Selenium accumulation, reproductive status, and histopathological changes in environmentally exposed redear sunfish

Abstract

Comparisons were made of the accumulation of selenium, histopathological damage, and reproductive status of redear sunfish (Lepomis microlophus) collected in July 1986 from Martin Lake (a contaminated site) and Lake Tyler (a reference site). Hepatic concentrations of selenium were four times higher in Martin Lake sunfish (7.6 +/- 0.5 ppm) than in fish from the reference lake (2.1 +/- 0.2 ppm). Redears collected from the contaminated lake had lower condition factors than individuals collected from the reference site. Sunfish with elevated levels of hepatic selenium had substantial alterations in the liver including necrosis, cytoplasmic vacuolation, and Kupffer cell proliferation. The ovaries of mature fish collected from Martin Lake frequently had atretic follicles, abnormally shaped follicles, connective tissue hypertrophy, asynchronous oocyte development, and an overall reduction in the number of developing oocytes. These histopathological changes in the ovaries of Martin Lake sunfish were not accompanied by alterations in gonadal steroid titers in the blood. No histopathological lesions could be detected in the testes of Martin Lake fish. Most of the males collected from the contaminated site were immature and had lower circulating levels of sex steroid hormones than reference males. The results show that tissue burdens of selenium have declined by 25% since this sunfish population was sampled last in 1981. Further, the results of this study indicate that the overall health and reproductive status of selenium-contaminated fish collected from Martin Lake is still seriously impaired.

Environmental contaminants and biomarker responses in fish from the Rio Grande and its U.S. tributaries: Spatial and temporal trends

“…Values in female bass from Station 514 were greater than any reported in bass previously but were related to a parasite infection; and the ovaries of one female carp from Station 64 contained no normal tissue, only necrotic, degenerated follicles. Elevated rates of atresia in fish have been associated with exposure to Se (Sorensen, 1988) and other contaminants (e.g., Cross and Hose, 1988), but may also be caused by environmental factors other than chemical exposure (e.g., June, 1970June, , 1977.…”

Evaluation of the Hazard Quotient Method for Risk Assessment of Selenium

“…A basic flaw with the HQ method is that it uses geometric mean waterborne concentrations of selenium. A large part of the selenium bioaccumulation and associated toxic impact to fish and wildlife in an aquatic system can result from onetime or periodic waterborne inputs that have high concentrations relative to the long-term mean (Garrett and Inman, 1984;Sorensen, 1988;Presser et al, 1994). On a mass-balance basis, these spikes in concentration deliver a disproportionately large amount of selenium that can load sediments and be cycled into detrital food chains long after the waterborne spike is gone (Lemly and Smith, 1987).…”

Hazard assessment of selenium to endangered razorback suckers (Xyrauchen texanus)

“…This scenario has occurred in other contaminant investigations. For example, Sorensen (1988) stated that 'Fish kills (at Belews Lake, NC, and Martin Lake, TX) were considered a direct result of selenium release into the main basin of the lakes because several hundred analyses for metals, metalloids, physiochemical parameters, and pesticides provided essentially negative results except for sufficiently high levels of selenium in the water (approximately 5 mgyl) to warrant concern. ' Lemly (1985) reviewed information in 10 studies of potential causes for the cause of fishery problems at Belews Lake (16 species eliminated, two species present as adults only, one species re-colonized, and one species unaffected), and of the 16 inorganic elements of concern, only selenium was present at elevated concentrations in water and fish.…”