Experimental evidence for recovery of mercury-contaminated fish populations.

Autor: Blanchfield PJ; Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada. Paul.Blanchfield@dfo-mpo.gc.ca.; Department of Biology, Queen's University, Kingston, Ontario, Canada. Paul.Blanchfield@dfo-mpo.gc.ca.; IISD Experimental Lakes Area, Winnipeg, Manitoba, Canada. Paul.Blanchfield@dfo-mpo.gc.ca., Rudd JWM; Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada.; R&K Research, Salt Spring Island, British Columbia, Canada., Hrenchuk LE; Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada.; IISD Experimental Lakes Area, Winnipeg, Manitoba, Canada., Amyot M; Département de Sciences Biologiques, Université de Montréal, Montreal, Quebec, Canada., Babiarz CL; Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI, USA., Beaty KG; Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada., Bodaly RAD; Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada., Branfireun BA; Department of Biology, Biological and Geological Sciences Building, University of Western Ontario, London, Ontario, Canada., Gilmour CC; Smithsonian Environmental Research Center, Edgewater, MD, USA., Graydon JA; Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada., Hall BD; Department of Biology, University of Regina, Regina, Saskatchewan, Canada., Harris RC; Reed Harris Environmental, Oakville, Ontario, Canada., Heyes A; University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, Solomons, MD, USA., Hintelmann H; Water Quality Center, Trent University, Peterborough, Ontario, Canada., Hurley JP; University of Wisconsin-Madison, Department of Civil and Environmental Engineering, Environmental Chemistry and Technology Program, Madison, WI, USA., Kelly CA; Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada.; R&K Research, Salt Spring Island, British Columbia, Canada., Krabbenhoft DP; US Geological Survey, Middleton, WI, USA., Lindberg SE; Oak Ridge National Laboratory, Oak Ridge, TN, USA., Mason RP; Department of Marine Sciences, University of Connecticut, Groton, CT, USA., Paterson MJ; Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada.; IISD Experimental Lakes Area, Winnipeg, Manitoba, Canada., Podemski CL; Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada., Sandilands KA; Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada.; IISD Experimental Lakes Area, Winnipeg, Manitoba, Canada., Southworth GR; Oak Ridge National Laboratory, Oak Ridge, TN, USA., St Louis VL; Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada., Tate LS; Fisheries and Oceans Canada, Freshwater Institute, Winnipeg, Manitoba, Canada.; Wisconsin Department of Natural Resources, Madison, WI, USA., Tate MT; US Geological Survey, Middleton, WI, USA.
Jazyk: angličtina
Zdroj: Nature [Nature] 2022 Jan; Vol. 601 (7891), pp. 74-78. Date of Electronic Publication: 2021 Dec 15.
DOI: 10.1038/s41586-021-04222-7
Abstrakt: Anthropogenic releases of mercury (Hg) 1-3 are a human health issue 4 because the potent toxicant methylmercury (MeHg), formed primarily by microbial methylation of inorganic Hg in aquatic ecosystems, bioaccumulates to high concentrations in fish consumed by humans 5,6 . Predicting the efficacy of Hg pollution controls on fish MeHg concentrations is complex because many factors influence the production and bioaccumulation of MeHg 7-9 . Here we conducted a 15-year whole-ecosystem, single-factor experiment to determine the magnitude and timing of reductions in fish MeHg concentrations following reductions in Hg additions to a boreal lake and its watershed. During the seven-year addition phase, we applied enriched Hg isotopes to increase local Hg wet deposition rates fivefold. The Hg isotopes became increasingly incorporated into the food web as MeHg, predominantly from additions to the lake because most of those in the watershed remained there. Thereafter, isotopic additions were stopped, resulting in an approximately 100% reduction in Hg loading to the lake. The concentration of labelled MeHg quickly decreased by up to 91% in lower trophic level organisms, initiating rapid decreases of 38-76% of MeHg concentration in large-bodied fish populations in eight years. Although Hg loading from watersheds may not decline in step with lowering deposition rates, this experiment clearly demonstrates that any reduction in Hg loadings to lakes, whether from direct deposition or runoff, will have immediate benefits to fish consumers.
(© 2021. Crown.)
Databáze: MEDLINE
Externí odkaz: