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Updated: Jul 14, 2026
09:33
An Anaerobic Biosensor Assay for the Detection of Mercury and Cadmium
Published on: December 17, 2018
Mercury speciation in piscivorous fish from mining-impacted reservoirs.
James S Kuwabara1, Yuji Arai, Brent R Topping
1U.S. Geological Survey, 345 Middlefield Road, Mail Stop 439, Menlo Park, California 94025, USA. kuwabara@usgs.gov
Environmental Science & Technology
|May 31, 2007
Summary
Mercury in fish from California and Nevada reservoirs, impacted by historical mining, is primarily methylmercury cysteine complexes. This finding suggests a universal model for assessing fish consumption risks across diverse environments.
Area of Science:
- Environmental Chemistry
- Ecotoxicology
- Analytical Chemistry
Background:
- California's Guadalupe Reservoir (GUA) and Nevada's Lahontan Reservoir (LAH) show mercury levels exceeding safe consumption limits.
- Historical gold and silver mining in the Sierra Nevada is a primary source of mercury contamination in these aquatic ecosystems.
Purpose of the Study:
- To identify the predominant chemical species of mercury accumulated in fish from GUA and LAH.
- To understand mercury's chemical form in high-trophic-level predatory fish exposed to mining-related contamination.
Main Methods:
- X-ray absorption near edge structure (XANES) analyses were performed on largemouth bass and hybrid striped bass.
- Fish muscle tissues from both reservoirs were analyzed to determine mercury speciation.
Main Results:
- XANES analyses revealed that methylmercury cysteine complexes were the dominant mercury species in fish from both GUA and LAH.
- This dominance was observed despite differences in mercury sources and environmental conditions between the two reservoirs.
Conclusions:
- The accumulation of methylmercury cysteine complexes in fish muscle is consistent across different mercury exposure scenarios, including marine environments.
- A generalized toxicological model for fish consumption may be applicable across various ecological settings due to the consistent mercury speciation.
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