The influence of biogeographical and environmental factors on the functional structure of fish communities in the Atlantic Ocean

• Grant number: 23/09925-9
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: November 09, 2023
• End date: April 30, 2024
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Hudson Tercio Pinheiro
• Grantee: Julia Marx de Souza
• Supervisor: Valeriano Parravicini
• Host Institution: Centro de Biologia Marinha (CEBIMAR). Universidade de São Paulo (USP). São Sebastião , SP, Brazil
• Institution abroad: Centre de Recherches Insulaires et Observatoire de l'Environnement (CRIOBE), France
• Associated to the scholarship: 22/08684-5 - Fish community structure in mesophotic ecosystems: an analysis between depth gradients in biogeographic provinces of the Atlantic Ocean, BP.MS

Abstract

The mesophotic reef ecosystems (MEs) are characterized by the presence of organisms that are less light dependent and harbour communities of fish and corals. Recently, the depth gradient has been suggested as an important driver for community assembly, and exploring shallow and deep ecosystems can elucidate the functional relationship between these habitats and the role of fish endemism. To better understand how biogeography and environmental factors drive the community functional structure in three biogeographic provinces of the Atlantic Ocean, we will analyse a database from underwater visual census (UVC) sampled across the coral reef depth gradient. This study will explore fish communities sampled in three Caribbean countries (Bermuda, Curaçao, and Honduras; NWA), two offshore Brazilian islands (SWA), and three islands of the Cape Verde Archipelago (TEA). Some studies indicate that shallow and ME seem to be structured by distinct rules, with dispersal and extinction as main predictors for functional community structuring. Thus, we predict that MEs from distinct provinces are most different in their shallow communities due to notable discrimination between the marginal and biogenic environments, which homogenises deeper along the deep coral reef depth gradient. Furthermore, we predict that endemism and isolation is the main driver that influences Saint Paul's Rocks and Bermuda assemblage structure. These study areas are internationally recognized as an environment of high economic and ecological value, having marine protected areas limited to shallow reefs. This characteristic suggests the importance of management policies for deep reefs, since they are affected by fishing exploitation and pollution. Similar to shallow reefs, MEs should also be included in environmental protection plans, giving attention to the unique ichthyofauna found at these depths. (AU)