An angler has hooked a record blue catfish in the Potomac River, but for wildlife specialists, this is not particularly good news — not because the big fish was caught, but because it was there.

The Maryland Department of Natural Resources reported last week that an Oregon man named Ed Jones caught a Maryland record blue catfish Aug. 13 in the river near Fort Washington.

The fish weighed 84 pounds and measured 52 inches long, with a 36.5-inch girth. But the blue catfish is an outsider in the waters of the Washington region, and for all its imposing size, not an especially welcome one.

“While fisheries scientists and managers recognize the enthusiasm and economic impact of anglers in search of record catfish,” said Tom O’Connell, the director of the DNR’s fisheries service, “we don’t want to encourage the development and spread of this species.”

They are top predators, and as such “they are a serious threat to our native species,” said O’Connell.

The DNR said blue catfish are natives of t he Mississippi Valley, but were introduced to Virginia’s James and Rappahannock Rivers in the 1970s. They have reproduced and spread throughout the tidal Potomac River system, the DNR said.

The fish are long-lived, fast-growing and opportunistic feeders, the DNR said in a statement. “Their introduction can cause irreversible changes in the food web,” DNR said.

This in turn could have a harmful effect on native fish species which are ecologically and economically important, DNR said.

So far, DNR said, catfish have been found in such Chesapeake tributaries as the Nanticoke and Susquehanna rivers, as well as upper parts of the bay.

Jones, who landed the record catfish and his guide, Josh Fitchett, of Montpelier, Va., kept it alive and took it to the Fort Washington Marina for weighing and certification.

Then it was tagged and returned alive to the Potomac near where it was caught. The tag and release was part of a study of invasive species being carried out by Maryland and Virginia fisheries biologists.

In general, while releasing fish after catching them is often encouraged, DNR officials discourage the practice when it comes to blue catfish.

According to the DNR, the old record for a blue catfish caught in Maryland waters was an 80-pound-12-ounce specimen, caught by a Pennsylvania man in February near where the new record was set.

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