Mesozooplankton community: Structure, functionality, and food availability in a tropical area of the Southwest Atlantic Ocean

We investigated the taxonomic and functional complexity of a mesozooplankton community and associated trophic relationships in a tropical area of the Southwest Atlantic Ocean. Mesozooplankton communities showed a clear distribution between coastal and oceanic regions. Along the continental shelf, areas influenced by the upwelling of the Cabo Frio and plume of the Paraíba do Sul River, characterized by high productivity and nutrient availability, showed the highest abundance of mesozooplankton. Small-to-medium-sized mesozooplankton species, characterized by current feeding and a broadcast spawning strategy, were dominant over other species. Picoplankton and microplankton were found to be key predictors of the abundance of current-feeding group. For cruise/ambush–feeding group, suspended particulate matter and autotrophic microplankton were significant predictors of their abundance. Ambush-feeding group is primarily influenced by the availability of current-feeding and cruise/ambush–feeding groups and suspended particulate matter. This study provides insights into the functional groups of the zooplankton community in the South Atlantic Ocean and addresses a notable gap in our understanding of interactions at the base of the marine food web across much of the western South Atlantic Ocean. This information is crucial for understanding the potential impacts of global climate change and local disturbances on marine trophic dynamics in the region.