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

当前大气二氧化碳分压和温度的上升对深海生态系统中的海洋钙化物构成了严重威胁。其中，冷水珊瑚（CWC）生态系统由于其位于接近碳酸盐饱和度极限的寒冷和深水中，似乎处于特别危险的境地。CWC珊瑚礁生长的一个未被充分探索的因素是季节性。此外，迄今为止，对化学武器的地球化学研究主要集中在作为环境档案的框架珊瑚上，其严重的生命影响是众所周知的。在这里，我们探索了一个有前途的替代模式生物，大蛤Acesta挖掘，作为CWC珊瑚礁生态系统的新环境档案。在其他海洋生物碳酸盐中已经建立的一系列地球化学代理将与一套分析方法和不同的采样技术一起应用。此外，地球化学数据将首次校准为高分辨率的原位海洋学数据（通过在样品地点部署的bbb10 - 1年着陆器记录）。这一综合办法旨在：(1)识别和评估A. excavata潜在的重要作用；(2)评估A. excavata作为地球化学代用物和年龄计时器的古海洋学档案；(3)解析挪威（特隆赫姆峡湾（Leksa礁）和近海Sula礁）和毛利塔尼亚（BandaMounds） CWC礁的季节性时空变化；最后(4)在冰期/间冰期时间尺度上研究CWC礁在高纬度和低纬度发生变化背景下的季节性作用。

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.