In-reservoir physical processes modulate aqueous and biological methylmercury export from a seasonally anoxic reservoir
Links
- More information: Publisher Index Page (via DOI)
- Data Release: USGS data release - Biomass and methylmercury concentrations in biweekly biological samples from Brownlee and Oxbow Reservoir outflows, Snake River Hells Canyon Complex (Idaho-Oregon), 2018-2019
- Open Access Version: Publisher Index Page
- Download citation as: RIS | Dublin Core
Abstract
Anoxic conditions within reservoirs related to thermal stratification and oxygen depletion lead to methylmercury (MeHg) production, a key process governing the uptake of mercury in aquatic food webs. Once formed within a reservoir, the timing and magnitude of the biological uptake of MeHg and the relative importance of MeHg export in water versus biological compartments remain poorly understood. We examined the relations between the reservoir stratification state, anoxia, and the concentrations and export loads of MeHg in aqueous and biological compartments at the outflow locations of two reservoirs of the Hells Canyon Complex (Snake River, Idaho-Oregon). Results show that (1) MeHg concentrations in filter-passing water, zooplankton, suspended particles, and detritus increased in response to reservoir destratification; (2) zooplankton MeHg strongly correlated with MeHg in filter-passing water during destratification; (3) reservoir anoxia appeared to be a key control on MeHg export; and (4) biological MeHg, primarily in zooplankton, accounted for only 5% of total MeHg export from the reservoirs (the remainder being aqueous compartments). These results improve our understanding of the role of biological incorporation of MeHg and the subsequent downstream release from seasonally stratified reservoirs and demonstrate that in-reservoir physical processes strongly influence MeHg incorporation at the base of the aquatic food web.
Study Area
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | In-reservoir physical processes modulate aqueous and biological methylmercury export from a seasonally anoxic reservoir |
| Series title | Environmental Science and Technology |
| DOI | 10.1021/acs.est.2c03958 |
| Volume | 56 |
| Issue | 19 |
| Year Published | 2022 |
| Language | English |
| Publisher | ACS Publications |
| Contributing office(s) | Forest and Rangeland Ecosys Science Center, Idaho Water Science Center |
| Description | 10 p. |
| First page | 13751 |
| Last page | 13760 |
| Country | United States |
| State | Idaho, Oregon |
| Other Geospatial | Brownlee Reservoir, Hells Canyon Reservoir, Oxbow Reservoir |
| Google Analytic Metrics | Metrics page |