Goodbody-Gringley Gretchen, Marchini Chiara, Chequer Alex D, Goffredo Stefano
Bermuda Institute of Ocean Sciences, 17 Biological Lane, St. Georges, Bermuda GE 01.
Marine Science Group, Department of Biological, Geological and Environmental Sciences, University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy, European Union.
PLoS One. 2015 Nov 6;10(11):e0142427. doi: 10.1371/journal.pone.0142427. eCollection 2015.
Mesophotic coral reef ecosystems remain largely unexplored with only limited information available on taxonomic composition, abundance and distribution. Yet, mesophotic reefs may serve as potential refugia for shallow-water species and thus understanding biodiversity, ecology and connectivity of deep reef communities is integral for resource management and conservation. The Caribbean coral, Montastraea cavernosa, is considered a depth generalist and is commonly found at mesophotic depths. We surveyed abundance and size-frequency of M. cavernosa populations at six shallow (10m) and six upper mesophotic (45m) sites in Bermuda and found population structure was depth dependent. The mean surface area of colonies at mesophotic sites was significantly smaller than at shallow sites, suggesting that growth rates and maximum colony surface area are limited on mesophotic reefs. Colony density was significantly higher at mesophotic sites, however, resulting in equal contributions to overall percent cover. Size-frequency distributions between shallow and mesophotic sites were also significantly different with populations at mesophotic reefs skewed towards smaller individuals. Overall, the results of this study provide valuable baseline data on population structure, which indicate that the mesophotic reefs of Bermuda support an established population of M. cavernosa.
中光层珊瑚礁生态系统在很大程度上仍未被探索，关于其分类组成、丰度和分布的信息非常有限。然而，中光层珊瑚礁可能是浅水物种的潜在避难所，因此了解深海珊瑚礁群落的生物多样性、生态和连通性对于资源管理和保护至关重要。加勒比珊瑚Montastraea cavernosa被认为是一种广深性物种，常见于中光层深度。我们调查了百慕大六个浅水（10米）和六个中光层上部（45米）站点的Montastraea cavernosa种群的丰度和大小频率，发现种群结构与深度有关。中光层站点的群体平均表面积明显小于浅水区站点，这表明中光层珊瑚礁上的生长速率和最大群体表面积受到限制。然而，中光层站点的群体密度明显更高，从而对总体覆盖百分比的贡献相同。浅水区和中光层站点之间的大小频率分布也存在显著差异，中光层珊瑚礁的种群偏向于较小个体。总体而言，本研究结果提供了关于种群结构的宝贵基线数据，表明百慕大的中光层珊瑚礁支持着一个已建立的Montastraea cavernosa种群。
