Persisting at the Edge of Ecological Collapse: The Impact of Urbanization on Fish and Amphibian Communities From Lake Xochimilco

Lake Xochimilco is on the brink of ecological collapse due to urbanization, with alien fish species dominating its low-diversity ecosystem. Despite severe degradation—evidenced by pollution and habitat loss—the study reveals that native and endemic fauna, including the threatened mexclapique fish (Girardinicthys viviparus), persist undetected by traditional surveys. Environmental DNA metabarcoding identified ca. 60% of historically recorded species, highlighting the potential for restoration while underscoring the critical role of wildlife refuges in preventing extinction, as seen with the Critically Endangered axolotl (Ambystoma sp.). The research also uncovered cryptic taxonomic diversity in Lithobates frogs and demonstrated that non-native fish families thrive in polluted conditions, offering insights into urban ecosystem resilience.

Maeda‐Obregon, A., Clare, E. L., Zambrano, L., Domínguez‐Domínguez, O., Horsbrough, G. J., Parsons, P., Dawson, D. A., Tapley, B., Michaels, C. J., Reynoso, V. H., Streicher, J. W., Murrell, D. J., & Day, J. J. (2025). Persisting at the Edge of Ecological Collapse: The Impact of Urbanization on Fish and Amphibian Communities From Lake Xochimilco. Environmental DNA, 7(4). Portico. https://doi.org/10.1002/edn3.70147