Estudio de macroinvertebrados acuáticos y caudal ecológico en la microcuenca “Río Cinto”, sector Lloa, cantón Quito. (2023)

Abstract

The Cinto River micro-watershed is of great importance due to livestock farming, fish farming, and tourism activities in the area. This research focused on studying aquatic macroinvertebrates and determining the ecological flow of the Cinto River. For macroinvertebrates, 6 sampling points were analyzed based on land use with 3 repetitions each. The method used for macroinvertebrate collection was the Surber net. A total of 11 orders and 22 families were identified and classified, with the most abundant organisms being the Gamarridae, Tubicidae, Oligochaeta, and Baetidae families.

Macroinvertebrates were analyzed as indicators of water quality using the ABI Index (Andean Biological Index). Since it is a river with high Andean characteristics, the analysis resulted in poor quality, with a score ranging from 3 to 35.

The Margalef Index of statistical analysis determined the diversity in family richness, with the Paramo zone having 7 orders and 11 families, and Mining with 9 orders and 13 identified families.

The Simpson Index, which evaluates the most complete diversity in terms of families, yielded higher results at livestock (0.6834), mining (0.595), and paramo (0.7917) points. The Shannon-Wiener Index, which evaluates diversity dominance, was low at all six points.

The Simpson abundance index, of families with greater presence in the closest points such as Mining, Fish Farming, and Wastewater Treatment Plant, are relatively close points with similar characteristics such as vegetation cover, mild flow, and flat areas.

Ecological flow was determined in the wastewater treatment plant area. Due to the lack of hydrological data, a gauging campaign was conducted, which helped implement the Tennant method developed in Python software for 30-day data, and the flow was estimated during low-flow periods for 10%, 30%, and 60%.