Ohio News Connection
Ohioans seeking fun on Lake Erie’s waters this Labor Day weekend will be confronted with some water-quality warnings. An algae bloom continues in the lake’s western basin, and measured toxin concentrations are said to be exceeding the recreational threshold.
Timothy Davis – an associate professor of biological sciences at Bowling Green State University – is considered a national expert on algal blooms, and also is an advisor to the Lake Erie Foundation. He explains at this point in the season, the bloom typically has its highest toxin concentrations and will not dissipate until around mid-October.
“But that can vary year to year,” says Davis. “And what we are starting to see, especially with climate change, is water temperatures staying warmer into the fall, and because of these warmer water temperatures, we’re seeing the bloom season extending.”
Lake Erie is not alone in its water quality woes. Buckeye Lake and Grand Lake St. Mary’s both have Recreational Public Health Advisories due to algal blooms, and several other lakes have contamination advisories due to high levels of bacteria.
Davis recommends avoiding any blue-green algae on the water – especially surface scum which he says is always dangerous. If a bloom is present, there always is the possibility of human health impacts.
“The human health aspect should keep us focused on doing the necessary treatments in the watershed in order to reduce these blooms, because the best way to protect ourselves from the negative impacts of bloom formation and toxin production is to not have the blooms form in the first place,” says Davis.
Davis says researchers are trying to understand all the biological factors that influence bloom toxicity. He explains there are two types of microcystin within the bloom, but only one has the genetic capability to produce toxins. And the toxicity of the bloom changes as the different microcystins shift.
“There’s all this complexity that drives how toxic the bloom is,” says Davis. “One of the main drivers is nitrogen concentrations out in Lake Erie. The microcystin toxin has between eight to 10 nitrogen per molecule, so it needs nitrogen to be able to produce the toxin.”
He contends that traditional nutrient agricultural management plans aimed at reducing algal blooms that focus solely on phosphorus should expand to include nitrogen.