Nekton in the Patagonian Shelf-Break Front: Fishes and Squids

Marine fronts affect the life of marine species at all trophic levels, determining distributional patterns. However, at higher levels such as nekton, behavior and swimming abilities become increasingly important, and the association with fronts becomes more intricate. The aim of this chapter is to provide a synthesis about nektonic species (fish and squids) at the Patagonian Shelf-break Front (PSBF), describing and compiling information on general aspects of nekton with emphasis on key species. A large number of nektonic species make use of the PSBF; more than 135 taxa of nekton are reported at this front between 1978 and 2019, during several scientific cruises and catches from commercial fleets. The PSBF is a complex adaptive system promoting suitable conditions for nektonic species and assemblages of high functional and ecological relevance. We highlight the PSBF as a key area due to its nekton biodiversity and the presence of threatened species, particularly cartilaginous fish. Moreover, key biological processes for the life cycle of fish and squids (feeding, reproduction, and/or migration) take place at the PSBF, improving survival opportunities. Nektonic species identified at the PSBF, due in part to complex trophic relationships, large home ranges, as well as extensive feeding and spawning migrations, connect the frontal system with other ecosystems, redistributing matter and energy.