In Berlin, New Hampshire, USA, the Androscoggin River flows adjacent to a former chlor-alkali facility that is a US Environmental Protection Agency Superfund site and source of mercury (Hg) to the river. The present study was conducted to determine the fate and bioaccumulation of methylmercury (MeHg) to lower trophic-level taxa in the river. Surface sediment directly adjacent to the source showed significantly elevated MeHg (10-40× increase, mean±standard deviation [SD]: 20.1±24.8 ng g-1 dry wt) and total mercury (THg; 10-30× increase, mean±SD: 2045±2669 ng g-1 dry wt) compared with all other reaches, with sediment THg and MeHg from downstream reaches elevated (3-7× on average) relative to the reference (THg mean±SD: 33.5±9.33 ng g-1 dry wt; MeHg mean±SD: 0.52±0.21ng g-1 dry wt). Water column THg concentrations adjacent to the point source for both particulate (0.23ng L-1) and dissolved (0.76ng L-1) fractions were 5-fold higher than at the reference sites, and 2-fold to 5-fold higher than downstream. Methylmercury production potential of periphyton material was highest (2-9ng g-1 d-1 dry wt) adjacent to the Superfund site; other reaches were close to or below reporting limits (0. 1ng g-1 d-1 dry wt). Total Hg and MeHg bioaccumulation in fauna was variable across sites and taxa, with no clear spatial patterns downstream of the contamination source. Crayfish, mayflies, and shiners showed a weak positive relationship with porewater MeHg concentration. Environ Toxicol Chem 2015;34:1649-1658.
Buckman, K. L., Marvin-Dipasquale, M., Taylor, V. F., Chalmers, A., Broadley, H. J., Agee, J., … Chen, C. Y. (2015). Influence of a chlor-alkali superfund site on mercury bioaccumulation in periphyton and low-trophic level fauna. Environmental Toxicology and Chemistry, 34(7), 1649–1658. https://doi.org/10.1002/etc.2964