The Effect of Bioaccumulated Selenium on Mortalities and Deformities in the Eggs, Larvae, and Fry of a Wild Population of Cutthroat Trout ( Oncorhynchus clarki lewisi )

Abstract

To determine if elevated concentrations of waterborne selenium (Se), caused by coal mining, in the Elk River in southeastern British Columbia, may be causing reproductive or teratogenic effects in wild cutthroat trout (Oncorhynchus clarki lewisi), fertilized eggs from exposed and reference fish were raised in the laboratory. Eggs from each female were reared separately and the percent mortalities and deformities were related to the selenium content of the eggs. Selenium concentrations in females from the exposed site were highest in the liver (36.6 +/- 22.5 microg/g dry weight, range: 18.3 to 114), followed by the eggs (21.0 +/- 18.3 microg/g, range: 8.7 to 81.3) and the muscle (12.5 +/- 7.7 microg/g, range: 6.7 to 41). Despite these elevated egg Se concentrations, there was no significant effect on fertilization; time to hatch; percent hatch; or egg, larvae, and fry deformities or mortalities. Reproductive failure and embryonic terata have been reported at much lower egg Se concentrations in other fish species. The lack of any toxic response in this study may be due to an evolved tolerance to higher tissue Se concentrations in a population of fish living in a seleniferous river system.

Evaluating Impacts of Mountain Top Removal/Valley Fill Coal Mining on Stream Fish Populations

“…Selenium has been documented to have toxic effects on aquatic life (Lemly 1993). In fact, mortality of rainbow trout, chinook salmon, striped bass, and bluegill has been documented at concentrations of selenium ranging from 4 to 10 µg/L (Kennedy et al 2000). As such, we grouped the Mud River sites according to presence (n=5) or absence (n=3) of selenium and repeated the analysis of total number of species and total number of benthic species (Fig.…”

The American Dipper as a Bioindicator of Selenium Contamination in a Coal Mine-Affected Stream in West-Central Alberta, Canada

“…In addition, Orr et al (2005) have recently shown that biota in coal mine-affected lentic systems accumulated more selenium than those in coal mine-affected lotic systems. However, contrasting with these results and fueling concern about potential effects of coal mining on selenium mobilization and bioaccumulation, are studies that reported increased levels of selenium in fish at sites downstream from coal mines in the Rocky Mountains of Canada (Kennedy et al, 2000;Palace et al, 2004;Holm et al, 2005). One of those studies reported a significant, selenium-dependent increase in deformities in trout fry hatched from fertilized eggs of fish from coal mine-affected streams (Holm et al, 2005), heightening to an even greater extent the level of concern about possible coal mining effects.…”

Assessment of Selenium Effects in Lotic Ecosystems

“…A recent paper by Kennedy et al (2000) examined the potential e!ects of selenium in a lotic environment by comparing mortalities and deformities in the progeny of cutthroat trout (Oncorhynchus clarki) collected from a selenium-laden river impacted by coal mining. A nearby lake in British Columbia, Canada, was used as the reference site.…”