Mercury distribution inthe great cormorant (Phalacrocorax carbo) from the Krogulna ponds and Nysa Kłodzka River (Poland).

Abstract

Mercury belongs among the highly hazardous substances present inthe environment and represents agreat health risk for many animals including predatory and piscivorous birds. The aim ofthis study was toassess the total mercury content inthe main detoxifying organs (liver and kidney) and inthe muscles ofadult great cormorants (Phalacrocorax carbo) caught attwo localities (the Krogulna ponds and the Nysa Kłodzka River) insouthern Poland. The aim was tocompare the locality with the iron ore mining history (the Krogulna ponds) with asite without such load (the Nysa Kłodzka River). The total mercury content inthe great cormorants decreases asfollows: kidneys> liver> muscle inboth monitored localities and significantly differs between the localities. Theaverage mercury content varied from 0.58±0.38mg/kg (muscle) to1.39±1.42mg/kg (kidney) inthe cormorantfrom the Krogulna ponds and from 1.09±0.40mg/kg (muscle) to3.12±1.55mg/kg (kidney) inthe cormorant from the Nysa Kłodzka River. The accumulation ofmercury does not correlate with the mining history asit was higher atthe Nysa Kłodzka River, but itis probably influenced bythe different fish stocks inthese two localities (omnivorous fish inthe Krogulna ponds versus predatory fish inthe Nysa Kłodzka River).