Tosetto E. G. auteur aut IRD Lett Christophe auteur aut IRD Neumann-Leitao S. auteur aut IRD Koch Larrouy Ariane auteur aut IRD Barrier Nicolas auteur aut IRD da Silva A. C. auteur aut IRD Salvetat J. auteur aut IRD Bertrand Arnaud auteur aut IRD text journalArticle eng text/pdf reformatted digital access The recruitment of marine species in isolated oceanic island systems can be challenged by prevailing currents, as exemplified by the Tropical Southwestern Atlantic. In this region, the Fernando de Noronha ridge hosts several seamounts, the Rocas Atoll and the Fernando de Noronha Archipelago, which are home to great marine biodiversity. However, along the ridge, the central branch of the South Equatorial Current (cSEC), flowing westward, poses a challenge to the recruitment of organisms toward Fernando de Noronha. To unveil critical insights into the intricate processes shaping biodiversity in these insular ecosystems, we use a dispersal Lagrangian tool to explore the role of diel vertical migration (DVM) to depth strata influenced by the South Equatorial Undercurrent (SEUC), which flows eastward bellow the cSEC, in shaping species dispersal and metacommunity dynamics. Our results show that while not a direct journey, the DVM into SEUC-influenced strata increases the possibility that the seamounts and the Rocas Atoll act as stepping stones between the continental shelf and Fernando de Noronha. Propagules of organisms originating primarily from the continental shelf are transported to the western seamounts of the ridge. Upon reaching the western seamounts, organisms can find suitable habitats to recruit. The progeny of these communities that migrate to SEUC-influenced strata have the opportunity to reach suitable habitats at the Rocas Atoll and the Eastern seamounts, ultimately connecting to the Fernando de Noronha archipelago. These results provide scientific fundaments for the development of a functional network of marine protected areas in the Tropical Southwestern Atlantic. specialized BRESIL ZONE TROPICALE 036 082 [Early access] [14 p.] 2024 0024-3590 https://www.documentation.ird.fr/hor/fdi:010091184 10.1002/lno.12648 0024-3590 [F B010091184] https://www.documentation.ird.fr/hor/fdi:010091184 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2024-09/010091184.pdf IRD - Base Horizon / Pleins textes 2024-09-27 2025-11-06 fdi:010091184 fre