An ancient fish species that might, or might not, haunt the Catawba-Wateree river basin is raising tension over Duke Energy's overdue hydroelectric license.

As Duke spars with the federal agency that protects the endangered shortnose sturgeon, millions of dollars in conservation and recreation benefits promised in the new license are on hold. Groups that negotiated those terms, and recently South Carolina's entire congressional delegation, are urging federal officials to fish or cut bait.

The debate plumbs the intricacies of federal laws protecting rare creatures, pitting the reality of new boat ramps against the hope that fading species can be pulled from the brink of extinction.

Duke's Catawba-Wateree hydro license expired in 2008. All Duke needs for a renewal is agreement from the National Marine Fisheries Service that its 13 dams won't hurt the sturgeon, which once swam far up Piedmont rivers.

That was in the days before dams, polluted water and overfishing landed the sturgeon on the endangered-species list in 1967. The fisheries service says Duke hasn't provided enough information to assess whether operating its dams will harm the fish.

Federal biologists say they're legally obliged to see if the sturgeon can reclaim its former territory if given the chance.

"We shouldn't be arguing about whether sturgeon should be in that river," said Prescott Brownell, who works for the federal agency in Charleston.

Shortnose sturgeon are found in most large rivers along the East Coast, cruising the bottom in search of clams, worms and insect larvae. Covered in bony plates instead of scales, they grow up to 4 feet long and can reach 50 pounds.

The fish once swam up Carolinas rivers to the fall line, where the soft coastal plain meets the hard-rock Piedmont, and were a mainstay of American Indian diets.

The Catawba Indian Nation near Rock Hill is now among groups urging the Federal Energy Regulatory Commission to issue Duke's new license. Under it, the tribe will get a new canoe landing at its riverfront reservation south of Charlotte and money to monitor archaeological sites.

Both Carolinas wildlife agencies, the N.C. Wildlife Resources Commission and the S.C. Department of Natural Resources, wrote similar letters.

"All the concerns we have for game lands, access areas and fishing piers, that's all on hold until this is settled," said Tim Gestwicki, executive director of the N.C. Wildlife Federation. "The sooner we get a license, the sooner those things go in."

New license terms that include steadier flows and injections of oxygen into the water released from the Wateree and Wylie dams will also improve fish habitat, Duke says.

Duke contends that it's not responsible for the sturgeon's plight. It says the species hasn't been documented in the Wateree River, which flows south of the Catawba below the Wateree dam in South Carolina, since 1896. Duke's first dam on the Catawba went up in 1904.

"The data isn't really establishing any cause-and-effect link between the sturgeon and our facilities," said licensing manager Mark Oakley.

Agencies disagree

Sturgeon have entered the Wateree River, said biologist Mark Collins of the S.C. Department of Natural Resources. It's unclear how far up the river they've traveled, he said.

The fish are known to have spawned in the cleaner Congaree River, Collins said. The Congaree and the Wateree both flow into the Santee River on the S.C. coastal plain. The fisheries service is working on similar assessments of effects on sturgeon by a dam of the state-owned utility Santee Cooper.

The Federal Energy Regulatory Commission, which will issue Duke's new license, found in 2009 that Duke's dams aren't likely to harm the sturgeon. The fisheries service disagreed, viewing the lack of sturgeon in the Wateree as "a clear indication" that the dams are a problem.

The fisheries service warns that if FERC issues a license before the service has weighed in, the energy agency could be charged with violating the Endangered Species Act.

Two advocacy groups, American Rivers and South Carolina's Coastal Conservation League, sided with the fisheries agency.

Oakley said Duke learned in December that the fisheries service wants it to build structures to lift sturgeon around its first four dams. That would cost $45 million to $50 million, it says.

David Bernhart, a fisheries service official in St. Petersburg, Fla, said fish passages would be the simplest approach. "We never said this is what has to happen," he added.

But because Duke's hydro license will be in effect for up to 50 years, Bernhart said, the agency wants to know how Duke would respond if sturgeon show up later in its waters.