Shells of the bivalve give new evidence of a strong pelagic-benthic coupling shift occurring since the late 1970s in the North Water polynya.

TitreShells of the bivalve give new evidence of a strong pelagic-benthic coupling shift occurring since the late 1970s in the North Water polynya.
Type de publicationJournal Article
Year of Publication2020
AuteursOlivier, F, Gaillard, B, Thebault, J, Meziane, T, Tremblay, R, Dumont, D, Bélanger, S, Gosselin, M, Jolivet, A, Chauvaud, L, Martel, AL, Rysgaard, S, Olivier, A-H, Pettré, J, Mars, J, Gerber, S, Archambault, P
JournalPhilos Trans A Math Phys Eng Sci
Volume378
Ticket2181
Pagination20190353
Date Published2020 Oct 02
ISSN1471-2962
Résumé

Climate changes in the Arctic may weaken the currently tight pelagic-benthic coupling. In response to decreasing sea ice cover, arctic marine systems are expected to shift from a 'sea-ice algae-benthos' to a 'phytoplankton-zooplankton' dominance. We used mollusc shells as bioarchives and fatty acid trophic markers to estimate the effects of the reduction of sea ice cover on the food exported to the seafloor. Bathyal bivalve living at 600 m depth in northern Baffin Bay reveals a clear shift in growth variations and Ba/Ca ratios since the late 1970s, which we relate to a change in food availability. Tissue fatty acid compositions show that this species feeds mainly on microalgae exported from the euphotic zone to the seabed. We, therefore, suggest that changes in pelagic-benthic coupling are likely due either to local changes in sea ice dynamics, mediated through bottom-up regulation exerted by sea ice on phytoplankton production, or to a mismatch between phytoplankton bloom and zooplankton grazing due to phenological change. Both possibilities allow a more regular and increased transfer of food to the seabed. This article is part of the theme issue 'The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning'.

DOI10.1098/rsta.2019.0353
Identifiant (ID) PubMed32862812
PubMed Central IDPMC7481671
Catégorie HCERES
ACL - Articles dans des revues à comité de lecture
Publication coopération et recherche SUD
Non