| Summary: | The contribution of metazoan zooplankton to internal phosphorus (P) cycling was
investigated in Meiliang and Wuli Bays of Lake Taihu, a eutrophic, shallow lake in China
by determining biomass and biomass specific P release rates. The zooplankton community of
eutrophic Meiliang Bay was dominated by cladocerans, particularly Daphnia
spp. and copepods, while dominant groups in hypereutrophic Wuli Bay included
rotifers, copepods, and cladocerans. Release rates of PO43--P ranged from 0.20 to 0.57 mg·g (dry weight)-1·h-1
in Meiliang Bay and 0.20 to 0.76 mg·g-1·h-1 in Wuli Bay. In most
cases, P release rates were higher in Wuli Bay than Meiliang Bay. Phosphorus fluxes from
zooplankton excretion varied from 5.34 to 57.41 mg·m-2·d-1 in
Meiliang Bay and 8.20 to 70.02 mg·m-2·d-1 in Wuli Bay. Since P
released by zooplankton in this study was in a form available to phytoplankton,
zooplankton may represent a significant source of P contributing to high phytoplankton
biomass in Lake Taihu.
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