Fish assemblages in an environmentally complex narrow coastal region in the Southwestern Atlantic Ocean: an alternative nursery habitat for fishery species

BRUN, ANAHÍ; MAENZA, REINALDO; ELISIO, M.; RUARTE, CLAUDIO; ALEMANY, DANIELA

Regional Studies in Marine Science

Elsevier

Año: 2024

2352-4855

The narrow coastal waters south of the Río de la Plata estuary are anoceanographically dynamic area where small-scale or artisanal fisheries occur. Weanalyzed 95 fishing bottom trawls from research surveys, along with oceanographicdata collected during 2016 and 2017. Multivariate analyses (PERMANOVA, SIMPER,CAP) were applied to determine the spatial distribution of fish density, diversity andassemblage structure, as well as their relationship with the oceanographicenvironment. We estimated the length-frequency distribution of Sciaenid species todetermine the presence of juveniles in the area. We recorded forty-three coastal fishspecies (15 commercial and 28 non-commercial) with the families Sciaenidae andRajidae accounting for approximately ~80 % of the catches. Marine migrants were themost dominant in terms of species, followed by marine stragglers and estuarineresidents. We detect differences in assemblages between surveys, primarilyassociated with nine species. Bottom salinity and temperature had a significantinfluence on the spatial structuring of discriminant species and functional groups.Sciaenid juveniles were found in areas with low salinities and shallow habitats, whileadults were distributed in deeper and saltier waters. This work highlights theimportance of physical conditions on fish assemblage dynamics in a complexenvironment, as well as the significant role of a narrow coastal