SANDUSKY — Halfway through another weekly sampling expedition along western Lake Erie’s Sandusky Bay, Bowling Green State University algae researcher George Bullerjahn is perplexed by what he’s been observing.
Or, more accurately, what he’s not been observing but would ordinarily have seen by this point of summer.
“The water quality is surprisingly good here,” the distinguished research professor of biological sciences said at a couple of locations while aboard the BGSU vessel known as the R/V Ziggy with his crew last Monday.
One would think that clearer water, deeper light penetration, and other signs of improved water quality would be cause for celebration by Mr. Bullerjahn, director of BGSU’s Great Lakes Center for Fresh Waters and Human Health.
But they’re not, at least not yet.
Instead, there’s a tone of bewilderment in his voice as he tries to understand what’s happening now to Sandusky Bay, one of the largest yet lesser-understood parts of western Lake Erie and is apparently in some sort of transition.
It still has algae, but it’s a different species, in different locations, and not as much as in years past.
Sandusky Bay has always been a bit of a rebel.
As recently as 2019, it was the only part of Lake Erie that consistently produced a harmful, toxin-producing algae known as planktothrix, year after year.
It did so like clockwork, often at least six to eight weeks before microcystis, the most common harmful algal bloom in the rest of Lake Erie and other parts of the planet, appeared each summer.
Both produce the same toxin, microcystin. Being more tolerant of cold water, though, planktothrix could arrive earlier and stay later. It also isn’t so dependent on the common fertilizer, phosphorus, to thrive. It prefers nitrogen, which can be pulled out of the air we breathe.
One of the research puzzles of late has been the sudden disappearance of planktothrix. It wasn’t found in Sandusky Bay in 2020 or 2021 and has been missing so far this summer too.
Mr. Bullerjahn and others who usually work the multiple sampling locations in Sandusky Bay most Mondays from April through October aren’t finding a trace of it.
That could be a good thing, except the bay is not consistently improving.
In some areas there now is yet another toxin-producing algae, aphanizomenon, also known by its nickname, “Fannie.”
Fannie looks like grass clippings submerged in water.
Mr. Bullerjahn and others, including oceanographer Rick Stumpf of the National Oceanic and Atmospheric Administration, have no idea if Sandusky Bay is actually improving or if they’re witnessing a biological arm-wrestling match in which one toxin-producing algae is out-muscling the other.
And, if that’s happening, then why?
“Sandusky Bay has a lot of surprises for us,” Mr. Bullerjahn said. “Things we never saw previously, we’re seeing now.”
Mr. Stumpf agreed, saying there’s almost been a competition between blue-green algae known as cyanobacteria and other types of algae that aren’t. Cyanobacteria produce the toxins in harmful algal blooms known to sicken — and in some cases even kill — people, pets, and wildlife.
“What I would say is it’s definitely in flux, because it’s been different each of the past three years,” Mr. Stumpf said of Sandusky Bay, by telephone from his Maryland office.
At each stop, Mr. Bullerjahn’s crew members do standard water-quality measurements for turbidity, light penetration, dissolved oxygen, temperature, and other parameters.
They use anything from a simple device known as a Secchi disk, created in 1865 by an Italian priest-astronomer named Angelo Secchi, to some of today’s most sophisticated and technologically advanced sondes instruments, which can digitally transmit reams of real-time data from underwater.
Ryan Wagner and Carol Rosenbaum, graduate students from BGSU and Michigan State University, respectively, used a syringe-like device to force Sandusky Bay water samples through a filter that takes out anything larger than 0.2 microns, which means the majority of microbes. Tests are done to determine the DNA and RNA of what’s removed.
“It gives us a glimpse of the physiology of the system, because it shows what genes are active,” Mr. Bullerjahn said.
Chris Ward, a BGSU assistant professor who specializes in aquatic microbial ecology, and BGSU graduate student Michelle Neudeck work in tandem with the sondes and record much of the data. They and the others bring back several huge sample jugs of water and plankton grabs for laboratory analysis.
One theory for improved water quality in some parts of Sandusky Bay is the Ballville Dam’s recent removal.
Almost immediately after its final bits of concrete were removed in 2018, walleye took to the Sandusky River’s upper reaches for spawning — almost as if the dam had never been built 105 years before.
But whether the dam’s removal is having enough of a positive effect miles downstream to drive planktothrix off from Sandusky Bay is just one of many theories at this point, Mr. Bullerjahn said.
And it doesn’t explain why aphanizomenon might be moving in behind planktothrix, he said.
The disappearance of planktothrix — if it indeed is truly gone — is kind of a chicken-or-egg thing, too, because the plant is light-sensitive. In areas where water clarity has improved, it is unlikely to return. But it hasn’t been determined if portions of the bay are clearer now because planktothrix disappeared, or vice versa, Mr. Bullerjahn said.
“One of the reasons planktothrix might be decreasing is because of light penetration,” he said.
Some researchers believe the Ballville Dam could have served as a reservoir for spawning planktothrix.
For as big as it is, relatively little has been written about Sandusky Bay — at least in comparison to the rest of Lake Erie.
Called Lac Sandouske on a 1718 French map, Sandusky Bay is perhaps best known as the site of Johnson’s Island, where more than 12,000 Confederate prisoners, including 26 rebel generals, were taken during the Civil War, according to Travel Lake Erie.
Scudder Mackey, Office of Coastal Management chief for the Ohio Department of Natural Resources, said he believes the bay gets little attention from the general public because most only see it from vehicles for a few seconds while crossing the Thomas A. Edison Memorial Bridge along State Rts. 2 and 269.
The bridge and its causeway, which combined span 2.5 miles, was completed in 1965 to replace an older crossing that now partially remains as a fishing pier.
“Sandusky Bay has not been on many people’s radar screen for a long time,” Mr. Mackey said.
That’s changing now, though, because of a state program known as the Sandusky Bay Initiative, an ongoing effort to create or rebuild wetlands that will better filter runoff and improve water quality.
One is along the Cedar Point Causeway, where $4 million was spent to create a waterborne holding cell for silt the Army Corps of Engineers dredges on a near-yearly basis to keep shipping channels open in that part of Lake Erie.
The first dredged material is expected to be deposited there in September. The site is to become a 32-acre wetland that will help improve wildlife habitat and kayaking opportunities while filtering out contaminants and keeping the excavated silt in place. The silt has to go somewhere because, after more than 30 years of debate, Ohio banned open-lake disposal of dredged material in 2020.
But that 32-acre cell only has the capacity for two, possibly three dredging seasons. The plan is to keep building cells along the causeway and the bay for many years, thereby rebuilding the shoreline and creating a series of interconnected wetlands, Mr. Mackey said.
“This is an innovative project. It’s one of the first in the Great Lakes,” he said.
That particular site is owned by and will be managed by the city of Sandusky, with Mr. Bullerjahn’s BGSU crew doing baseline sampling of water quality and sampling after the dredged material arrives to check for any major impacts.
Sandusky Bay is only six or seven feet deep there, and rarely more than 10 feet anywhere. That’s why the nearby shipping channel that gives lake freighters access to Sandusky’s coal dock is dredged so often.
“The idea is we’re absorbing the wave energy and improving water clarity to grow plants,” Mr. Mackey said.
Construction began Nov. 1 and was completed March 31. Ducks took an immediate liking to it, meaning it was “almost serving as a waterfowl staging area” even before it had silt deposited and aquatic plants growing, Mr. Mackey said.
First Published July 31, 2022, 10:00 a.m.
