Officials Taint Virgin River To Flush Out Invading Fish

November 4, 2007

Release from: Mark Havnes
Salt Lake Tribune (Utah)

ST. GEORGE - Wildlife crews are working to get the red out of the Virgin River - the red shiner, that is.

The pesky fish is threatening the southwestern Utah stream's six native species, so the Division of Wildlife Resources recently poisoned a portion of the Virgin in hopes of wiping out the invasive intruder.

"We're optimistic that this will work," said Rick Fridell, DWR's native-aquatic-project leader for southern Utah. "It's a daunting task."

Teams put rotenone into the river near Washington while others neutralized the poison before the waters flowed into Arizona.

The project is the latest effort by the Virgin River Program, a collection of federal, state and area agencies that aims to balance conservation of the river system with human needs.

Two of the Virgin's six native species are listed as endangered while three others carry some form of protection. Last month, officials released more than 6,000 endangered woundfin into the river near La Verkin.

Fridell said experts believe the red shiner - native to waters in the central United States - was introduced illegally into Nevada's Lake Mead in the 1970s, probably as a bait fish. From there, it began colonizing the Colorado River and tributaries like the Virgin River.

The shiner, which reaches 2 to 3 inches in length, devastates native fish by devouring their eggs and young while competing for the same food resources, Fridell said. The shiner also reproduces year-round, while the Virgin's native species produce far fewer eggs when triggered by spring runoffs.

To help keep the shiner out of Utah, Fridell said Arizona is expected to build barriers in the Virgin River Gorge.

Before using the rotenone - a poison made from the root of a South American tree that cripples a fish's ability to remove oxygen from water - crews netted and removed the native species from the treatment area to be released later.

Steve Meismer, the Virgin River Program coordinator in Washington County, said his teams neutralized the poison with potassium permanganate two miles before the river entered Arizona, "We want to move to recover the whole range of native species in the river," Meismer said, "and hopefully this will help."

Crews will monitor the river to see if the eradication works.

The Washington County Water Conservancy District, another member of the Virgin River Program, helped by releasing additional water into the Virgin to help flush out the poison, which is harmless to humans.

Watershed coordinator Corey Cram noted the district also is funneling federal and state grants into piping projects to move irrigation water and eliminate the open canals the shiner can use for habitat.

"It's possible to meet the needs of the fish and development," Cram said. "It's a win-win situation."