, Great Lakes National Program Office,
Region V, Chicago, Illinois. The Ohio State University, CLEAR Tech.
Report No. 239.
Monaco, M.E., and C.E. Herdendorf. 1982. Cladophora surveillance pogram —
western basin of Lake Erie, 1981 season. Prepared for the U.S.
Environmental Protection Agency, Great Lakes National Program Office,
Region V, Chicago, Illinois. The Ohio State University, CLEAR Tech.
Report No. 255.
-------
DATA TABLES OF RESULTS
-------
TABLE 1
CLADOPHORA SAMPLING DATES SOUTH BASS ISLAND, OHIO 1982
Month/Day
Jan. 5
Jan. 15
Feb. 15
March 15
May 19
June 7
June 22
July 6
July 20
Aug. 5
Aug. 19
Sept. 1
Sept. 15
Oct. 23
Dec. 17
Julian Date
05
15
46
74
139
158
173
187
201
216
230
243
258
296
352
Comments
Visual observations along shore
Visual observations and collections through ice
Visual observations along shore
Visual observation and collections through ice
Begin routine sampling
Routine sampling
Routine sampling
Routine sampling
Routine sampling
Routine sampling
Routine sampling
Visual observations
Routine sampling
End routine sampling
Visual observations
-------
TABLE 2
SAMPLE ANALYSIS BREAKDOWN AS OF APRIL 1983
Complete
Incomplete
(anticipated
completion
date)
Biological
Percent coverage
Filament length
Wet weight
104°C weight
Ash weight
Ash-free weight
Physical
Temperature
Light
Secchi depth
Water Nutrients
Soluble reactive phosphorus (SRP)
Total filterable phosphorus (TFP)
Total phosphorus (TP)
Tissue Nutrients
Total tissue carbon (TTC)
Total tissue phosphorus (TTP)
Total tissue nitrogen (TTN)
X
X
X
X
X
X
X
X
X
X
X
X
X
X (May 1983)
X (May 1983)
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TABLE 3
CLADOPHORA STANDING CROP DATA
SOUTH BASS ISLAND, OHIO, 1982
Date
139
158
173
187
201
216
230
Depth
(m)
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
Coverage Length (cm)
(%) mean max
40
30
30
T
70
55
45
T
70
70
50
T
80
T
T
T
T
T
T
T
T
T
T
T
0
0
0
0
3.5 6
2.5 5
2 2.5
15 25.5
10 15
7 10
15 30
10 20
7 15
30 75
— —
__
—
old dead
holdfasts
old dead
holdfasts
very few
holdfasts
present
p
Biomass per 1/4 m (g)
Dry Dry Ash-
wet 64°C 104°C Ash free
trace
116.23
87.75
11.00
100.79
108.64
20.24
227.26
trace
trace
trace
amounts - biomass not collected
11.83 11.08 3.38 7.70
12.22 11.83 6.65 5.18
3.09 3.05 2.34 0.71
16.21 15.09 5.74 9.35
18.02 16.83 7.64 9.19
7.44 7.16 6.31 0.85
21.94 21.29 5.87 15.42
amounts - biomass not collected
amounts - biomass not collected
amounts - biomass not collected
tetraspora present
biomass not collected
-------
TABLE 3 CONT.
Date
243
258
296
352
Depth
(m)
0.5
•1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
Coverage
(%)
0
0
0
0
T
T
T
T
85
T
T
T
70
T
T
T
Length (cm)
mean max
very few
holdfasts
present
1-2 trace
12 15
10 25
o
Biomass per 1/4 m (g)
Dry Dry Ash-
wet 64t)C 104°C Ash free
biomass not collected
amounts - biomass not collected
54.98 7.61 7.12 2.55 4.57
biomass not collected
T = trace amounts
-------
TABLE 4
CLADOPHORA TISSUE NUTRIENTS, SOUTH BASS ISLAND, OHIO, 1982
Date
139
158
173
187
201
230
296
Depth (m)
S3
0.5
1.0
2.0
S
0.5
1.0
2.0
S
0.5
1.0
2.0
S
0.5
1.0
S
0.5
S
S
0.5
1.0
2.0
TTC %1
14.78
8.94
19.61
16.33
35.43
27.03
23.50
37.54
35.50
30.96
16.91
37.53
32.16
19.18
8.95
21.50
34.64
38.78
29.60
35.12
36.18
TTN %2
0.50
1.12
1.32
1.30
4.05
3.33
2.56
3.10
2.77
4.25
1.51
2.28
2.66
1.37
1.92
1.67
1.61
2.88
4.53
3.56
3.34
TTC = Total tissue carbon
o = Total tissue nitrogen
S = Splash zone
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TABLE 5
CLADOPHORA WATER NUTRIENT DATA
Date
139
158
173
187
201
216
230
SOUTH
Depth
(meters)
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
BASS ISLAND,
SRP
(ppb)
64.0
2.2
2.0
8.7
2.6
7.0
4.4
_ _ _
—
—
—
4.9
4.0
2.6
3.0
2.4
2.7
3.7
2.5
2.6
2.7
2.7
8.8
2.0
1.9
3.4
OHIO, 1982
TFP
(ppb)
59.18
15.33
3.08
19.73
7.48
10.29
10.00
34.13
28.98
15.90
15.80
9.35
9.10
7.57
7.76
7.67
7.39
16.92
20.57
7.57
9.44
5.80
6.54
5.61
6.08
7.48
8.23
TP
(ppb)
83.03
21.88
25.43
36.37
28.70
24.50
24.60
78.54
45.44
37.68
63.49
27.86
27.96
22.44
21.32
28.05
39.08
35.44
31.80
31.79
31.79
34.60
34.41
35.53
33.38
40.11
44.13
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TABLE 5 CONT.
Date
258
296
Depth
(meters)
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
SRP
(ppb)
—
—
—
1.5
5.5
3.7
7.8
TFP
(ppb)
10.28
9.44
10.28
11.69
11.13
14.50
14.02
14.96
TP
(ppb)
33.66
33.75
33.66
33.94
26.93
35.62
38.62
39.08
SRP = Soluble reactive phosphorus
TFP = Total filterable phosphorus
TP = Total phosphorus
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TABLE 6
CLADOPHORA PHYSICAL AND METEOROLOGY DATA
SOUTH BASS ISLAND, OHIO, 1982
(CS-2)
Date
139
158
173
187
201
216
230
Depth
(m)
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
Temperature
Surface Bottom
18.0
18.0
17.5
19.0
19.0
18.0
18.0
20.0
20.0
19.5
20.0
23.0
23.0
23.0
23.0
24.4
24.4
24.2
23.9
24.4
24.4
24.4
24.4
23.3
23.3
23.3
23.3
17.5
17.5
17.0
19.0
19.0
18.0
18.0
20.0
20.0
19.5
20.0
22.7
22.5
22.8
22.8
24.4
23.9
24.1
23.9
24.4
24.4
24.4
24.4
23.3
23.3
23.0
23.0
Weather
Secchi Waves Clouds
(m) (ft.) («)
B 1-2 70
1.75
1.75
_ _ «
.60 1-2 40
.79
1.30
— — —
B 0 25
1.32
1.36
___
B 0-1 30
1.20
1.10
«. — —
B 0.5-1 0
1.21
1.22
— _ _
B 0-1 95
B
1.30
_ _ .
B 0-1 10
1.08
1.30
Air Temp.
°C
7.2
18.3
18.3
28.9
29.4
29.4
23.3
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TABLE 6 CONT.
Date
258
296
352
Depth
(m)
0.5
1.0
2.0
3.0
0.5
1.0
2.0
3.0
Temperature
Surface
22.0
22.0
21.0
21.0
11.0
11.0
11.5
11.5
6.0
Bottom
22.0
22.0
22.0
22.0
11.7
11.2
11.5
11.5
Weather
Secchi Waves Clouds
(m) (ft.) %
1.00 0-1 10
1.21
1.08
— — —
.80 1-2 60
.90
1.00
2-3 15
Air Temp.
°C
21.1
9.0
1.7
B = Bottom (Secchi disk visible on bottom)
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TABLE 7
COMPARISON OF OBSERVED WESTERN LAKE ERIE DEPTH
OF CLADOPHORA GROWTH (m).WITH PREDICTED GROWTH DEPTHS,
BASED ON A 50
Location
Marblehead Peninsula
Kelleys Island
Gull Island Shoal
N. Bass Island
Chickenolee Reef
E. Sister Island
Colchester Reef
Middle Ground Shoal
Stony Point
S. Bass island
W. Sister Island
Catawba Cliffs
Average
Kl
2.00
0.79
0.90
0.64
1.1
1.21
0.52
0.71
2.52
0.96
0.72
1.86
ec"1 LIMITING LIGHT
Predicted
1.7
4.7
4.1
5.8
3.3
3.1
7.1
5.2
1.5
3.8
5.1
1.8
REGIME, 1982
Max.
Observed
1.6
4.0
2.5
5.0
5.0
3.5
7.0
4.3
1.7
3.0
3.5
1.8
Percent
Difference
5.8
14.9
39.0
13.8
87.1
12.9
1.4
17.3
13.3
21.1
31.4
0.0
21.5
K = Light extinction coefficient
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FIGURES
-------
CO
oo
I
o
oo
en
>
O)
S-
3
co
<0
o
.c
Q.
o
•o
CO
n—
o
O)
•r™
J_
UJ
o>
-^
n)
c
O)
O)
(U
-------
APPENDIX
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J. Great Lakes Res. 8(l):42-53
Internal. Assoc. Great Lakes Res., 1982
GROWTH DYNAMICS OF CLADOPHORA GLOMERATA IN WESTERN
LAKE ERIE IN RELATION TO SOME ENVIRONMENTAL FACTORS
Richard C. Lorenz1 and Charles E. Herdendorf
Center for Lake Erie Area Research
The Ohio State University
Columbus, Ohio 43210
ABSTRACT. Cladophora was monitored at two sites in western Lake Erie during 1979 and 1980 as
part of a lake-wide Lake Erie Cladophora Surveillance Program. Two distinctive zones within the
littoral region were colonized by the alga, the eulittoral (splash zone) and infratittoral (defined in the
present study as the 0.5-4 m depth zone). Cladophora of the eulittoral zone became established in May
and remained present until late fall. The infralittoral zone Cladophora exhibited a bimodal growth
pattern related to the seasonal temperature regime, with growth occurring from April to July and
again from September to November. The infralittoral zone supported the largest share of biomass,
which resulted in nuisance accumulations upon the beaches in the island region. Peak biomass was
observed from mid-June to early July, obtaining maximum values of 102 gDWjm2 and 214 gDWjm2
for the 1979 and 1980 seasons, respectively. The depth to which Cladophora colonized was limited by
light availability; maximum depth of growth occurred between 2 and 4 m in western Lake Erie due to
the turbid nature of the basin. Phosphorus and nitrogen were not limiting to Cladophora growth in
western Lake Erie; tissue nutrients remained above the critical levels defined by Gerloffand Fitzgerald
(1976) throughout the season.
INTRODUCTION
The filamentous, epilithic green alga Cladophora
glomerata is well-adapted to the rocky littoral
zones found along the lower Laurentian Great
Lakes, as evidenced by its profuse growth (Shear
and Konasewich 1975). The distribution of
Cladophora has been mapped with the aid of
remote sensing techniques in Lake Ontario by
Wezernak et al. (1974). In Lake Erie, Taft and
Kishler (1973) studied the alga's temporal and areal
distribution in the island area of western Lake Erie,
and Shear and Konasewich (1975) reviewed investi-
gations in eastern Lake Erie. Ecological studies of
Cladophora in the Great Lakes have included
investigations of nutrients (Gerloff and Fitzgerald
1976, Lin 1977, Mantai 1978, Auer and Canale
1980), temperature (Bellis 1968, Storr and Sweeney
1971), and photosynthesis (McMillan and Verduin
1953, Wood 1975, Adams and Stone 1973, Mantai
1974).
Cladophora has been reported in Lake Erie since
the late 1800s (Kishler 1967, Taft and Kishler 1973).
In the last few decades, this alga has become
increasingly important due to the large production
1 Present address: Division of Water, Water Research Laboratory, 940
Dublin Rd., Columbus, Ohio 43215
of biomass. Abundant growth of this alga is (1)
creating nuisance accumulations and obnoxious
odors along recreational shores, (2) clogging water
intakes, (3) fouling fishing nets, boat hulls, and
submerged structures, and (4) influencing the
benthic environment by its abundant presence
(Shear and Konasewich 1975, Herbst 1969, Posten
and Garnet 1964, Verduin 1969). In response to
increasing concern for Great Lakes water quality,
the Lake Erie Cladophora Surveillance Program
has been established as a means of assessing
management strategies. The information presented
herein pertains to two Cladophora monitoring sites
established in the western basin of Lake Erie as part
of the lakewide Cladophora Surveillance Program
as outlined by Millner and Sweeney (1982). The
objectives of this study were to monitor in situ
growth rates, densities, and distribution of Cla-
dophora in the western basin of Lake Erie and to
determine possible relationships between environ-
mental conditions and Cladophora growth.
METHODS
Two monitoring sites representing different envi-
ronmental conditions were selected in western Lake
Erie. The westernmost site was established at Stony
42
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GROWTH DYNAMICS OF CLADOPHORA GLOMERATA
43
Point, Michigan (Figure 1). Stony Point is a
submerged bedrock outcrop, with overlying
cobbles at the shallower depths (0-2 m) and is one
of the few areas along the western shore to provide
suitable natural substrate for Cladophora. Stony
Point protrudes approximately 2 km into the lake
and is generally influenced by the flow from the
United States side of the Detroit River (Herdendorf
1969), which receives wastewater effluent from the
City of Detroit. The second site was established on
the eastern shore of South Bass Island, Ohio
(Figure 1). The South Bass Island site is approxi-
mately 10 km north of the Ohio mainland and is
representative of mid-western basin conditions.
The substrate at this site and much of the island
region is gently sloping dolomite bedrock.
MICHIGAN
Chickenolee Reef
.Gull Island Shoal
Bass Island
C^Kelly's Island
FIG. 1. Western Lake Erie Cladophora sites.
Each site was visited at 2-week intervals from
mid-April to mid-November in 1979 and 1980.
Sampling operations were conducted from small
boats utilizing SCUBA techniques for collection
and observation. Monitoring stations at each site
were established along a bottom transect at depths
of 0.5, 1, 2, and 3 m. These depths were based on
mean projected water levels for this season; 1.036 m
and 1.128 m above low water datum for 1979 and
1980, respectively (U.S. Army Corps of Engineers
1980). Water levels during the present study were
approximately 0.457 m above the 80-year average
and 0.305 m below the 1972-1973 record high
levels. The actual sample location was chosen to
reflect an area of representative density at the
station. At each station Cladophora biomass,
filament length, and percent coverage were deter-
mined in situ from natural substrate. Biomass was
determined by hand harvesting the alga within a
0.25 m2 ring subjectively placed on the bottom.
Algal material was cleaned of debris and rinsed
prior to analysis. Biomass was assessed on a g/m2
basis for dry weight at 104°C (gDW), and ash-free
weight (AFW) after ashing at 550° C.
Total tissue phosphorus, total tissue carbon, and
total tissue nitrogen analyses were performed with
64°C dried, ground Cladophora using a potassium
persulfate-sulfuric acid digestion (APHA 1975) for
phosphorus and a Perkin-Elmer carbon-hydrogen-
nitrogen elemental analyzer for carbon and nitro-
gen. Tissue nutrients are expressed as percent of
alga dry weight (64° C), (mg nutrient/100 mg alga).
Water samples for the analysis of soluble reactive
phosphorus (SRP), total dissolved phosphorus
(TDP), total phosphorus (TP), ammonia nitrogen
(NH3), nitrate + nitrite nitrogen (NO3+NO2), total
Kjeldahl nitrogen (TKN), total suspended solids,
and corrected chlorophyll a were collected from
0.25 m above the bottom at each station along the
transect and analyzed by methods prescribed by
APHA (1975) and described by Lorenz (1981).
Temperature was measured at 0.1 m below the
surface and 0.25 m above the bottom. Light was
measured as Secchi disk transparency and photo-
synthetically active radiation (PAR) using an
underwater spherical Quantum Sensor (Li-Cor,
Inc.).
OBSERVATIONS AND RESULTS
During 1979 and 1980 ice covered the two sites
from January to March with water temperatures
warming to 4-8° C by mid-April (Figures 2 and 3).
Temperatures rose into the middle teens by mid-
May and reached a maximum of 24-26° C in early
August, with Stony Point warming slightly faster
than the mid-basin, South Bass site. From
May-June, during the period of increasing bio-
mass, temperatures ranged from 10°C to 22°C.
Lake temperatures dropped below 20° C in late
September, reaching 5°C by late November.
Light levels are often low in western Lake Erie
due to rapid attenuation by suspended solids,
particularly at Stony Point (Table 1). Secchi disk
transparency for the 2-m staiton at the Stony Point
site averaged 0.6 m over the two seasons, with
transparencies greater than 1 m measured on four
out of the 32 sampling periods (Figure 2). PAR at
the 2 m depth at Stony Point remained less than
50/iE/m2»sec from mid-April to mid-July 1980,
except during early June when a maximum of 114
/iE/m2»sec was measured. Light levels at the 3-m
depth never exceeded 50 /jE/m2«sec for the same
-------
44
LORENZ and HERDENDORF
Temperature x
Transparency
0.5m
I.Om • •
2_0m x x
0
J ASON AMJ J A
1979 1980
FIG. 2. Seasonal cycles at Stony Point, Michigan, of Secchi disk transparency and lake water temperature; soluble
reactive phosphorus (SRP) and nitrate plus nitrite (NOj+NOJ; total tissue phosphorus and total tissue nitrogen at the
1-m station; and Cladophora standing crop (biomass) at monitoring stations (0.5,1,2 and 3 m) along a bottom transect
perpendicular to the shore, for 1979 and 1980.
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GROWTH DYNAMICS OF CLADOPHORA GLOMERATA
45
2.9m
Temperoture x x
Tronsporency
0.5m
I.Om • •
2.0m x x
3.0m • •
FIG. 3. Seasonal cycles at South Bass Island, Ohio, of Secchi disk transparency and lake water temperature; soluble
reactive phosphorus (SRP) and nitrate plus nitrite (NO3+NO2); total tissue phosphorus and total tissue nitrogen at the
1-m station; and Cladophora standing crop (biomass) at monitoring stations (0.5,1,2 and 3 m) along a bottom transect
perpendicular to the shore, for 1979 and 1980.
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46
LORENZ and HERDENDORF
period; zero values were not uncommon in April
and May.
Light penetration at the South Bass site was
roughly twice as great as Stony Point, with Secchi
disk transparency averaging 1.2 m for the 2 years
(Figure 3). Levels of PAR at 3 m were less than 50
nE/ m2 • sec in April and greater than 100 /uE/ m2 • sec
from late May through July 1980. Light data are
summarized in Table 1.
A survey conducted throughout the western
basin during the period of maximum standing crop
(late June) revealed Cladophora colonization on all
suitable substrate surveyed in the western basin.
The depth to which Cladophora was observed to
grow was governed by light penetration. Cladoph-
ora was found growing to depths of 4.6 m on
Chickenolee Reef (Secchi transparency 2.2 m); 3.8
m on Gull Island Shoal (Secchi transparency 1.95
m); 3.4 m on the east shore of Kelly's Island (Secchi
transparency 1.6 m); 3.0 m at the South Bass Island
site (Secchi transparency 1.4 m); and 1.6 m at the
Stony Point site (Secchi transparency 0.7 m)
(Figure 1).
Chemical Environment
Water quality in the western basin of Lake Erie
exhibits wide fluctuations, particularly at the Stony
Point site where the Detroit River has a pro-
nounced influence (Herdendorf 1969). Western
basin levels of phosphorus and nitrogen were
relatively high compared with other regions of the
Great Lakes. The nutrients measured generally
peaked in the spring and declined throughout the
summer, increasing again in the autumn (Figures 2
and 3). Average nutrient levels and ranges are
presented in Table 1.
Concentrations of soluble reactive phosphorus
measured at the two sites for the period from April
to August of both years remained above 1 MgP/ L,
except during the end of April 1980. Total phos-
phorus levels were greatest at Stony Point, with an
increase in mean concentration from 1979 to 1980
occurring at both sites. Levels of total phosphorus
generally remained above 15 MgP/ L throughout the
two seasons. Nitrate + nitrite levels for the period
from April to August during both years remained
above 200 /igN/L.
Major Filamentous Algae
of the Littoral Region
The littoral zone is an important component of
aquatic systems as it forms an interface between the
land and open water. This zone is of particular
interest to ecologists due to the associated high
productivity and the development within of distinc-
tive zones. Little information exists on the distribu-
tion, seasonal growth dynamics, and interaction
among the algal species and environment within
this dynamic zone. The following description of the
littoral zone resulted from observations made over
a period of several years throughout the western
basin. These observations were made from the
shore, boats, and underwater utilizing SCUBA
techniques.
TABLE 1. Summary of water quality observations at the Stony Point and South Bass sites, 1979 and 1980.
STONY POINT
1979 1980
SOUTH BASS
1979 1980
range
mean
range
mean
range
mean
range
mean
SRP (Mg P/L)
TOP (Mg P/L)
TP (Mg P/L)
NO, + N02 (Mg N/L)
NH3 (Mg N/L)
TKN (Mg N/L)
Secchi disk
transparency (m)
PAR (ME/m2«sec)lm
2m
3m
Total suspended
solids (mg/L)
Corrected chloro-
phyll a (Mg/L)
<0.5-6.5
3-17
24-200
<5- 1,570
2-67
501-1,667
0.3-1.3
—
—
—
—
—
3.1
6.4
73
460
21
849
0.7
1.0-17.5
4-36
35-214
15-2,480
2-250
590-1,622
0.2-1.4
1.5-735
0-114
0-48
9.8-69.8
7.3-93.3
5.6
12
93
570
82
1,064
0.6
263
30
9
27.1
29.5
<0.5-15.0
1-17
12-53
<5 1,120
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GROWTH DYNAMICS OF CLADOPHORA GLOMERATA
47
Cladophora is generally the dominant alga (in
terms of biomass) found along the rocky littoral
regions of Lake Erie; however, it is only one of the
numerous epilithic filamentous algae found in this
zone. Three distinctive environments within the
littoral region are inhabited by these algae; the
infralittoral zone (defined as the region below mean
water level for a particular season, represented here
by the 0.5-, 1-, 2-, and 3-m stations), the eulittoral
or "splash" zone (the wave-influenced region ex-
tending from approximately 20 cm below to 20 cm
above mean water level), and the supralittoral zone
(a zone associated with vertical shorelines that is
entirely above the water line but is influenced by
the spraying of waves). Cladophora inhabits both
the infralittoral and eulittoral zones (Figure 4).
Bang/a
Phormidtum
P/ectonema
Osci/latoria spp
Tetrosporo
Stigeoclonium
Ulothrix
Cladophora
Suprolillorol I
- I
Meiers
| Infrolittorol
-2
-3
Eulittoral
FIG. 4. Generalized zonation of the major macroscopic
algae in western Lake Erie.
The distribution, abundance, and zonation of the
major filamentous algae in the littoral regions of
western Lake Erie is complex due to the hetero-
geneity of the shoreline and the endless diversity of
microhabitats encountered. Each location is unique,
reflecting differences in biological and physico-
chemical interaction resulting from varying degrees
of slope, aspect, water movement, water quality,
substrate, light, and other factors. The zonation of
the algae depicted in Figure 4 is a generalization of
conditions found in the western basin of Lake Erie,
as are the following descriptions. All species and
zones are not necessarily present throughout the
basin or at one particular time. Four major
taxonomic groups are represented in the littoral
region, the Chlorophyceae (Cladophora, Tetra-
spora Stigeoclonium and Ulothrix), Cyanophyceae
(Phormidium, Oscillatoria, and Plectonema),
Rhodophyceae (Bangia), and Bacillariophyceae.
The Bacillariophyceae, although abundant and
important, have been omitted from the present
study.
The littoral region is a dynamic, high-energy
environment that is susceptible to wide seasonal
fluctuations in environmental conditions that in-
variably influence the algal association. In response
to changing environmental conditions, a seasonal
succession of algae is observed. Perhaps the
harshest seasonal event encountered is the scouring
action of ice. At the start of the open water season
the exposed area of the eulittoral and upper
infralittoral zones are denuded of previous algal
growth. During early April the filamentous green
alga Ulothrix zonata colonizes much of the littoral
zone from the water line to a depth of approxi-
mately 0.5 m. Coverage may be as great as 100% in
some areas while the alga may be absent in similar
adjacent areas. In late April, when water tempera-
tures approach 10°C, the maximum standing crop
and distribution of Ulothrix is observed. Substrates
are colonized to a depth of 1-1.5 m, with maximum
filament lengths of 3-4 cm occurring just below the
water line. The abundance of Ulothrix declines as
the season progresses, but has been observed as late
as July in a few locations.
Sparse patches of Bangia atropurpurea (a fila-
mentous red alga) are found in the upper portions
of the eulittoral zone concurrently with the coloni-
zation of Ulothrix. Bangia slowly increases in
abundance, obtaining its maximum coverage and
length in June. Filaments of Bangia at Stony Point
in June averaged 4-6 cm with a maximum length of
12 cm. Bangia has been observed to be most
abundant on fairly vertical substrate, such as
boulders, breakwalls, and steep rocky shorelines.
This conspicuous red alga occupies a narrow (5-20
cm), interrupted band along the shoreline. Bangia,
unlike Cladophora, is a recent invader into the
Great Lakes and was not reported in western Lake
Erie until 1969 (Kishler and Taft 1970). The alga
has been observed throughout the basin, but did
not colonize the South Bass Island site or other
similar areas that possess a gently sloping horizon-
tal splash zone. The abundance of this alga declines
after June and it is generally absent by late August.
Zonation of the major attached filamentous
algae is most prominent in the spring (April and
May). The initial growth of Cladophora at 1 m
represents the deepest colonization of the major
filamentous algae. Ulothrix heavily colonizes the
shallower depths, from 0.5 m to the water line.
Above Ulothrix, on vertical substrates, Bangia
------- An error occurred while trying to OCR this image.
-------
GROWTH DYNAMICS OF CLADOPHORA GLOMERATA
49
TABLE 2. Maximum standing crop values of Cladophora for the Stony Point and South Bass sites, 1979 and 1980.
Site
Stony Point
South Bass
Year
1979
1980
1979
1980
Month
July
Nov.
June
June
Depth
0.5
0.5
2.0
0.5
DW*
(g/m2)
100
184
102
214
AFW**
(g/m2)
55
110
55
116
Maximum
Filament
Length (cm)
37
40 (July)
90
45
*Dry weight 104°
**Ash free weight
from mid-April through July. The amount of
Cladophora fluctuated throughout this period,
depending largely on the direction and velocity of
the wind. A maximum value of 15 kg/m2 dry
weight was observed for beach-accumulated
Cladophora and associated debris. This beach
accumulation represented only a small fraction of
the total potential sloughed biomass present from
the luxurious beds found just within this area. A
large percentage of this biomass is probably ex-
ported from this area. Observations with SCUBA
have revealed extensive mats of detached green
Cladophora thalli suspended just off the bottom of
the lake in areas not capable of supporting its
growth because of unsuitable substrate (mud).
In June, several weeks prior to the peak biomass
period, the appearance of the Cladophora filaments
began to change from a bright green to a duller
olive-green color. This darkening of appearance
was the result of increasing numbers of epiphytes
colonizing the filaments. The epiphytes first ap-
peared on filaments growing at depths of 2-3 m and
continued to increase in density as the season
progressed. By July and August, at which time
biomass was declining, microscopic examination
revealed Cladophora cells completely covered by
epiphytes. The two most abundant epiphytes were
the diatoms Cocconeis sp. and Rhoicosphenia
curvata. Cladophora colonizing the eulittoral zone
remained relatively free of epiphytes. The number
of epiphytes on filaments during the fall resurgence
in the infralittoral zone increased with increasing
depth. Filaments of the deeper depths (1 m) were
heavily colonized by diatoms except at the extreme
apical portions.
Tissue Nutrients
The tissue nutrients nitrogen, phosphorus, and
carbon were observed to increase after the onset of
growth in the spring, then decrease as biomass
declined (Figures 2 and 3). Tissue nutrients again
increased with the new growth in the fall. The
yearly ranges and means of the tissue nutrients are
presented in Table 3. Carbon and nitrogen values
followed similar patterns of increases and decreases
within the cells. The carbon content averaged an
order of magnitude higher than nitrogen as indi-
cated by the C/ N ratios. Phosphorus values tended
to fluctuate to a greater degree than the nitrogen
and carbon values. Detailed data for each station in
western Lake Erie have been presented by Lorenz
and Herdendorf (1980).
DISCUSSION
Cladophora is conspicuously present from May to
December in the littoral zone of the island region of
western Lake Erie. Within this region, the numer-
ous bedrock reefs and gently sloping bedrock
shorelines (Herdendorf and Braidech 1972) provide
a substrate suitable for Cladophora colonization. A
significant portion of the littoral region along the
Michigan and Ohio shorelines does not provide
suitable substrate to support this alga. Much of this
region is low-lying with sandy or silt/ clay reaches
of shoreline, lacking the firm, non-shifting sub-
strate required for Cladophora. Within the rocky
littoral region Cladophora inhabits the infralittoral
and eulittoral zones, displaying distinctively dif-
ferent growth dynamics in each zone. Growth of
Cladophora in the infralittoral zone appears in late
April and exhibits a bimodal pattern with peak
standing crops developing in the early summer
(June-July) and the fall (October-November). It is
this zone that supports the greatest amount of
biomass and is most responsible for the nuisance
conditions associated with Cladophora. The infra-
littoral zone does not support Cladophora growth
during most of August and September.
-------
50
LORENZ and HERDENDORF
TABLE 3. Cladophora tissue nutrient yearly ranges and means for the Stony Point and South Bass sites, 0.5-3 meter
stations, 1979 and 1980.
Total Tissue P %
Site
STONY POINT
SOUTH BASS
Year
1979
1980
1979
1980
Range
0.103-0.411
0.141-0.810
0.081-0.715
0.097-0.381
Mean
0.232
0.332
0.251
0.212
Total Tissue N %
Range
1.44-5.14
1.31-4.85
9.90-3.96
1.36-4.92
Mean
3.17
3.39
2.64
3.06
Total Tissue C %
Range
17.5-37.8
13.7-37.1
12.2-35.3
13.8-40.5
Mean
29.4
29.7
25.8
30.3
C/N
Range
7.2-14.5
7.4-10.4
7.9-16.3
7.1-14.7
Mean
9.6
9.1
10.1
10.3
Establishment of the alga in the eulittoral zone
occurs during May. It remains present in this zone
throughout the summer and on into November,
declining noticeably in density during the late
summer (August). The eulittoral zone is colonized
slightly later than the infralittoral, probably due to
the effects of ice scour, rising water levels, and
competition with Ulothrix.
Growth of Cladophora at the two western basin
sites in 1979, as measured by maximum standing
crop, was similar to the value reported from the
United States shoreline in eastern Lake Erie at
Hamburg, N. Y. (Millner el al. 1982). This maxi-
mum standing crop of approximately 100 g DW/ m2
ocurred at the 0.5-m depth at Stony Point, 2-m
depth at South Bass, and 3-m depth at Hamburg.
The 1979 lakewide Lake Erie Cladophora Surveil-
lance Program reported that the Canadian shore of
eastern Lake Erie at Rathfon Point (Neil 1981)
supported the greatest quantity of Cladophora (983
g DW/m2 at 0.5 m) and the central basin site,
Walnut Creek, PA, (Millner et al. 1982) supported
the least (24 g DW/m2 at 0.5 and 2 m). For Lake
Ontario, Neil (1975) reported a maximum standing
crop value of 1,062 gDW/m2, approximately five
times greater than the 1980 value for western Lake
Erie. Conversion of 1966 data from Kishler (1967)
to g/ m2 at site locations close to the South Bass site
result in an average maximum standing crop of 92
gDW/m2 at 1 m, similar to 102 g/m2 maximum at 2
m in 1979, but lower than the 214 gDW/m2
maximum of 1980 at 0.5 m. Kishler noted that peak
standing crop and seasonal distribution vary from
year to year depending on environmental condi-
tions. The wide variation between 1979 and 1980
biomass values supports this contention (Figure 5).
The maximum depth at which Cladophora
growth was observed varied with location. For
example, in late June 1980 the alga at Stony Point
colonized to 1.5 m, and at Chickenolee Reef growth
was present to 4.6 m. Kishler (1967) reported
maximum depth of growth in the island region
ranging from 1.5 m at Catawba Cliffs, located
along the Ohio shore, to 4.1 m at Kelly's Island
Reef. Cladophora has been reported at depths of 15
m (Casey et al. 1973) and 46 M (Kindle 1915) in
Lake Ontario and at 183 m in Lake Superior (Eddy
1943). The depth of Cladophora colonization in
western Lake Erie is limited by light availability.
Light measurements, in conjunction with observa-
tions on maximum depth of algal colonization,
indicate that values of less than approximately 50
juE/m2«sec are limiting to growth. This is sup-
ported by a laboratory study of Graham et al.
(1982) showing that levels of 10, 25, and 35
juE/ m2»sec are limiting to Cladophora production.
Using the above value of 50 juE/m2»sec as limiting
and comparing western Lake Erie PAR values to
Secchi disk transparencies, it is estimated that
Cladophora growth at 3 m is light limited by a
Secchi transparency of less than 1 m. Similarly,
limiting light values (<50 /zE/m2»sec) will occur at
the 2-m depth with a Secchi disk transparency of
less than 0.7 m. Due to the absence of sustained
Secchi disk transparencies above 0.7 m at Stony
Point in 1980, Cladophora was not able to colonize
the 2-m depth as it did when greater Secchi
transparencies ocurred during June of 1979 (Fig-
ure 2).
The summer (July-August) decline of biomass in
the infralittoral zone (Figures 2 and 3) was not the
direct result of light or nutrient limitation. Light
levels remained above 80 /uE/m2»sec in areas that
previously supported growth during the "dieback"
period. Nutrient concentrations in the lake, al-
though showing a general declining trend as the
season progressed, did not reach limiting levels
(Figures 2 and 3). Soluble reactive phosphorus at
-------
GROWTH DYNAMICS OF CLADOPHORA GLOMERATA
51
the sites ranged from 1-3 ngP/L during the
declining biomass periods, with the South Bass site
not falling below 2 /ug P/ L. Levels of SRP greater
than 1 /*g P/L do not pose limiting conditions as
was evident by the lush growth at Rathfon Point,
Ontario, where SRP values for 1979 averaged 1 Mg
P/L (Neil 1981). Total phosphorus levels averaged
above 30 jug P/L at both sites. Thomas (1975)
reported that prolific growth of Cladophora is
present in areas where average spring and annual
total phosphorus concentrations exceed 15 /ug P/L.
Nitrate + Nitrite and ammonia levels, both avail-
able forms of nitrogen (Gerloff and Fitzgerald
1976), did not become limiting, remaining above
300 jug N/L and 2 Mg N/L respectively during the
declining biomass period.
Tissue levels of nitrogen and phosphorus gen-
erally rose as biomass increased from May to June.
The increasing nutrient levels may reflect the
maturation of the algal cells, slowing of growth,
and the cell's ability to store surplus nutrients
(luxury consumption). Tissue phosphorus levels
appeared to respond to environmental fluctuations
in available phosphorus, whereas tissue nitrogen
did not. The response of tissue phosphorus levels to
several spikes of high SRP concentrations at Stony
Point in 1980 were evident as elevated tissue phos-
phorus levels (Figure 2). The declining biomass and
subsequent absence of Cladophora in the infralit-
toral zone during the summer months (July-
September), although accompanied by declining
tissue nutrient levels, was not the result of limiting
phosphorus and nitrogen in the lake water. This is
evident by tissue nitrogen and phosphorus levels
(Figures 2 and 3) remaining above the critical levels
for optimal growth of 0.06 and 1.1% for phosphorus
and nitrogen, respectively (Gerloff and Fitzgerald
1976).
The bimodal growth pattern observed in the
infralittoral zone (Figures 2 and 3) is the result of
several environmental factors influencing the ener-
getics of Cladophora. As water temperatures rise
from approximately 4°C to 10° C new Cladophora
growth begins to appear. The new growth appears
at a depth of 0.5-1.0 m arising from small filaments
which have overwintered. At these low tempera-
tures Ulothrix is the dominant alga on the shal-
lower exposed substrate, out-competing Cladoph-
ora. Growth of Cladophora occurs rapidly once
water temperatures approach 10°C and Ulothrix is
replaced. Maximum biomass production takes
place in the late spring (May-June) as water
temperatures rise from 10 to 23° C. Standing crop
begins to decline when water temperatures reach
23-26° C with incident light and photoperiod close
to maximum levels. The higher temperatures of
early summer (June-July) increase respiration to
rates that are greater than the gross production
(Graham et al. 1982), resulting in a negative net
production and the senescence of the alga. As a
result of this temperature-induced negative energy
balance, growth ceases, the condition of the cells
deteriorates as evidenced by declining tissue nu-
trients, and the cells become weakened and suscept-
ible to detachment.
Several factors may additionally contribute to
the decline in biomass of Cladophora in the early
summer. The increasing thickness of the cell wall
(Cronshaw et al. 1958) can inhibit nutrient diffu-
sion and light availability. Water agitation,
important to Cladophora growth (Whitton 1970),
generally is at a low during the summer. Periods of
calm decrease water movement past the cells,
resulting in slower nutrient exchange (Whitford
and Schumacher 1961) and less filament move-
ment, causing self shading. The higher water tem-
peratures and algal senescence may result in the
secretion of dissolved organic matter. Levels of
phosphorus, nitrogen, and carbon within the cells
all showed a decline after peak biomass was
reached. Epiphyte growth at this time becomes
dense, possibly in response to the high levels of
nutrients secreted by the senescing Cladophora.
Fitzgerald (1969) concluded that dense epiphyte
populations on Cladophora could be used as
evidence that surplus nitrogen was available in the
environment. The epiphytic growth found on the
filaments of Cladophora in western Lake Erie
further reduces the availability of light and nutri-
ents to the algal cells.
The reduced light conditions of the infralittoral
zone results in Cladophora at depth being unable to
balance the increasing respiration requirements
brought about by the increasing temperatures of
summer. Presence of the alga in the eulittoral zone
throughout much of the summer (July-September)
indicates that the alga in this zone is able to
maintain a positive net photosynthetic rate. In this
zone, tissue phosphorus and nitrogen levels remain
relatively high and the filaments generally free of
epiphytes throughout the summer.
CONCLUSIONS
Cladophora colonizes the littoral zone throughout
western Lake Erie, wherever suitable substrate is
available. Within this littoral zone two distinctive
-------
52
LORENZ and HERDENDORF
growth patterns, representative of two different
environments, are exhibited. The eulittoral zone
supports growth from May to December in con-
trast to the bimodal growth pattern of the infralit-
toral zone that lacks growth in the late summer
(August and September).
Light and substrate availability limit the extent
of Cladophora growth in western Lake Erie. Field
observations indicate light levels of approximately
50 /iE/m2»sec or less are limiting. In the island
region an extensive infralittoral zone composed of
bedrock shorelines and reefs provides an excellent
substrate for the alga to colonize. Much of the
remaining Ohio and Michigan shorelines consists
of low-lying marshes and unconsolidated sediment,
unsuitable for colonization. Available forms of
phosphorus and nitrogen are abundant and do not
become limiting, as evidenced by tissue nutrient
analysis.
The absence of the alga in the infralittoral zone
during the late summer months (July and August)
is the result of a negative energy balance. Respira-
tion surpasses productivity as temperatures rise in
the summer. The decreasing biomass of the infralit-
toral zone in the summer is accompanied by
increasing epiphyte colonization and declining, but
not limiting, tissue phosphorus and nitrogen levels.
ACKNOWLEDGMENTS
The authors would like to acknowledge the guid-
ance and support of Mr. Nelson Thomas and Mr.
Robert Bowden of the United States Environmen-
tal Protection Agency (Grant No. R-804612).
Thanks are additionally owed to Dr. Martin Auer
who provided valuable insight, advice, and critical
review of the manuscript; Ms. Julie Letterhos for
the water nutrient analysis; and Mr. Gordon Keeler
and Mr. Timothy Bartish for field assistance.
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