ABSTRACT: Mangroves are important habitats for a variety of ecologically, commercially and culturally important fishes. However, little is known about their role within the Tropical Eastern Pacific (TEP), and particularly in the Galapagos Archipelago, the westernmost limit for mangroves in the Americas, and the only oceanic islands in the TEP where mangroves are present. We describe patterns of fish composition in the 2 Galapagos bioregions where mangroves are present and assess potential environmental factors influencing fish community composition. Underwater Visual Census and Stereo Baited Remote Underwater Video stations (stereo-BRUVS) were used to sample fish communities. We identified 35029 fish representing 93 species, 67 genera and 36 families. Pomacentridae, Mugilidae, Haemulidae and Lutjanidae were the most common families. Juveniles made up 43% of the fish, 30 species were of importance to local artisanal fisheries and 80% of species were associated with reef habitats, suggesting mangroves in Galapagos may provide nursery habitats for economically valued species. Fish assemblage composition varied across bioregions, with 6 taxa responsible for driving these differences, including species of economic importance: Lutjanus novemfasciatus and Mycteroperca olfax. Species richness was 17% higher in the Central-Southeastern than in the Western region; while higher species richness, Shannon-Wiener diversity and Pielou’s evenness were detected with BRUVS than through visual censuses. Our results highlight the role of mangroves as a habitat for a unique fish community composed of young, endemic and commercially important species, whose composition is likely driven by the isolation of the islands and its location in a convergence zone.

中文翻译：

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红树林鱼群反映了加拉帕戈斯群岛的环境多样性

摘要：红树林是各种具有生态，商业和文化重要性的鱼类的重要栖息地。然而，人们对于它们在热带东太平洋（TEP）中的作用知之甚少，尤其是在加拉帕戈斯群岛，美洲红树林的最西端限制以及TEP中仅有红树林的海洋岛屿中。我们描述了存在红树林的两个加拉帕戈斯生物区中鱼类组成的模式，并评估了影响鱼类群落组成的潜在环境因素。水下视觉普查和立体声诱饵远程水下视频台（stereo-BRUVS）用于采样鱼类群落。我们确定了35029条鱼，它们代表93种，67属和36个科。禾本科，穆吉科，Haemulidae和Lutjanidae是最常见的科。幼鱼占鱼类的43％，其中30种对当地手工渔业很重要，而80％的物种与珊瑚礁生境有关，这表明加拉帕戈斯的红树林可能为经济上有价值的物种提供苗圃生境。在整个生物区域中，鱼类的组成组成各不相同，其中有6个类群是造成这些差异的原因，其中包括具有重要经济意义的物种：Lutjanus novemfasciatus和Mycteroperca olfax。中部-东南部的物种丰富度比西部地区高17％。而通过BRUVS检测到的物种丰富度，香农-维纳多样性和Pielou的均匀度要比通过视觉普查更高。我们的研究结果强调了红树林作为由年轻，特有和重要商业物种组成的独特鱼类群落的栖息地的作用，其组成可能是由岛屿的孤立及其在汇合区中的位置所驱动的。