Potential application of macroinvertebrates indices in bioassessment of Mexican streams

Biomonitoring of surface waters using benthic macroinvertebrates is a common practice in developed countries. However, the use of biomonitoring metrics as part of regular monitoring programs in developing countries is scarce. This study is aimed at identifying the macroinvertebrate-based monitoring approaches which can be potentially applied to assess the ecological status of Mexican streams, and to provide guidelines and practical tools to implement such approaches. In this study, a total of 35 biomonitoring metrics were selected, divided into the following classes: 5 metrics of richness, 11 metrics to list the macroinvertebrates organisms (enumeration metrics), 6 diversity and similarity indices, 7 biotic indices, 5 functional feeding metrics and 1 multimetric approach. This selection was made using the a posteriori approach. Characteristics such as: sensitivity, ecological relevance, representativity, feasibility, metric interpretation, performance, and geographical suitability were also taken into consideration during the selection process. A description of the sampling and analytical procedures necessary to compute the selected metrics are also described. We provide an inventory of macroinvertebrate metrics that could be used in Mexico and nearby areas. However, further work is required to determine the accuracy and performance of these metrics for ecological assessment of Mexican streams