This study was conducted to determine organochlorine (OC) pesticide residue in various environments such as waters, sediments and soils and in organisms such as blue crabs (Callinectes sapidus); fish [grey mullet (Mugil cephalus) and carp.(Cyprinus carpio)]; and waterbirds [coot (Fulica atra), mallard (Anas platyrynchos) and little egret (Egretta garzetta)] during the period of October 1991-October 1993 at Goksu Delta-Tasucu, which is an internationally important-wetland for the waterbirds. According to results, it was found that various;environs and organisms in Goksu Delta were contaminated by 13 different OC pesticides and their residues, besides OC concentrations in soils from the agricultural areas higher than water and sediments (ranging from 0.006 ppm beta-BHC in water to 5.416 ppm pp' DDE in agricultural soil). Residue analysis showed that OC pesticides and their residues were generally more accumulated in carp adipose tissue (o,p' DDT 4.217 ppm mean) and waterbird adipose tissue (beta-BHC; 2.147 ppm in coots, heptachlor epoxide; 2.744 ppm in mallards). Also it was confirmed that OC pesticide residues were accumulated more in adipose tissues than in liver of fish and waterbirds. OC residues were highly encountered in eggs of waterbirds, especially in eggs of the little egret (heptachlor 0.980 ppm, pp' DDT 1.254 ppm). (C) 1997 Elsevier Science B.V.