Paddlefish Program is Having Mixed Results

Pittsburgh Tribune-Review
7 August 2011
By Bob Frye

A program aimed at restoring one of the state's most unique fish to the waters of Western Pennsylvania might be faltering.

In 1991, the Pennsylvania Fish and Boat Commission launched an effort to restore paddlefish to the rivers around Pittsburgh. The fish — unmistakable because of their large bill, or rostrum, which is used to find food — are native to the Ohio River watershed, having been historically documented in the Ohio, Allegheny, Clarion and Kiski rivers.

They need clean water to survive, however, and eventually disappeared when industrial pollution fouled those waterways. The last known fish was seen in 1919.

The commission's goal has been to bring them back, and it's been stocking fish in area rivers every year toward that goal. Thirteen thousand paddlefish were released into the Ohio River last year. Commission biologists will be at the agency's Linesville hatchery the next three days, putting radio tags into the rostrums of at least 10,000 fingerling paddlefish that will be stocked in the Allegheny River this year.

But that might be the last effort of its kind because — 20 years into the project — the results have been mixed.

This year, for example, researchers from California (Pa.) surveyed the Allegheny River around Harmarville and the Highland Park Bridge, looking for paddlefish, and more specifically for evidence that they are reproducing on their own. They found the former but not the latter.

"Well, we seem to be able to catch pretty good-sized fish. We got three that were all three-feet long or longer," said David Argent, the biology professor leading the study. "But one of our objectives this year was to document natural reproduction. That's kind of the next piece of the puzzle.

"Unfortunately, we were not able to document that."

Big paddlefish are not new. Argent surveyed the Allegheny in 2005 and 2006 and found paddlefish then, including one 42-pounder. Anglers have periodically caught big paddlefish by accident, too.

But biologists have found just one with eggs, in 2006, and just one juvenile paddlefish without a tag in its bill, Argent said, though there's no telling whether it was born in the river or just lost its tag.

All of that's got some wondering whether it might be time to give up on the fish.

"There's been some talk about maybe taking the program off the books," said Bob Ventorini, the Fish and Boat Commission's three rivers biologist. "The program is kind of expensive, and it might have reached the time where it's just no longer feasible."

It costs the agency about $1,000 each year for 10,000 paddlefish tags, he said. The cost of renting the machine used to imbed them in the fish is $5,000 a year, he added.

Add in the cost of raising the fish in the hatchery and it's a significant investment, he said, though he could not provide a specific overall cost figure.

The problem with restoration might be that paddlefish are kind of finicky. According to Fish and Boat Commission reports, it takes a male paddlefish 6 to 9 years to become sexually mature, and females 8 to 12 years. Even when they reach that age, though, they need specific conditions to breed: a rise in temperature, high-water flows, clean gravel bars, suitable food supplies.

"They need a lot of things to go right, all at the same time, to successfully reproduce," Ventorini said.

Still, Argent remains optimistic. There's probably not a lot of suitable breeding habitat left in Pittsburgh's river, given that they've been dredged for decades, he said. But there is likely some, and it would be wonderful to see paddlefish present and using it into the future, he said.

"I'm still very excited that the state has been supporting the restoration of this fish. It's nice to know an agency has made a commitment to a non-game species like this," Argent said.

Bob Frye can be reached at bfrye@tribweb.com or 724-838-5148.