Biologists Leave No Stone Un-Terned in Effort to Relocate Hungry Birds

Government biologists have decided that the Caspian terns that moved onto a man-made island in the Columbia River and began feasting on millions of young salmon have to go.

But where to send them?

With more salmon runs up and down the West Coast going on the endangered species list, the team looking for alternative nesting areas for the voracious birds has run into the kind of reaction they might expect from a nuclear waste dump.

“It is a ‘Not in My Backyard’ sort of issue,” said Bob Willis, a biologist with the U.S. Army Corps of Engineers.

Problems began about a dozen years ago when Caspian terns discovered Rice Island, a 220-acre lump of dredged sand located about eight miles from the mouth of the Columbia.

From a tern’s point of view, it is paradise: lots of bare sand on which to lay their eggs, and a veritable buffet of young salmon swimming by on their way to the ocean. And unlike the natural islands in the Columbia, the sandy parts don’t flood in the spring.

But from the salmon’s point of view, it’s like reaching the next level on a video game. They have just survived the gantlet of hydroelectric dams, with their grinding turbines and long stretches of slackwater filled with hungry northern pike minnows, only to be swooped down upon by thousands of screaming terns.

As historic nesting sites, mostly inland, have succumbed to fluctuating water levels, development, encroaching vegetation and even growing numbers of eagles, Rice Island kept getting bigger, and so did the numbers of terns.

They now number some 20,000, making them the largest nesting colony of Caspian terns in the world, according to the Pacific Seabird Group. The colony represents a quarter of the North American population and three-quarters of the West Coast population.

But the salmon they eat are in trouble. More than $3 billion has been spent trying to restore dwindling Pacific salmon populations, and the government is considering breaching four hydroelectric dams on the Snake River to improve the survival of young salmon on their migration to the sea.

The 80 million young salmon and steelhead that swam down the Columbia River this year included 11 groups on the endangered species list and represented an investment of more than $500 million.

Based on observations and the collection of some 40,000 coded wire tags injected into salmon before they were released from hatcheries, biologists figure the terns on Rice Island ate as many as 20 million salmon and steelhead, or about 25% of the total, said Ben Meyer, a National Marine Fisheries Service biologist and chairman of the group of government experts who will recommend what to do with the terns.

Details are still being debated, but the members of the group agree that the terns have to go from Rice Island.

Attempts to make Rice Island less attractive by planting winter wheat on the bare sand nesting areas last winter were foiled by heavy rains.

But biologists are confident they have a better plan. They will string great swaths of bright orange plastic snow fence across the open sands so the terns won’t want to nest there. They like open spaces, and the snow fence will cut off their view. ATV patrols will roar around to scare off any diehards.

Luring the birds to new nesting sites is no problem either.

This summer, the Caspian Tern Relocation Project successfully lured a couple thousand terns to East Sand Island, near the mouth of the Columbia, by setting out tern decoys and playing a recording of the croaking calls that ecologist Don Lyons calls “Caspian Tern Greatest Hits.”

Because they are closer to the mouth of the river, where there are more ocean fish, the terns’ diet consisted of only about 50% salmon and steelhead, compared to about 80% at Rice Island, Meyer said.

The ideal would be to create many new nesting colonies up and down the coast, so each one would have only a couple of hundred birds and the impact on fish would be small.

But Oregon isn’t interested in any more sites. And though Washington has agreed to look, it won’t allow any that hurt a threatened or endangered run of salmon, said Herb Pollard, an NMFS biologist based in Boise who also serves on the working group.

“They are just about as welcome as morning glories in your garden,” Pollard said.

Washington Department of Fish and Wildlife biologists are considering some islands in Grays Harbor, Wash., where terns used to nest, and hope to find another in southern Puget Sound.

“I’m convinced we will be able to find places to assure the long-term survival of terns in the Northwest and still not jeopardize salmon and steelhead,” said Fred Dobler, southwest regional wildlife program manager for the department. “It won’t be easy.”

Authorities got a taste of the reception awaiting them when they lured the terns to East Sand Island. Another pile of dredge spoils, it was the first spot where terns nested in the Columbia back in 1984, but they soon moved on to Rice Island.

Since about 2,000 have been lured back, people have spotted them hanging around the mouth of Washington’s Chinook River, where the Sea Resources Watershed Learning Center is working to restore depleted salmon runs.

Les Clark, who has fished for salmon in the Columbia for 53 years, has heard fishermen talk about taking matters into their own hands: releasing possums and raccoons on East Sand Island to chase off the birds the way someone did on Rice Island.

“They say that’s one of the biggest colonies in the world,” he said of the terns. “They might be, but we don’t want them exactly on our doorstep.”

NMFS biologist Pollard said the terns are a frustrating new kink in what has become an unnatural ecosystem.

“When you start tugging on a string in Mother Nature’s sweater, you just don’t know where she is going to unravel,” he said. “I suspect when some of those islands were first built, a wildlife biologist looked at them and was saying, ‘Boy, here’s a good goose-nesting spot.’

“We’re not very smart sometimes.”