Monitoreo de macroinvertebrados en el río Guachicos, usando los como bioindicadores para determinar la calidad del agua.

La calidad de agua es un factor que incide directamente sobre la calidad de vida de las comunidades y la academia puede hacer aportes significativos a entidades y comunidades organizadas que manejan el recurso hídrico. Esta investigación da continuidad a un proceso de iniciado en el 2018, monitoreando la cuenca del río Guachicos, que abastece el acueducto del municipio de Pitalito. La calidad de agua se evaluó utilizando el método BMWP/Col de Roldán (2016), que a partir de la identificación de las familias de macroinvertebrados, asigna puntuaciones que sumadas dan una calificación que permite evaluar el nivel de contaminación. Para la investigación se seleccionaron 4 puntos de muestreo, en las partes alta, media, antes de la bocatoma del acueducto y cerca de la desembocadura del río Guachicos y en la parte baja de la quebrada El Cedro, principal afluente; se hicieron 5 muestreos en los meses de mayo, junio, julio y dos en el mes de agosto del 2019. El muestreo se hizo siguiendo las indicaciones de IDEAM (2006), en el documento Macroinvertebrados acuáticos, determinación taxonómica y conteo. Se colectaron 1818 macroinvertebrados pertenecientes a 10 órdenes y 26 familias, siendo la familia más abundante la Hydropsychidae con un 37,62%, la Leptophlebiidae con el 15,51% y la Perlidae con el 14,03%. Los valores promedio encontrados del índice BMWP/Col corresponden a 106 en el río Guachicos parte alta Porvenir, indicando buena calidad de agua; en la parte media en Bombonal su valor fue de 58 (aguas de clase III, calidad dudosa), indicando aguas moderadamente contaminadas. En la parte baja de la quebrada El Cedro y antes de la bocatoma del acueducto sobre el río Guachicos, el valor fue de 36 y 37 respectivamente (aguas de clase III, calidad dudosa y en la parte baja, cerca de la desembocadura y luego de recorrer los centros urbanos de Bruselas y Pitalito presenta un valor de 23 - aguas de clase IV, calidad critica), indicando aguas muy contaminadas. Comparando los valores encontrados con investigaciones anteriores, como las de Sánchez Molano y García (2018) y Martínez & Quiroz (2019), en mediciones similares sobre el río Guachicos y la quebrada El Cedro, se encontraron disminuciones en los valores del índice BMWP/Col, que pueden indicar que la calidad de agua está en deterioro.

Water quality is a factor that directly affects the quality of life of communities and the academy can make specific contributions to the entities and organized communities that manage the water resource. The investigation continues a process of initiation in 2018, monitoring water sources in the Guachicos river basin, which supplies the aqueduct of the municipality of Pitalito. Water quality was assessed using the BMWP / Col method of Roldán (2016), based on the identification of macroinvertebrate families, assignments that added together give a rating that allows the level of contamination to be assessed. In the upper part of the basin there are forest redoubts, which disappear once human settlements are presented that pour their sewage directly to the sources, in addition to coffee crops, whose processing is also a cause of contamination. For the investigation, 4 sampling points were selected, in the upper, middle parts, before the entrance to the aqueduct and near the mouth of the Guachicos river and in the lower part of the El Cedro creek, the main tributary; 5 samples were made in the months of May, June, July and two in the month of August 2019. Sampling was done following the indications of IDEAM (2006), in the document Macroinvertebrates aquatic, taxonomic determination and counting. Within the limitations of the study, there were episodes of heavy rains at the time of macroinvertebrate collection, which could affect the number of families found. 1818 macroinvertebrates belonging to 10 orders and 26 families were collected, the most abundant family being Hydropsychidae with 37.62%, Leptophlebiidae with 15.51% and Perlidae with 14.03%. The average values found in the BMWP / Col index correspond to 106 in the Guachicos River high part of Porvenir, indicating good water quality; in the middle part in Bombonal its value was 58 (class III waters, doubtful quality), indicating moderately contaminated waters. In the lower part of the El Cedro gorge and before the entrance of the aqueduct on the Guachicos river, the value was 36 and 37 respectively (class III waters, dubious quality and in the lower part, near the mouth and after touring the urban centers of Brussels and Pitalito has a value of 23 (class IV waters, critical quality), indicating heavily polluted waters. Comparing the values found with previous research, such as those of Sánchez Molano and García (2018) and Martínez & Quiroz (2019), in similar measurements on the Guachicos river and the El Cedro creek, decreases were found in the BMWP / Col index values , which may indicate that water quality is deteriorating, due to the lack of treatment of wastewater discharges from coffee processing and the poor disposal of household solid waste that is deposited on the banks. The recognition of the communities and the public service company EMPITALITO stand out for these investigations, which document the quality of water consumed by the inhabitants of the municipality of Pitalito and will allow improving decision-making regarding the conservation of water sources.