- DENVER - A disease that attacks the bone structure of young fish has
wiped out 90 percent of Colorado's wild rainbow trout in six of the state's
best trout streams, a state study shows.
- The study by the Colorado Division of
Wildlife also found that Whirling disease has reached 12 of the state's
15 trout hatcheries, threatening the state's $420 million-a-year fishing
- "It's like getting pounded by a
sledgehammer. The disease is having a devastating effect," said Barry
Nehring, state fishery biologist and author of the five-year study. "These
were the best of the best rivers in Colorado."
- Whirling disease has killed millions
of fish in such rivers as the Colorado, South Platte, Gunnison, Rio Grande,
Cache la Poudre and Dolores.
- The disease, which poses no threat to
human health, is caused by a microscopic spore that attacks the bone structure
of baby fish. While it may not kill the fish, the resulting whirling behavior
makes the fish unable to feed normally and more vulnerable to predators.
- State officials say Colorado's fish became
infected after a private hatchery unwittingly accepted a shipment of diseased
fish from Idaho. The disease affects trout streams in 22 states.
- Eradicating the disease from state fish
hatcheries and making improvements to prevent another outbreak are expected
to cost at least $13 million. The hope is to have all hatcheries disinfected
- and producing 3.5 million fish a year - by 2002.