Zooplankton are free-floating aquatic microorganisms that are consumers (consume other organisms for food), such as crustaceans and aquatic mites. Zooplankton serve as a critical link in the food chain by supporting organisms that then support larger organisms, such as fish. Also, zooplankton are sensitive to water quality conditions and make excellent indicators of water quality. Because of these reasons, the Louisville District Water Quality Team monitors phytoplankton communities at all Louisville District reservoirs annually.
Left - Kemmerer bottle filled with water from a Daphnia lumholtzi bloom. Right - Daphnia lumholtzi female with eggs.