ABSTRACT: Seamounts, pinnacles, and crests are abrupt seafloor features that modify physical processes and ecological patterns. Fishers often target these local bathymetric highs, which can have high catch-per-unit-effort. Increases in the abundance of target species has been qualitatively noted around these features and promontories, however, a quantitative evaluation of local highs as preferred habitat for fishes is still lacking. Here, we used an extensive database of fish abundances (N = 2381) from mesophotic and upper bathyal depths (40-300 m) gathered over 8 yr around the Main Hawaiian Islands to evaluate the effects of macro-scale habitat categorized by combining bathymetric position index (BPI) and slope. A numerical model simulating physical ocean processes was used to test the hypothesis that local highs, herein called crests, are distinct and preferred habitat for many species due to their modified flow conditions. We show that crests host a unique, diverse fish assemblage with double the abundance relative to other habitats. Therefore, fishes are concentrated at crests rather than being uniformly distributed along the island shelf at preferred depths. These habitats are characterized by enhanced current amplitudes and convergence zones. Direct correlations between fish abundance, convergence, and current amplitude strongly suggest that flow-enhanced food availability is likely the driver of habitat-related changes in fish assemblage. These results have important implications for conservation and management. We identify a simple and informative method to classify habitat, quantitatively link bathymetry-induced flow alterations to fish abundances, and provide information for refining definitions of essential fish habitat for species that are important commercial targets worldwide.

中文翻译：

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大规模测深生境类型对中生和深层浸没式鱼类群的生物地球物理影响：夏威夷案例研究

摘要：海山，尖峰和波峰是突然的海底特征，可改变物理过程和生态格局。渔民通常将目标定为这些当地的测深高点，这可能具有很高的单位捕获量。定性地指出了这些特征和海角周围目标物种的数量增加，然而，仍然缺乏对当地高点作为鱼类首选栖息地的定量评估。在这里，我们使用了一个广泛的数据库，该数据库从主要夏威夷群岛周围8年中收集的中生和上层深海深度（40-300 m）的鱼类丰度（N = 2381）中，通过结合水深位置来评估宏观生境的影响指数（BPI）和斜率。使用模拟物理海洋过程的数值模型来检验以下假设：局部高点（此处称为波峰）由于其流动条件的改变，它们是许多物种的独特且首选的栖息地。我们显示，波峰拥有独特而多样的鱼类组合，相对于其他栖息地，其鱼类的丰度高出一倍。因此，鱼类集中在波峰，而不是沿岛架均匀分布在优选深度。这些栖息地的特征是电流振幅和会聚区增强。鱼的丰度，会聚度和水流幅度之间的直接相关性强烈表明，流动性增强的食物供应量可能是与鱼群栖息地相关的变化的驱动力。这些结果对保护和管理具有重要意义。我们确定了一种简单而有用的方法来对栖息地进行分类，将测深法引起的流量变化与鱼的数量定量地联系起来，