Notwithstanding the importance of analyzing the variations of population dynamic traits along environmental gradients for assessing coral resilience to global climate change, temperate areas are more understudied than tropical regions. In the Mediterranean Sea, some studies are available for its western basin, while there is a lack of information for its eastern basin. This study starts to fill this gap, by determining the demographic characteristics of the solitary zooxanthellate scleractinian Balanophyllia europaea in the Dardanelles (Turkey) along a 1–21 m depth transect. The population dynamics of B. europaea from this site in the eastern Mediterranean Sea was compared with the populations in the NW Mediterranean Sea. In particular, the sites of Calafuria and Palinuro (Tyrrhenian Sea, Italy) were chosen for the comparison since their temperature and latitude, respectively, were similar to that of the Dardanelles population. The population density in the Dardanelles increased exponentially with depth, possibly due to lower current and wave action, and higher salinity at depth. Age structure in the Dardanelles was relatively overrepresented in younger age classes with increasing depth. Nevertheless, this difference in age structure was not strong enough to cause trends with depth for all derived demographic parameters. In comparison with Italian populations, age structure presented a higher frequency of young individuals and were more stable in the Dardanelles, likely due to the less intense wave action. Hosting different clades of symbiotic algae may also contribute to these differences, but molecular studies are necessary to verify this hypothesis.

中文翻译：

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达达尼尔海峡沿深度梯度的温带珊瑚种群动态

尽管分析环境梯度下的种群动态特征的变化对于评估珊瑚对全球气候变化的抵御能力很重要，但温带地区比热带地区的研究要少。在地中海，对西部盆地有一些研究，而对东部盆地则缺乏信息。通过确定在达达尼尔海峡（土耳其）沿1-21 m深度样带的单独的人兽共患病的巩膜侧柏毛虫Balanophyllia europaea的人口统计学特征，本研究开始填补这一空白。欧洲油菜的种群动态将来自地中海东部这个站点的数据与西北地中海的人口进行了比较。特别是，选择了卡拉富里亚和帕利努罗（意大利第勒尼安海）的地点进行比较，因为它们的温度和纬度分别与达达尼尔海峡的人口相似。达达尼尔海峡的人口密度随深度呈指数增长，这可能是由于较低的电流和波浪作用以及较高的深度盐度所致。达达尼尔海峡（Dardanelles）中的年龄结构在越来越年轻的年龄段中相对较高。然而，年龄结构的这种差异不足以引起所有派生人口统计学参数的深度趋势。与意大利人口相比，年龄结构呈现出较高的年轻频率，并且在达达尼尔海峡地区较为稳定，这可能是由于波浪作用较弱所致。容纳不同种类的共生藻类也可能导致这些差异，但是必须进行分子研究以验证这一假设。