HBIs and sterols in surface sediments across the East Siberian Sea: implications for palaeo sea‐ice reconstructions

• Published in: Geochemistry, Geophysics, Geosystems
• Main Authors: Su, Liang, Ren, Jian, Sicre, Marie-Alexandrine, Bai, Youcheng, Jalali, Bassem, Li, Zhongqiao, Jin, Haiyan, Astakhov, Anatolii, S, Shi, Xuefa, Chen, Jianfang
• Other Authors: Zhejiang University, Key Laboratory of Marine Ecosystem Dynamics, Variabilité de l'Océan et de la Glace de mer (VOG), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), State Key Laboratory of Satellite Ocean Environment Dynamics (SOED), State Oceanic Administration (SOA), V.I.Il'ichev Pacific Oceanological Institute, Key Laboratory of Marine Geology and Metallogeny, First Institute of Oceanography, Ministry of Natural Resources, Qingdao
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: Sea-ice; biomarkers; IP25; PIP25 index; East Siberian Sea; Arctic Estuary; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Arctic; Arctic Ocean; Phytoplankton; Sea ice
• Online Access: https://hal.science/hal-03552116; https://hal.science/hal-03552116/document; https://hal.science/hal-03552116/file/Su%20et%20al.,%20G-cubed%202022.pdf; https://doi.org/10.1029/2021GC009940

International audience Highly branched isoprenoids (HBIs) in marine sediments have emerged as promising semi-quantitative proxies to reconstruct seasonal sea-ice in polar oceans. In this work, we examine the distribution of sympagic HBIs (IP25 and HBI II), pelagic phytoplankton biomarkers (brassicasterol, dinosterol and HBI-III) as well as terrestrial sterols (campesterol and β-sitosterol) in the surface sediments of the East Siberian Sea (ESS) to test their reliability as sea-ice proxies under continental runoff influence. Our data suggest that dinosterol performs better than brassicasterol to assess sea-ice across the ESS shelf, yet the correlation between PDIP25 and spring sea-ice is relatively weak but improves when removing sites with salinity <25. Strongest relationship is found between PIIIIP25 and summer sea-ice in regions remote from riverine influence. Overall, our results show that semi-quantitative estimates of sea-ice based on biomarkers can be problematic in Arctic Ocean margins because of biases induced by continental runoff on biological productivity and sea-ice production.