1/19/2005
Division of Wildlife

WILDLIFE COMMISSION APPROVES EMERGENCY FISHING CLOSURE FOR PORTION OF BOULDER CREEK

A portion of Boulder Creek will be closed to fishing to reduce the risk of spreading New Zealand mudsnails.

The Colorado Wildlife Commission recently approved an emergency regulation closing a two-and-one-half mile stretch of Boulder Creek northeast of Boulder to fishing to reduce the risk of anglers accidentally moving exotic New Zealand mudsnails to other streams and lakes.

The closure, approved last week during a Commission meeting, is effective immediately and will remain in place for 90 days for the portion of Boulder Creek between Valmont Road and 95th Street.

“We are taking this action as a precaution because of the threat this invasive species presents to native wildlife and Colorado’s streams,” said Eric Hughes, the DOW’s aquatic wildlife manager.

Mudsnails, tiny mollusks first found in North America more than a decade ago, were discovered in Boulder Creek where it flows under 61st Street last November by an observant angler who had recently read about the tiny invasive species. The angler showed the snails to a University of Colorado scientist who confirmed they were New Zealand mudsnails. The men then informed DOW aquatic managers who confirmed the presence of mudsnails in Boulder Creek.

A subsequent inspection found that a nearby private trout rearing unit adjacent to the portion of Boulder Creek was also infested with mudsnails. That facility has been drained and the trout on the facility were destroyed to help prevent the snail from moving to other steams and lakes.

In some North American waters the mudsnails have taken advantage of the lack of predators to rapidly expand, clogging streambeds and crowding out native invertebrate species. The snails are so small that hundreds of thousands can cover a square meter of streambed.

Mudsnails can survive for weeks in dried mud and hitchhike to new streams on fishing equipment, boats, clothing, and even on the feathers of waterfowl. The tiny snails are capable of curling up tightly within their tiny shells and passing through the gut of a trout unharmed, taking up residence wherever the trout may swim or be transported.

DOW aquatic managers are concerned about other exotic species, too, including zebra mussels, predatory snakehead fish and other exotic mollusks reaching Colorado.

Wildlife commissioners agreed that over the next several months, the DOW should develop new regulations to better allow agency managers to effectively deal with invasive species. Options include immediate closure of waters to fishing and hunting, closure of fish rearing units, prohibitions on moving fish, and thorough public information efforts to inform people on how best to avoid inadvertently moving exotic species into or around Colorado.

“During the next three months, the DOW will be working on a statewide management plan designed to stop or slow down the spread of New Zealand mudsnails,” said Robin Knox, the aquatic biologist heading up the agency’s invasive species work.

For more information about New Zealand mudsnails, visit http://wildlife.state.co.us/WildlifeSpecies/Profiles/InvasiveSpecies/NewZealandMudsnail.htm    # # #    

Division of Wildlife