CHEMICAL CONTAMINANTS IN HARBOR PORPOISE (PHOCOENA-PHOCOENA) FROM THENORTH-ATLANTIC COAST - TISSUE CONCENTRATIONS AND INTRA-ORGAN AND INTER-ORGAN DISTRIBUTION

Concentrations of chlorinated hydrocarbons (CHs), such as polychlorina ted biphenyls (PCBs), were measured in subsamples taken from different anatomical locations of blubber and liver of three apparently healthy harbor porpoises (Phocoena phocoena) incidentally caught in a gill-ne t fishery along the northwest Atlantic coast; selected elements (e.g., mercury) were measured in subsamples of liver. The vertical distribut ion (skin to muscle) of contaminants within blubber was also determine d. Additionally, the concentrations of CHs and elements were determine d in individual samples of brain, lung, kidney, and testis to assess h ow the disposition of toxic chemicals may be dependent on the physiolo gical characteristics of a specific organ. Statistical analyses of the results showed that the anatomical location of the blubber or liver s ample had no significant effect on concentrations of either CHs in blu bber and liver, or of selected elements in liver. However, there were statistical differences between strata of blubber (skin to muscle) for the concentrations of CHs. As expected, the results showed that the C H concentrations, based on wet weight, were considerably higher in the blubber than in the other tissues; however, the concentrations of CHs in the different tissues were more comparable when values were based on total lipid weight with the exception of the brain where lipid norm alized concentrations were lower than in all other tissues. This low r elative accumulation of lipophilic contaminants in the brain tissue ma y be due to the presence of the blood-brain barrier, or due to a lower proportion of neutral lipids, such as triglycerides, as analysis for percent lipid and for the proportion of specific lipid classes showed.