| Abstract Title: | Selenium’s Influence on Mercury Accumulation in Fish Across Ecologically Relevant Scales in Western United States |
| Presenter Name: | Robin Stewart |
| Company/Institution: | USGS |
| Session: | Special Session - Selenium-mercury interactions in aquatic food webs: The state of the science and future research directions |
| Day and Session: | Wednesday 27th July - Session Four |
| Start Time: | 16:00 UTC |
| Co-Authors: | Robin Stewart |
Abstract Information :
Mercury (Hg) has a strong chemical affinity for selenium (Se) such that Se, when found in excess of Hg, has been shown to modify Hg bioavailability, bioaccumulation, and in some cases mitigate Hg toxicity. Yet, questions remain regarding how Hg and Se tissue concentrations can be used to assess protection against Hg toxicity in nature. We evaluated paired Hg-Se concentrations for 8,657 freshwater fishes in the Western United States, representing a range of exposure gradients, tissue types, species, and habitats, to evaluate the influence of Se on Hg bioaccumulation. The distributions of paired Hg and Se concentrations were weakly correlated (Pearson’s r = 0.21) in whole body tissues and not correlated in muscle tissue. Indeed, statistical models comparing the influence of different factors on Hg concentrations found that Se explained only a small proportion (
