The findings suggest cyanobacteria -- sometimes known as pond scum or blue-green algae -- that get a toe-hold in low-to-moderate nutrient lakes can set up positive feedback loops that amplify the effects of pollutants and climate change and make conditions even more favorable for blooms, which threaten water resources and public health worldwide. The findings shed new light on what makes cyanobacteria so successful and may lead to new methods of prevention and control.