water Article Influence of Intensive Agriculture on Benthic Macroinvertebrate Assemblages and Water Quality in the Aconcagua River Basin (Central Chile) Pablo Fierro 1,* , Claudio Valdovinos 2, Carlos Lara 3 and Gonzalo S. Saldías 4,5 1 Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia 5090000, Chile 2 Departamento de Sistemas Acuáticos, Facultad de Ciencias Ambientales, Universidad de Concepción, y Centro de Ciencias Ambientales (EULA), Universidad de Concepcion, Concepcion 4070386, Chile;
[email protected] 3 Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Concepción 4090541, Chile;
[email protected] 4 Departamento de Física, Facultad de Ciencias, Universidad del Bío-Bío, Concepción 4051381, Chile;
[email protected] 5 Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Valdivia 5090000, Chile * Correspondence: pablo.fi
[email protected] Abstract: This study assessed natural variation in the macroinvertebrate assemblages (MIB) and water quality in one of the main basins with the largest agricultural activities in Chile (Aconcagua River Basin). We sampled throughout the annual cycle; nine sampling sites were established along Citation: Fierro, P.; Valdovinos, C.; the basin, classifying according to agricultural area coverage as least-disturbed, intermediate, and Lara, C.; Saldías, G.S. Influence of most-disturbed. We collected 56 macroinvertebrate taxa throughout the entire study area. Multi- Intensive Agriculture on Benthic variate analysis shows significant differences among the three disturbance categories in different Macroinvertebrate Assemblages and seasons, both water quality variables and the MIB structure. Distance-based linear model (DistLM) Water Quality in the Aconcagua River analysis for all seasons explained more than 95.9% of the macroinvertebrate assemblages, being Basin (Central Chile).