Mercury in Barents Sea fish in the Arctic polar night: Species and spatial comparison

Although mercury (Hg) in polar ecosystems has been well-studied, there is little information on Hg in the Arctic during low-productivity seasons like the polar night. We quantified Hg concentrations, carbon, and nitrogen stable isotope ratios (δ13C and δ15N) in the muscle of polar cod (Boreogadus sa...

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Bibliographic Details
Published in:Marine Pollution Bulletin
Main Authors: Gopakumar, Anjali, Giebichenstein, Julia, Raskhozheva, Evgeniia, Borgå, Katrine
Format: Article in Journal/Newspaper
Language:English
Published: 2021
Subjects:
Online Access:http://hdl.handle.net/10852/90174
http://urn.nb.no/URN:NBN:no-92782
https://doi.org/10.1016/j.marpolbul.2021.112501
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Summary:Although mercury (Hg) in polar ecosystems has been well-studied, there is little information on Hg in the Arctic during low-productivity seasons like the polar night. We quantified Hg concentrations, carbon, and nitrogen stable isotope ratios (δ13C and δ15N) in the muscle of polar cod (Boreogadus saida), Atlantic cod (Gadus morhua), and capelin (Mallotus villosus) sampled from the North-West and North-East Barents Sea during November–December 2019. Hg concentrations varied between species (14–175 ng/g dw), dependent on region, but were well below the toxicity threshold for fish health and the EU-accepted threshold for human consumption. Interspecific differences were observed only in the North-East region, with Atlantic cod having highest Hg concentrations, explained by its larger size, higher trophic position and benthopelagic feeding. Spatial differences in polar cod with higher Hg concentrations in the North-East than the North-West were likely due to a combination of differences in food web structure and Hg exposure.