Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Vitória, Espírito Santo, Brazil.
PeerJ. 2023 Feb 27;11:e14585. doi: 10.7717/peerj.14585. eCollection 2023.
The Brazilian continental margin (BCM) extends from the Tropical to the Subtropical Atlantic Ocean, with much of its seafloor within deep waters, supporting rich geomorphological features and under wide productivity gradients. Deep-sea biogeographic boundaries on the BCM have been limited to studies that used water mass and salinity properties of deep-water masses, partly as a result of historical under sampling and a lack of consolidation of available biological and ecological datasets. The aim of this study was to consolidate benthic assemblage datasets and test current oceanographic biogeographical deep-sea boundaries (200-5,000 m) using available faunal distributions. We retrieved over 4,000 benthic data records from open-access databases and used cluster analysis to examine assemblage distributions against the deep-sea biogeographical classification scheme from Watling et al. (2013). Starting from the assumption that vertical and horizontal distribution patterns can vary regionally, we test other schemes incorporating latitudinal and water masses stratification within the Brazilian margin. As expected, the classification scheme based on benthic biodiversity is in overall agreement with the general boundaries proposed by Watling et al. (2013). However, our analysis allowed much refinement in the former boundaries, and here we propose the use of two biogeographic realms, two provinces and seven bathyal ecoregions (200-3,500 m), and three abyssal provinces (>3,500 m) along the BCM. The main driver for these units seems to be latitudinal gradients as well as water mass characteristics such as temperature. Our study provides a significant improvement of benthic biogeographic ranges along the Brazilian continental margin allowing a more detailed recognition of its biodiversity and ecological value, and also supports the needed spatial management for industrial activities occurring in its deep waters.
巴西大陆边缘（BCM）从热带延伸到亚热带大西洋，其大部分海底都位于深水区，拥有丰富的地貌特征和广泛的生产力梯度。BCM 的深海生物地理边界仅限于使用深水团的水团和盐度特性进行的研究，部分原因是历史上采样不足以及缺乏对现有生物和生态数据集的整合。本研究的目的是整合底栖生物群数据集，并使用现有动物群分布来检验当前海洋生物地理深海边界（200-5,000 米）。我们从开放获取的数据库中检索了超过 4,000 个底栖数据记录，并使用聚类分析来根据 Watling 等人（2013 年）的深海生物地理分类方案检查集合体的分布。从垂直和水平分布模式可能会在区域上变化的假设出发，我们测试了其他方案，这些方案将纬度和水团分层纳入了巴西边缘。不出所料，基于底栖生物多样性的分类方案总体上与 Watling 等人（2013 年）提出的一般边界一致。然而，我们的分析允许在前边界上进行更多的细化，在这里，我们建议使用两个生物地理区域、两个省份和七个半深海生态区（200-3,500 米），以及三个深海省份（>3,500 米）来沿着 BCM。这些单位的主要驱动因素似乎是纬度梯度以及水团特征，如温度。我们的研究为巴西大陆边缘的底栖生物地理范围提供了重大改进，使人们能够更详细地认识其生物多样性和生态价值，并支持在其深水区开展工业活动所需的空间管理。
