Abstract：
Tropical deep reefs (>30 m) are biologically and ecologically unique ecosystems with a higher geographic reach to shallow (<30 m) reefs. Yet they are poorly understood and rarely considered in conservation practices. Here, we characterise benthic and fish communities across a depth gradient (10-350 m) in remote coral atolls in Seychelles, Western Indian Ocean. Using taxonomic and trait-based approaches we present the taxonomic and functional composition of shallow and deep reef communities, with distinct communities and traits dominating different depths. Depth-related changes in community metrics (taxa richness, abundance and biomass) and functional diversity metrics (richness, dispersion, and evenness) indicate complex relationships across different biological components (fish, benthos) that differ between shallow and deep reefs. These in turn translate into different patterns of reef resilience against disturbance or species invasions with depth. Notably, deep reefs host on average fewer and less abundant taxa but with higher functional contribution and originality scores, some of which are of conservation concern. Overall, the results highlight the unique nature of deep reefs that requires their explicit consideration in conservation and management activities.
摘要：
热带深礁（>30m）是生物学和生态学上独特的生态系统，具有更高的地理范围到浅层（<30m）的珊瑚礁。然而，人们对它们知之甚少，很少在保护实践中考虑。这里,我们描述了塞舌尔偏远珊瑚环礁中深度梯度（10-350m）的底栖和鱼类群落，西印度洋。使用分类学和基于性状的方法，我们介绍了浅海和深礁群落的分类学和功能组成，具有不同的群落和特征，支配着不同的深度。社区指标的深度相关变化(分类单元丰富度，丰度和生物量)和功能多样性指标(丰富度，色散，和均匀度)表明不同生物成分之间的复杂关系(鱼，底栖动物）在浅礁和深礁之间有所不同。这些反过来又转化为不同的珊瑚礁抵御深度干扰或物种入侵的恢复力模式。值得注意的是,深层珊瑚礁平均拥有越来越少的类群，但具有更高的功能贡献和原创性得分，其中一些是保护问题。总的来说,结果突出了深礁的独特性质，需要在保护和管理活动中明确考虑。
