OLYMPIA - State fisheries managers are working to limit the spread of invasive New Zealand mudsnails recently found at the Ringold Hatchery, north of Richland.

The Washington Department of Fish and Wildlife (WDFW) confirmed the presence of mudsnails at the hatchery in late August. New Zealand mudsnails also were detected along the banks of the Columbia River, which flows past the hatchery, and in the spring that supplies water to Ringold.

"Based on the density of the snails we've found, we suspect the original infestation at the hatchery site occurred three or four years ago," said Allen Pleus, WDFW aquatic invasive species coordinator.

New Zealand mudsnails initially were detected in Washington in 1996 in the Columbia River and have spread to several of the state's lakes and rivers, including Olympia's Capitol Lake, the Chehalis River and Lake Washington. Once established in a river or lake, mudsnails are difficult and costly to remove without damaging the aquatic habitat.

New Zealand mudsnails are tiny - about one-eighth of an inch long - but prolific snails that can disrupt the food chain in a lake or river by outcompeting native species. Due to their size, these snails can easily be picked up and transported from one river or lake to another on people's boots, fishing equipment or boats. Fish also can transport New Zealand mudsnails, which can survive passing through their digestive tracts.

WDFW raises several species of fish at its Ringold facility but has not released any fish from the hatchery since discovering mudsnails there. The department is evaluating its options for the fish on hand, which include tiger muskies, steelhead and rainbow trout, said Kelly Cunningham, deputy assistant director of WDFW's fish program. One option includes isolating the fish for a period of time to allow them to expel the mudsnails prior to release.

"Although we know New Zealand mudsnails have been present in the lower Columbia River for nearly two decades, we're trying to prevent these snails from spreading to lakes and streams that are not infested," Cunningham said.

WDFW is exploring options to keep mudsnails out of the spring water that flows into the hatchery and decontaminate the fish raceways and ponds at Ringold.

The department also is checking other fish hatcheries for New Zealand mudsnails, because WDFW routinely moves fish between hatcheries. No mudsnails have been detected at the Meseberg Hatchery, which is adjacent to Ringold and is supplied water by a separate spring.

The section of the Columbia River that flows past the hatchery is a popular steelhead and chinook salmon fishery. The department has posted signs in the area to inform anglers of the steps to take to minimize the spread of these mudsnails. WDFW also is setting up stations for anglers fishing along the banks to clean their boots and gear to help prevent the spread of New Zealand mudsnails.

"We're also asking boaters recreating in the area to help out by cleaning, draining and drying their boats and equipment," Pleus said.

Anglers and others recreating in the area should check WDFW's webpage atwdfw.wa.gov/ais/youcanhelp.html for information on preventing the spread of mudsnails and other aquatic invasive species.

The first discovery of New Zealand mudsnails in the United States was in 1987 in Idaho. Since then, the species has spread to 10 western states as well as the Great Lakes. To learn more about New Zealand mudsnails, visit WDFW's webpage at wdfw.wa.gov/ais/molluscs.html.

Contacts: Allen Pleus, Invasive species, (360) 902-2724
John Easterbrooks, Hatcheries, (509) 457-9330 or (360) 489-2647 (cell)
Michelle Dunlop, Public Affairs, (360) 902-2255