Forest cover influences fish mercury concentrations in national parks of the western U.S.

Autor: Flanagan Pritz CM; National Park Service, National Resource Stewardship and Science Directorate, Air Resources Division, PO Box 25287, Lakewood, CO 80225, USA. Electronic address: colleen_flanagan_pritz@nps.gov., Johnson BL; U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97330, USA., Willacker JJ; U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97330, USA., Kennedy CM; U.S. Fish & Wildlife Service, Fish and Aquatic Conservation, Colorado Fish and Wildlife Conservation Office, 1131 Fairway Club Circle, B2, Estes Park, CO 80517, USA., Daniele NR; National Park Service, Yosemite National Park, Resources Management and Science Division, PO Box 700, El Portal, CA 95318, USA., Eagles-Smith CA; U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97330, USA.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Dec 10; Vol. 955, pp. 176936. Date of Electronic Publication: 2024 Oct 15.
DOI: 10.1016/j.scitotenv.2024.176936
Abstrakt: The global prevalence of mercury (Hg) contamination and its complex biogeochemical cycling has resulted in elevated Hg concentrations in biota in remote and pristine environments. However, there is uncertainty in the relative importance of Hg deposition and landscape factors that control Hg cycling and bioaccumulation. To address this, we measured total mercury (THg) concentrations in 1344 fish across 60 subalpine lakes from 12 national parks (NPs). These parks represent three distinct high-elevation regions across the western U.S.: Cascades and Olympic Peninsula, Sierra Nevada and Great Basin, and Rocky Mountains. Within these regions, three NPs (Mount Rainier, Yosemite, and Rocky Mountain) were intensively studied representatives of each region. This study aimed to (1) assess the magnitude of mercury contamination in a collection of remote, small catchment lakes; (2) quantify the variability of fish THg concentrations among and within parks; and (3) test the relative importance of Hg inputs in comparison to landscape characteristics on lake-specific fish THg concentrations. The spatial variability in fish THg concentrations was 2.6-fold higher than variation in deposition to watersheds, suggesting that factors other than Hg delivery are important determinants of Hg accumulation in these environments. Spatially, fish THg concentrations (ng/g ww ± standard error) were lower in the Rockies (46.2 ± 5.0) and Sierra (56.5 ± 5.8) compared to the Cascades (67.8 ± 6.1). Additionally, fish THg concentrations increased with increasing conifer forest cover (Intensive parks: P < 0.0001, R 2  = 0.43; All parks: P = 0.0001, R 2  = 0.23) but were not correlated with wet Hg deposition across the catchment. These findings suggest that forest composition is likely an important aspect of Hg delivery to lake food webs, and although the mechanisms are unclear, could be tied to some combination of forest influences on catchment organic carbon and increased surface area for dry Hg deposition.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: NR Daniele reports financial support was provided by San Francisco Public Utilities Commission. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Published by Elsevier B.V.)
Databáze: MEDLINE
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