(Table 2) Radiocarbon dating on cold-water corals collected in the Mediterranean Sea

This study presents newly obtained coral ages of the cold-water corals Lophelia pertusa and Madrepora oculata collected in the Alboran Sea and the Strait of Sicily (Urania Bank). These data were combined with all available Mediterranean Lophelia and Madrepora ages compiled from literature to conduct a basin-wide assessment of the spatial and temporal occurrence of these prominent framework-forming scleractinian species in the Mediterranean realm and to unravel the palaeo-environmental conditions that controlled their proliferation or decline. For the first time special focus was placed on a closer examination of potential differences occurring between the eastern and western Mediterranean sub-basins. Our results clearly demonstrate that cold-water corals occurred sparsely in the entire Mediterranean during the last glacial before becoming abundant during the Bølling-Allerød warm interval, pointing to a basin-wide, almost concurrent onset in (re-)colonisation after ~13.5 ka. This time coincides with a peak in meltwater discharge originating from the northern Mediterranean borderlands which caused a major reorganisation of the Mediterranean thermohaline circulation. During the Younger Dryas and Holocene, some striking differences in coral proliferation were identified between the sub-basins such as periods of highly prolific coral growth in the eastern Mediterranean Sea during the Younger Dryas and in the western basin during the Early Holocene, whereas a temporary pronounced coral decline during the Younger Dryas was exclusively affecting coral sites in the Alboran Sea. Comparison with environmental and oceanographic data revealed that the proliferation of the Mediterranean corals is linked with enhanced productivity conditions. Moreover, corals thrived in intermediate depths and showed a close relationship with intermediate water mass circulation in the Mediterranean sub-basins. For instance, reduced Levantine Intermediate Water formation hampered coral growth in the eastern Mediterranean Sea during sapropel S1 event as reduced Winter Intermediate Water formation did in the westernmost part of the Mediterranean (Alboran Sea) during the Mid-Holocene. Overall, this study clearly demonstrates the importance to consider region-specific environmental changes as well as species-specific environmental preferences in interpreting coral chronologies. Moreover, it highlights that the occurrence or decline of cold-water corals is not controlled by one key parameter but rather by a complex interplay of various environmental variables.本研究报道了在阿尔沃兰海（Alboran Sea）与西西里海峡（Strait of Sicily）的尤拉尼亚滩（Urania Bank）采集的冷水珊瑚（cold-water corals）——粗糙珊瑚（Lophelia pertusa）与眼状杯珊瑚（Madrepora oculata）的全新测年数据。本研究将该数据集与已公开发表文献中收录的全部地中海区域粗糙珊瑚及眼状杯珊瑚测年数据进行整合，以开展全盆地尺度的系统性评估，解析这两种典型造架石珊瑚（scleractinian）在地中海海域的时空分布特征，并揭示调控其繁盛与衰退的古环境条件。本研究首次重点关注了地中海东西两个次盆地间可能存在的分布差异。研究结果清晰表明：末次冰期阶段，冷水珊瑚在整个地中海海域分布稀疏；至博令-阿勒罗德暖期（Bølling-Allerød warm interval）时种群丰度显著提升，指示约13.5 ka后全盆地几乎同步启动（重新）定植过程。该时间节点与地中海北部陆缘融水径流峰值期重合，此事件引发了地中海温盐环流的重大重组。在新仙女木期（Younger Dryas）与全新世（Holocene）期间，不同次盆地间的珊瑚繁盛模式存在显著差异：例如东地中海在新仙女木期出现大规模珊瑚增殖，而西地中海次盆地则在早全新世迎来珊瑚繁盛阶段；与之形成鲜明对比的是，新仙女木期出现的短暂且剧烈的珊瑚衰退现象，仅波及阿尔沃兰海的珊瑚群落。通过与环境及海洋学数据的对比分析发现，地中海冷水珊瑚的繁盛与海洋生产力提升条件密切相关。此外，珊瑚多栖息于中层水深环境，并与地中海次盆地的中层水团环流呈现紧密关联。例如，在萨佩尔S1事件（sapropel S1 event）期间，黎凡特中层水（Levantine Intermediate Water）生成量减少，抑制了东地中海的珊瑚生长；而在全新世中期，地中海最西端（阿尔沃兰海）的冬季中层水生成量下降，同样对当地珊瑚生长产生了抑制作用。总体而言，本研究明确证实，在解读珊瑚年代学时，需兼顾区域特异性环境变化与物种特异性环境偏好。同时，本研究也强调，冷水珊瑚的出现或衰退并非由单一关键参数控制，而是由多种环境变量的复杂相互作用共同驱动。