Fishes are known to use deep-sea coral and sponge (DSCS) species as habitat, but it is uncertain whether this relationship is facultative (circumstantial and not restricted to a particular function) or obligate (necessary to sustain fish populations). To explore whether DSCS provide essential habitats for demersal fishes, we analyzed 10 years of submersible survey video transect data, documenting the locations and abundance of DSCS and demersal fishes in the Southern California Bight (SCB). We first classified the different habitats in which fishes and DSCS taxa occurred using cluster analysis, which revealed four distinct DSCS assemblages based on depth and substratum. We then used logistic regression and gradient forest analysis to identify the ecological correlates most associated with the presence of rockfish taxa (Sebastes spp.) and biodiversity. After accounting for spatial autocorrelation, the factors most related to the presence of rockfishes were depth, coral height, and the abundance of a few key DSCS taxa. Of particular interest, we found that young-of-the-year rockfishes were more likely to be present in locations with taller coral and increased densities of Plumarella longispina, Lophelia pertusa, and two sponge taxa. This suggests these DSCS taxa may serve as important rearing habitat for rockfishes. Similarly, the gradient forest analysis found the most important ecological correlates for fish biodiversity were depth, coral cover, coral height, and a subset of DSCS taxa. Of the 10 top-ranked DSCS taxa in the gradient forest (out of 39 potential DSCS taxa), 6 also were associated with increased probability of fish presence in the logistic regression. The weight of evidence from these multiple analytical methods suggests that this subset of DSCS taxa are important fish habitats. In this paper we describe methods to characterize demersal communities and highlight which DSCS taxa provide habitat to demersal fishes, which is valuable information to fisheries agencies tasked to manage these fishes and their essential habitats.

中文翻译：

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深海珊瑚和海绵类群增加了底层鱼类的多样性和鱼类存在的可能性

众所周知，鱼类使用深海珊瑚和海绵 (DSCS) 物种作为栖息地，但不确定这种关系是兼性的（偶然的，不限于特定功能）还是专性的（维持鱼类种群所必需的）。为了探索 DSCS 是否为底栖鱼类提供必要的栖息地，我们分析了 10 年的潜水调查视频横断面数据，记录了南加州湾 (SCB) 中 DSCS 和底栖鱼类的位置和丰度。我们首先使用聚类分析对鱼类和 DSCS 分类群发生的不同栖息地进行了分类，该分析揭示了基于深度和基质的四种不同的 DSCS 组合。然后，我们使用逻辑回归和梯度森林分析来确定与石鱼分类群（Sebastes spp. ) 和生物多样性。考虑到空间自相关后，与岩鱼存在最相关的因素是深度、珊瑚高度和一些关键 DSCS 分类群的丰度。特别令人感兴趣的是，我们发现年幼石斑鱼更有可能出现在珊瑚较高且 Plumarella longispina、Lophelia pertusa 和两种海绵类群密度增加的地方。这表明这些 DSCS 分类群可能是岩鱼重要的饲养栖息地。同样，梯度森林分析发现鱼类生物多样性最重要的生态相关性是深度、珊瑚覆盖、珊瑚高度和 DSCS 分类群的一个子集。在梯度森林中排名靠前的 10 个 DSCS 分类群（在 39 个潜在的 DSCS 分类群中），6 个也与逻辑回归中鱼类存在的可能性增加有关。这些多种分析方法的证据权重表明，这个 DSCS 分类群的子集是重要的鱼类栖息地。在本文中，我们描述了表征底层群落的方法，并强调哪些 DSCS 分类群为底层鱼类提供栖息地，这对于负责管理这些鱼类及其基本栖息地的渔业机构来说是宝贵的信息。