Increased sea ice cover alters food web structure in East Antarctica

• Published in: Scientific Reports
• Main Authors: Michel, Loïc, Danis, Bruno, Dubois, Philippe, Eleaume, Marc, Fournier, Jérôme, Gallut, Cyril, Jane, Philip, Lepoint, Gilles
• Other Authors: MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège, FOCUS - Freshwater and OCeanic science Unit of reSearch - ULiège
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2019
• Subjects: stable isotopes; food webs; antarctica; global change; sea ice; southern ocean; Life sciences; Zoology; Environmental sciences & ecology; Aquatic sciences & oceanology; Sciences du vivant; Zoologie; Sciences de l’environnement & écologie; Sciences aquatiques & océanologie; Antarc*; Antarctic; Antarctica; East Antarctica; Sea ice; Southern Ocean
• Online Access: https://orbi.uliege.be/handle/2268/236151; https://orbi.uliege.be/bitstream/2268/236151/1/Michel%20et%20al%2019%20Sci%20Rep.pdf; https://doi.org/10.1038/s41598-019-44605-5

peer reviewed In recent years, sea ice cover along coasts of East Antarctica has tended to increase. To understand ecological implications of these environmental changes, we studied benthic food web structure on the coasts of Adélie Land during an event of unusually high sea ice cover (i.e. two successive austral summers without seasonal breakup). We used integrative trophic markers (stable isotope ratios of carbon, nitrogen and sulfur) to build ecological models and explored feeding habits of macroinvertebrates. In total, 28 taxa spanning most present animal groups and functional guilds were investigated. Our results indicate that the absence of seasonal sea ice breakup deeply influenced benthic food webs. Sympagic algae dominated the diet of many key consumers, and the trophic levels of invertebrates were low, suggesting omnivore consumers did not rely much on predation and/or scavenging. Our results provide insights about how Antarctic benthic consumers, which typically live in an extremely stable environment, might adapt their feeding habits in response to sudden changes in environmental conditions and trophic resource availability. They also show that local and/or global trends of sea ice increase in Antarctica have the potential to cause drastic changes in food web structure, and therefore to impact benthic communities. vERSO - Ecosystem Responses to global change: a multiscale approach in the Southern Ocean (BR/132/A1/vERSO)