Persistent Cyanobacteria Blooms in Artificial Water Bodies—An Effect of Environmental Conditions or the Result of Anthropogenic Change

Abstract

Algal blooms are an emerging problem. The massive development of phytoplankton is driven partly by the anthropogenic eutrophication of aquatic ecosystems and the expansion of toxic cyanobacteria in planktonic communities in temperate climate zones by the continual increase in global temperature. Cyanobacterial harmful algal blooms (CyanoHABs) not only disturb the ecological balance of the ecosystem, but they also prevent the use of waterbodies by humans. This study examines the cause of an unusual, persistent bloom in a recreational, flow-through reservoir; the findings emphasize the role played by the river supplying the reservoir in the formation of its massive cyanobacterial bloom. Comprehensive ecosystem-based environmental studies were performed, including climate change investigation, hydrochemical analysis, and bio-assessment of the ecological state of the river/reservoir, together with monitoring the cyanobacteria content of phytoplankton. Our findings show that the persistent and dominant biomass of Microcystis was related to the N/P ratio, while the presence of Aphanizomenon and Dolichospermum was associated with the high-temperature end electric conductivity of water. Together with the increase in global temperature, the massive and persistent cyanobacterial bloom appears to be maintained by the inflow of biogenic compounds carried by the river and the high electric conductivity of water. Even at the beginning of the phenomenon, the reservoir water already contained cyanobacterial toxins, which excluded its recreational use for about half the year.

Ecological Implications in a Human-Impacted Lake—A Case Study of Cyanobacterial Blooms in a Recreationally Used Water Body

“…According to potential pollution sources, the lake was divided into five sampling zones, including profundal, inflow, channel fuel, and mooring zones. Generally, high total phytoplankton biomass ranged within 28–70 mg L −1 , typical for strong blooms which lasted throughout the whole growing season, similar to other small water bodies under strong pressure [ 8 , 24 , 25 , 53 , 54 ]. Such high biomass is characteristic of lakes with progressive eutrophication.…”

Daily process and key characteristics of phytoplankton bloom during a low-water level period in a large subtropical reservoir bay

“…However, in this study, the influence of meteorological and hydrological factors was less than that of physiochemical factors ( Figure 5 ). Excessive nutrient enrichment in water bodies undoubtedly promotes the growth of harmful cyanobacteria ( Nowicka-Krawczyk et al., 2022 ). Throughout the study period, the density of Microcystis aeruginosa showed a stronger correlation with NH 4 -N ( Figure 4 ).…”

“…Although TP reduction is widely used as a primary strategy to mitigate the severity of harmful algal blooms ( Pick, 2016 ), cases have shown that TP decreases can be accompanied by increases in chlorophyll a concentrations, suggesting that other abiotic factors may also influence the observed trends ( Huang et al., 2020 ). The study by Nowicka-Krawczyk et al. (2022) showed that the composition of cyanobacterial blooms is strongly influenced by the nitrogen/phosphorus (N/P) ratio, with N/P explaining 13.3% of the variation and PO 4 -P explaining 10.5%.…”

Zintegrowana ocena stanu hydrochemicznego doliny rzecznej w obszarze podmiejskim na przykładzie Strugi Dobieszkowskiej (Młynówki) (gm. Stryków)

“…Jest to bardzo niepokojące, gdyż zmiany takie zachodzą na obszarze wododziałowym z wielką ilością naturalnych wypływów wód podziemnych, inicjalnych odcinków cieków i zbiorników małej retencji. Jednym z przejawów zanieczyszczenia, niosącego za sobą groźbę dalszych szkodliwych zmian w środowisku wodnym okolic Łodzi, są wysokie stężenia biogenów (Nowicka-Krawczyk i in. 2022).…”