Blue Cats On The James River~~

Sunday, Apr 27, 2008 - 12:09 AM

By REX SPRINGSTON
TIMES-DISPATCH STAFF WRITER
Giant catfish are taking over the James River.

The creatures, blue catfish, have grown in numbers and size ever since state workers stocked them in the tidal James in the mid-1970s to give anglers a new challenge.

"They've gone crazy. . . . They reproduce like mad dogs," said Bob Greenlee, a state Department of Game and Inland Fisheries biologist.

The population explosion shows how humans' introduction of a nonnative species -- whether catfish or kudzu -- can have unintended consequences. For example, kudzu, a Japanese vine planted in the South decades ago to control erosion, strangles native plants today.

The blue catfish often weigh 50 to 70 pounds, and some approach 100 pounds. Thirty years ago, a big fish in the James was a 20-pound channel catfish.

At some point, the blue catfish population should level off, but no one knows when that will happen.

So ubiquitous are the blue catfish now that they constitute up to 75 percent, by weight, of all fish in parts of the James, according to Virginia Commonwealth University scientists.

Whether the result in the case of blue catfish is good or bad is about as murky as the James itself.

Greenlee estimates that anglers -- many from out of state -- spend more than $2 million a year on motel rooms, guides and other services in pursuit of the fish. Commercial watermen caught $1 million worth of catfish in Virginia last year, almost all of them believed to be blue catfish.

But evidence suggests the blue catfish, a voracious predator, is crowding out native or long-established species such as white catfish and channel catfish.

"We've changed the river in some pretty dramatic and fundamental ways," said Greg Garman, a VCU fish ecologist. He called blue catfish a form of "bio-pollution" -- living threats that, once established, last forever.

Through stocking or their own expansion, blue catfish now inhabit all major Virginia tidal waters. But their growth is most dramatic in the James, where they inhabit fresh and brackish water from Richmond to Williamsburg and below.

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The blue cat is not the bottom-feeding sluggard most people envision when they think catfish. All but the smallest are top-of-the-food-chain predators occupying a niche in the James similar to that of sharks in the sea.

Native to the Mississippi River region, the blue cat is the largest North American catfish. (The national record is a 124-pounder caught in Illinois in 2005.) It will eat virtually anything it can get in its mouth, including fish, muskrats, crabs, herons and other blue catfish.

Virginia game officials stocked blue catfish in the James and Rappahannock rivers in 1973-77. A lot of anglers have gotten hooked.

"I love chasing the big fish," said Amelia County drywall contractor Archie Gold. "I guess the reason is you can catch them fairly often. Instead of going somewhere and hoping for a big fish, you can go out there and wonder how big it's going to be."

Downriver from Hopewell in July 2006, Gold caught the state record blue catfish -- 95 pounds, 11 ounces. After it was weighed, he threw it back.

The blue catfish has chemical and electrical sensors that allow it to find food at night and when the water is cloudy. That gives it a tremendous advantage over native fish, VCU's Garman said.

He fears the blue catfish -- through feeding or taking over habitats -- may be hurting such species as the largemouth bass, white catfish, channel catfish, blue crabs and the long-struggling American shad.

"Nobody has the data to show cause and effect, but there is an awful lot of circumstantial evidence. We can show correlations -- as one species goes up, the other species goes down."

These other species are important to recreational or commercial fishermen, and they might have yielded greater economic benefits than the blue catfish, Garman said. "I'm not convinced the blue catfish are an economic windfall."

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Greenlee, the state biologist, has led a game-department study since 1999 looking into the ecological effects of blue catfish. He said surveys indicate that blue catfish have caused declines in native white catfish and long-established channel catfish.

But Greenlee is not convinced that blue catfish are hurting largemouth bass, crabs and American shad.

Among other reasons, a reduced bass population has recently rebounded, and crabs and shad face problems in places blue catfish don't inhabit, he said.

The growth of blue catfish appears to be leveling off in the Rappahannock. But in the bigger James, the boom has been most astounding in recent years.

In the late 1990s, state researchers caught five to six blue catfish an hour in the James. In 2007, they caught more than 250 an hour, on average.

Near Curles Neck on Thursday, Greenlee and fisheries technician Matt Blommel caught blue catfish for study. They sent an electrical charge into the water from their boat, and Blommel netted the stunned fish.

In about three minutes, they caught 23 blue catfish ranging from a 1¼-pound, 13-inch youngster, to a 42½-pound bruiser about 3½ feet long. Earlier in the day, they caught a monster -- 65½ pounds and 49 inches.

Sometimes, the biologists shock the water with a lower frequency designed to stun only catfish. "You'll see anywhere from thousands to tens of thousands" of blue catfish in just a few minutes, Greenlee said.

Greenlee and Garman say we have yet to see the full impact of blue catfish on the James