Shifts in water column microbial composition associated to lakes with different trophic conditions: “Lagunas de Montebello” National Park, Chiapas, México

Abstract

Eutrophication is a global problem causing the reduction of water quality and the loss of ecosystem goods and services. The lakes of the “Lagunas de Montebello” National Park (LMNP), Chiapas, Mexico, not only represent unique and beautiful natural scenic sites in southern Mexico but are also a national protected area and RAMSAR site. Unfortunately, some of these lakes started showing eutrophication signs since 2003. Anthropogenic activities ( e.g. , land-use change from forested to agricultural and urban development) are leading to water quality and trophic state alterations of the lakes of the LMNP. This study shows the results of a coupled limnological characterization and high-throughput sequencing of the V4 hypervariable region of the 16S rRNA gene to analyze the microbial composition of the water column in a set of oligotrophic and eutrophic lakes. Chlorophyll a (Chl-a) was the main environmental parameter correlated with the trophic conditions of the lakes. Although the microbial diversity was similar, the microbial composition changed significantly from oligo to eutrophic lakes. Proteobacteria, Firmicutes, and Cyanobacteria were the main components of oligotrophic lakes, and Cyanobacteria, Proteobacteria, and Bacteroidetes of eutrophic lakes. While Acinetobacter (Proteobacteria) and Cyanobium (a unicellular cyanobacterium) dominated in oligotrophic lakes, the filamentous, bloom-forming, and toxin-producing cyanobacteria Planktothrix was the dominant genus in eutrophic lakes. High-throughput sequencing allowed the detection of changes in the composition of the microbial component in oligotrophic lakes, suggesting a shift towards eutrophication, highlighting the relevance of sensitive monitoring protocols of these ecosystems to implement remediation programs for eutrophicated lakes and conservation strategies for those yet pristine.

Metagenomics reveals the diversity and role of surface-water microbes in biogeochemical cycles in lakes at different terrain ladders

“…In the oligotrophic environment, there are more species of microbes in lakes (Yao et al, 2017;Yanez-Montalvo et al, 2022). In this study, the lakes in Yunnan Guizhou Plateau are obviously the most abundant in microbial composition, which may be due to the oligotrophic condition and large water depth span providing a suitable living environment for microbes.…”

Polyphasic Approach and Potential Cyanotoxin Production by Planktothrix from the Río Grande de Comitán and Montebello Lakes National Park, Southern Mexico

“…In recent years, Montebello Lakes National Park has registered an increase in phytoplankton biomass, reflected by evident changes in water color [ 30 , 31 , 51 ]. Likewise, high concentrations of carbon, nitrogen, sulfur, organic matter, and chlorophyll a have also been found in the sediment and seston [ 52 ].…”

“…This area is of great ecological, cultural, and economic importance for the region, leading to it becoming established as a protected natural area by presidential decree published in the Diario Oficial de la Federación on December 16, 1959, and later designated as a RAMSAR site in 2003. Since 2003, however, color changes have been observed in the lakes, reportedly related to the increase in phytoplankton biomass as a consequence of the increasing eutrophication of the lakes [ 26 , 30 , 31 ]. The human communities surrounding these lakes utilize the water for both direct use and consumption, as well as for agricultural and silvopastoral activities [ 28 , 32 ].…”