Big algae bloom forecast in Lake Erie this summer

May 30, 2017

The more rain we have this spring, the bigger the Lake Erie algae bloom this summer -- and it’s been a wet spring.

Algae blooms in western Lake Erie are primarily due to excess nutrients from fertilizer chemicals running off farm land.  Some blooms can become toxic, shutting down beaches or sickening people and pets.

Rain helps phosphorus travel from farms to the lake through rivers including the Maumee in western Ohio – and tracking from the National Oceanic and Atmospheric Administration can predict the size of an algae bloom.

This year’s projections started small, with little rainfall in March and April.

But as soon as May hit, “there was huge rainfall events – I believe three to four inches over the area,” said NOAA oceanographer Richard Stumpf. “That led to a big jump in how much water and how much phosphorus is going into the lake.”

Stumpf says because of the rain, the amount of phosphorus pouring into the lake this year has surpassed levels in 2012 and 2016 . 

With two months left in the phosphorus loading season, Stumpf says there’s a lot to learn about this year’s bloom.

“The big question now is, it’s been somewhat wet through the rest of May, and how much longer that will go into June before it finally starts to dry out,” said Stumpf.

There’s one thing we don’t – and won’t - know until later this summer: just how severe the algae bloom will be. Stumpf says NOAA is working on models to predict the bloom’s toxicity, but they’re not ready yet.

Early season projections continue through the end of July, when a twice-weekly forecast of the bloom will begin.