In 1975, future presidential candidate Michael Dukakis, then governor of Massachusetts, bet 20 pounds of New England cod that the Red Sox would defeat the Reds in the World Series. If things went south for Boston, Ohio governor James Rhodes promised to send Dukakis 10 pounds of Lake Erie perch and 10 pounds of Ohio River catfish. The Reds ended up winning and the cod was sent to the Convalescent Home for Children, in Cincinnati.

At the time, people were still eating catfish from the Ohio without too much concern. The fish were also served at several restaurants along the river.

There were warnings in 1977

But two years later, in 1977, The Ohio River Valley Water Sanitation Commission released the results of a study of contaminants found in the tissues of Ohio River fish. They warned anglers in cities such as Pittsburgh, Cincinnati, Louisville, Wheeling and Gallipolis that man-made chemicals known as PCBs, or polychlorinated biphenyls, had been discovered in the river fish. Later, high concentrations of mercury were discovered in the fish, too.

Thanks to the Clean Water Act of 1972 and the environmental regulations that followed, the river is now cleaner than it was in the seventies. And it’s still teeming with a variety of fish, including catfish, striped bass, drum and black bass, among other species.

But even though PCBs were banned by the Environmental Protection Agency in 1979, they are still found in fish, since they remain in the sediment in the bottom of the river. “Organisms live in the sediment and fish feed on them,” Rich Cogen, the executive director of the Ohio River Foundation told The Enquirer. Mercury is also a big problem, according to Cogen.

So the question is: Can you eat fish caught in the Ohio River?

The short answer is yes. But it depends on what species you are eating and where along the river you caught it.

There are also very strict limitations on how frequently you should eat them, according to the web site for the Ohio Sport Fish Consumption Advisory, part of the Ohio Department of Health.

In areas of the river between the Belleville Lock, located 204 miles downstream from the river’s origins in Pittsburgh, to the Indiana border, the advisory agency currently recommends consuming Ohio River fish no more than once a month max. That area includes Adams, Brown, Clermont, Gallia, Hamilton, Lawrence, Meigs and Scioto counties.