Toxicity of Organochlorine Pesticides to Zooplankton of Vellar Estuary

168-169Toxicity of organochlorine pesticides (p,p'-DDT, lindane and endosulfan) to zooplankton (Acartia sp., Eucalanus sp., Lucifer sp. and Sagitta sp.), collected from Vellar Estuary, Tamil Nadu, India, was studied by determining 24 h LC50 values and their confidence limits. DDT was highly toxic to the zooplankton assayed, followed by lindane and endosulfan. Sagitta sp., was more tolerant to DDT and endosulfan than the others