In the summer of 2014, the city of Toledo told its more than 400,000 residents not to drink the water, thanks to a toxic, sickly green algal bloom that took over Lake Erie. At the time, researchers warned that the Great Lakes should expect more of those gross-looking blooms. Now experts are making a more specific forecast: Severe toxic algae blooms in Lake Erie could double in the next century, reports Michael Byrne for Vice.
To make the forecast, engineers and ecologists at Ohio State University looked to climate change models and predications about nutrient runoff from agriculture—fertilizers containing phosphorus and nitrogen are intended to help crops grow, but they can wash down creeks and rivers, eventually fueling the growth of algae in lakes.
Some microscopic blue-green algae produce toxins that can irritate skin, poison fish and contaminate drinking water. When the waters get warm enough, conditions can be ripe for the algae to reproduce rapidly, creating a bloom.
Warmer lake waters and more intense summer storms, with heavy rain to provide more flushing of the land, would contribute to longer lasting, more intense algal blooms, Byrne reports. The team presented their data at the fall meeting of the American Geophysical Union this week.
High winds also exacerbated the 2014 problem, Victoria Jaggard reports for Smithsonian.com. Winds scudding across the lake can mix algae deeper into the water column and spread the blooms closer to water intake pipes, which feed drinking water to nearby cities. These winds, too, can be linked to climate change.
The new study suggests that pledges by Ohio, Michigan and Ontario, Canada to reduce excess phosphorus in runoff by 40 precent during the next decade might not be enough when predicted climate changes are taken into account.
“Right now, we can only make recommendations based on the past, but the climate is not a constant," Jay Martin, a professor of ecological engineering at Ohio State University, says in a press release. "We need to look to climate models of the future to protect water quality in Lake Erie and around the world."
The good news is that cutting back on excess fertilizer is likely to help farmers save money, so they’ll be interested in making it happen. However, blooms of algae that produce toxins are a problem around the world. It will take a concentrated effort from many people to keep our drinking water algae-free.