Effects of coastal managed retreat on mercury biogeochemistry

Sizmur, T. ORCID: https://orcid.org/0000-0001-9835-7195, Godfrey, A. and O'Driscoll, N. J. (2016) Effects of coastal managed retreat on mercury biogeochemistry. Environmental Pollution, 209. pp. 99-106. ISSN 0269-7491 doi: 10.1016/j.envpol.2015.11.016

Abstract/Summary

We investigated the impact of managed retreat on mercury (Hg) biogeochemistry at a site subject to diffuse contamination with Hg. We collected sediment cores from an area of land behind a dyke one year before and one year after it was intentionally breached. These sediments were compared to those of an adjacent mudflat and a salt marsh. The concentration of total mercury (THg) in the sediment doubled after the dyke was breached due to the deposition of fresh sediment that had a smaller particle size, and higher pH. The concentration of methylmercury (MeHg) was 27% lower in the sediments after the dyke was breached. We conclude that coastal flooding during managed retreat of coastal flood defences at this site has not increased the risk of Hg methylation or bioavailability during the first year. As the sediment becomes vegetated, increased activity of Hg-methylating bacteria may accelerate Hg-methylation rate.

Additional Information	Mercury concentration doubled in sediments after coastal flooding but methylmercury concentration deceased
Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/48003
Identification Number/DOI	10.1016/j.envpol.2015.11.016
Refereed	Yes
Divisions	Science > School of Archaeology, Geography and Environmental Science > Earth Systems Science Science > School of Archaeology, Geography and Environmental Science > Department of Geography and Environmental Science
Uncontrolled Keywords	Mercury, Methylmercury, Biogeochemistry, Sediment deposition, Coastal
Additional Information	Mercury concentration doubled in sediments after coastal flooding but methylmercury concentration deceased
Publisher	Elsevier
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