Ohio's Lake Erie Faces Mild-to-Moderate Algae Bloom Forecast

COLUMBUS, Ohio — The National Oceanic and Atmospheric Administration (NOAA) forecasts a mild-to-moderate harmful algal bloom (HAB) in western Lake Erie for summer 2026, measuring 3 on the HAB severity index with a potential range of 2 to 4.[1] Unlike the above-average severity hinted in initial reports, this prediction aligns with average spring phosphorus loads from the Maumee River watershed, a key nutrient source fueling the cyanobacteria known as blue-green algae.[1][2] The bloom is expected to become visible by early July, primarily in the western basin near Ohio's Lake Erie shoreline, including areas around Toledo and Sandusky.[1][4] HABs produce toxins that sicken humans and animals, foul beaches and kill fish, impacting Ohio's $1 billion recreational fishing industry and drinking water for 500,000 residents served by the Toledo water intake in Maumee Bay.[4][6] In 2025, the bloom registered a mild severity index of 2.4, starting in early July in Maumee Bay and peaking in early August, below the prior year's 4.2.[2] The 2024 bloom hit 6.6, moderately severe, while the target below 2.9 remains unmet most years despite progress in 2018, 2020, and 2023.[5][6] Ohio's agricultural heartland contributes heavily via phosphorus runoff from fertilizers during heavy rains, though this spring's average rainfall tempers the outlook.[3] NOAA's late-July update will refine the forecast based on Maumee River nutrient data, with winds potentially shortening the bloom's typical July-to-October span.[1][7] Local officials in Lucas and Ottawa counties advise avoiding green scum and checking Ohio EPA beach advisories to protect swimmers and boaters.