Effect of suspended solids on interaction between filter-feeding fish Aristichthys nobilis and zooplankton in a shallow lake using a mesocosm experiment

Abstract

Suspended solids (SS) resulting from sediment resuspension (SR) can impact ecosystems through direct and indirect effects on freshwater organisms and their interactions. This study was conducted to determine whether the SS can affect the interaction between filter-feeding fish (Aristichthys nobilis) and zooplankton using a mesocosm experiment with sediments from Lake Taihu, a large shallow lake in China. SR using pump was divided into three intensities: strong, weak and no SR representing different concentrations of SS. Zooplankton abundance was significantly higher in the no-fish treatments than in the fish treatments under all three SR conditions. SR intensity had significantly negative effect on zooplankton abundance. There were interactions between fish and SR intensity on abundances of copepod, rotifer, total zooplankton and dominant zooplankton species except cladoceran abundance. The results indicate that SS had a lesser effect on zooplankton predation by filter-feeding fish, which suggests that zooplankton communities in shallow lakes can be affected by the filter-feeding fish even under high level of SS condition.

Keywords

• Sediment resuspension
• shallow lakes
• zooplankton
• filter-feeding fish
• predation