Western Lake Erie’s summer algae is coming — and researchers are back on the job, pulling water samples and trying to give water-treatment plant operators a fighting chance against toxin-producing blooms.
Though plants can handle most of what’s thrown at them, the 2014 Toledo water crisis underscored the need for early detection, along with the need for a greater investment in limiting the amount of phosphorus- and nitrogen-based farm runoff that grows harmful algal blooms, also known as HABs. The 2014 event occurred when a dense plug of algal toxins overwhelmed the city’s treatment process, poisoning tap water distributed to nearly 500,000 people for three days.
Tom Bridgeman, a University of Toledo limnologist — or lake expert — has been pulling Lake Erie water samples in the Toledo area annually from late spring to early fall since 2002.
He and his team of students were doing it again Tuesday aboard UT’s Lake Erie Center research vessel, the latest of several trips they’ve made since May. He said they expect to continue well into October, going out at least weekly during the summer and once every two weeks in the spring and fall.
Lake Erie has more than 200 types of algae, most of which - like diatoms out there now - are actually good because they are part of the natural food chain. They are consumed by the plankton that fish eat.
As summer wears on, though, the good algae gets out-muscled by bad, toxin-producers such as microcystis that grow like mad when the lake gets so rich in nutrients.
Mr. Bridgeman knows microcystis is coming, not just because it has assaulted the lake annually since 1995 or because of all of the rain the region’s had this year.
Tiny little specks of it are in samples he and his students have been pulling out of the lake. They find more with each trip.
Three weeks from now, Mr. Bridgeman figures, Lake Erie’s western basin will be a disgusting, pea-green hue again. On Thursday, the National Oceanic Atmospheric Administration and Heidelberg University are expected to announce they expect this summer’s outbreak to once again be substantial, probably the fourth largest bloom since NOAA began compiling satellite images of them at different intervals each summer 15 years ago.
“In two weeks, it’ll be visible on calm days,” Mr. Bridgeman said. “In three weeks, it’ll be about everywhere.”
By that, he means across the lake’s warm and shallow western basin. Only a couple of years has it been large enough to migrate into the central basin near Cleveland. It’s never been known in modern times to enter — at least in any sizable quantity — Lake Erie’s much colder, deeper eastern basin out near Ashtabula, Ohio, and Erie, Pa.
Right now, there’s a different Battle of Lake Erie going on than the one Commodore Oliver Hazard Perry fought on Sept. 10, 1813.
It’s within the water column itself, with microcystis regaining its foothold as the lake’s dominant algae as it has almost every summer the past 22 years.
Microcystis -—believed to be 3.5 billion years old and one of the Earth’s oldest living-organisms — is on the rise throughout the world.
It is the chief producer of the toxin microcystin which killed 75 people in a kidney dialysis center in Brazil in 1995.
Another producer, planktothrix, for years has exerted dominance over Sandusky Bay. The other known microcystin-producer is a form of harmful, blue-green algae known as dolichospermum, which used to be called anabaena.
During Tuesday’s sampling expedition, Mr. Bridgeman — using a lab device that instantly calculates the breakdown between different types of algae — learned that about a third of one sample was microcystis or other forms of blue-green algae. The other two-thirds were diatoms and healthy, green algae which Mr. Bridgeman jokingly equated to microscopic “lettuce.”
Another sample drawn near the Maumee River’s mouth showed a concentration of 20 percent blue-green algae. Both are higher than what Mr. Bridgeman’s seen in recent weeks, more evidence that the bloom is coming.
The region’s on-again, off-again heat this summer likely won’t be as much of a factor as all of the nutrients from farm runoff, he said.
“The water temperature’s now about 73 degrees. It only has to be 68 degrees or warmer for microcystis to grow,” Mr. Bridgeman said. “If it’s a cool year, it might delay the bloom a week or two. But we never have a summer that’s so cold the blue-green algae is limited by temperature.”
Buoys deployed by UT’s Lake Erie Center, Ohio State University’s Stone Laboratory, Bowling Green State University, the National Oceanic and Atmospheric Administration, and the city of Toledo provide an array of real-time lake conditions as they are changing.
Earlier Tuesday, Ohio Sea Grant released an update of the Harmful Algal Bloom Research Initiative, a 10-university collaboration on algae research between UT, OSU, BGSU, Heidelberg, Defiance College, the University of Akron, Kent State University, Sinclair Community College, Central State University, and the University of Cincinnati, funded in large part by the Ohio Department of Higher Education.
It concluded the public’s better prepared with the additional and more sophisticated warning systems that have been deployed since Toledo’s 2014 crisis for what it described as an “emerging global threat.”
Contact Tom Henry at thenry@theblade.com, 419-724-6079 or via Twitter @ecowriterohio.
First Published July 12, 2017, 4:14 a.m.
