What is it: After year of detecting harmful algae in Sandusky Bay, Bowling Green State University researchers recently discovered that a toxic cyanobacterium–also known as blue-green algae–has essentially disappeared.
While there are still other algae present in the water, the researchers have determined that the drastic decrease in the cyanobacterium, called Planktothrix, notes “a major improvement for a body of water that millions rely upon for life work, and play,” according to a Aug. 5 press release from BGSU.
"The water looked pretty bad in 2019, but we didn't know that it was actually slowly improving," says Dr. George Bullerjahn, BGSU emeritus professor of
biology via the release. "In 2020, we started to go out to the bay every week but there was nothing. Since then, we've found benign algae, but no toxins."
With no major adjustments to nutrient loads and not enough time passing for significant changes, BGSU researchers turned their attention to the Sandusky River, which feeds into the bay and experienced a dam removal near the city of Fremont in 2018 to improve fish habitats.
"What we think has happened is that the dam was holding back a reservoir that was full of toxic Planktothrix and it was slowly feeding into the bay where it was flourishing again," Bullerjahn says. "Improving water quality by improving water movement and removing stagnation may be the cause for lower [Planktothrix] levels in Sandusky Bay."
Why is it important: For decades, the western waters of Lake Erie have been plagued with seasonal harmful cyanobacterial algal blooms. In 2014, a major bloom shut down the city of Toledo's water supply, leaving nearly half a million people without drinkable water. Since then, BGSU has deepened its commitment to leading research into understanding and preventing toxic algal blooms that impact freshwater sources, including Sandusky Bay and
Africa's Lake Victoria, according to the release.
Since the dam's removal, Bullerjahn says water quality in Sandusky Bay has improved within internationally established drinking standards and is nowhere close to the "no contact" advisory standard that encouraged people to avoid the bay in recent years. Data trends showed continued improvements in 2021, 2022 and 2023. The research team's full findings are described in a
recent article published in the journal "Harmful Algae," according to the release.
"Poor water quality affects drinking water, makes drinking water treatment more expensive and cuts down on recreational activities," Bullerjahn says. "When the World Health Organization contact advisory was posted, people couldn't swim or go water skiing. This recent data provides residents with optimism that those levels are a thing of the past."
Bullerjahn says the bay's positive change lies outside original improvement plans, which emphasized reducing sediment load to eliminate the toxin.
What’s next: While things appear to be changing for the better, Bullerjahn and his team continue to monitor water quality through weekly trips and constant sampling of monitoring from buoys placed throughout the bay.
"It's still early in 2024,” he says, “but the data shows the same pattern that we've seen over the past few years. I'm expecting similar data to come in throughout the year.”