Using carbon, nitrogen, and mercury isotope values to distinguish mercury sources to Alaskan lake trout
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- Data Release: USGS data release - Assessment of mercury sources in Alaskan lake food webs (version 1.1, September 2023)
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Abstract
Lake trout (Salvelinus namaycush), collected from 13 remote lakes located in southwestern Alaska, were analyzed for carbon, nitrogen, and mercury (Hg) stable isotope values to assess the importance of migrating oceanic salmon, volcanic activity, and atmospheric deposition to fish Hg burden. Methylmercury (MeHg) bioaccumulation in phytoplankton (5.0–6.9 kg L–1) was also measured to quantify the basal uptake of MeHg to these aquatic food webs. Hg isotope values in lake trout revealed that while the extent of precipitation-delivered Hg was similar across the entire study area, volcanic Hg is likely an important additional source to lake trout in proximate lakes. In contrast, migratory salmon (Oncorhynchus nerka) deliver little MeHg to lake trout directly, although indirect delivery processes via decay could exist. A high level of variability in carbon, nitrogen, and Hg isotope values indicates niche partitioning in lake trout populations within each lake and that a complex suite of ecological interactions is occurring, complicating the conceptually linear assessment of the contaminant source to the receiving organism. Without connecting energy and contaminant isotope axes, we would not have understood why lake trout from these pristine lakes have highly variable Hg burdens despite consistently low water Hg and comparable age-length dynamics.
Study Area
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | Using carbon, nitrogen, and mercury isotope values to distinguish mercury sources to Alaskan lake trout |
| Series title | Environmental Science and Technology Letters |
| DOI | 10.1021/acs.estlett.2c00096 |
| Volume | 9 |
| Issue | 4 |
| Year Published | 2022 |
| Language | English |
| Publisher | American Chemical Society |
| Contributing office(s) | Upper Midwest Water Science Center |
| Description | 8 p. |
| First page | 312 |
| Last page | 319 |
| Country | United States |
| State | Alaska |
| Other Geospatial | Katmai National Park and preserve, Lake Clark Nation Park |
| Google Analytic Metrics | Metrics page |