Influence of sea-ice dynamics on coastal Antarctic benthos: A case study on lantern clams (Laternula elliptica) in Adélie Land

• Published in: Marine Environmental Research
• Main Authors: Thébault, Julien, Uvanović, Hana, Amice, Erwan, Chauvaud, Laurent, Peharda, Melita
• Other Authors: 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 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)-Centre National de la Recherche Scientifique (CNRS), Institute of Oceanography and Fisheries
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: East Antarctica; Food source; Growth; Ice; Laternula elliptica; Master chronology; Sclerochronology; Sympagic algae; Benthic-pelagic coupling; Clams; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Antarctic; Antarc*; Antarctica; Sea ice
• Online Access: https://hal.science/hal-04259908; https://doi.org/10.1016/j.marenvres.2023.106220

International audience Polar regions are warming faster than the world average and are profoundly affected by changes in the spatio-temporal dynamics of sea ice, with largely unknown repercussions on the functioning of marine ecosystems. Here, we investigated the impacts of interannual sea-ice variability on coastal benthic communities in Antarctica, focusing on a close-to-pristine area (Adélie Land). We investigated shell growth of the circum-Antarctic bivalve Laternula elliptica, considered a key species in these soft bottom benthic communities. Chondrophores of live-collected clams were prepared using standard sclerochronological methods to study the interannual variability of shell growth from 1996 to 2015. Our results show that the master chronology varied with sea-ice dynamics. When sea ice breaks up too early, sympagic algae do not have time to accumulate sufficiently high biomass, thus strongly limiting the energy input to the benthos. This negatively affects the physiological performance of L. elliptica, thereby altering their population dynamics and hence the functioning of these soft-bottom ecosystems.