A study on the summer heatwave of 2003 in Europe highlights how rising temperatures and reduced mixing in lakes promote harmful cyanobacteria blooms. The research, conducted in Lake Nieuwe Meer, a hypertrophic lake in the Netherlands, shows that high temperatures increase cyanobacteria growth rates and stabilize the water column, reducing vertical mixing. This favors buoyant cyanobacteria like Microcystis, which can form dense surface blooms. The study also found that reduced wind speed and cloudiness further enhance bloom development. The model simulations confirmed that these factors, combined with high temperatures, significantly increase Microcystis concentrations. The findings suggest that climate change will likely increase the threat of harmful cyanobacteria in eutrophic freshwater ecosystems. The study emphasizes the importance of understanding the complex interactions between meteorological conditions and phytoplankton dynamics to predict and manage harmful algal blooms.A study on the summer heatwave of 2003 in Europe highlights how rising temperatures and reduced mixing in lakes promote harmful cyanobacteria blooms. The research, conducted in Lake Nieuwe Meer, a hypertrophic lake in the Netherlands, shows that high temperatures increase cyanobacteria growth rates and stabilize the water column, reducing vertical mixing. This favors buoyant cyanobacteria like Microcystis, which can form dense surface blooms. The study also found that reduced wind speed and cloudiness further enhance bloom development. The model simulations confirmed that these factors, combined with high temperatures, significantly increase Microcystis concentrations. The findings suggest that climate change will likely increase the threat of harmful cyanobacteria in eutrophic freshwater ecosystems. The study emphasizes the importance of understanding the complex interactions between meteorological conditions and phytoplankton dynamics to predict and manage harmful algal blooms.