Masterchronology on Arctica islandica from Spiekeroog

Sclerochronological records of interannual shell growth variability were established for eight modern shells (26 to 163 years of age) of the bivalve Arctica islandica, which were sampled at one site in the inner German Bight. The records indicate generally low synchrony between individuals. Spectral analysis of the whole 163-yr masterchronology indicated a cyclic pattern with a period of 5 and 7 years. The masterchronology correlated poorly to time series of environmental parameters over the last 90 years. High environmental variability in time and space of the dynamic and complex German Bight hydrographic system results in an extraordinarily high noise' level in the shell growth pattern of Arctica islandica.

本研究针对采自德国湾内某一站点的8枚年龄介于26至163年的现代双壳类冰岛北极蛤（Arctica islandica）个体，建立了其年际壳生长变异性的硬体年代学（sclerochronology）记录。该记录整体显示，个体间的生长同步性普遍较低。对全长163年的主年代序列（masterchronology）进行频谱分析后发现，其呈现出5年与7年的周期性波动模式。在过去90年的时间尺度上，该主年代序列与环境参数时间序列的相关性极低。德国湾水文系统兼具动态性与复杂性，其环境在时间与空间上均存在高度变异性，这使得冰岛北极蛤的壳生长模式呈现出极高的噪声水平。