Resumen

Aquatic macroinvertebrates as bioindicators of water quality in the Casacay Microbasin, Pasaje canton. RCTU [online]. 2025, vol.12, n.2, pp.38-47. ISSN 1390-7697.  https://doi.org/https://doi.org/10.26423/gqt3xm85.

The aquatic ecosystems of the Casacay micro-basin face threats from pollutants that affect their quality. This study evaluated water quality at five points in the middle and lower reaches of the Casacay River using macroinvertebrates as bioindicators. A total of 273 individuals belonging to 21 families and 7 orders were collected, with Baetidae, Blephariceridae, and Leptophlebiidae being the most prominent. The BMWP/COL, EPT, ASPT, and IBF indices were applied to assess biological integrity. The results showed spatial variations in water quality, with acceptable values in mountainous areas and deterioration in agricultural and recreational areas. The descriptive analysis revealed that the BMWP/COL index had a mean of 69 and a standard deviation of 26.44, indicating variability in water quality. The EPT index had a mean of 57 with a standard deviation of 19.14, suggesting sensitivity to pollution in impacted areas.

Palabras clave : Upper basin; lower basin; trophic diversity; biotic indices; biological monitoring.