PORT CLINTON – Despite toxic algal blooms, fish from Lake Erie are safe to eat, according to early results of a study from Ohio State University.
Researchers have finished one year of the study into how harmful algae affects walleye, yellow perch and white perch,… said Jay Martin, professor of ecological engineering at OSU’s Department of Food, Agricultural and Biological Engineering.
Researchers say they have discovered only trace amounts of microcystin in the fish.
“The main message is the fish are safe to eat,” said Martin, who admitted to eating perch and walleye on a recent trip to the lake. “The average person doesn’t have anything to fear eating fish from Lake Erie.”
The results are consistent with results from Ohio Department of Natural Resources testing during a harmful 2011 algal bloom, which was the worst on record.
Microcystin can cause liver problems and gastrointestinal illness in people and can be fatal to dogs. In early August, the city of Toledo advised its more than 400,000 water customers not to drink water from its water treatment plant for two days because it was contaminated with the toxin.
Eating fish that contain microcystin is another possible pathway for exposure to the toxin, Martin said.
The study shows walleye have the highest concentrations of microcystin, followed by white perch. Yellow perch had the smallest amount, he said.
But each species had a very small amount, Martin stressed.
Walleye, the largest of the three fish, and yellow perch are two of the most prized game fish on Lake Erie and often are served in local restaurants.
White perch, an invasive species, was chosen for study because its numbers have increased as Lake Erie has warmed through climate change in recent decades. Although not a popular game fish, white perch could become more popular in the future, Martin said.
Researchers aren’t sure why walleye have the highest concentration nor why yellow perch have the lowest. They’re trying to determine how the toxin get into the fish, whether it’s through what they eat or what they absorb.
“It could be based on where they’re swimming,” Martin said. “It could be coming in through their gills.”
Walleye swim in the upper water column, which sometimes is closer to harmful blooms, he said. Or they could have higher concentrations because they eat other fish that might contain the toxin.
Yellow perch tend to feed closer to the lake bottom, where there would be less harmful algae. Yellow perch eat other fish, but not as much as walleye.
Scientist also are trying to determine whether toxin levels in fish are higher during a particularly bad bloom or whether the levels increase in fish over time.
The study is timely as climate change continues to warm Lake Erie, making algal blooms worse. The harmful algae — actually a bacteria — prefer warmer water, scientists say.
Climate change also has resulted in more intense storm events that spur two contributors to harmful algae: farm runoff and combined sewer overflows, in which a wastewater system is overwhelmed and sends untreated sewage into waterways. Phosphorous from both sources feeds the algae, which was a problem on Lake Erie in the 1960s and ’70s and then re-emerged in 2002.
The current study will continue through October, and Ohio State is trying to get funding to keep it going longer.
“There’s a need to continue monitoring this,” Martin said.
The university is working with the ODNR to catch yellow and white perch in the Maumee Bay area. Charter boat captains have been helping by sending in pieces of fillets from walleye caught in the Sandusky Bay area, an effort coordinated by Justin Chaffin at OSU’s Stone Laboratory.
Both bays are in the Western Basin, which is the part of Lake Erie most affected by harmful algal blooms.
Fertilizer program begins
The Ohio Department of Agriculture will begin offering training courses for the state’s new fertilizer certification program in September. The program is meant to teach farmers how to best apply fertilizer to control costs and reduce the amount that runs into streams and eventually in lakes or the ocean. Farm runoff is the main cause of toxic algae blooms in Lake Erie. More information on the program can be found atwww.ohioagriculture.gov/CommercialFertilizerCert.
Photo caption: A pair of fishing charter boats head out on Lake Erie for an afternoon of fishing on Tuesday, Aug 26, 2014.
(Photo: Jonathon Bird/Gannett Ohio )
View original article at: Study shows fish safe to eat, despite algal bloom