Contaminant exposure and biochemical effects in outmigrant juvenile chinook salmon from urban and nonurban estuaries of puget sound, Washington

Abstract

AbstractJuvenile chinook salmon (Oncorhynchus tshawytscha) were sampled in Puget Sound, Washington, for 2 consecutive years from contaminated urban estuaries, a nonurban estuary, and from the respective hatcheries to assess exposure to anthropogenic chemicals and to determine if biochemical changes were occurring as a consequence of exposure. Exposure to polycyclic aromatic hydrocarbons (PAHs), chlorinated hydrocarbons, and butyltins was determined. The mean concentrations of PAHs and PCBs in stomach contents and PCBs in liver were significantly higher in salmon from the urban estuaries compared to fish from the nonurban estuary in both sampling years. Higher hepatic concentrations of PCBs than DDTs were found in fish from the urban estuaries, but butyltins were rarely detected. Further, mean concentrations of fluorescent aromatic compounds in bile, an estimate of exposure to PAHs, and hepatic cytochrome P4501A and levels of hepatic DNA adducts were also significantly higher in salmon from the urban estuaries compared to either the nonurban estuary or the hatcheries. Results demonstrated increased exposure to chemical contaminants in outmigrant juvenile salmon during their relatively brief residence in urban estuaries of Puget Sound. Moreover, the exposure was sufficient to elicit biochemical responses, which suggest a potential for other biological effects to ensue.