Increased Mercury and Reduced Insect Diversity in Linked Stream–Riparian Food Webs Downstream of a Historical Mercury Mine

Autor: Johanna M. Kraus, JoAnn M. Holloway, Michael J. Pribil, Ben N. McGee, Craig A. Stricker, Danny L. Rutherford, Andrew S. Todd
Rok vydání: 2022
Předmět:
Zdroj: Environmental Toxicology and Chemistry. 41:1696-1710
ISSN: 1552-8618
0730-7268
DOI: 10.1002/etc.5342
Popis: Historical mining left a legacy of abandoned mines and waste rock in remote headwaters of major river systems in the western United States. Understanding the influence of these legacy mines on culturally and ecologically important downstream ecosystems is not always straightforward because of elevated natural levels of mineralization in mining-impacted watersheds. To test the ecological effects of historic mining in the headwaters of the upper Salmon River watershed in Idaho (USA), we measured multiple community and chemical endpoints in downstream linked aquatic-terrestrial food webs. Mining inputs impacted downstream food webs through increased mercury accumulation and decreased insect biodiversity. Total mercury (THg) in seston, aquatic insect larvae, adult aquatic insects, riparian spiders, and fish at sites up to 7.6 km downstream of mining was found at much higher concentrations (1.3-11.3-fold) and was isotopically distinct compared with sites immediately upstream of mining inputs. Methylmercury concentrations in bull trout and riparian spiders were sufficiently high (732-918 and 347-1140 ng MeHg g
Databáze: OpenAIRE
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