Microcystins presence threatens the ecosystem health of a tropical National Park: Lagunas de Montebello, Chiapas

Microcrustacean (Cladocera and Copepoda) Assemblages of a Tropical Karst Lake District

“…Some authors [24,53] reported high nutrient, Chl-a, seston, and particulate organic carbon concentrations in the impacted/eutrophic lakes. The nuisance cyanobacterial scums in some of the PNLM lakes ratified the advanced state of eutrophication, which negatively impacts tourism and the general economic development of the area [55]. Anthropogenic impacts have altered the water column and the sediments of the lakes [54].…”

“…The decrease in size of zooplanktonic organisms has been explained by several factors, among them the most mentioned are predation by fish that select large over small sizes organisms [61][62][63], the cyanobacteria dominance in eutrophic lakes with low nutritional quality, toxic, and potentially could inhibit the cladocerans filtration mechanism [20,21,64,65]. From the abovementioned causes, [55] reported high dominance (>90%) and large den-sities of cyanobacteria in the phytoplankton but also the presence of microcystins (2.0 to 5.3 µg L −1 ) in the eutrophic lakes of the "Lagunas de Montebello" National Park. On the other hand, the CCA showed a positive relationship between the Daphnia spp.…”

Regional Pelagic Rotifer Biodiversity in a Tropical Karst Lake District

“…Although biomass of rotifers is not often reported, in tropical lakes, biomass varies from 5 to 10% of the total zooplankton biomass [35,52,53]. The rotifer biomass of the PNLM lakes contributed a similar percentage (5%) to the total zooplankton [54] Several authors [19,22,55] mention that the species richness and abundance of zooplankton have a positive relationship with the primary productivity of lakes because, when there is more food available in an aquatic system, there is the potential to support more species and in higher densities. Accordingly, it would be expected to have higher values of rotifer species richness and abundance in the eutrophic lakes, while lower in the oligotrophic [55], which was the case in PNLM lakes where eutrophication influenced the rotifer assemblages by augmenting species richness, abundance, and biomass.…”

“…In the oligotrophic lakes, phytoplankton is represented by small centric diatoms (Cyclotella) [31], a "high-quality" food but in rather limited amount (<2 µg L −1 , Vera-Franco et al [35]). On the other hand, in eutrophic lakes of the PNLM, phytoplankton is dominated (95%) by large filamentous −40 to >100 µm-cyanobacteria (e.g., Limnothrix, Planktothrix and Cylindrospermopsis [54]), a "low quality" food (e.g., hard to manage, low nutritional value with insufficient essential components, production of cyanotoxins [60][61][62][63], but rather abundant (>14 µg L −1 , Vera-Franco et al [35]). In both cases, rotifers could be limited by competition for better-quality food [64,65], which often leads to lower rotifer fitness as observed in other studies [66].…”

“…Microcyclops ceibaensis and Thermocyclops inversus are characteristic examples of cyclopoid copepods inhabiting the eutrophic lakes of the PNLM [67]. Cyclopoid copepods composed 40 ± 15% of the total zooplankton biomass of the eutrophic lakes of the PNLM [54]. Therefore, copepods predation [68,69] could also be limiting rotifers in the eutrophic lakes of the PNLM.…”