Se is an environmental concern as it can be toxic if present in high concentrations even though it is a dietary requirement for all animals. Se levels are a special concern in the Fountain Creek Watershed located in southeastern Colorado whose geological source is the Se-rich Pierre Shale. Segments of Fountain Creek have Se water levels that exceed the current EPA limit of 5 µg/l. In the studies described here, the effects of river water containing selenium were examined on fish populations at different sites along the Fountain Creek Watershed. Based on the hypothesis that high levels of Se present in the Creek and resident bryophytes should be an indicator of diversity in the river fish we explored the possibility that the low toxicity of the selenium could be due to speciation. A speciation analysis was conducted to determine the selenium(IV) and selenium(VI). Our results show that sites with higher ratios of the more toxic Se(IV) relative to total selenium exhibit lower fish diversity and number of fish. Our results indicate that factors, other than total Se, such as Se speciation may be involved in controlling the bioavailability and toxicity of this element to aquatic organisms in Fountain Creek.
Bibliographical noteFunding Information:
JSC and SJB would like to thank the Board of Pueblo, Colorado, County Commissioners, the Lower Arkansas Valley Water Conservancy District, Colorado, and the Board of Water Works of Pueblo. JSC, SJB and DCC would like to thank Colorado State University—2014–2015 Faculty SEED Grant. DCC thanks the Arthur Cope Foundation for funding.
© 2017, SBIC.
- Metal determination