Spatial variability in total and organic mercury levels in Antarctic krill Euphausia superba across the Scotia Sea

Seco, José; Xavier, Jose C. ORCID: https://orcid.org/0000-0002-9621-6660; Coelho, João P.; Pereira, Bárbara; Tarling, Geraint ORCID: https://orcid.org/0000-0002-3753-5899; Pardal, Miguel A.; Bustamante, Paco; Stowasser, Gabriele ORCID: https://orcid.org/0000-0002-0595-0772; Brierley, Andrew S.; Pereira, Maria E.. 2019 Spatial variability in total and organic mercury levels in Antarctic krill Euphausia superba across the Scotia Sea. Environmental Pollution, 247. 332-339. https://doi.org/10.1016/j.envpol.2019.01.031

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Official URL: http://dx.doi.org/10.1016/j.envpol.2019.01.031

Abstract/Summary

Total and organic mercury concentrations were determined for males, females and juveniles of Euphausia superba collected at three discrete locations in the Scotia Sea (South Orkney Islands, South Georgia and Antarctic Polar Front) to assess spatial mercury variability in Antarctic krill. There was clear geographic differentiation in mercury concentrations, with specimens from the South Orkney Islands having total mercury concentrations 5 to 7 times higher than Antarctic krill from South Georgia and the Antarctic Polar Front. Mercury did not appear to accumulate with life-stage since juveniles had higher concentrations of total mercury (0.071 μg g−1 from South Orkney Islands; 0.014 μg g−1 from South Georgia) than adults (0.054 μg g−1 in females and 0.048 μg g−1 in males from South Orkney Islands; 0.006 μg g−1 in females and 0.007 μg g−1 in males from South Georgia). Results suggest that females may use egg laying as a mechanism to excrete mercury, with eggs having higher concentrations than the corresponding somatic tissue. Organic mercury makes up a minor percentage of total mercury (15–37%) with the percentage being greater in adults than in juveniles. When compared to euphausiids from other parts of the world, the concentration of mercury in Antarctic krill is within the same range, or higher, highlighting the global distribution of this contaminant. Given the high potential for biomagnification of mercury through food webs, concentrations in Antarctic krill may have deleterious effects on long-lived Antarctic krill predators.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1016/j.envpol.2019.01.031
ISSN:	02697491
Additional Keywords:	food-web, egg laying, crustacean, Southern Ocean, contaminant
Date made live:	27 Mar 2019 08:58 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/522691

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1016/j.envpol.2019.01.031

ISSN:

02697491

Additional Keywords:

food-web, egg laying, crustacean, Southern Ocean, contaminant

Date made live:

27 Mar 2019 08:58 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/522691