Impoverished fish assemblages of temperate 1 Neotropical streams respond to 2 environmental degradation and support a sensitive Index of Biotic Integrity

BERTORA, ANDREA; GROSMAN, FABIÁN; SANZANO, PABLO; ROSSO, JUAN JOSE

HYDROBIOLOGIA

SPRINGER

Lugar: Berlin; Año: 2023

0018-8158

Fish as bioindicators are a widely used tool for environmental monitoring of freshwaterecosystems worldwide. However, its adaptation to temperate Neotropical streams constitutes achallenge due to the presence of pauperised ichthyofauna with high tolerance to environmentaldegradation. We designed, evaluated, and validated an Index of Biotic Integrity (IBI) that usesfish as bioindicators of the ecological integrity of streams of the Pampa Plain, Argentina. Anintegral characterization of the environmental conditions (water quality, habitat structure, andriparian condition) and fish assemblages were performed in 17 study sites (natural grasslands,urban, and livestock reaches). The IBI was designed with 10 metrics and showed to besensitive to different environmental conditions due to significant differences between study sitesand land uses. The IBI also showed to be responsive due to its significant associations withwater quality, habitat structure variables, and some multimetric indexes. Moreover, whenvalidated against a recently fish database, it demonstrated to be sensitive for use in othertemperate streams exposed to similar environmental conditions. An integral environmentalassessment as the one designed can lead to optimized strategies for the management andconservation of these fragile ecosystems.