Production and turnover rates of C-37 alkenones in the eastern Bering Sea: implication for the mechanism of a long duration of Emiliania huxleyi bloom

• Published in: Progress in Oceanography
• Main Authors: Shin, Kh, Tanaka, N, Harada, N, Marty, Jc
• Other Authors: Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2002
• Subjects: [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Bering Sea; Canada; Pacific
• Online Access: https://hal.archives-ouvertes.fr/hal-03483038; https://doi.org/10.1016/S0079-6611(02)00073-3

10th Annual Meeting of the North-Pacific-Marine-Science-Organization (PICES), VICTORIA, CANADA, OCT, 2001 Production and turnover rates of C-37 alkenones were determined by a C-13-labeling technique during the Emiliania huxleyi blooms in the eastern Bering Sea. The production rates of C-37 alkenones are variable in the surface water of the Bering Sea (during Emiliania huxleyi blooms), ranging from 0.019-0.043 mug 1(-1) day(-1) for C-37.2 and 0.057-0.16 for mug 1(-1) day(-1) C-37.3 respectively. The temperature difference (dT*) between in situ temperature and U-37(k')-based temperature (estimated by C-37 alkenone unsaturation index: U-37(k'),) for seston is generally larger than the temperature difference between in situ temperature and Pr-U-37(k')-based temperature (estimated by the unsaturation index of C-37 alkenone production rate). Therefore, the application of Pr-U-37(k') determined by the C-13 labeling can be suggested as a more accurate calibration of in situ temperature. On the other hand, the C-37 alkenones concentration (3.1 mug 1(-1)) at BR-10 (middle shelf) is 4-16 fold larger than the concentrations (0.19-0.77 mug 1(-1)) at other stations. In addition, the U-37(k')-based seawater temperature at BR-10 (4.0 degreesC) was much lower than the in situ temperature (7.5 degreesC), showing the largest seawater temperature difference (dT*). This low temperature and high abundance of C-37 alkenones may be the result of turbulent mixing, like that caused by eddies on the continental slope area, considering the existence of very loco temperature and high ammonium concentration water in the water mass beneath the surface layer. The uncoupling between the in situ temperature and U-37(k')-based seawater temperature in the middle of shelf area (BR-10) may indicate a link between the nutrient supply mechanism and the sustained Emiliania huxleyi bloom from summer through autumn. (C) 2002 Elsevier Science Ltd. All rights reserved.