Occurrence and Toxigenic Potential of Planktonic Cyanobacterial Blooms and Benthic Mats in the Tropical Rio Grande de Comitán and Montebello Lakes National Park, Southern Mexico
- 1Postgraduate Program in Marine Science and Limnology UNAM Mexico City Mexico unam.mx
- 2Genetic Ecology Laboratory Department of Ecology and Natural Resources Faculty of Science UNAM Mexico City Mexico unam.mx
- 3River Ecosystem Laboratory Department of Ecology and Natural Resources Faculty of Science National Autonomous University of Mexico (UNAM) Mexico City Mexico unam.mx
Abstract
The tropical aquatic ecosystems of the Río Grande de Comitán and Lagunas de Montebello National Park (southern Mexico) exhibit signs of advanced eutrophication, with environmental conditions that can promote the proliferation of potentially toxic cyanobacteria. This study assessed the distribution and ecotoxicological risk of planktonic blooms and benthic mats throughout the subbasin. Using a polyphasic approach combining cultured‐based analysis, molecular detection and HPLC, we found a low‐diversity cyanobacterial community dominated by Planktothrix agardhii, which reached densities up to 2.2 × 105 cells/mL during the warmest months. Benthic Microcoleus sp. and localized blooms of Anabaenopsis elenkinii were documented. Molecular analyses confirmed the presence of microcystin and anatoxin synthesizing genes, with high microcystin concentrations detected (67.5–3169 μg/L). Seasonal analyses revealed significant differences in temperature in both lakes (H = 20.8, p < 0.001) and rivers (H = 13.1, p = 0.0098), as well as in river K25 (H = 10.7, p = 0.0169). PCA explained 65% and 64% of the variance in the first two axes for lakes and rivers, respectively, separating sites according to gradients in nutrients, conductivity, and other water‐quality variables. In lakes, redundancy analysis (RDA) showed that the first two axes explained 72% of the constrained variation, with total nitrogen, specific conductance, total phosphorous, catchment disturbance index, pH, and dissolved oxygen contributing to the environmental gradients structuring cyanobacterial composition. Wastewater discharges from the upper basin (Comitán) act as a continuous source of nutrients and cyanobacterial inoculant, whereas tourism and fishing activities mechanically disperse these populations across the lakes. These results demonstrate the widespread occurrence of potentially toxic cyanobacteria across the subbasin and highlight the need for early‐warning and monitoring programs, particularly in areas affected by wastewater inputs and intensive human activities.
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BibTeX
@article{salas2026occurrence,
title = {{Occurrence and Toxigenic Potential of Planktonic Cyanobacterial Blooms and Benthic Mats in the Tropical Rio Grande de Comitán and Montebello Lakes National Park, Southern Mexico}},
author = {Aída Isabel Sánchez Salas and Angela Piedad Caro Borrero and Javier Carmona-Jiménez and Kenia Paola Márquez-Santamaria},
journal = {International Journal of Microbiology},
year = {2026},
month = nov,
doi = {10.1155/ijm/6195685},
url = {https://doi.org/10.1155/ijm/6195685},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Occurrence and Toxigenic Potential of Planktonic Cyanobacterial Blooms and Benthic Mats in the Tropical Rio Grande de Comitán and Montebello Lakes National Park, Southern Mexico
AU - Aída Isabel Sánchez Salas
AU - Angela Piedad Caro Borrero
AU - Javier Carmona-Jiménez
AU - Kenia Paola Márquez-Santamaria
PY - 2026
DA - 2026/11/03
JO - International Journal of Microbiology
DO - 10.1155/ijm/6195685
UR - https://doi.org/10.1155/ijm/6195685
AB - The tropical aquatic ecosystems of the Río Grande de Comitán and Lagunas de Montebello National Park (southern Mexico) exhibit signs of advanced eutrophication, with environmental conditions that can promote the proliferation of potentially toxic cyanobacteria. This study assessed the distribution and ecotoxicological risk of planktonic blooms and benthic mats throughout the subbasin. Using a polyphasic approach combining cultured‐based analysis, molecular detection and HPLC, we found a low‐diversity cyanobacterial community dominated by Planktothrix agardhii, which reached densities up to 2.2 × 105 cells/mL during the warmest months. Benthic Microcoleus sp. and localized blooms of Anabaenopsis elenkinii were documented. Molecular analyses confirmed the presence of microcystin and anatoxin synthesizing genes, with high microcystin concentrations detected (67.5–3169 μg/L). Seasonal analyses revealed significant differences in temperature in both lakes (H = 20.8, p < 0.001) and rivers (H = 13.1, p = 0.0098), as well as in river K25 (H = 10.7, p = 0.0169). PCA explained 65% and 64% of the variance in the first two axes for lakes and rivers, respectively, separating sites according to gradients in nutrients, conductivity, and other water‐quality variables. In lakes, redundancy analysis (RDA) showed that the first two axes explained 72% of the constrained variation, with total nitrogen, specific conductance, total phosphorous, catchment disturbance index, pH, and dissolved oxygen contributing to the environmental gradients structuring cyanobacterial composition. Wastewater discharges from the upper basin (Comitán) act as a continuous source of nutrients and cyanobacterial inoculant, whereas tourism and fishing activities mechanically disperse these populations across the lakes. These results demonstrate the widespread occurrence of potentially toxic cyanobacteria across the subbasin and highlight the need for early‐warning and monitoring programs, particularly in areas affected by wastewater inputs and intensive human activities.
SN - 1687-918X
SN - 1687-9198
ER -