Seasonal maturity development of Baltic cod in different spawning areas : importance of the Arkona Sea for the summer spawning stock

Polycyclic aromatic hydrocarbons (PAH) are important environmental contaminants in the North Sea and Baltic Sea which may lead to increased levels of neoplastic aberrations or tumors in fish liver. To assess the PAH contamination of fish, concentrations of PAH metabolites were determined in bile fluid. PAH are rapidly metabolised and excreted in fish. Therefore, the determination of PAH parent compounds is not often used. Dab (Limanda limanda) caught in the North Sea in 2004 had mean values of 10 to 160 ng/ml (0.6 - 15 ng/AE380 nm) 1-hydroxypyrene. The highest values were found in the German Bight. In flounder (Platichthys flesus) caught in the western Baltic in 2004, 1-hydroxypyrene levels averaged 60 - 90 ng/ml (17 - 52 ng/AE380 nm). Levels of 1-hydroxyphenanthrene in fish bile were considerably lower and reached only about 7% of the 1-hydroxypyrene concentrations. Significant differences were found among the 1-hydroxypyrene levels determined in the summer and winter surveys, and among sampling sites. No time trend in contamination level was visible.