Water Quality\nMonitoring in Ecuadorian Streams Using\na New Diatom-Based Index

The use of diatoms as ecological indicators of water\nquality is\nwell established globally, with numerous studies supporting the effectiveness\nof diatom-based biotic indices for monitoring the ecological status\nof freshwaters. These metrics typically rely on the relative abundance\nof “indicator taxa,” their overall sensitivity to impairment,\nand their environmental optimum along a pollution gradient. In South\nAmerica, microalgal assemblages have only recently been used to monitor\nand evaluate the water quality in continental waters. This study aims\nto design and validate a new diatom metric, the Ecuador Diatom Index\n(EDI), to enhance water quality assessment in Ecuadorian river basins.\nThe EDI reflects the overall limnological condition of a river, measured\nthrough various abiotic parameters integrated into the water quality\nindex. Biological sampling was conducted at 111 stations across the\nEcuadorian river basins. Notable differences were observed in floristics\nand autoecological parameters compared to other diatom-based methods.\nStatistical analyses revealed that beyond optimum and tolerance, incorporating\nspecific frequency of occurrence and goodness-of-fit to a Gaussian\nresponse curve improves the reliability of this metric, surpassing\nthe results of the commonly used specific pollution sensitivity index.