Impacts of land use and hydrological alterations on water quality and fish assemblage structure in headwater Pampean streams (Argentina)

PAREDES DEL PUERTO, J. M.; GARCIA, I.; MAIZTEGUI, T.; PARACAMPO, A.; RODRIGUES CAPÍTULO, L.; GARCIA DE SOUZA, J. R.; MAROÑAS, M. E.; COLAUTTI, D. C.

AQUATIC SCIENCES

BIRKHAUSER VERLAG AG

Lugar: BASEL; Año: 2022 vol. 84

1015-1621

Headwater streams play an essential role in catchment ecosystem processes and are particularly vulnerable to land use degradationand anthropic hydrological alterations. Considering that fish assemblages are reliable indicators of the ecologicalintegrity of streams, we evaluated the ichthyofauna structure in four headwater Pampean streams located at catchment areaswith contrasting land uses and hydrological man-made alterations. During autumn and spring of 2017 and 2018, fish assemblageswere sampled and physicochemical and water table depth were measured. Specific richness, abundance, and diversityof fish assemblages were estimated. The degree of anthropic intervention of drainage networks and wetland coverage wasestimated for each catchment. Statistical analyses assessed the differences between rural and periurban sampling sites interms of environmental variables and fish assemblage structure, as well as the relationships between the biotic and abioticvariables. Results showed differences among headwater streams according to their land uses, hydrological alterations, andfish assemblage structure, evidencing a combined effect of land use and hydrologic alterations on fish assemblage. Changesin these communities can reflect not only alterations in water quality caused by local land use but also the influence of thecatchment environmental integrity related to hydrological modifications and other phenomena that can occur simultaneouslyand at different geographical scales.