High-resolution records of environmental change in cold-water coral reefs: geochemical evidence recorded in the skeleton of the marine bivalve Acestaexcavata

目前大气二氧化碳浓度和温度的上升对深海生态系统中的海洋钙化生物构成了严重威胁。其中，冷水珊瑚(CWC)生态系统似乎面临特别危险，因为它们位于接近碳酸盐饱和极限的冷水和深水。对《化学武器公约》珊瑚礁生长影响较小的一个因素是季节性。此外，到目前为止，对化学武器公约的地球化学研究主要集中在将珊瑚作为环境档案的框架结构上，这些珊瑚具有严重的重要影响。在这里，我们探索了一种很有前途的替代模式生物，大型文蛤，作为CWC珊瑚礁生态系统的新环境档案。已经在其他海洋生物成因碳酸盐中建立的一系列地球化学指标将与一套分析方法和不同的采样技术一起应用。此外，化探数据将首次校准为高分辨率的就地海洋学数据(通过在样本点部署一年着陆器进行记录)。这一综合办法旨在：(1)查明和评价考古挖掘的潜在重要影响；(2)评估考古挖掘作为地球化学指标和年龄计时器的古海洋学档案；(3)解决挪威近海CWC珊瑚礁(Trondheimsfjord(Leksa Reef)和离岸苏拉礁)和Mauretania(BandaMound)的季节性时空变化；以及(4)在高纬度和低纬度CWC珊瑚礁在冰川/间冰期时间尺度上变化的背景下，讨论季节性的作用。

The current rise in atmospheric pCO2 and temperature is a serious threat for marine calcifiers in deep sea ecosystems. Among these, cold-water coral (CWC) ecosystems appear to be under particular risk due to their position in cold and deep waters close to the limit of carbonate saturation. One factor poorly explored for the growth of CWC reefs is seasonality. Moreover, to date geochemical research on CWC is mainly focused on framework building corals as environmental archives for which severe vital effects are known. Here, we explore a promising alternative model organism, the large clam Acesta excavata, as a new environmental archive for CWC reef ecosystems. A series of geochemical proxies already established in other marine biogenic carbonates will be applied with a suite of analytical methods and different sampling techniques. In addition, the geochemical data will be calibrated for the first time to high-resolution in situ oceanographic data (logged via >1 year lander deployments at the sample sites). This integrated approach aims to: (1) identify and evaluate potential vital effects of A. excavata, (2) assess A. excavata as paleoceanographic archive for geochemical proxies and age chronometers, (3) resolve temporal and spatial variations of seasonality in CWC reefs off Norway (Trondheimsfjord (Leksa Reef) and off-shore Sula Reef) and Mauretania (BandaMounds), and finally (4) address the role of seasonality in the context of shifts in CWC reef occurrencesat high and low latitudes on glacial/ interglacial time scales.