After discovering whirling disease in the middle Provo River in March, wildlife officials knew someday it would work its way into the Midway fish hatchery -- but not nearly as fast as it did.
The latest test results show five Midway fish with positive signs of the disease. As a result, the Utah Division of Wildlife Resources has asked the Fish Health Board to let it destroy close to 1 million fish and redirect nearly a million more fish to previously contaminated waters."I think we can say the entire state will feel this loss," said Tom Pettengill, chief of sport fishing for the DWR. "This is a major blow to our stocking program. Midway supplies 21 percent of the state's catchable trout."
Areas hardest hit will be the Northern and Northeastern regions, which get 30 percent and 48 percent of their fish, respectively, from Midway. The two regions hold some of the state's most popular family fishing waters, such as the Logan and Weber rivers and sections of the Provo river, along with Bear Lake, Pineview, Rockport, East Canyon and Scofield reservoirs.
In response to the loss of hatchery fish, the division has directed the state's five regional offices to cut stocking this summer by 21 percent and redirect fish to waters that were supplied by Midway. Most of the cutbacks will be made in streams and rivers.
In early March, it was reported that fish in the Provo River upstream from Jordanelle and between Deer Creek and Jordanelle had tested positive for whirling disease. Officials had expected it would take several years to reach Midway.
As a precaution, DWR fish biologists immediately began testing fish in Midway using an early detection method that is a more sensitive to errors.
"We had one fish test positive with this test. We hoped it was a mistake or that the sample was contaminated. When five fish came back from a second test showing early stages we could no longer hope it was a mistake," said Pettengill.
"We could either act now or wait two or three months until the fish begin to show more pronounced signs of the disease. We chose to act now. We want to make Midway test clean so we can begin stocking fish again."
The 190,000 catchable rainbow, between 8 and 10 inches long, valued at more than $140,000, will be destroyed or sold to commercial businesses, such as the mink-farm industry. The two dirt ponds where the contaminated fish were found, used to grow smaller fish to catchable size, will be covered and never used again. About 600,000 newly hatched albinos will be destroyed and another 600,000 fingerlings or 2-inch fish will be stocked in Jordanelle, where it's unlikely any will survive.
The disease was first discovered in Utah back in 1991 in a private fish-producing operation owned by the family of Gov. Mike Leavitt near Loa. It has since spread to most areas of the state.
Whirling disease begins with a small parasite, which is eaten by a tubiflex worm. Young fish that consume the worms eventually exhibit symptoms of the disease, which include deformities in the head and a curving of the spine, which causes the fish to swim in circles or whirl.
The most susceptible fish are trout and salmon. Among trout, rainbows are hit the hardest. Nearly 80 percent of the rainbows in the famed Madison River in Montana died from whirling disease. Brown trout show the least vulnerability.
No one is certain how it jumped from the Provo River to the Midway hatchery, which has not direct connection to the river.
Biologists speculate that the parasite, tubiflex worm or a contaminated fish were carried either by birds or a mammals from the river to the hatchery.
In which case, said Pettengill, "We've got to look at enclosing the raceways, not only at Midway but all (10) state hatcheries. We spent several hundred thousand dollars to cover the raceways at the Kamas hatchery because whirling disease was found in the area. Now it looks like we'll have to spend a lot more."
You can reach Ray Grass by e-mail at grass@desnews.com