Vergotti Marina J, D'Olivo Juan P, Brachert Thomas C, Capdevila Pol, Garrabou Joaquim, Linares Cristina, Spreter Philipp M, Kersting Diego K
Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany.
Unidad Académica de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Puerto Morelos, Mexico.
J Anim Ecol. 2025 Jan;94(1):125-138. doi: 10.1111/1365-2656.14225. Epub 2024 Nov 19.
The impact of warming on zooxanthellate corals is widespread, from tropical to temperate seas, with its associated mortalities causing global concern. The temperate coral Cladocora caespitosa is the only zooxanthellate coral with reef building capacity in the Mediterranean Sea, a climate change hotspot with warming rates triple the global average. During the past two decades, C. caespitosa populations have suffered severe mortality events associated with marine heatwaves (MHWs). However, with monitoring efforts beginning, at best, in the 2000s, the occurrence of MHWs before that period, as well as the sublethal effects of these events remain poorly understood. Here, we use sclerochronology to reconstruct the histories of past stress events and long-term sublethal effects on C. caespitosa in three locations along a latitudinal gradient within the NW Mediterranean Sea, each with different environmental conditions. Skeletal extension, density and calcification rates were compared with the in situ seawater temperature of each site to assess their relationship. Furthermore, we assessed the occurrence of skeletal growth anomalies to reconstruct stress events between 1991 and 2021, a period that encompasses the onset and evolution of warming-related mass mortality events in the NW Mediterranean Sea. Our results reveal a positive association between calcification and temperature, following a latitudinal temperature gradient. However, the evolution of the likelihood distribution of growth rates in the warmest site (Columbretes Islands) since the 1990s indicates a decrease in linear extension and calcification rates during the most recent years. With the increase in the frequency of MHWs and growth anomalies during the last decade, this decline suggests recurrent physiological stress events. These results unravel information on the long-term impacts of warming on coral growth and highlight the potential of applying sclerochronology to reconstruct the sublethal effects of warming using C. caespitosa.
气候变暖对共生有虫黄藻的珊瑚的影响广泛存在，从热带海域到温带海域均受波及，其导致的珊瑚死亡引起了全球关注。温带珊瑚密枝鹿角珊瑚是地中海唯一具有造礁能力的共生有虫黄藻的珊瑚，而地中海是气候变化热点地区，变暖速度是全球平均水平的三倍。在过去二十年中，密枝鹿角珊瑚种群遭受了与海洋热浪相关的严重死亡事件。然而，由于监测工作最早始于21世纪初，在此之前海洋热浪的发生情况以及这些事件的亚致死效应仍知之甚少。在此，我们利用骨骼年代学来重建地中海西北部沿纬度梯度的三个地点过去应激事件的历史以及对密枝鹿角珊瑚的长期亚致死效应，每个地点都有不同的环境条件。将骨骼延伸率、密度和钙化率与每个地点的现场海水温度进行比较，以评估它们之间的关系。此外，我们评估了骨骼生长异常的发生情况，以重建1991年至2021年期间的应激事件，这一时期涵盖了地中海西北部与变暖相关的大规模死亡事件的发生和演变。我们的结果显示，钙化与温度之间存在正相关关系，遵循纬度温度梯度。然而，自20世纪90年代以来，最温暖地点（科布雷特斯群岛）生长速率的似然分布演变表明，近年来线性延伸率和钙化率有所下降。随着过去十年海洋热浪频率和生长异常的增加，这种下降表明反复出现生理应激事件。这些结果揭示了气候变暖对珊瑚生长的长期影响，并突出了利用骨骼年代学通过密枝鹿角珊瑚重建气候变暖亚致死效应的潜力。
