The effect of manganese ions (II) on representatives of aquatic biota

Abstract

The work is devoted to the consideration of the peculiarities of the impact of manganese (II) on representatives of freshwater biota. Manganese plays an important role in the aquatic environment, since it determines the course of the most important metabolic processes in hydrobiont organisms of varying degrees of organization. The analysis of processes involving manganese has shown that the main chemical factors affecting the accumulation of manganese in the aquatic environment are anaerobic biochemical processes caused by active silting of the riverbed due to the washout of organic substances from agricultural fields. The use of various physiological endpoints in daphnids is considered as an inexpensive and simple alternative, the criterion of which corresponds to the rule “replacement, reduction, refinement”. It has been shown that manganese (II) ions in the concentration range of 0.1-1000 LOCvr do not have an acute toxic effect on D. magna crustaceans, chronic toxicity is manifested in samples with concentrations of more than 10 LOCvr. The acute toxicity of solutions of manganese (II) salts in relation to S. Quadricauda was revealed by the change in the fluorescence level of microalgae at a concentration of Mn2+ from 0.05 mg/l.

Short‐term effects of a large dam decommissioning on biofilm structure and functioning

“…Biofilms are highly sensitive to environmental changes (Battin et al 2016), so such metal concentrations below the dam may have negatively affected biofilm structure and functioning, both during its operation and decommissioning. Indeed, against the pattern most often found below dams (Munn & Brusven 2004; Ponsatí et al 2015), neither biofilm biomass or Chl‐ a nor metabolism were higher below Enobieta Dam, since Fe and Mn precipitating at circumneutral pH could have caused indirect physical impacts on benthic communities (Cadmus et al 2018), such as sunlight blocking (Chon & Hwang 2000), in addition to direct toxic effects (Morin et al 2012; Harford et al 2015; Kosarev et al 2022). Additionally, as it was maintained unused and full for decades, Enobieta Reservoir had little or no regulating effect, and it may not have offered enough hydrological stability to reduce scouring and consequently enhance biofilm growth below the dam.…”

Physicochemistry of Iko River Channel in Nigeria and the Related Human Health Problems

“…Manganese (Mn) is an essential element that is required by both aquatic organisms and humans for functioning 100,101 . In this study, Mn varied from 0.22 to 0.40 mg LG 1 with an average concentration of 0.32±0.08 mg LG 1 .…”

Ecological monitoring of water quality in the Bystraya Sosna River

“…As modern experience shows, such water bodies are subject to the most stringent requirements -fishery MPCs (maximum permissible concentration of a substance in water). The assessment of the effect of chemical pollutants on aquatic biota [7,8] and the identification of the quality of water treatment [9] are especially relevant. Therefore, in the future, in relation to the Bystraya Sosna River, MPCs will be considered both for recreational waters and for fisheries.…”