University of Michigan researchers are forecasting that western Lake Erie will experience a moderate harmful algal bloom this summer.
Researchers say this year's bloom is expected to measure 4.5 on the severity index—among the smaller blooms since 2011—but could possibly range between 4 and 5.5, compared to 7.3 last year. An index above 5 indicates the more severe blooms.
Lake Erie blooms consist of cyanobacteria, also called blue-green algae, which are capable of producing the liver toxin microcystin and which pose a risk to human and wildlife health. T
The severity index is based on the amount of algae over a sustained period. The largest blooms occurred in 2011, researchers say.
"This year's predicted moderate bloom is not to be interpreted as significant progress toward the Great Lakes Water Quality Agreement goal of reducing phosphorus inputs in Lake Erie by 40% because year-to-year changes are driven primarily by the amount of spring rain," said U-M aquatic ecologist Don Scavia, a member of the forecast team, in a press release.
"We cannot cross our fingers and hope that drier weather will keep us safe," Scavia said.
"These blooms are driven by diffuse phosphorus sources from the agriculturally dominated Maumee River watershed. Until the phosphorus inputs are reduced significantly and consistently so that only the mildest blooms occur, the people, the ecosystem and the economy of this region are being threatened."
Researchers said the blooms can prevent people from enjoying fishing, swimming, boating and visiting the shoreline.
"A smaller bloom forecast for Lake Erie and the surrounding coastal communities is encouraging, but we cannot be complacent," said Nicole LeBoeuf, acting director of NOAA's National Ocean Service, in a press release. "It is our hope that these science-based tools will help local leaders plan for the predicted bloom and best position the community and its visitors to deal with what comes."
Current extremely high lake levels are not expected to have a significant effect on the bloom size, researchers said.