Residual organochlorinated compounds in two fish species from Ciénaga Grande del Bajo Sinú, Córdoba, Colombia

Objective: To determine the levels of organochlorinated pesticides (OCPs) in two fish species, obtained from Ciénaga Grande del Bajo Sinu. Materials and methods. A gas chromatograph (Perkin Elmer XL Autosystem) with electron capture detector and capillary column 5% diphenyl and 95% dimethylpolysiloxane, with 30 m in length, 0.25 mm internal diameter and 0.25 mm thick film were used. Two species were studied: Prochilodus magdalenae and Hoplias malabaricus during wet and dry seasons. Results. The percentages of pesticides recovered were 80 and 84% whereas the detection and quantification limit was 0.02 to 0.18 ng/g and 0.2 to 1.8 ng/g for both species, respectively. Relative standar deviation remained below 7% in all cases. Among those organochlorinated investigated here, a-clordane, endrín and aldrín were detected in both fish species. In one of the species studies, it was observed that when weight and size of fishes incresed the pesticides concentration also increased. The concentration levels of OCPs were in the range of 0.35-3.75 and 0.48-5.49 ng/g for moncholo (Hoplias malabaricus) and bocachico (Prochilodus magdalenae) respectively. Conclusions. The frequency of OCPs and the levels detected in these species might be the result of anthropogenic activities conducted in the vicinity of the lake. The correlation between the biometric measurements and concentration was depending on the fish species. The concentrations found in the studied species Hoplias malabaricus and Prochilodus magdalenae do not represent an immediately lethal toxicity.