Understanding the impact of physico-chemical parameters on aquatic invertebrates in Lake Chalco, Mexico City

Abstract

Many urban environments are places with strong stressors that substantially modify water quality. Although tests evaluating water quality are usually physico-chemical, including biological components can also provide relevant information. Lake Chalco, at the border between Mexico City and Estado de México, interacts with the surrounding human population. We investigated some water quality parameters and the community of macroinvertebrates living in Lake Chalco. From January to October 2017, we sampled water along the shoreline in 4 permanent areas of the lake. We recorded the NH4+, NO3-N, NO2-N, total P, Zn, Cu2+, ORP, DO, TDS, conductivity, and pH. In addition, we characterized the richness, composition, and abundance of the macroinvertebrate community. There was spatial and temporal variation in physico-chemical parameters, perhaps due to the agricultural activity around the lake. Nevertheless, water quality was unable to be placed in a category of the national law. Four out of 20 macroinvertebrate RTU's significantly correlated with environmental variables. Thus, no bioindicators could be proposed. In general, lake water quality is poor, so it is not recommended for anthropic activities. Yet, the lake may be important as a center of dispersion for aquatic invertebrates.