Grazing and production by zooplankton in lakes of contrasting trophic status : a progress report

• Main Authors: Welch, E. B. (Eugene B.), Pederson, G. L., Stoll, Richard Kenneth, U.S. International Biological Program. Coniferous Forest Biome, University of Washington
• Format: Report
• Language: English; unknown
• Published: Seattle : University of Washington
• Subjects: Primary productivity (Biology) > Washington (State) > Sammamish; Lake; U.S. International Biological Program. Coniferous Forest Biome; Primary productivity (Biology) > Washington (State) > Chester Morse Lake; Lake ecology > Washington (State) > Sammamish; Zooplankton > Washington (State) > Findley Lake; Zooplankton > Washington (State) > Sammamish; Lake ecology > Washington (State) > Chester Morse Lake; Zooplankton > Washington (State) > Chester Morse Lake; Lake ecology > Washington (State) > Findley Lake; Primary productivity (Biology) > Washington (State) > Findley Lake; Morse; Copepods; morse
• Online Access: https://ir.library.oregonstate.edu/concern/defaults/tx31qk05n

Grazing rates and density of the crustacean zooplankton were measured in Findley and Chester Morse Lakes and Lake Sammamish, Washington. Sample analysis is incomplete at reporting time, thus estimates of production from examination of life stage biomass changes was not possible. Maximum density of crustacean zooplankton was about 10/1 in the water column of oligotrophic Findley and Chester Morse Lakes and 70/1 in mesotrophic-eutrophic Lake Sammamish during 1972. Densities averaged about 10 times greater in Lake Sammamish than in the other lakes. Copepods comprised most of the numbers in all three lakes. Grazing apparently represents a sizable loss to phytoplankton in the three lakes feeding rates experimentally determined in situ from changes in ¹⁴C tagged phytoplankton ranged from nearly one half to over six times the algal biomass per day. However, feeding rate was always less than phytoplankton productivity.