Anglers wondering just how big the invading newcomer flathead catfish may eventually get in the Susquehanna River have a new benchmark.

Huge.

On Aug. 30, a Maryland Department of Natural Resources survey crew hoisted a 56.5-pound flathead from a hoop net about a mile below the Lancaster County line in the Conowingo Pond section of the river.

“We had to use the muscle on the boat to get it out,” chuckled Brett Coakley, a fisheries biologist onboard.

That’s the weight of an average 8-year-old boy.

The monster was kept to obtain its otolith, an organ in a fish’s inner ear, to determine the fish’s age.

The fish tipped the scales after it had regurgitated a 19-inch walleye.

To another level

The discovery takes the speculation about flatheads’ future in the Susquehanna to another level.

The first flathead was caught in 2002 by a Lititz angler fishing from the catwalk at the Safe Harbor Dam.

Since then, the largest flathead caught by anglers or nabbed in search surveys in the river has been a 44-pounder the Pennsylvania Fish and Boat Commission caught in survey nets this spring above the Safe Harbor Dam, close to the York County side of the river, across from Turkey Point.

This is a quantum 12.5-pound jump.

It’s safe to speculate the flathead cruised around the Lancaster County section of the river. If it had been caught by an angler there, it would have been the heaviest freshwater fish on record in Pennsylvania.

He hooked a Susquehanna River monster

Brandon Chapman of Maytown holds a 41-pound, 8-ounce flathead catfish he caught in 2013 in the Susquehanna River near Marietta.

The current record is a 54-pound, 3-ounce muskie caught in 1924 from a lake in Crawford County.

However, Atlantic sturgeon, which once inhabited the Susquehanna before dams, grew larger. In fact, there is a 6-foot-3-inch sturgeon that was captured in the Susquehanna off Bainbridge in 1846 at the North Museum of Nature and Science in Lancaster.

The state-record flathead weighs 48 pounds, 6 ounces and was caught in the spillway of Blue Marsh Lake in Berks County in 2006.

No surprise

Was it a surprise that such a monster fish was lurking in the Susquehanna? Yes and no.

“It did surprise me how much larger it was than our largest (in Pennsylvania),” says Geoff Smith, a Pennsylvania Fish and Boat Commission biologist for the Susquehanna River.

“We’d heard rumors and reports that people were flirting with 50 pounds seasonally in late May or early June, right before the spawn.”

He wasn’t surprised that the huge flathead turned up in a reservoir section of the Susquehanna, as the flatwater means flatheads have to work less in fighting the current. That makes it easier to add weight.

The flathead was caught as part of a Fish and Boat Commission study to determine how abundant and fast flatheads grow, since they somehow made it to the Lower Susquehanna around 1999. Smith speculates the latest behemoth is 15 to 16 years old.

So far, flatheads have turned up in the Lower Susquehanna as far upriver as Sunbury, in the Juniata River and another pocket population 70 miles upriver around Wilkes-Barre. They also are found in abundance below the Conowingo Dam in Maryland.

How big will they get?

Flatheads are native to the Ohio River basin. When they arrived in the Susquehanna, the Fish and Boat Commission declared them unwelcome and worried about their effects on the river ecosystem and small game fish such as sunfish and rock bass.

But the flatheads have gained a spirited following, and a small guide industry has sprung up in lower parts of the river.

Now, some fishing groups are pressing the Fish and Boat Commission to better protect flatheads as a resource.

Current regulations are almost nonexistent. There is no closed season, no minimum size, and the limit is a hefty 50 a day.

Some flathead fans want to see a limit of six flathead or channel catfish in a day, with only one allowed over 35 inches.

The commission has resisted for now. “We don’t think it’s warranted,” Smith says. “We’re still talking about an invasive species.”

Besides, he says, surveys show the flathead population is healthy and there are no signs of them being overfished.

Meanwhile, how big might they get?

“We frankly have no idea,” Smith says. “I personally thought when we were seeing fish in the mid-40 pounds that that would be it.”

But consider this: Over Memorial Day weekend, a Virginia angler used a $20 fishing rod from Walmart to land a 68-pound flathead from Lake Smith, a freshwater lake near Virginia Beach.

What to Read Next