Field Reports

FISHERIES

Snail invades Deschutes River

A tiny New Zealand mud snail capable of taking nutrients needed by fish has turned up in one of Oregon’s more famous trout rivers.

The invasive foreigner has been identified in the Deschutes River downstream from Maupin and also near where it joins the Columbia River.

The snail, Potamopyrgus antipodarum, is fast-spreading and has also been found in the Columbia, Snake, Rogue, Umpqua and New rivers and in some coastal lakes.

Researchers don’t know what effect the snail has when it crowds out native invertebrates crucial to the food chain of trout, salmon and other fish. But they are worried.

“We’re concerned about these invasive species that can have a big ecological or economic impact,” said Robyn Draheim, assistant aquatic species coordinator with Portland State University’s Center for Lakes and Reservoirs.

“Huge numbers of these mud snails form streambed carpets that compete for food and space with native invertebrate communities.”

Parasitic worms keep the population in check in its native New Zealand, but no natural defenses exist in the United States.

The snail has spread to 10 Western states after being found in 1987 in the Snake River in Idaho. Seven years later, they were reported in the Columbia River estuary of Youngs Bay at Astoria.

A female, which can reproduce without fertilization by a male, can account for more than 3 million offspring in two years.

Studies have found densities of more than 500,000 per square yard in rivers in Yellowstone National Park.

“They are so hardy that anything we would do to eliminate them would cause damage to the native species that are there,” said Paul Heimowitz, aquatic invasive species and research coordinator for the U.S. Fish & Wildlife Service in Portland.

Heimowitz and Draheim said preventing their spread to other watersheds by people is the only tool against the invasion.

“People who use Oregon’s lakes and rivers need to be aware of them, and to make sure their boats and fishing equipment aren’t contaminated,” Heimowitz said. “Then it’s possible that we can keep them in check.”

Associated Press

HUNTING

Comment on hunt proposals

The Washington Department of Fish and Wildlife is asking the public to log on to the Internet and participate in a survey to help develop alternatives that will be presented at public meetings and considered by the Fish and Wildlife Commission in April.

Initial proposals for the 2006-2008 seasons cover issues such as black bear seasons, electronic calls and decoys, pheasant and turkey seasons, muzzleloader and archery regulations, mule deer and white-tailed deer seasons, elk hunting opportunities and drawings for goat, sheep and moose.

The survey ends Nov. 28. Go to www.wdfw.wa.gov/wlm/game/scoping.htm or call Wildlife Program officials in Olympia, (360) 902-2515.

Rich Landers

HUNTING/FISHING

Sportsmen fatalities reported

Deon Campbell, 39, of Vancouver, Wash., died from a gunshot wound to the chest suffered while elk hunting on Nov. 9 when his high-power rifle discharged accidentally, apparently as he slipped and fell in rugged terrain about a mile northeast of Cougar, Cowlitz County sheriff’s deputies said.

•Frederick Benson, 57, of Calgary drowned last Friday while flyfishing in the Missouri River near Great Falls, Mont. Benson had dropped his fly rod while releasing a fish. According to his wife, he slipped when he tried to retrieve the fly rod and his chest-high waders filled with water, pulling him under.

Staff and wire reports