Assessment of tolerant sunfish populations (Lepomis sp.) inhabiting selenium-laden coal ash effluents. 3. Serum chemistry and fish health indicators.

Sunfish were collected from fly ash discharge-receiving streams to assess the possible effects of exposure to elevated selenium. Concentrations of selenium, copper, and arsenic were statistically higher in fish tissue (liver) samples from effluent-exposed fish than in reference fish. Several biomarkers were indicative of metal exposure and effect. Plasma protein levels and cholesterol levels were significantly lower in exposed fish, indicating nutritional stress. Ion levels (i.e., K) increased with exposure to ash pond metals, indicating possible gill damage. Fish from the receiving streams also had increased serum glucose and osmolality indicating possible acute stress due to sampling. Fish health assessments revealed a lower incidence of fin erosion, kidney discoloration, urolithiasis or nephrocalcinosis, liver discoloration, and parasites in exposed fish and a higher incidence of skin, eye, and gill aberrations. Condition factors of exposed fish were correlated with biomarker response and were the same as or lower than those of reference fish, but not related to selenium levels. Although several serum biochemical indicators differed between the ash pond-receiving stream and reference sites, pollutant exposure was apparently not sufficient to cause functional damage to critical organ systems.