Evaluation of trace metals in (Ichthyoelephas humeralis) and socio-environmental perception of river pollution in Babahoyo Canton, Ecuador

Abstract

The concentrations of cadmium (Cd) and mercury (Hg) were evaluated in the muscle tissue of the endemic detritivorous fish Ichthyoelephas humeralis from the river system of Babahoyo canton, Ecuador, along with the socio-environmental perception of artisanal fishers regarding water pollution. Thirty specimens were analyzed using atomic absorption spectrophotometry, and structured surveys were administered to artisanal fishers. Morphometric variables showed a significant positive correlation between length and weight (rho = 0.994; p < 0.001). In all individuals, Cd and Hg concentrations remained below the analytical limits of quantification (<0.014 mg/kg for Cd and <0.09 mg/kg for Hg) and the maximum limits established by international regulations. Most fishers perceived a high degree of pollution in the river system and expressed concern over the quality of hydrobiological resources and food security, although they demonstrated limited knowledge about pollution sources and low participation in mitigation actions. It is concluded that these results establish an ecotoxicological baseline for I. humeralis and provide insight into the socio-environmental perception of fishing communities, which is useful for future monitoring programs and the sustainable management of hydrobiological resources.