Coffee processing affect the strcucture of mayflies assemblages in streams of the Sierra Nevada de Santa Marta, Colombia

The order Ephemeroptera is widely used as a bioindicator of water quality due to its ecological characteristics, due to this group is ideal for studying the impact of activities like as coffeee hulling on stream ecosystems. Objective: To evaluate the effect of coffee crop on the abundance and diversity of nymphs of Ephemeroptera. Methodology: 2 sites affected by coffee hulling (Palmichal and Guáimaro) and two localities without stressors (reference sites: Libertad and Nuevo mundo) were studied during the months of November and December of 2021. In each site, Ephemeroptera were collected with surber and type D nets in the microhabitats present. Additionally, physicochemical data were taken. To establish the effect of coffee hulling on the order Ephemeroptera, the abundance and richness of genera in disturbed and conserved places were compared. Results: Cluster analysis based on incidence showed the formation of two groups: one constituted by Libertad, Nuevo mundo, Palmichal sites and another by Guáimaro. Likewise, there were significant differences among the abundance of the study sites (ANOSIM R=0.48 p= 0.0007). In the environmentally affected sites Thraulodes and Camelobaetidius dominated in Guáimaro and Leptohyphes and Baetodes in Palmichal, with respect to the reference sites: Baetodes, Leptohyphes, Mayobaetis and Nanomis dominated. Conclusions: The results of the present study showed that the effect of water produced by coffee hulling affects the structure of mayflies, which can be observed in the decreasing of abundance and richness, in the differentiation of dominant taxa, in comparison with reference sites.