title: Health of lake whitefish (Coregonus clupeaformis) with elevated tissue levels of environmental contaminants.
abstract: Lake whitefish (Coregonus clupeaformis) were collected in 1996 from the St. Lawrence River, Quebec, Canada. Histologic examination was performed on major organs of 497 specimens and on the liver of 48 additional individuals. Preneoplastic and neoplastic hepatic changes consisted of vacuolated cell (n = 65), clear cell (n = 17), and acidophilic (n = 16) foci of altered hepatocyte, hepatocellular carcinoma (n = 12), cholangioma (n = 5), and cholangiocarcinoma (n = 28). Six fish were intersexes (1.2%), and 11.7% of the ovaries (26/223) had ducts containing spermatogonia or more differentiated cells of the male germ cell line. Asynchronous nodular maturation of the testes was present in 8.2% of the male fish (22/267). The mean hepatic concentrations of various contaminants, including polychlorinated biphenyls (PCBs), chlorobenzenes, pesticides, and trace metals, were 6 to 8 times higher in lake whitefish than in three other fish species (Ictalurus punctatus, Catostomus commersoni, and Stizostedion vitreum) collected at the same site. Condition factor of lake whitefish from this study was lower than that previously reported 40 to 50 years ago at this site and from contemporary pristine sites in the Great Lakes, USA. The presence of liver neoplasms, gonadal lesions, and a decreased condition factor in lake whitefish from the St. Lawrence River may be etiologically related to elevated tissue concentrations of toxic chemical contaminants.
authors.affiliation: Canadian Cooperative Wildlife Health Centre and Centre québécois sur la santé des animaux sauvages, Saint-Hyacinthe, Quebec, Canada.
authors.forename: Igor
authors.initials: I
authors.lastname: Mikaelian
authors.forename: Yves
authors.initials: Y
authors.lastname: de Lafontaine
authors.forename: John C
authors.initials: JC
authors.lastname: Harshbarger
authors.forename: Lucy L J
authors.initials: LL
authors.lastname: Lee
authors.forename: Daniel
authors.initials: D
authors.lastname: Martineau
mesh_terms: D002759:Adenoma, Bile Duct / Q000209:etiology / Q000662:veterinary*; D000818:Animals; D002273:Carcinogens / Q000009:adverse effects*; D006528:Carcinoma, Hepatocellular / Q000209:etiology / Q000662:veterinary*; D018281:Cholangiocarcinoma / Q000209:etiology / Q000662:veterinary*; D012734:Disorders of Sex Development / Q000209:etiology / Q000662:veterinary*; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000009:adverse effects*; D005260:Female; D006066:Gonads / Q000002:abnormalities*; D006304:Health Status; D008113:Liver Neoplasms / Q000209:etiology / Q000662:veterinary*; D008297:Male; D011792:Quebec; D012487:Salmonidae
chemical_list: D002273:Carcinogens; D004785:Environmental Pollutants