Size matters on Polybrominated Diphenyl Ethers, Organochlorine Pesticides and Polychlorinated Biphenyls levels in brown trout, Argentinean Patagonia

ONDARZA PAOLA MARIANA; GONZALEZ MARIANA; FILLMANN GILBERTO; MIGLIORANZA KARINA SILVIA BEATRIZ

Portland

Congreso; the SETAC North America 31st Annual Meeting; 2010

Organochlorine Pesticides (OCPs), Polychlorinated Biphenyls (PCBs) and Polybrominated Diphenyl Ethers (PBDEs) are lipophilic, persistent and globally distributed pollutants that could be accumulated in biota. Aquatic ecosystems are subject to poisoning risks due to the inputs of these contaminants from agricultural or industrial activities. The knowledge of contaminant residues in fish is an important tool for assessing the state of the environment and human health perspectives. The present study aims to investigate the influence of size on bioaccumulation of OCPs, PCBs and PBDEs in brown trout (Salmo trutta). Specimens were catched from a fruit and hops production area (41º56’S-72º29’W) from Argentinean Patagonia, and were divided in two size groups: juveniles (11-18 cm) and females (26-35 cm). Muscle, liver, gonads and gills were analyzed with a GC-17A Shimadzu for OCPs and PCBs and with GC-MS 500 Perkin-Elmer for PBDEs. Concentrations were normalized to lipid content. A marked difference in contaminant levels between size was observed mainly in liver and gonad (Wilconox p<0.05). These results were probably due to a possible increase in metabolic capacity in older fish or a dilution effect produced by the increase of the body weight. In addition, a seasonal elimination of lipophilic compounds during roe could also explain the lower contaminants levels in females. Gills do not show differences with size suggesting that the pollutant concentration reaches equilibrium between uptake and depuration from the water column. Females liver showed a pronounced decrease of PBDEs and PCBs which could be mainly related to different dietary behavior between organisms, where juveniles are preferently bottom feeders and sediments are the main source of these hydrophobic pollutants. PBDEs levels (ng g-1 lipid) in juveniles ranged from 75 to 1920 in muscle and gonad, respectively, while females showed the lowest levels in liver (19 ng g-1 lipid) and the highest in muscle (77 ng g-1 lipid). However, similar distribution of individual PBDE congeners was found in both fish groups: 47(44-82%)>99>100. These results were consistent with the general pattern found in worldwide fish. In conclusion, fish size influence the bioaccumulation of OCPs, PCBs and PBDEs in brown trout, and it is related with biological characteristics and physiological processes.