Selenium concentrations in coho salmon out-migrant smolts and returning adults: a comparison of wild versus hatchery-reared fish

Abstract

Selenium levels were compared in wild and hatchery-reared coho salmon (Oncorhynchus kisutch ). Selenium concentrations were measured in the liver of returning adult fish and in whole body samples of outmigrant smolts. In each case, selenium levels in wild coho salmon were approximately twice as high as those in hatchery-reared fish. These comparisons will offer some guidelines to investigators conducting studies relating selenium concentrations with disease potentials and/or resistances in fishes. The significance of differences in the concentrations of selenium and other micronutrients found in cultured and wild fish is discussed.