Diatom valve distribution and sedimentary fatty acid composition in Larsen Bay, Eastern Antarctica Peninsula

• Published in: Continental Shelf Research
• Main Authors: Sañé, E., Isla, E., Pruski, Audrey, M, Bárcena, M. A., Vétion, G., Demaster, D., J.
• Other Authors: Institute of Marine Sciences / Institut de Ciències del Mar Barcelona (ICM), Consejo Superior de Investigaciones Cientificas España = Spanish National Research Council Spain (CSIC), Laboratoire d'Ecogéochimie des environnements benthiques (LECOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Universidad de Salamanca, Department of Marine, Earth, and Atmospheric Sciences NCSU (MEAS), North Carolina State University Raleigh (NC State), University of North Carolina System (UNC)-University of North Carolina System (UNC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: Sedimentation; Larsen ice shelf; Antarctica; Fatty acids; Diatoms; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Antarctic; Antarctic Peninsula; Austral; Larsen Ice Shelf; Larsen Bay; Antarc*; Ice Shelf; Ice Shelves
• Online Access: https://hal.sorbonne-universite.fr/hal-02908657; https://hal.sorbonne-universite.fr/hal-02908657/document; https://hal.sorbonne-universite.fr/hal-02908657/file/Sane-2011accepted.pdf; https://doi.org/10.1016/j.csr.2011.04.002

International audience During austral summer 2006–2007, five sediment cores were recovered from the Eastern Antarctic Peninsula (EAP) continental shelf. Microscopic observations and sediment fatty acid (FA) composition analyses were carried out to investigate whether the drastic changes at the sea surface in EAP may be reflected in the sedimentary record. A sharp decrease in the number of diatom valves was observed below 2 cm depth. This difference between the upper 2 cm of sediment and the deeper part of the sediment column was attributed to the drastic change in the upper water column conditions after the collapse of the ice shelves, which allowed the arrival of phytoplankton debris and fresh organic matter to the sea floor in EAP. The presence of bacterial-, zooplankton- and detrital-related FA throughout EAP cores suggests that there has been an input of older and more refractory organic matter into the region, presumably by lateral transport before the Larsen ice shelves disintegration.