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.