1. Evidence-based decisions relating to effective marine protected areas as a means of conserving biodiversity require a detailed understanding of the species present. The Caribbean island nation of St Lucia is expanding its current marine protected area network by designating additional no-take marine reserves on the west coast. However, information on the distribution of fish species is currently limited.
2. This study used baited remote underwater stereo-video to address this shortcoming by investigating the effects of depth and seabed habitat structure on demersal fish assemblages and comparing these assemblages between regions currently afforded different protection measures.
3. From the 87 stations visited a total of 5,921 fish were observed comprising 120 fish taxa across 22 families. Species richness and total abundance were higher within the highly managed region, which included no-take reserves. Redundancy analysis explained 17% of the total variance in fish distribution, driven predominantly by the seabed habitats. The redundancy analysis identified four main groups of demersal fishes each associated with specific seabed habitats.
4. The current no-take marine reserves protected two of these groups (i.e. fishes associated with the ‘soft corals, hard corals or gorgonians’ and ‘seagrass’ groups). Importantly, habitats dominated by sponges, bacterial mats, algal turfs or macroalgae, which also supported unique fish assemblages, are not currently afforded protection via the marine reserve network (based on the five reserves studied). These results imply that incorporation of the full breadth of benthic habitat types present would improve the efficacy of the marine reserve network by ensuring all fish assemblages are protected.

中文翻译：

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圣卢西亚西海岸底层鱼类群落的分布：对规划禁捕海洋保护区的意义

1. 将有效的海洋保护区作为保护生物多样性的一种手段的基于证据的决策需要对现有物种的详细了解。加勒比岛国圣卢西亚正在通过在西海岸指定额外的禁捕海洋保护区来扩大其目前的海洋保护区网络。然而，目前关于鱼类分布的信息有限。
2. 本研究通过调查深度和海底栖息地结构对底栖鱼类组合的影响，并在目前提供不同保护措施的区域之间比较这些组合，使用带饵的远程水下立体视频来解决这一缺陷。
3. 从访问的 87 个站点中，共观察到 5,921 条鱼，包括 22 个科的 120 个鱼类分类群。高度管理区域内的物种丰富度和总丰度更高，其中包括禁采区。冗余分析解释了鱼类分布总差异的 17%，主要由海底栖息地驱动。冗余分析确定了四类主要的底层鱼类，每类都与特定的海底栖息地有关。
4. 目前的禁捕海洋保护区保护了其中两个群体（即与“软珊瑚、硬珊瑚或柳珊瑚”和“海草”群体相关的鱼类）。重要的是，以海绵、细菌垫、藻类草皮或大型藻类为主的栖息地，它们也支持独特的鱼类组合，目前没有通过海洋保护区网络（基于研究的五个保护区）提供保护。这些结果意味着，通过确保所有鱼类组合得到保护，纳入现有的所有底栖栖息地类型将提高海洋保护区网络的效率。