Oxygen isotope disequilibrium in the juvenile portion of oyster shells biases seawater temperature reconstructions
Oxygen isotope disequilibrium in the juvenile portion of oyster shells biases seawater temperature reconstructions
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牡蛎壳幼年部分的氧同位素不平衡使海水温度重建产生偏差
DOI：
10.1016/j.ecss.2020.106777
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
F. Lartaud
中科院分区：
文献类型：
--
作者：
D. Huyghe;L. Emmanuel;M. Rafélis;M. Renard;M. Ropert;N. Labourdette;F. Lartaud
几十年来，双壳类生物是基于稳定同位素方法的古气候档案中最常见的支撑之一。本文采用化学标记和捕获技术，对法国诺曼底自然环境中饲养的Magallana gigas牡蛎壳δ18O值的变化进行了为期两年的研究。结果与连续监测的温度、盐度和逐月记录的海水δ18O进行了比较。在铰链区域进行了同位素测量，该区域重新组合了牡蛎的整个生命。在这里，我们证明了牡蛎在两年的实验中，即使在低于6°C的温度下，它们的外壳也没有明显的生长中断。结果证实，成年牡蛎（即bbb10 - 1年）的壳在平衡状态下矿化。然而，幼年期样品表现出强烈的同位素不平衡，δ18O值在冬季最大位移为3‰，可能是由于动力学同位素的影响。这相当于重建的温度比预期高出13°C。本研究表明，尽管这些牡蛎壳可以作为（古）环境条件的准确档案，但在古温度重建中应避免在幼期（即< 1年）矿化的贝壳部分。鉴于双壳类动物被广泛用作环境档案，需要对其他物种进行类似的研究。
For decades, bivalve shells have constituted one of the most common supports for paleoclimatic archives based on stable isotope approaches. In this work, we conducted chemical marking and recapture techniques to study the fluctuation of δ18O values of oyster shells of the species Magallana gigas reared in natural environment in Normandy (France) for two years. The results were compared to the continuous monitoring of temperature and salinity and monthly records of seawater δ18O. Isotopic measurements were performed on the hinge area that regroups the whole life of the oysters. Here we demonstrate that oysters mineralized their shells with no significant growth breaks during the two-years experiment, even at temperatures below 6 °C. The results confirm that adult oysters (i.e. > 1 yr) mineralized their shells at equilibrium. However, juvenile specimens exhibit a strong isotopic disequilibrium, with a maximum shift of the δ18O values of 3‰ in winter, likely due to kinetic isotope effects. This corresponds to a reconstructed temperature up to 13 °C warmer than expected. This work indicates that although these oyster shells can be used as an accurate archive of (paleo)environmental conditions, the shell portion mineralized during the juvenile stage (i.e. < 1 yr) should be avoided for paleotemperature reconstructions. Given the wide use of bivalve shells as environmental archives, similar studies on others species are required.
大西洋东北部巨型深海牡蛎 Neopycnodonte zibrowii sp n 的壳结构、元素组成和稳定同位素特征
DOI：
10.1016/j.dsr.2008.10.002
发表时间：
2009
期刊：
影响因子：
--
作者：
Wisshak M;López Correa M;Gofas S;Salas C;Taviani M;Jakobsen J ;Freiwald A
通讯作者：
Freiwald A