Increasing Frequency of Thyroid Goiters in Coho Salmon ( Oncorhynchus kisutch ) in the Great Lakes

Abstract

Coho salmon collected during the 1976 spawning runs from Lakes Michigan, Ontario, and Erie had overt goiter frequencies of 6.3, 47.6, and 79.5%, respectively. These represent significant increases over the frequencies observed in previous years. Epizootiological data suggest that environmental goitrogens (possibly pollutants) may be involved in the etiology of the thyroid disorder.