REPRODUCTIVE STATUS AND LIPID-CONTENT AS FACTORS IN PCB, DDT AND HCH CONTAMINATION OF A POPULATION OF PIKE (ESOX-LUCIUS L)

Levels of persistent pollutants, including PCBs, SIGMADDT, and gamma-h exachlorocyclohexane, were examined in a pike population inhabiting a eutrophic lake in southern Scandinavia. For females, levels of persist ent pollutants decreased linearly with age, weight, or length. This de cline was ascribed to the seasonal elimination of the lipophilic pollu tants in roe, which contained up to 10 times higher fat levels compare d to muscle and over 10 times the amounts of pollutants. Male pike con tained higher levels of pollutants than females, probably due to the l ower elimination via gonadal products, as germinal tissue constitutes only 2% of the male total body weight and has a lower fat content than ovaries. Female germinal tissue can account for as much as 15% of the body weight. No major fat deposits other than those in germinal tissu e were found in pike, which also had a low muscle fat content, suggest ing that the importance of roe elimination in removing pollutants may be greater in pike than in salmonids. Uptake of persistent pollutants can vary greatly within a species, owing to differences in sex, age, a nd so forth, as well as between species, owing to differences in fat d eposition strategies.