Beating the heat in the US is a little harder this summer than it used to be: E. coli and cyanobacteria are causing widespread beach closures at lakes and rivers. It turns out that climate change-fueled warmer waters — and more prolific downpours — are amazing vibes for bacteria.
Between 1985 and 2009, lakes and ponds warmed at a rate of roughly 0.6F (0.3C) per decade, a trajectory that is increasing the risk of bacteria blooms in historically cold places. The bacteria can cause a host of symptoms, including blisters, rashes, diarrhea, muscle weakness, and liver damage, to name a few. Outbreaks can also tax ecosystems; plus, they’re expensive.
Heavy rain often provides the “fuel and supplies” for bacterial spikes, says Kaitlin Reinl, a limnologist with NOAA. Stormwater drives bacterial growth by washing phosphorus and nitrogen into lakes and rivers, where heat waves can drive bacteria and algae growth.
“Basically, temperature speeds up everything,” says Hans-Peter Grossart, a professor of aquatic microbial ecology at Potsdam University.