VARIATION IN CONTAMINANT CONTENT OF LIVERS FROM CORMORANTS PHALACROCORAX-CARBO SINENSIS LIVING NEARBY A POLLUTED SEDIMENTATION AREA IN LAKE IJSSELMEER, THE NETHERLANDS

Abstract

The livers of 23 Cormorants drowned in fishing gear in the vicinity of the contaminated lake Ketelmeer, part of the lake IJsselmeer area, The Netherlands, were analysed for contents of a series of heavy metals and chlorinated hydrocarbons. Individual differences found were related to age, sex and apparent individual differences in food choice. Not surprising ly, contaminant levels were found to be generally lower in immature birds than in adult birds. Sex-related differences were slight and only noticeable in some of the compounds analysed. Comparing the results with data on contaminant loads in different prey fish species in the same area, it was suggested that an increase in the proportion of Eel in the diet might cause up to a twofold increase in contaminant level in some organochlorine compounds.