Seasonal bioaccumulation of organohalogens in tigerfish, Hydrocynus vittatus Castelnau, from Lake Pongolapoort, South Africa.

The study determined current exposure of tigerfish in Lake Pongolaqpoort to organohalogens. Levels of DDT, PCB, HCB, HCH, PBDE and CHLs were measured in tigerfish muscle on a seasonal basis. Historical use of DDT was reflected in the bioaccumulation patterns (5,400-6,000 ng/g lipid) as well as current use of HCBs (7.7-15.7 ng/g lipid) in the agricultural areas. External factors, i.e. increased flow did not play a role in organic pollutant exposure. Levels are a function of the lipid content of the muscle tissue, i.e. 3.8% during low and 9% during high flow, implying that organohalogen exposure remains fairly constant throughout the year.