Diversity, distribution and spatial structure of the cold-water coral fauna of the Azores (NE Atlantic)
Diversity, distribution and spatial structure of the cold-water coral fauna of the Azores (NE Atlantic)
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DOI：
10.5194/bg-10-4009-2013
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发表时间：
2013-01-01
期刊：
影响因子：
4.9
通讯作者：
Santos, R. S.
中科院分区：
文献类型：
--
作者：
Braga-Henriques, A.;Porteiro, F. M.;Santos, R. S.
冷水珊瑚被广泛认为是底栖栖息地的重要结构组成部分，有可能提高当地多种鱼类和无脊椎动物物种的丰富度。然而，目前对这些脆弱、生长缓慢的生物体的分类多样性和分布模式的了解很少且支离破碎，限制了空间管理和保护措施的有效性。我们对目前可用的 Alcyonaceans、Antipatharians、scleractinians 和 stylasterids 的记录进行了详尽的汇编，以评估亚速尔群岛专属经济区 (EEZ) 珊瑚群落的多样性、分布和空间结构。由此产生的数据库包含 2501 个有关历史海洋探险和其他已发布来源的条目，以及来自海底延绳钓副渔获物的未发布数据。对于已探索的栖息地，我们的分类清单似乎相当完整，包括 164 个物种（79 种桫椤动物、58 种石珊瑚动物、18 种反动物动物和 9 种柱星动物），其中 9 种是首次记录。亚速尔群岛专属经济区拥有具有多种动物地理起源的混合珊瑚动物群，显示出与卢西塔尼亚-地中海地区最密切的亲缘关系。发现的明显地方病很少（14%），并且只有部分得到一致抽样的支持。在专属经济区 100 英里范围内被视为传统渔场或可开发鱼类栖息地的区域，珊瑚多样性在 300 米至 900 米深度之间特别高。珊瑚组合的组成显示了研究区域在可比深度（100-1500 m）的纵向剖面中的重要地理结构。没有证据表明大西洋中脊或该模式背后的纬度效应可能发挥作用，这表明它可能反映了特征之间的组合变异性。沿着测深梯度发现了物种组成的更强变化。尽管珊瑚的垂直分布特征是部分重叠的狭深和广深物种的混合，但从浅层（100-600 m）到中层（600-1000 m）深度存在明显的过渡。本文提出的分析对珊瑚相关脆弱海洋生态系统的有效保护政策及其作为捕捞区的可持续利用做出了宝贵贡献。
Cold-water corals are widely considered as important structural components of benthic habitats, potentially enhancing local abundance in a variety of fish and invertebrate species. Yet, current knowledge of the taxonomic diversity and distribution patterns of these vulnerable, slow-growing organisms is scarce and fragmented, limiting the effectiveness of spatial management and conservation measures. We have conducted an exhaustive compilation of records of alcyonaceans, antipatharians, scleractinians and stylasterids available through present day to assess the diversity, distribution and spatial structure of coral assemblages in the Azores exclusive economic zone (EEZ). The resulting database comprises 2501 entries concerning historical oceanographic expeditions and other published sources, as well as unpublished data from bottom longline by-catch. Our taxonomic inventory appears to be fairly complete for the explored habitats, accounting for 164 species (79 alcyonaceans, 58 scleractinians, 18 antipatharians and 9 stylasterids), nine of which were documented for the first time. The Azores EEZ harbours a mixed coral fauna with several zoogeographic origins, showing the closest affinity with the Lusitanian-Mediterranean region. Very few apparent endemics were found (14 %), and only in part supported by consistent sampling. Coral diversity is particularly high between 300 and 900m depths, in areas recognized as traditional fishing grounds or exploitable fish habitat within the 100-mile limit of the EEZ. The composition of coral assemblages shows significant geographical structure among longitudinal sections of the study area at comparable depths (100-1500 m). There is no evidence of a possible role of the Mid-Atlantic Ridge or latitudinal effects underlying this pattern, which suggests that it may instead reflect assemblage variability among features. Stronger changes in species composition were found along the bathymetric gradient. Notwithstanding the mix of partially overlapping steno- and eurybathic species that characterize the vertical distribution of corals, there is a distinct transition from shallow (100-600 m) to intermediate (600-1000 m) depths. The analysis presented here constitutes a valuable contribution for efficient conservation policies of coral-associated vulnerable marine ecosystems and their sustainable use as fishing areas.