Lake Comparisons:
Zooplankton and Benthos
With a few comments on Wolf Lake
Helen Czech
SUNY ESF
Zooplankton: Why are we interested?
• Zooplankton are important indicators of aquatic systems
• They can indicate predator-prey relationships
• They effect phytoplankton and zoo populations are driven in turn by
predatory inverts and fish
• Rotifers are not well studied
Zooplankton Collection Methods
•
A Schindler trap was used to collect samples.
•
One sample per layer (epi, meta and hypo)
was collected / lake (except for Green Lake,
which had 2 / layer including a chemo layer).
•
Collected samples were washed into a
collection bottle and then treated with
Alka seltzer and eventually ethanol.
•
2 whole lake net tows were taken from
bottom to top
»http://aslo.org/photopost/showphoto.php?photo=196
In Lab Analysis of Preserved
Zooplankton
• Zooplankton samples were counted in
lab using a dissecting microscope
and a tray.
• 100 of the most common species
(typically 3 -5) per layer
Wolf Lake
www.fieldmuseum.org/.../images/wolflake_lg.jpg
Wolf Meta
Wolf Hypo
14
14
12
12
12
10
10
10
cladocerans
8
copepods
rotifers
6
protzoan
8
cladocerans
copepods
6
rotifers
Individuals/L
14
Individuals/L
Individuals/L
Wolf Epi
8
copepods
4
4
4
2
2
2
0
0
rotifers
0
Zooplankton Types
Zooplankton Types
cladocerans
6
Zooplankton Types
•Meta has greatest number of major groups
•Rotifers are most abundant, followed by copepods
www.ksu.edu
•Common in samples were Calaniod and Cyclopoid copepods and nauplii
www.stetson.edu
•Observed rotifers: Keratella, Kellicotia and Polyarthra
•One protozoan, Difflugia
www.stetson.edu
192.171.163.165
www.serc.si.edu
faculty-staff.ou.edu
Onondaga Lake
Onondaga Epi
Onondaga Meta
600
600
500
500
500
400
300
Copepods
400
Cladocerans
300
Copepods
Individuals/L
Cladocerans
Individuals/L
400
Individuals/L
Onondaga Hypo
600
200
200
200
100
100
100
0
0
Zooplankton Groups
Cladocerans
300
Copepods
0
Zooplankton Types
Zooplankton Types
•The epi had the greatest number of individuals
•Cladocerans were the most common, followed by copepods
www.yale.edu
•Bosmina was most common, followed by Daphnia and Cyclopoid copepods
•The invasive Cercopagis was observed
www.dnr.cornell.edu
www.nysm.nysed.gov
Arbutus Lake
www.efloras.org
Arbutus Hypo
60
50
Inds/L
40
copepods
cladocerans
30
rotifers
dipterans
20
10
0
Zooplankton Types
•Copepods were the most common, and all zooplankton were more
common in the epi layer.
•Chaoborus was the dipteran
www.microscopy-uk.org.uk
Catlin Lake
Catlin Epi
Catlin Hypo
12
12
12
10
10
10
8
Copepods
6
Rotifers
Dipterans
4
2
8
Copepods
Ind/L
Cladocerans
6
Cladocerans
Rotifers
4
Rotifers
2
0
Zooplankton Types
Cladocerans
6
4
2
0
Copepods
Inds/L
8
Ind/L
Catlin Meta
Zooplankton Types
0
Zooplankton Types
•Again, copepods and rotifers were the most common.
•Numbers were not large, few in the samples
www.gobacktothebasics.com
Oneida Lake
www.esf.edu/.../gallery/oneida/xingye3small.jpg
•
Data not available for analysis
•
Zooplankton observed are listed in Table 1
•
The meta layer appears to have the greatest
diversity
www.microscope-microscope.org
cfb.unh.edu
Zooplankton
Epi
Meta
Hypo
Cyclopoids
X
X
X
Calanoids
X
X
X
X
X
X
X
Nauplius
Bosmina
X
Daphnia
X
Diaphanasoma
X
X
Polyarthra
X
X
X
X
Keratella
X
Hydra
X
Table 1. Zooplankton in Oneida Lake
Green Lake
•The hypo layer had the greatest number of cladocerans and copepods
•Calanoids were the most common.
•The chemo and mono layer had very few zooplankton
Lake Comparison
• The Adirondack lakes have good diversity, but few zoo in
samples. Copepods were common, as were rotifers
• Onondaga Lake had a lot of zoo in comparison to the
other lakes
• Green Lake also had low numbers
• Oneida had some diversity.
• Typically the epi or meta had the greatest #
And let’s not forget benthos!
Benthos are defined the organisms found inhabiting the
bottoms of lakes, rivers and streams, and are often
important indicators of health and diversity, pollution
Common benthic organisms include molluscs, aquatic
insects, oligochaetes
Benthos collection
• Benthos were collected with an Eckman
Dredge
• Sample were seived and inverts were
preserved in ethanol
www.cee.vt.edu
Benthos we Found
• Catlin Lake - Molannidae caddisfly, Chaoborus midge
• Arbutus Lake: No data
• Wolf Lake- Molannidae caddisfly, Chaoborus midge,
Unionid mussel, Chironimidae
• Onondaga Lake – YUCK – no benthos taken
• Oneida Lake – Chironimidae, gastropoda, Zebra Mussel
• Green Lake – we collected, but there was nothing in the
sample.
Problems
• Errors in data collection could be
from improperly washing out the
Schindler.
• Human error in counting or
improper mixing.
Wolf Lake
• Very pristine lake
• High diversity in zoo, but low numbers
• Phyto numbers very low, which could explain low zoo
numbers
• Not a lot of silica, and not a lot of diatoms in the samples
• pH is average, not too low
• Seems to be oligotrophic, not a lot of N
• Turbidity is low
• DO was fairly high