Fish assemblages of Pampasic streams: relationships with anthropogenic and environmental variables (Buenos Aires, Argentina)

ARIEL PARACAMPO; NATALIA MARROCHI; GARCÍA, IGNACIO; MAIZTEGUI TOMÁS; PEDRO CARRIQUIBORDE; CARLOS BONETTO

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

ACAD BRASILEIRA DE CIENCIAS

Lugar: Rio de Janeiro; Año: 2020

0001-3765

The present work assesses the effect of natural and anthropogenic environmental variables on the fish assemblages in Pampean streams, in the coastal strip along the Río de la Plata, Buenos Aires province, Argentina. Five streams were sampled at 12 sites surrounded by land devoted to different uses. A correspondence analysis sorted them into two groups: a less impacted group formed by sites surrounded by natural, livestock-raising pastures and a most impacted group formed by urban sites and a stream with a village and a dairy industry in its basin. Nutrients concentrations were significantly higher in the most impacted group, and richness, diversity, abundance and biomass were significantly lower. The analysis of canonical correspondence related the most impacted sites with high concentrations of PRS and impoverished fish assemblages, composed of species tolerant to environmental pollution. By contrast, sites with higher oxygen and pH were related with richer assemblages pointing to good environmental conditions at the sites surrounded by natural pastures on which livestock is raised. The downstream sites on the less impacted streams showed fish assemblages in which juvenile stages of species corresponding to the Río de la Plata were dominant.