Reference : Unusually high sea ice cover influences resource use by benthic invertebrates in coas...
Scientific congresses and symposiums : Poster
Life sciences : Environmental sciences & ecology
Life sciences : Aquatic sciences & oceanology
Life sciences : Zoology
Unusually high sea ice cover influences resource use by benthic invertebrates in coastal Antarctica
Michel, Loïc mailto [Université de Liège > Département de Biologie, Ecologie et Evolution > Océanographie biologique >]
Dubois, Philippe [Université Libre de Bruxelles - ULB > > Marine Biology Laboratory > >]
Eleaume, Marc [[Musée National d'Histoire Naturelle - MNHN > Institute of Systematics, Evolution and Biodiversity > UMR 7205 > >]
Fournier, Jérôme [Musée National d'Histoire Naturelle - MHNH > Concarneau Biological Marine Station > UMR 7208 BOREA > >]
Gallut, Cyril [Université Pierre et Marie Curie - Paris 6 - UPMC > Institute of Systematics, Evolution and Biodiversity > UMR 7205 > >]
Jane, Philip [Aquarium de Paris - Cinéaqua > > > >]
Lepoint, Gilles mailto [Université de Liège > Département de Biologie, Ecologie et Evolution > Océanographie biologique >]
JESIUM (Joint European Stable Isotopes User group Meeting) 2016
Benelux Association of Stable Isotope Scientists (BASIS)
Ghent University
[en] Stable isotopes ; Antarctica ; Global change ; Benthic invertebrates ; SIAR ; Mixing model
[en] Antarctica currently undergoes strong and contrasted impacts linked with climate change. While the West Antarctic Peninsula is one of the most rapidly warming regions in the world, resulting in sea ice cover decrease, the sea ice cover of East Antarctica unexpectedly tends to increase, possibly in relation with changes in atmospheric circulation. Changes in sea ice cover are likely to influence benthic food web structure through modifications of benthic-pelagic coupling, disruption of benthic production and/or modifications of benthic community structure (i.e. resource availability for benthic consumers).
Here, we studied shallow (0-20 m) benthic food web structure on the coasts of Petrels Island (Adélie Land, East Antarctica) during an event of unusually high spatial and temporal (two successive austral summers without seasonal break-up) sea ice cover. Using stable isotope ratios of C and N and the SIAR mixing model, we examined importance of 4 organic matter sources (benthic macroalgae, benthic biofilm, sympagic algae, suspended particulate organic matter) for nutrition of dominant primary consumers and omnivores. 14 invertebrate taxa including sessile and mobile polychaetes, gastropods, bivalves, sea stars, sea urchins and sea cucumbers were studied.
Our results indicate that most benthic invertebrates predominantly relied on sympagic algae. Despite its very high abundance, trophic role of benthic biofilm seemed limited. However, interpretation of data was complicated by the peculiar ecophysiological features of Antarctic invertebrates, whose very low metabolic rates could be associated to low isotopic turnover and long time to reach isotopic equilibrium with their food items. Resource use by consumers from Adélie Land markedly differed from literature data about invertebrate diet in coastal Antarctica, suggesting 1) important influence of increased sea ice cover on benthic food web structure and 2) high spatial and/or temporal variation in the feeding habits of studied organisms, likely linked with a high degree of trophic plasticity. Our results provide insights about how Antarctic benthic consumers, which have evolved in an extremely stable environment, might adapt their feeding habits in response to sudden man-driven changes in environmental conditions and trophic resource availability.
Centre Interfacultaire de Recherches en Océanologie - MARE
Politique Scientifique Fédérale (Belgique) = Belgian Federal Science Policy ; Fonds de la Recherche Scientifique (Communauté française de Belgique) - F.R.S.-FNRS
vERSO - Ecosystem Responses to global change: a multiscale approach in the Southern Ocean
Researchers ; Professionals ; Students

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