Because it is shallow and warm, Erie is the most biologically diverse of the Great Lakes. 15,000 years ago, the lake formed as retreating mile-high glaciers scoured the land. Only 24 feet from the hard limestone in the western basin, but shale in the east basin is more pliable and went down 210 feet.
Arguably, Lake Erie’s next geological event of significance was the Industrial Age. The deep history of Erie is explored in the photography exhibit, Lake Erie: On the Edge, and in a panel discussion attended by 300 people last night at the Cleveland Museum of Natural History.
1969’s infamous conflagration on the Cuyahoga River, and a national punchline lake “where fish go to die,” as comic Johnny Carson once quipped, inspired the nation and a cottage industry in Cleveland. Many rolled up their sleeves and invented methods for monitoring and cleaning up the river and lake.
Lake Erie experienced a level of clean probably not seen since its pre-European days from the passage of the Clean Water Act in 1972 into the 1990s, said Dr. Jeff Reutter, retired director of the Ohio Sea Grant Program, Ohio State University’s Stone Lab and the Center for Lake Erie Area Research.
“Clean up in the 1970s was expensive,” he said, adding, it supports a fishing and tourism industry in Ohio valued at $4 billion.
By the 1980s, Cleveland was getting the worst of the industrial pollution and sewage treatment under control, and the lake was rebounding.
Then, in 1989, the first zebra mussel arrived, inside the ballast tanks of oceanic cargo ships. Invasive species, they reproduce exponentially and filter feed on important micro organisms; the lake’s biodiversity took a hit. The completion of the St. Lawrence Seaway in 1954, while a boon to port cities like Cleveland, brought international ships straight into the Great Lakes, and with them 194 different invasive species.
“We want to keep them out,” Reutter said, “because once they are here, it is very difficult to control their population.”
Lake Erie’s current threat, harmful algal blooms (HABs), was first detected in 2003. The National Center for Water Quality Research at Heidelberg University in Tiffin, Ohio samples Lake Erie three times a day looking at the levels of microcystin, a toxic byproduct of algae feeding on phosphorus. The phosphorus “load” can be traced to farms in the Maumee River basin. As they started using broadcast sprayers and no till methods, big green blooms started to appear in the lake every summer, culminating in the 2014 bloom that shut off water supply to Toledo.
“Most farmers have come to terms with (being the main source),” said Dr. Laura Johnson who directs the Center, “but they are confused as to why. Less than 1% of the phosphorous they apply is leaking into the river. It doesn’t take a lot to create blooms, and we have a lot of farms leaking a little phosphorous.”
Moderator and Museum Science Communications Officer, John Mangels, asked if climate change, which is bringing heavier rain events to Northern Ohio, is a factor.
“Absolutely,” said Reutter. “When you have gentle rain, you have very little agricultural run off.”
Reutter thinks its possible for farmers to inject fertilizers instead of broadcasting it, while Johnson acknowledged that will slow things down.
Adding to the problem, Science Magazine wrote this year, is the irrigation at industrial scale and mono crop farms of the Midwest. So much water is being dumped on corn and soy crops that it is creating its own weather pattern; as water evaporates and moves on the jet stream east to Ohio, it will add to the peak rain problem and more loads.
The panel also included Dr. Kristin Stanford, Education and Outreach Coordinator at Ohio State University’s Stone Lab and Dr. David Kriska, Restoration Ecologist at the Cleveland Museum of Natural History. Stanford talked about mounting a public service campaign for the Lake Erie water snake. She addressed the challenge of educating people about the ecological niche that water snakes fill.
“We discovered they switched their diet to an invasive fish species (round goby).” Respect the Snake is the Stone Lab campaign.
Kriska presented on the turnaround of Mentor Marsh an 800 acre wetland that had been invaded by a single plant, phragmites. They had to keep mashing it with military style amphibious vehicles and a water-safe chemical for years to let the seeds of native plants sprout. Today, it is a landscape transformed with 154 species of native plants attracting lots of wildlife, from muskrat to bald eagle.