1. Mike Holdsworth Jackie Anderson
Zooplankton
Mike Holdsworth
Jackie Anderson

2. Importance of Zooplankton
Food Web
Trophic link
Indicator
Ecosystem
Contaminants
Biological processes
Nutrient cycling
Biocontrol
Algal blooms

3. Parameters studied Species abundance Community dominance
Whole lake interactions
Differences between lakes

4. Lakes Studied Oneida Lake Arbutus Lake Deer Lake Rich Lake
Onondaga Lake
Green Lake

5. Sampling Methods Shindler trap Net tow
Distinctive depths
Lake zones
Net tow
Whole water column (excluding Green Lake)
Samples anesthetized with Seltzer
Preserved in ethanol

6. Lab Methods Concentrated sample Diluted to known volume
Examined known subvolume
Identification of individuals from subvolumes
100 specimens of same species
Data

7. Data Manipulation; Net Tows
Took net tow averages from each lake
Calculated relative percentages of taxa present in samples
Graphical representations

8. Data Manipulation; Schindler Traps
Relative percentages of taxa by lake zones for each lake
Table of most concentrated Schindler depth and deepest point sampled depth

9. Whole Water Column; Net tows
Calenoid copepods dominant in all lakes but Onondaga
85% Arbutus Lake
47% Oneida
Daphnia dominated in Onondaga
Fewer total zooplankton

11. Specific Depths; Schindler Trap
Oneida lake
Cyclopoid dominate epilimnion
Calonoid dominate hypolimnion

12. Arbutus Lake
Rotifers at depth
Possible explanations

13. Green lakes 100% calanoid dominance in monimolimnion Why?
Dominant in all layers but epilimnion

14. Daphnia dominated Rich Lake
Epilimnion
Hypolimnion
Differs from net tow data

15. Schindler Summary Lake Depth of most zoops (m)
Deepest depth sampled (m)
Oneida 1 8
Deer 3
Arbutus 7
Green
11 to 15 35
Rich 11
Onondaga 14

16. Conclusions
Net tow data and Schindler trap data did not always correspond
Patchiness
Net tow may not reach bottom
Net tow mixes layers
Copepods were important to all communities
Communities could be very different between lake layers

17. Sources of Errer Identification difficulties Subsample stirring
Recounting
Lake patchiness