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Explore the zooplankton assessment at Ox Ranch focusing on comparing offshore and onshore zones, Daphnia abundance, biomass, and implications for pond management. Suggestions for macrophyte removal, dredging, fish habitat enhancement, and overall pond status are highlighted.
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Pond Zooplankton Analysis at OX Ranch Grace Gardner, Joe Buchanan, Casey Kristofferson
Outline • Background • Methods • Data • Results • Management • Summary
Background • Purpose of ponds • Macrophytes • Location- middle pond • Zooplankton Assessment • October 7th and 8th
Methods • Onshore vs. Offshore • Equipment • Sampling • Lab Analysis • Reasoning
Onshore vs. Offshore X Volume of offshore= 14015 m^3 Volume of onshore =1300 m^3 X X X Black X: Offshore sites Gray X: Onshore sites X X
Sampling wildco.com vesr.ucnrs.org
Reasoning: Daphnia • Pond Community • Role of Daphnia
Data and Results • Comparisons of Offshore and Onshore zones • Abundances of all Zooplankton genera present • Average length of zooplankton • Average length of Daphnia specifically • Average biomass of Daphnia • If time permits: abundances between night and day within the offshore zone
Large-bodied Daphnia benefits • Burns et al. 1968, found a correlation between length of zooplankton and diameter of particle able to filter • This means that the larger-bodied zooplankton within onshore zone are providing top-down control upon algal blooms • Management implications with removal of these zooplankton (Burns 1968)
Management • Ox Ranch Plan • Suggestions • Role of management plan
Pond Status • Pond is in great condition for Daphnia. • High densities of Macrophytes • Good for daphnia • Bad for fish
Management Suggestion • Macrophyte removal • Dredging • Fish habitat • Fish stocking • Shading • Role
Macrophyte Removal • Remove 30-40% of macrophytes • Mostly near/around dock • Significance
Dredging • 3 meters deep • In front of dock • Depth for fish habitat
Fish habitat • Brush piles in open water • In dredging area • Christmas trees, brush, anything. • (Bassett et al. 1994)
Stocking • Conservative • Fish population boom at beginning • Ecosystem reaction
Shading • Plant willows • Shading of pond • Bank stabilization
Role of Management plan • Economically effective • Maintain balance • Supply fishing opportunities
Summary • Background • Methods • Data • Results • Management • Questions?
Citations • Bassett, C. E. 1994. Use and evaluation of fish habitat structures in lakes of the eastern United States by the USDA Forest Service. Bulletin of Marine Science, 55: 1137-1148. http://idahoid.library.ingentaconnect.com/content/umrsmas/bullmar/1994/00000055/F0020002/art00070 • Burks, R.L., Jeppersen, E., and Lodge, D.M. 2001. Littoral zone structure as Daphnia refugia against fish predators. Limnology and Oceanography 46: 230-237. • Burns, C.W. 1968. The relationship between body size of filter-feeding cladocera and the maximum size of particle ingested. Limnology and Oceanography 13: 675-678. • Wetzel, R.G. 2001. Limnology. 3rd Ed. Academic Press, San Diego, CA, U.S.A.