Resilience of rotifers and cladocerans communities in four reservoirs with eutrophication pollution and lead concentrations in Aguascalientes, Mexico

• Published in: Chemosphere (Oxford) 2024-04, Vol.353, p.141577-141577, Article 141577
• Main Authors: Guerrero-Jiménez, Gerardo, Santos-Medrano, Gustavo, Robles-Vargas, Daniel, Rubio-Franchini, Isidoro, Silva-Briano, Marcelo, Rico-Martínez, Roberto
• Format: Article
• Language: English
• Subjects: adaptation; Bioaccumulation; Diapausing eggs; Ecotoxicology; Metal toxicity; Zooplankton
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2024.141577

Pollution in aquatic ecosystems has been increasing drastically worldwide changing their water quality. Therefore, species must be adapted to these new scenarios. In Aguascalientes City, four representative urban reservoirs contain lead in the water column and extremely high concentrations of sediments. Therefore, an analysis was conducted to evaluate the resilience of zooplankton species to lead exposure in each reservoir using dormant and organisms. Results demonstrated a decrease range from 57.5 to 22.5% in overall diapausing egg hatching rate, while survivorship rate also decreased from 98 to 54% when organisms were exposed to the water of the four reservoirs and increasing lead concentrations. When Pb exposure increased, results showed a global negative effect on both hatching rate (decreasing from 58 to 30% at 0.09 mg L−1) and survivorship levels (decreasing from 100% to 0.07% at 0.09 mg L−1). We provide Species Sensitivity Distribution for both water reservoir dilutions and lead concentration to analyze diapausing eggs hatching and survivorship of offspring in the presence of same polluted conditions or lead of the autochthonous species found in reservoirs. Furthermore, specific analysis with two populations of the cladoceran Moina macrocopa showed clear dissimilar hatching patterns that suggested a different adaptive mechanism. Niagara population shows a hatching rate of approximately 25% in the first two days of reservoir water exposure, while UAA population drastically increased hatching rate to 75% on exposure at day seven. We provide the first record of bioaccumulation in ephippia of M. macrocopa. [Display omitted] •Reservoirs in Aguascalientes present pollution, forcing to measure zooplankton resilience.•Pollution was assessed using hatching rate and survivorship of autochthonous species.•Dormant stage is efficient to tolerate pollution, which is compromising zooplankton biodiversity.•Some species are modifying their hatching rate patterns to get adapted to pollution.