Multiscale spatial patterns and environmental drivers of seamount and island slope megafaunal assemblages along the Mozambique channel

作者：Mélissa Hanafi‐Portier, Sarah Samadi, Laure Corbari, Marion Boulard, Elda Miramontes, Pierrick Penven, Boris Leroy, Thibault Napoléon, Stéphan Jorry, Karine Olu · 发表于：Deep Sea Research Part I Oceanographic Research Papers · 年份：2023 · DOI：10.1016/j.dsr.2023.104198 · 被引用次数：5 · 研究领域：Coral and Marine Ecosystems Studies、Marine and fisheries research、Marine Biology and Ecology Research

Seamounts are vulnerable ecosystems targeted by fishing and potentially by future mineral exploitation. Their abundance, widespread distribution, and heterogeneity of faunal and abiotic components require integrated studies at multiscale to describe spatial patterns and identify environmental drivers needed by conservation plans. There is also a lack of knowledge on seamount benthic ecosystems in some regions, such as the Indian Ocean. These gaps, in the context of Marine Protected Areas establishment in the region, have motivated the present study focusing on the Mozambique Channel Eparses islands and flat top seamounts, along a 10-degree latitude gradient. These structures are characterized by complex volcanic and carbonate geomorphologies at multiscale and are distributed along a highly dynamic turbulent ocean circulation area with large anticyclonic eddies. For the first time, we analysed, from seabed image transects obtained by towed-camera on four seamounts, and two volcanic islands - Bassas da India and Mayotte - external slopes, and from multiscale environmental data, how benthic communities respond to this high habitat heterogeneity at regional, and local scales. This study reveals high discrepancies of benthic megafauna richness, density, and beta diversity between seamounts and between slopes of the same islands. Moreover, at similar latitude, seamounts display higher densities than island slopes. The highest densities found on a seamount of the Glorieuses archipel...