Benthic Assemblage Composition of South Atlantic Seamounts
Benthic Assemblage Composition of South Atlantic Seamounts
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DOI：
10.3389/fmars.2021.660648
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发表时间：
2021-10-22
影响因子：
3.7
通讯作者：
Howell, Kerry L.
中科院分区：
文献类型：
--
作者：
Bridges, Amelia E. H.;Barnes, David K. A.;Howell, Kerry L.
海山和海洋岛屿从海底升起，为包括脆弱海洋生态系统（VMEs）在内的各种生物群落提供了适宜的栖息地。虽然它们一直是全球一些工作的重点，但对南大西洋海底山的生物和物理环境的描述却很少。本研究对阿森松岛、圣赫勒拿岛和特里斯坦达库尼亚专属经济区（eez）内跨越8-40°S的13个海山和海洋岛屿的底栖生物群落组成进行了研究。跌落相机在170 - 1000米之间采集图像。对图像中存在的所有动物群进行了识别和量化，并使用多元统计来描述生物组合并确定其环境驱动因素。温带地区（特里斯坦达库尼亚群岛）的底栖生物群落与热带地区的底栖生物群落不同，纬度和深度被确定为组合组成的关键环境驱动因素。我们的结果与目前对南大西洋生物地理学的理解是一致的，无论是在热带和温带地区的区分方面，还是在深度和水体结构对组合分布的影响方面。就功能群而言，动物群组合与在北大西洋观察到的相似。海洋生态系统存在于这三个地区的专属经济区内，可能受到大型海洋保护区（MPAs）的保护，免受某些威胁。我们的图像、数据和分析为南大西洋海底山提供了一个基线，以便未来的监测能够确定现有的保护状态是否足以保护独特的生物多样性和重要生态系统服务的巨大潜力。
Seamounts and oceanic islands rise from the seafloor and provide suitable habitat for a diverse range of biological assemblages including Vulnerable Marine Ecosystems (VMEs). Whilst they have been the focus of some work globally, there has been little description of the biological and physical environments of seamounts in the South Atlantic Ocean. In this study, we characterized benthic assemblage composition from 13 seamounts and oceanic islands spanning 8-40 degrees S within the exclusive economic zones (EEZs) of Ascension Island, Saint Helena and Tristan da Cunha. Drop camera imagery was collected between 170 and 1000 m. All fauna present in images were identified and quantified, and multivariate statistics were used to describe biological assemblages and identify their environmental drivers. Benthic communities of temperate regions (Tristan da Cunha archipelago) were shown to be distinct from those found in the tropics, with latitude and depth identified as key environmental drivers of assemblage composition. Our results are consistent with the current understanding of the biogeography of the South Atlantic, both in terms of the distinction between tropical and temperate regions, and the influence of depth and water mass structure on assemblage distribution. Faunal assemblages are similar to those observed in the North Atlantic in terms of functional groups. VMEs are present within the EEZs of all three territories and are potentially protected from some threats by large marine protected areas (MPAs). Our imagery, data and analyses provide a baseline for south Atlantic seamounts so that future monitoring can establish whether existing protected status is sufficient to conserve both unique biodiversity and considerable potential for vital ecosystem services.