Evaluación de los impactos de la industria de trucha arcoíris en la calidad del agua del río Quinuas, Parque Nacional El Cajas

Abstract

In Andean regions, ‘páramos’ provide vital services for downstream populations. In Ecuador, Cajas National Park ‘páramos’ are one of the main quality water providers to the city of Cuenca. Fishing farms are one of the main socio-economic activities in the Quinuas basin. This industry can generate environmental impact because the discharged effluents can have a great amount of waste and can become a serious threat to water quality from mountain regions. The aim of this study was to evaluate the changes in water quality parameters from four fish farms (Dos Chorreras, Reina del Cisne, Estación Arco Iris, and ETAPA), that catch its water and discharge it to the Quinuas river. The analysis was made in all types of flows, as well as in low, medium, and high flows. Weekly monitoring was executed between July, 2014 and July, 2017. Mann Whitney U (p<0.05) was performed and found statistically significant differences in Dos Chorreras (turbidity, COD, BOD, TOC, DOC, NO2, NO3, and TN); Reina del Cisne (turbidity); Estación Arco Iris (turbidity, conductivity, BOD, DOC, NO2, NO3, PO4, and SO4); and ETAPA (NO2, NO3, PO4, and SO4). Evident changes were observed in the farms that use larger amounts of food. In addition, the impact on water quality was greatly reduced when there is effluent treatment previous the discharge to the river.