Análisis de riesgo ecológico asociado a contaminantes en el agua y la tilapia Oreochromis niloticus (Linneaus, 1758), de la presa Tenango, Puebla

Abstract

In response to growing demands for water derived from population growth, industry, livestock, and agriculture, people have built dams; some of which were built in areas that later were designated as protected natural areas. There is little information regarding the water conditions of these sites, the influence of the human activities settled on the periphery on these water bodies and, in turn, the impact on the surrounding ecosystems due to man-made water pollution, which is why it is necessary to implement ecological risk studies (ERE). Therefore, a study was carried out in the Tenango Dam, Puebla, whose objective was to analyze the ecological risk represented by the possible exposure to metals: lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu) and the pesticide Benomilo, through the determination of the water quality and tilapia (Oreochromis niloticus) health, its bioconcentration and some biomarkers in the fish (acetylcholinesterase and metallothioneins levels). To carry out the present work, five field collections were done during 2015. 34 geo-referenced water collection stations were established, in which physicochemical parameters such as temperature, pH, dissolved oxygen and hardness were analyzed; nutrients such as nitrates, nitrites, and phosphorus; metals (Cd, Cr, Cu, and Pb) as well as the pesticide Benomyl were determined. In each collection, 30 specimens of tilapia (Oreochromis niloticus) were captured and identified. Fish were assessed through the quality specifications of SAGARPA for the commercialization of tilapia, and the same metals, quantified in water, and Benomyl levels were evaluated. Also, the bioconcentration factor and metallothionein levels in liver and muscle were quantified. Acetylcholinesterase activity