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, 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
• 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.