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Ecology and salmon related articles

Pests Seek a Northwest Passage

by Bill Monroe
The Oregonian, August 10, 2004

Not every visitor to the Northwest will be greeted with a red carpet next spring as the region welcomes the 200th anniversary of North America's greatest exploration.

Exotic invaders proliferating along the Lewis and Clark Trail's Midwest river routes have the full attention of fish and wildlife managers, hydropower producers, irrigators and a broad spectrum of other water users across the Northwest.

"I have nightmares about Asian carp," said Stephen Phillips, a program manager for the Portland-based Pacific States Marine Fisheries Commission.

Phillips heads a team of concerned scientists, state and federal agency representatives, dam operators, university researchers and volunteers who periodically gather and frown in a conference room below Sellwood Bridge.

Like the Dutch boy who plugged a dike to save a nation, they've spread their fingers down the Missouri River to curb the bicentennial's potentially bitter legacy -- unwanted foreign plants and animals poised to breach the Rocky Mountains with the unwitting aid of millions of tourists retracing Meriwether Lewis and William Clark's incredible journey.

Among the foes:

"The most important factor for the survival of salmon and steelhead is control of zebra mussels," said Bill Zook, a retired Washington fish biologist who established that state's early warning systems and now contracts as a consultant to spread the word. "There's so much damage already at the dams that if these things clog up juvenile bypass systems, their sharp shells are going to descale and further confuse the fish." He said those fish that don't die outright will be confused and disoriented, becoming even more susceptible to predators.

"It could be the end of salmon and steelhead in the Columbia system."

Jim Athearn, a fish biologist with the U.S. Army Corps of Engineers in Portland and a member of Phillips' team, said fish passage is largely unique to Western dams and said the corps has been working on systems to cope with zebra mussels in its Tennessee research laboratories with little success.

The mussel grows to adulthood within a year, reproduces by itself and lays thousands of microscopic eggs. Larvae are so small they pass through normal filters.

And, Athearn said, "You can't install ceramic filters on a dam."

Most water systems in zebra zones rely on expensive duo systems for intakes and water passage. When one becomes infested and clogged with mussels, it's shut down and cleaned while the backup system does the work.

Mussels can be controlled with chlorine-based chemicals, but environmental laws limit their use. One species of carp eats zebra mussels, but in the few areas it's been tried it also eats less-numerous native mussels, potentially pitting it against the Endangered Species Act.

And, Athearn said, given the spread of the jumping carp -- electric barriers keep them from entering the Great Lakes through the Mississippi -- few agencies want to try biological control.

"If we get zebra mussels, there isn't a cure," he said. "Prevention is where it's at."

Phillips presides over the Columbia Basin Team of the 100th Meridian Initiative, put together by the U.S. Fish and Wildlife Service's Aquatic Nuisance Species program. The initiative -- other teams deal with the Missouri and Colorado river systems and El Dorado Reservoir in Kansas -- aims to keep zebra mussels east of the 100th meridian, the line of longitude cutting from mid-Texas through North Dakota. But they've approached within 50-100 miles of the line in the Missouri River.

Phillips said he's spent about $500,000 in the past four years to gear up for next spring's public awareness program timed to greet Lewis and Clark Trail visitors. The programs target boaters because of the high interest in following the explorer's route down the Columbia River.

Pleasure boaters will tow their craft to explore the river, and anglers from across the nation have heard about the Columbia's abundant smallmouth and largemouth bass and near-record size walleye. Any boat that's recently been in mussel- or hydrilla-infested waters might carry unseen larvae in bilges, live bait wells, around outboard motors, in standing water inside trailer frames, adhering to trailer axles or even as inconspicuous locations such as fishing tackle.

Their efforts to education and alert boaters include:

Marinas and sporting goods and marine supply stores will be stocked with posters and educational material. More than 1,000 placards are posted at boat ramps along the Missouri. Randy Henry of the Oregon State Marine Board said more will appear at the most-used boat ramps along the Columbia to warn about invaders and caution visitors to wash their boats and gear before and after using the river. Henry said the Marine Board can't afford to build wash stations at boat ramps, but signs at several will help boaters locate the nearest carwash.

A public service announcement for radio stations in the Midwest; it's been used sparingly, usually well-after prime listening hours.

Highway signs will lead travelers to tune in to AM radio frequencies explaining the issues and how to clean their boats.

A brochure, "Zap the Zebra," is being distributed nationwide.

Marine deputies and law enforcement officers from most Western states are being trained to look for mussels and weeds when they see out-of-state license plates or boat registrations.

In May, a Washington State Patrol trooper on Interstate 90 east of Spokane spotted live mussels on the trim tabs of a 38-foot boat from Tennessee, headed for fishing along the Washington's coast. That boat's owner thought he'd cleaned the boat.

Then, in mid-July, a Chicago boat owner towed his craft to Lake Mead, Nevada, and took it in for a tune up before launching. The mechanic discovered the outdrive's interior infested with dead mussels.

The Northwest's strong boating market adds to the threat. Buyers find and ship boats from the Great Lakes because prices are lower. Usually, the boats have been high and dry for a while, but sooner or later one will come here directly from an infested lake and may not be inspected, Phillips and Zook said.

While inspecting boats is key to prevention, monitoring the water is just as critical for control, said Mark Sytsma, an associate professor at Portland State University. Sytsma and a team of graduate students and volunteers are building and distributing hundreds of small sections of plastic tubing across the Missouri and Columbia rivers. The tubes can be placed in a lake, river or reservoir and periodically checked for zebra mussels or mud snails, which adhere to them.

"If we can detect them in time, there might be something we can do to deal with them," Sytsma said. The tubes already have turned up mud snails in Garrison Lake near Port Orford, the lower Rogue River and Devil's Lake near Lincoln City.

"Fishermen bring their boats to the boat ramp and flush their engines," said Janette Goolsby of Warrenton, who monitors one of the tubes in Cullaby Lake, near Fort Clatsop, Lewis and Clark's winter quarters in 1805-1806. Hers has been invader-free so far.

"Most boat-owners want to cooperate," Zook said. "It's just a matter of education."

While Phillips keeps a stoic face on holding the line on zebra mussels at the 100th meridian, individually his committee members believe they eventually will arrive.

"The carp are absolutely coming," said Sytsma, but he adds that zebra mussels will be first.

"But I'm not fatalistic," he said. "Even if we slow the spread west, that's a savings to us whether it's a year or two or five.

Zook is a little more hopeful.

"I used to think it was inevitable," he said. "Now I don't know if it is or not. There's a real parallel with walleye, which spread quickly all the way to the mouth of the Columbia after they were first brought into the Spokane River in the 1940s.

"Just one big leap is all it takes."

That leap may or may not be blocked by the 100th Meridian Initiative.

"You draw the line in the sand as far out there as possible," Zook said. "And then if you have to retreat, do it just a bit at a time."

Bill Monroe
Pests Seek a Northwest Passage
The Oregonian, August 10, 2004

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