Douglas E. Jessmer and Jill Jentes

  1. An airborne campaign assisted in improvements to the NOAA harmful algae bloom forecast. The smokestacks are those of DTE Energy’s Monroe Power Plant in Monroe, Mich., on Lake Erie’s western shore. (Aerial Associates Photography/Zachary Haslick)

    Moderate to larger-than-moderate harmful algal bloom predicted for western Lake Erie

    Jun. 27, 2024

    NOAA and its research partners are forecasting a moderate to larger-than-moderate harmful algal bloom (HAB) in western Lake Erie this summer. This year’s bloom is expected to measure 5, with a potential range of 4.5-6 on the severity index — similar to last year’s bloom, which had a severity index of 5.3. An index above 5 indicates more severe HABs. Blooms over 7.5 are particularly severe, with extensive scum formation and coverage affecting the lake. The largest HABs occurred in 2011, with a severity index of 10, and 2015, with a severity index of 10.5. The HAB severity index is based on the bloom’s biomass (the amount of algae) during the peak 30 days of the bloom. “Understanding hazards such as harmful algal blooms helps us ensure the Great...