PARENT SESSION
PT1 - Aquatic Toxicology
Tuesday, 19 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P500) Pesticides and PCBs in sediments and fish from the Salton Sea, California, USA .
Sapozhnikova, Yelena*,1, Bawardi, Ola1, Schlenk, Daniel1, 1 University of California, Riverside, Riverside, CA, USA
ABSTRACT- The Salton Sea, the largest manmade lake in California, is officially designated by the State of California as an agricultural drainage reservoir. The purpose of this study was to test organochlorine and organophosphorous pesticides, as well as polychlorinated biphenyls (PCBs) concentrations in sediments and fish tissues in Salton Sea. Sediment samples were taken during 2000-2001 and fish tissues (Tilapia mossambique, Cynoscion xanthulu) were collected in 2001. All samples were analyzed for 12 chlorinated pesticides, 6 organophosphorus pesticides, and 55 polychlorinated biphenyl (PCB) congeners. Following standard EPA methods, quantification of organics was performed using gas chromatography - (HP6890) equipped with an electron-capture detector. Total pesticides concentration in sediments ranged from 22 to 67 ng/g dry wt. Among DDT pesticides found in sediments, ppDDE was the most abundant, reaching up to 30 ng/g dry wt. Total PCB concentrations observed in sediments ranged from 116 to 304 ng/g dry wt. Total amount of pesticides detected in Orange mouth Corvina (Cynoscion xanthulu) and Tilapia (Tilapia mossambique) were in the range 16-97 ng/g and 18-69 ng/g for muscles, 86-564 ng/g and 38-537 ng/g for liver, 43-182 ng/g and 36-294 ng/g for gonads, 35-125 ng/g and 22-150 ng/g for gills. opDDE and ppDDE were the most abundant among DDT pesticides in fish. Also, other organochlorine pesticides (lindane, chlorothalonil, hexachlorobenzene, heptachlor, dieldrin) were detected in both fish and sediment samples. Organophosphorous pesticides: dimethoate, diazinon, malathion, chlorpyrifos, disulfoton varied from ND to 9.5 ng/g dry wt in sediments and from ND to 80.3 ng/g in fish tissues. These results demonstrate the need of the further studies on Salton Sea ecosystem.
Key words: Pesticides, PCBs, sediments, fish