Water quality in Lake Xochimilco, Mexico: zooplankton indicators and Vibrio cholerae

Lake Xochimilco, a eutrophic water body in Mexico City, exhibits severe contamination with high levels of phosphorus (2.5–7.8 mg/L) and chlorophyll a (66–136 µg/L), alongside the presence of toxigenic (Vibrio cholerae No-O1/No-O139) and non-toxigenic strains closely associated with littoral zooplankton such as Brachionus quadridentatus. Saprobic indices (1.5–2.0) and low species diversity (~2 bits/ind.) indicate β meso-saprobic conditions, signaling degraded water quality. The study analyzed monthly samples from two sites (Lake Xaltocan and Santa Cruz Canal) over eight months in 2012, assessing zooplankton diversity, bacterial concentrations, and physico-chemical variables. Findings underscore the need for urgent improvements to address eutrophication and public health risks linked to water contamination.

Nandini, S., Ramirez García, P., & Sarma, S. S. S. (2015). Water quality in Lake Xochimilco, Mexico: zooplankton indicators and Vibrio cholerae. Journal of Limnology. https://doi.org/10.4081/jlimnol.2015.1213