Department of Biological Sciences, National University of Singapore, 117558, Singapore.
Department of Biological Sciences, National University of Singapore, 117558, Singapore; Tropical Marine Science Institute, National University of Singapore, 119227, Singapore.
Mar Environ Res. 2019 May;147:101-112. doi: 10.1016/j.marenvres.2019.04.010. Epub 2019 Apr 19.
Depth range is an important species trait for coral reef organisms, yet it remains to be quantified and analysed adequately among tropical coral species. Filling this knowledge gap is crucial as the depth limits of corals are related to important environmental factors such as light and temperature. Furthermore, the health and survivorship of corals may be threatened due to warming-induced sea-level rise, particularly for colonies living at the deeper limits of species depth ranges. Here we collected benthic and environmental data along the reef profile to characterise the depth ranges of coral species, and analysed species diversity and community structure in relation to possible depth-related biophysical parameters on the sediment-stressed reefs of Singapore. The results reveal clear environmental covariations with depth, expectedly with light availability showing the most marked decline as depth increases. Live coral cover, species richness and diversity are associated positively and significantly with light, which also structures coral communities along the reef profile more strongly than temperature or sediment levels. Relatedly, we detect species-specific depth distributions with two main strategies observed among coral species: shallow specialists and depth generalists. We suggest that corals in Singapore are unlikely to be impacted by light limitation specifically as sea level rises due to the wider depth range of the deeper species. Our data will inform conservation efforts especially in the selection of sites and depths for coral transplantation.
深度范围是珊瑚礁生物的一个重要物种特征，但在热带珊瑚物种中，它仍然需要被充分地量化和分析。填补这一知识空白至关重要，因为珊瑚的深度限制与光和温度等重要环境因素有关。此外，由于海平面上升导致的变暖，珊瑚的健康和存活率可能会受到威胁，特别是对于生活在物种深度范围较深的群体。在这里，我们沿着珊瑚礁剖面收集了底栖和环境数据，以描述珊瑚物种的深度范围，并分析了物种多样性和群落结构与新加坡受沉积物压力影响的珊瑚礁上可能与深度相关的生物物理参数之间的关系。结果显示，深度与环境之间存在明显的相互关系，随着深度的增加，光的可用性预期会出现最显著的下降。活珊瑚覆盖率、物种丰富度和多样性与光呈正相关且显著相关，光对珊瑚群落的结构影响也比温度或沉积物水平更强。相关地，我们检测到具有两种主要策略的特定物种深度分布：浅海专家和深海专家。我们认为，由于较深物种的深度范围更广，新加坡的珊瑚不太可能受到光限制的具体影响，因为海平面上升。我们的数据将为保护工作提供信息，特别是在珊瑚移植的地点和深度选择方面。
