B.W. Ho, A. R. Pape, C. Stice, N.S. Penoncello, L. Gauthier B.W. Ho, A. R. Pape, C. Stice, N.S. Penoncello, L. Gauthier Zooplankton Community Assessment in Baron Pond

Introduction Location Magee Rd. (5.6 miles N.E. of Gennesse ID.) Interest in management and fishery

Objectives Determine the biotic community of Baron Pond. –Determine zooplankton and macro-invertebrate species abundance and distribution –Assess whether zooplankton and macro-invertebrate community is sufficient to support a fishery within the pond

Hypotheses 1: Zooplankton and macro-invertebrate species vary in abundance between the littoral and pelagic areas of the pond. –H o : There is no difference between littoral and pelagic abundances. 2: The zooplankton and macro-invertebrate community is sufficient to support a fishery within the pond. –H o : The community will not be sufficient to support a fishery within the pond.

Methods 1.Sampled 2 pelagic sites with Wisconsin-style zooplankton tow net (12.5 cm, 80 µm) 2.Sampled 2 littoral sites with D-net (251.6 cm 2, 500 µm). 3.Samples preserved with formalin (10%) 4.Counted zooplankton using dissecting microscopes 5.Analyzed data using Microsoft Excel

Methods: 1 Two sampling sites –Pelagic zone 1: 1.9 m (6.5 Liters) –Pelagic zone 2: 3.0 m (19.6 Liters) Obtained triplicate samples Sampling limitations –Tow length = site depth-net length –Not representative of entire water column –Bias toward surface

Study Site Pelagic zone 2 (1.9m) Pelagic zone 1 (3 m)

Methods: 2 Two littoral sampling sites –1.5 m from shore –Volume sampled 26,312 L/site Obtained triplicate samples Sampling limitations –Shape of net difficult to calculate area of sample --Accuracy

Study Site Littoral zone 2 Littoral zone 1 Pelagic zone 2 Pelagic zone 1

Methods: 3 Pelagic samples condensed using 80 µm mesh Littoral samples condensed using 500 µm Samples were preserved in formalin until analysis

Methods: 4 Samples washed of formalin Complete pelagic tow counts –Direct enumeration /back calculation Littoral zone samples counted – Subdivided/ back calculated

Results: Littoral

Results: Pelagic

Results Statistical analysis compared abundances in littoral vs. pelagic sites Significantly more Calanoids in pelagic (p-value=.01) More Chironomids in littoral sample (p-value=.03) Previous research indicates zooplankton vital to supporting fisheries : –Daphnia –Bosmina

Future Research Refine sampling methods –Time of year influences estimates –Many invertebrates entering quiescence/diapause by November Sample size –Schindler trap may reduce bias of pelagic sampling –Seine net may be better for sampling littoral zone

Acknowledgements Frank M. Wilhelm, Tara Johnson (U of I) Mike and Beverly Baron (Landowners) www. missouristate.edu