Mercury biomagnification in a Southern Ocean food web

Autor: Sophie Fielding, Ryan A. Saunders, Geraint A. Tarling, João P. Coelho, Miguel A. Pardal, Sara Aparício, Ricardo S. Matias, Filipe R. Ceia, José C. Xavier, Sue Gregory, José Seco, Paco Bustamante, Gabriele Stowasser, Andrew S. Brierley, Eduarda Pereira, Richard A. Philips
Přispěvatelé: University of St Andrews. Pelagic Ecology Research Group, University of St Andrews. School of Biology, University of St Andrews. Scottish Oceans Institute, University of St Andrews. Centre for Research into Ecological & Environmental Modelling, University of St Andrews. Marine Alliance for Science & Technology Scotland, CESAM & Department of Chemistry, Universidade de Aveiro, Pelagic Ecology Research Group, Scottish Oceans Institut, Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Marine and Environmental Sciences Centre (MARE UC), Universidade de Coimbra [Coimbra], Centre for Environmental and Marine Studies [Aveiro] (CESAM), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Government of South Georgia and the South Sandwich Islands, Centre for Functional Ecology, University of Coimbra [Portugal] (UC), Centro de Estudos do Ambiante e do Mar (CESAM)
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Environmental Pollution (Elsevier)
Environmental Pollution (Elsevier), 2021, 275, pp.116620. ⟨10.1016/j.envpol.2021.116620⟩
Repositório Científico de Acesso Aberto de Portugal
Repositório Científico de Acesso Aberto de Portugal (RCAAP)
instacron:RCAAP
ISSN: 0269-7491
Popis: Funding Information: We acknowledge the financial support of the Portuguese Foundation for the Science and Technology (FCT / MCTES) through a PhD grant to Jose Seco (SRFH/PD/BD/113487) and CESAM (UIDP/50017/2020+UIDB/50017/2020), through national funds. The Institut Universitaire de France is acknowledged for its support to P. Bustamante as a Senior Member. This research was also within strategic program of MARE (MARE - UID/MAR/04292/2020). The work is a contribution to the Ecosystems component of the British Antarctic Survey Polar Science for Planet Earth Programme, funded by the Natural Environment Research Council, which is part of UK Research and Innovation. Funding Information: We thank the officers, crew and scientists aboard RSS James Clark Ross during cruises JR177 and JR16003 for their assistance in collecting samples. We also thank Giulia Pompeo for her help with the Hg analysis. We are grateful to G. Guillou from the “Plateforme Analyses Isotopiques” of LIENSs for his assistance during stable isotope analyses at the University of La Rochelle. We acknowledge the financial support of the Portuguese Foundation for the Science and Technology ( FCT / MCTES ) through a PhD grant to José Seco ( SRFH/PD/BD/113487 ) and CESAM ( UIDP/50017/2020+UIDB/50017/2020 ), through national funds. The Institut Universitaire de France is acknowledged for its support to P. Bustamante as a Senior Member. This research was also within strategic program of MARE (MARE - UID/MAR/04292/2020). The work is a contribution to the Ecosystems component of the British Antarctic Survey Polar Science for Planet Earth Programme, funded by the Natural Environment Research Council , which is part of UK Research and Innovation . Publisher Copyright: © 2021 Elsevier Ltd Copyright: Copyright 2021 Elsevier B.V., All rights reserved. Biomagnification of mercury (Hg) in the Scotia Sea food web of the Southern Ocean was examined using the stable isotope ratios of nitrogen (δ15N) and carbon (δ13C) as proxies for trophic level and feeding habitat, respectively. Total Hg and stable isotopes were measured in samples of particulate organic matter (POM), zooplankton, squid, myctophid fish, notothenioid fish and seabird tissues collected in two years (austral summers 2007/08 and 2016/17). Overall, there was extensive overlap in δ13C values across taxonomic groups suggesting similarities in habitats, with the exception of the seabirds, which showed some differences, possibly due to the type of tissue analysed (feathers instead of muscle). δ15N showed increasing enrichment across groups in the order POM to zooplankton to squid to myctophid fish to notothenioid fish to seabirds. There were significant differences in δ15N and δ13C values among species within taxonomic groups, reflecting inter-specific variation in diet. Hg concentrations increased with trophic level, with the lowest values in POM (0.0005 ± 0.0002 μg g−1 dw) and highest values in seabirds (3.88 ± 2.41 μg g−1 in chicks of brown skuas Stercorarius antarcticus). Hg concentrations tended to be lower in 2016/17 than in 2007/08 for mid-trophic level species (squid and fish), but the opposite was found for top predators (i.e. seabirds), which had higher levels in the 2016/17 samples. This may reflect an interannual shift in the Scotia Sea marine food web, caused by the reduced availability of a key prey species, Antarctic krill Euphausia superba. In 2016/17, seabirds would have been forced to feed on higher trophic-level prey, such as myctophids, that have higher Hg burdens. These results suggest that changes in the food web are likely to affect the pathway of mercury to Southern Ocean top predators. Changes in foodweb dynamics influence Hg bioaccumulation in top predators. Postprint
Databáze: OpenAIRE
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