Are metal mining effluent regulations adequate: identification of a novel bleached fish syndrome in association with iron-ore mining effluents in Labrador, Newfoundland

Water quality guidelines for industrial effluents are in place in many coun tries but they have generally evolved within a limited ecotoxicological fra mework. Effluents from iron-ore mines have traditionally been viewed by reg ulatory bodies as posing little or no risk to the aquatic environment. Howe ver, it was recently reported that lake trout taken from a large iron-ore c ontaminated Lake in Labrador (Wabush Lake) had elevated levels of DNA oxida tive damage and were markedly depleted in levels of vitamin A (Payne et al. , 1998) in comparison with fish from a Lake (Shabogamo Lake) receiving less er levels of effluents. Through further observations, it has now been estab lished that the lake trout in Wabush Lake are commonly affected with a mark ed skin bleaching syndrome in comparison with fish in Shabogamo Lake and a nearby Lake (Ashuanipi) which does not receive effluents. To the authors' k nowledge such a syndrome which is characterized by marked reduction in skin pigmentation and overall increase in skin whitening has not been reported before in any fish population in association with contamination. Preliminar y information for liver histopathological and blood cell differences have a lso been obtained in fish in Wabush Lake in comparison with Ashuanipi Lake. It has also been observed through studies on phosphatidyl liposomes that i ron-ore leachate contains redox-active material (iron but possibly other tr ansition metals) that has considerable potential for causing oxidative dama ge to cellular constituents. Using the weight of evidence approach it is in dicated that iron-ore effluents may pose more of a risk to the aquatic envi ronment than traditionally considered by regulatory agencies. (C) 2001 Else vier Science B.V. All rights reserved.