Coral reefs exhibit consistent patterns in biodiversity across multiple spatial scales, from local to global clines in species richness, abundance and community structure. Knowledge of fundamental processes driving these patterns is largely derived from studies of shallow, emergent and nearshore reefs. Although research efforts are expanding to deeper mesophotic coral reef ecology, distinct and isolated reef morphologies like submerged pinnacles or seamounts have received scant attention. Despite being potentially important for connectivity and as refugia, the extent to which established patterns and processes in coral reef ecology apply to these systems is unknown. Here we examine the fish and benthic communities associated with coral reefs found on submerged pinnacles in Kimbe Bay, Papua New Guinea. Community structure and diversity metrics are compared with emergent reefs at the same depth in both near and offshore settings. We then explicitly test whether benthic complexity variables known to influence reef fish communities exhibit similar patterns at each reef type. Pinnacles were characterised by 3.70 times the mean fish abundance and 1.98 times the species richness recorded at the same depths on emergent reefs. Fish community structure showed distinct separation across reef morphologies, with pinnacles most similar to offshore reefs. Benthic habitat complexity did not vary across reef types while fish assemblages were weakly related to benthic habitat variables, with reef morphology the most consistent predictor of fish community metrics. The pinnacles in our study support high coral reef fish biodiversity despite their small habitat area and relative isolation by depth and offshore setting. Our results suggest that habitat-specific environmental conditions are generated by the distinct geomorphology of pinnacles. As coastal reefs become more increasingly disturbed, understanding ecological patterns on deep patch reef habitats like pinnacles will be useful to provide a more holistic understanding of coral reef seascapes and their resilience.

中文翻译：

---

与浅水涌出的珊瑚礁相比，水下珊瑚礁尖顶上的鱼群高度多样性、丰富度和独特的鱼群

珊瑚礁在多个空间尺度上表现出一致的生物多样性模式，从本地到全球的物种丰富度、丰度和群落结构。驱动这些模式的基本过程的知识主要来自对浅层、新兴和近岸珊瑚礁的研究。尽管研究工作正在扩展到更深的中光珊瑚礁生态学，但水下尖峰或海山等独特和孤立的珊瑚礁形态却很少受到关注。尽管对于连通性和作为避难所具有潜在重要性，珊瑚礁生态学中已建立的模式和过程在多大程度上适用于这些系统尚不清楚。在这里，我们研究了与巴布亚新几内亚金贝湾水下尖峰上发现的珊瑚礁相关的鱼类和底栖群落。将群落结构和多样性指标与近海和近海环境中相同深度的新兴珊瑚礁进行比较。然后，我们明确测试了已知影响珊瑚礁鱼类群落的底栖复杂性变量是否在每种珊瑚礁类型上表现出相似的模式。尖峰石阵的特征是在相同深度的涌出珊瑚礁上记录的平均鱼类丰度的 3.70 倍和物种丰富度的 1.98 倍。鱼类群落结构显示出不同珊瑚礁形态的明显分离，尖峰与近海珊瑚礁最相似。底栖栖息地的复杂性在珊瑚礁类型之间没有变化，而鱼类组合与底栖栖息地变量的相关性较弱，珊瑚礁形态是鱼类群落指标最一致的预测指标。尽管栖息地面积小，深度和近海环境相对隔离，但我们研究中的尖峰支持高珊瑚礁鱼类的生物多样性。我们的结果表明，栖息地特定的环境条件是由尖峰石阵的独特地貌产生的。随着沿海珊瑚礁受到越来越多的干扰，了解尖峰等深礁栖息地的生态模式将有助于更全面地了解珊瑚礁海景及其恢复力。