Efficiency of sympagic-benthic coupling revealed by analyses of n-3 fatty acids, IP 25 and other highly branched isoprenoids in two filter-feeding Arctic benthic molluscs: Mya truncata and Serripes groenlandicus

• Published in: Organic Geochemistry
• Main Authors: Amiraux, Rémi, Archambault, Philippe, Moriceau, Brivaëla, Lemire, Mélanie, Babin, Marcel, Mémery, Laurent, Massé, Guillaume, Tremblay, Jean-ERic
• Other Authors: Takuvik International Research Laboratory, Université Laval Québec (ULaval)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Laval Québec (ULaval), Centre de recherche du CHU de Québec-Université Laval (CRCHUQ), CHU de Québec–Université Laval, Université Laval Québec (ULaval)-Université Laval Québec (ULaval), The first author (RA) received financial support from the Université Bretagne Loire (UBL) "post-doctoral attractiveness” program and the Sentinel North postdoctoral program of Université Laval, made possible in part by funding from the Canada First Research Excellence Fund. RA also received a postdoctoral grant from the Littoral Research Chair at Université Laval, which is mainly funded by Sentinel North and the Northern Contaminant Program of the Crown and Indigenous Relations and Northern Affairs Canada. This research was supported by the GreenEdge project, which was funded by the following French and Canadian programs and agencies: ANR (Contract #111112), CNES (project #131425), IPEV (project #1164), CSA, Foundation Total, ArcticNet, LEFE and the French Arctic Initiative (Green Edge project)., ANR-14-CE01-0017,Green Edge,Productivité biologique dans l'Océan Arctique: réponse passée, présente et future aux fluctuations climatiques, et impacts sur les flux de carbone, le réseau trophique et les communautés humaines locales(2014)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: Arctic shelves; Sympagic-benthic coupling; IP25 HBI; n-3 PUFA; EPA; DHA; Mya truncata; Serripes groenlandicus; ice-derived HBI III; Acl; envir; geo; Arctic; Baffin Bay; Greenland; Baffin; Greenland cockle; Sea ice
• Online Access: https://doi.org/10.1016/j.orggeochem.2020.104160; https://hal.archives-ouvertes.fr/hal-03019232/file/Amiraux%20et%20al%202020%20preproof.pdf; https://hal.archives-ouvertes.fr/hal-03019232

International audience The aim of this work was to determine the impact of sympagic (ice-associated) algal primary production on the quality of Arctic filter-feeding bivalves. For this purpose, we investigated the sea ice production of lipids (including omega−3 polyunsaturated fatty acids (n-3 PUFA) and highly branched isoprenoids (HBI)), as well as their subsequent incorporation into the truncate softshell clam (Mya truncata) and the Greenland cockle (Serripes groenlandicus) during the melting periods of two consecutive years in Baffin Bay. Lipid and primary production exhibited seasonal variability and overall contrasts between the two years as a result of distinct physical forcings and the ensuing biological responses. Whilst less productive in terms of total lipids or chlorophyll a, Spring 2016 was more productive than Spring 2015 for n-3 PUFA, which are essential for benthic fauna. The sea ice diatom HBI biomarker IP25 was quantified in sea ice from both years. Interestingly, such production was preceded by a production of the hitherto ‘pelagic’ biomarker, HBI III, in sea ice. In bivalves, HBI contents and correlations confirmed the tightness of the Arctic sympagic-benthic coupling and highlighted that S. groenlandicus can be used as a sentinel species for assessing the degree of this coupling. The confirmation that bivalves incorporate sea-ice derived HBI III and not only IP25, may introduce uncertainties into the use of some HBI-based indices. Monitoring of the fatty acid contents of bivalves allowed identification of their spawning periods and suggests that M. truncata did not store enough n-3 PUFA to sustain its reproductive effort.