An analysis out this week from the National Oceanic and Atmospheric Administration reports that algae blooms were "fewer, less dense, and less toxic" this year than in 2014 or 2015.
That's good news for the region, because the blooms can cause sickness in people and animals. They also can create problems in treating drinking water.
NOAA says the primary reason for the relatively mild bloom was a dry spring that sent less phosphorus flowing into Lake Erie from the Maumee River, near Toledo, Ohio.
NOAA oceanographer Richard Stumpf says new regulations for farming have not had an impact yet. But they hold promise for reducing the flow of nutrients into the lake.
"We’re not at a point where those are being implemented to show a change in the phosphorus load, but there are now some ideas coming into play that can be implemented, and we should start seeing changes over the next few years," said Stumpf.
The severity index of this year’s bloom was 3.2. Last year’s severity index set a record at 10.5.
Previously, environmental advocates said a lack of rain limited agricultural runoff into the lake. They said policy changes are needed to ensure the water's health in coming years.
NOAA's bi-weekly Harmful Algal Bloom forecasts ended Oct. 24, when there was no longer a risk for a cyanobacteria bloom in western Lake Erie. Toxins produced by Microcystis, the dominant cyanobacteria in the lake, can cause headaches, nausea and skin irritation.
To report the size of the blooms, NOAA used its own research along with sampling results from universities and citizen programs.
The weekly bulletins started in 2009 and increased to twice weekly last summer.