Document Type

Article

Publication Date

3-12-2013

Publication Title

PloS One

Department

Department of Biological Sciences

Abstract

Marine food webs are the most important link between the global contaminant, methylmercury (MeHg), and human exposure through consumption of seafood. Warming temperatures may increase human exposure to MeHg, a potent neurotoxin, by increasing MeHg production as well as bioaccumulation and trophic transfer through marine food webs. Studies of the effects of temperature on MeHg bioaccumulation are rare and no study has specifically related temperature to MeHg fate by linking laboratory experiments with natural field manipulations in coastal ecosystems. We performed laboratory and field experiments on MeHg accumulation under varying temperature regimes using the killifish, Fundulus heteroclitus. Temperature treatments were established in salt pools on a coastal salt marsh using a natural temperature gradient where killifish fed on natural food sources. Temperatures were manipulated across a wider range in laboratory experiments with killifish exposed to MeHg enriched food. In both laboratory microcosms and field mesocosms, MeHg concentrations in killifish significantly increased at elevated temperatures. Moreover, in field experiments, other ancillary variables (salinity, MeHg in sediment, etc.) did not relate to MeHg bioaccumulation. Modeling of laboratory experimental results suggested increases in metabolic rate as a driving factor. The elevated temperatures we tested are consistent with predicted trends in climate warming, and indicate that in the absence of confounding factors, warmer sea surface temperatures could result in greater in bioaccumulation of MeHg in fish, and consequently, increased human exposure.

DOI

10.1371/journal.pone.0058401

Original Citation

Dijkstra JA, Buckman KL, Ward D, Evans DW, Dionne M, Chen CY. Experimental and natural warming elevates mercury concentrations in estuarine fish. PLoS One. 2013;8(3):e58401. doi: 10.1371/journal.pone.0058401. Epub 2013 Mar 12. PMID: 23554891; PMCID: PMC3595298.

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