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Zooplankton Community Assessment in Baron Pond . B.W. Ho, A. R. Pape , C. Stice , N.S. Penoncello , L. Gauthier. www.ri.net. Introduction. Location Magee Rd. (5.6 miles N.E. of Gennesse ID.) Interest in management and fishery. Objectives. - PowerPoint PPT Presentation
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B.W. Ho, A. R. Pape, C. Stice, N.S. Penoncello, L. Gauthier
Zooplankton Community Assessment in Baron Pond
www.ri.net
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
www.noaa.gov
Hypotheses• 1: Zooplankton and macro-invertebrate species vary in
abundance between the littoral and pelagic areas of the pond.– Ho: 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.– Ho: The community will not be sufficient to support a fishery
within the pond.
Methods1. 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 cm2, 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
www.dynamicaqua.com
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 www.dynamicaqua.com
Study SiteLittoral 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
Ephem
eropte
ra
Chiron
omida
e
Oligoc
haeta
Odona
ta
Ostrac
od
Cyclop
oids
Chaob
orus
Corixid
ae
Gastro
poda
Nemato
da0
0.02
0.04
0.06
0.08
0.1
0.12
Littoral Zone Site 1Littoral Zone Site 2
Taxon
Mea
n O
rgan
ism
s/L
Results: Pelagic
Chironomidae Daphnia Ceriodaphnia Ostracod Cyclopoids Calanoids Harpacticoid Nauplii0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
Pelagic Site 1: Depth (1.9m)Pelagic Site 2: Depth (3.0m)
Taxon
Mea
n O
rgan
ism
s /L
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