An epizootic of diffuse glomerulonephritis in white perch (Roccus americanus) from a heavily polluted industrial basin in Lake Ontario.

Examination of 43 white perch from a heavily polluted water basin showed all had severe diffuse glomerulonephritis. There were fibrinoid necrosis of tuft vessels, especially the afferent and efferent arterioles, and thickened basement membranes which ultrastructurally contained dense deposits in a subendothelial location. None of these lesions was found in white bass, a closely related species, from the same source nor in white perch from other relatively nonpolluted sites in Lake Ontario or Lake Erie. This is a dramatic example of a rare lesion in fish and possible represents an immune-complex mediated response to an environmental pollutant.