The outlook reflects less discharge from the Maumee River and a return to an average nutrient runoff into the lake.
“With a return to average spring discharge, and much lower river flow in June than in the recent years, the western basin should look better. However, the phosphorus inputs to the lake are still high enough to support bloom development,” said Richard Stumpf, PhD, NOAA’s National Centers for Coastal Ocean Science’s lead for the Lake Erie bloom forecast.
The 2016 bloom is expected to measure 5.5 on the severity index, but could range anywhere between 3.0 and 7.0. The severity index is based on a bloom’s biomass - the amount of its harmful algae. An index above 5.0 indicates blooms of concern. Last year’s bloom was 10.5, the greatest on record.
This year’s bloom is expected to first appear in late July and increase in August in the far western basin of Lake Erie. The location and effects will depend on prevailing winds. During calm winds, some areas may experience scums that contain substantial concentrations of algal toxins.
Despite the improved outlook from last year, “The need to reduce phosphorus and other nutrient from fertiliser, manure, and sewage remains,” said Chris Winslow, PhD, interim director of the Ohio Sea Grant College Programme.
"This year’s forecast not only highlights NOAA’s forecast, but it will also focus attention on current efforts to assess bloom impacts on human health, to educate water treatment plant operators, to inform and implement landscape best management practices, and to determine the best way to track our progress toward a 40 per cent reduction in phosphorous loading, the target set by Annex IV of the Great Lakes Water Quality Agreement."