Abstract The abyssal seafloor of the Clarion Clipperton Zone (CCZ) in the central Pacific has the largest known deposits of polymetallic nodules and associated benthic faunal communities with high biodiversity. The environmental factors that structure these communities, both at regional and local scales, are not well understood. In this study, seabed image surveys were used to assess distribution patterns in invertebrate and fish megafauna (>1 cm) at multiple scales in relation to key environmental factors: food supply to the seabed varying at the regional scale (hundreds of km), seabed geomorphological variations varying at the broad local scale (tens of km), and seabed nodule cover varying at the fine local scale (tens of meters). We found significant differences in megafaunal density and community composition between all study areas. Variations in faunal density did not appear to match with regional productivity gradients, although faunal density generally decreased with increasing water depth (from E to W). In contrast, geomorphology and particularly nodule cover appeared to exert strong control on local faunal abundance and community composition, but not in species richness. Local variations in faunal density and beta-diversity, particularly those driven by nodule presence (within study areas), were of comparable magnitude to those observed at a regional level (between study areas). However, regional comparisons of megabenthic assemblages showed clear shifts in dominance between taxonomic groups (perceivable even at Phylum levels) across the mid-eastern CCZ seabed, suggesting a higher regional heterogeneity than was previously thought.

中文翻译：

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克拉里昂克利珀顿区中东部无脊椎动物和大型鱼类的多尺度变化

摘要 中太平洋克拉里昂克利珀顿区 (CCZ) 的深海海底拥有已知最大的多金属结核矿床和相关的生物多样性高的底栖动物群落。在区域和地方尺度上构建这些社区的环境因素尚不清楚。在这项研究中，海底图像调查用于评估与关键环境因素相关的多尺度无脊椎动物和大型鱼类（> 1 厘米）的分布模式：海底食物供应在区域尺度（数百公里）、海底地貌变化在广泛的局部尺度（几十公里）上变化，海底结核覆盖在局部精细尺度（几十米）上变化。我们发现所有研究区域之间的巨型动物密度和群落组成存在显着差异。动物群密度的变化似乎与区域生产力梯度不匹配，尽管动物群密度通常随着水深（从 E 到 W）的增加而降低。相比之下，地貌和特别是结核覆盖似乎对当地动物群的丰度和群落组成有很强的控制，但对物种丰富度没有影响。动物群密度和 β 多样性的局部变化，特别是由结核存在（研究区域内）驱动的变化，与区域水平（研究区域之间）观察到的变化幅度相当。然而，大型底栖动物组合的区域比较显示，CCZ 中东部海床上的分类群之间的优势明显发生了变化（即使在门级别也可以感知），这表明区域异质性比以前认为的更高。