Issue 2, 2016

Key contributors to variations in fish mercury within and among freshwater reservoirs in Oklahoma, USA

Abstract

Elevated fish mercury (Hg) concentrations in freshwater ecosystems worldwide are a significant human and ecological health concern. Mercury bioaccumulation and biomagnification in lakes and reservoirs are controlled by numerous biogeochemical and ecological factors, contributing to variability in fish Hg concentrations both within and among systems. We measured total mercury concentrations ([THg]) and stable isotopes (δ15N, δ13C) in over 30 fish species in two connected subtropical freshwater reservoirs (Grand Lake and Lake Hudson, Oklahoma, USA), their tributaries, and local farm ponds, all of which are potentially impacted by nearby atmospheric Hg sources. We also conducted an inter-system analysis among 61 reservoirs in Oklahoma to explore biological, chemical and physical factors associated with fish [THg] across systems. We found that [THg] for most species in Grand Lake and Lake Hudson were relatively low compared to other reservoirs in Oklahoma. There were significant spatial variations in many species within and between Grand Lake and Lake Hudson, even after accounting for length and/or trophic position (based on δ15N). Fish in local farm ponds, commonly used in agricultural regions for raising game fish, had 2–17 times higher [THg] than fish of a similar length in nearby reservoirs. The inter-system analysis revealed that pH, water color, rainfall, and nutrients are the best predictors of fish [THg] across systems. Our results provide insight into the key factors associated with fish [THg] variations both within and across systems, and may be useful for exposure assessment and for identifying sites and water bodies prone to high fish [THg] as monitoring priorities.

Graphical abstract: Key contributors to variations in fish mercury within and among freshwater reservoirs in Oklahoma, USA

Supplementary files

Article information

Article type
Paper
Submitted
01 Okt. 2015
Accepted
08 Dec. 2015
First published
09 Dec. 2015

Environ. Sci.: Processes Impacts, 2016,18, 222-236

Key contributors to variations in fish mercury within and among freshwater reservoirs in Oklahoma, USA

Z. Dong, R. A. Lynch and L. A. Schaider, Environ. Sci.: Processes Impacts, 2016, 18, 222 DOI: 10.1039/C5EM00495K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements