One Good Tern Deserves an Island
Will a square island in Eugene save the Columbia's salmon
By Camilla Mortensen
The Marines have been enlisted to get rid of them. They've been hazed and chased with kites and balloons. They've been the subjects of endless research studies and are being blamed for the death of millions of baby salmon. Now the U.S. Army Corps of Engineers has built them a one-acre square island in Fern Ridge Reservoir as part of a "relocation program."
They are Caspian terns — 20-inch, gull-like, grey and white birds with black heads and sharp red beaks. They've been living it up on an island in the Columbia River, but if they like their square new island, some of them will be moving to Lane County this month.
While sea lion shooting is in the news, the Caspian tern saga comes from the same problem — whom or what do you blame for low salmon numbers in the Columbia River? Rather than logging or dams, some of the blame is placed on these fish-eating migratory birds. The U.S. Army Corps of Engineers thinks that they can solve the tern problem by relocating the birds to other islands. Fern Ridge Reservoir is now the site of one of these islands, and while some people look forward to the possible bird colony, others think relocating the terns is not a solution to the salmon problem. Brian Sharp, who worked for Fish and Wildlife for 20 years as a wildlife biologist, says, "The whole thing is a farce."
Tern and Re-Tern
Caspian terns have been spotted nesting in the Northwest since about 1957. They are migratory birds and are found across the world from Africa to Australia to Europe, and the Caspian tern is the largest of all tern species. The Caspian terns that the Army Corps hopes will move into Fern Ridge spend their winters in South and Central America and then come to the Northwest to nest. They are found migrating throughout North America, but the largest nesting colony in the world, with estimates of up to 9,000 nesting pairs, is found at the mouth of Columbia River. (A flock or colony of terns is also called a "ternery of terns," for those in the know).
The Columbia tern saga began in 1984, according to Daniel Roby, a professor in the Department of Fisheries and Wildlife at Oregon State. The terns began nesting at East Sand Island near the mouth of the Columbia, probably because of "loss of habitat, some natural, some human caused" in the Northwest. But they soon began moving to another island, Rice Island, that is further upstream. Rice Island is made of sand dredged up to deepen the river channel for ships.
Terns, Roby says are "pre-adapted to moving around" when it comes to where they nest. One colony even took up nesting on mounds of contaminated soil at a Superfund site near Tacoma. Roby tempted those terns to a temporary home on sand-covered barges floating in Commencement Bay, Wash.
When the terns moved to Rice Island, they happily began feasting on millions of salmon and steelhead smolts, including 13 species of endangered salmon and steelhead. A smolt is a juvenile salmon migrating down the river and gradually adapting to life in salt water. Roby says that with estimates of about 12 million smolts being devoured by the voracious terns, researchers determined the birds were "a significant factor impeding the recovery of Columbia Basin salmon."
Many of the salmon being eaten were hatchery salmon, Sharp points out. Salmon hatcheries were put into place to make up for the loss of salmon caused by hydroelectric dams on the Columbia. Hatchery salmon are notoriously slow and stupid. "Genetically inferior," says Sharp, making them easy pickings for hungry terns.
"The plan that was hatched by the federal, state and tribal agencies," says Roby, was to move the tern colony back to East Sand Island where they would hopefully eat "marine forage fish" like herring and anchovies, and fewer of the endangered species.
That's when they called in the Marines.
East Sand Island had been overtaken by vegetation, and Caspian terns prefer bare, sandy islands. A Marine Corps reserve unit stormed the beaches and removed vegetation and debris to fix the island up for the terns.
There was a plan to actively harass the terns on Rice Island, but it was stopped by a lawsuit from Defenders of Wildlife and some bird-oriented conservation groups. The lawsuit said that the Army Corps had not complied with the National Environmental Policy Act (NEPA) and that USFWS had allowed tern eggs to be "taken" to prevent nesting. Terns are federally protected by the Migratory Bird Treaty Act. The terns were moved through kinder, gentler tern-disturbing tactics, like discouraging nesting with balloons and kites and through planting wheat and putting up fences on former nesting sites.
This isn't the only odd method for protecting salmon that Oregon agencies have devised. Federal workers have shot noisemakers at the sea lions that feast on Chinook at the dams on the Columbia river, and they now want to lethally shoot them or send them to new homes at marine parks like Sea World. The Bonneville Power Administration, which runs the dams in conjunction with the Army Corps, has a bounty on northern pikeminnows, a fish that likes to eat baby salmon. If you catch one on the Columbia, they'll pay you.
The terns relocated to East Sand Island so successfully, that they soon become the largest and healthiest tern colony in the world, says Roby.
The new tern location cut the terns' salmon consumption in half. But that wasn't enough for the salmon protection agencies. And the Army Corps claims in its Environmental Impact Statement that it is in the terns' best interest to be dispersed into other, smaller colonies. Thus the tern relocation program came into being.
If You Build It, Will They Come?
The Army Corps devised a plan to persuade some of the Columbia River Caspian terns to relocate to other areas in Oregon, as well as San Francisco Bay. Fern Ridge, a popular water recreation site on the edge of Eugene, was chosen to be one of the new tern campsites, along with Crump and Summer Lakes in central Oregon. The reservoir was seen as an ideal site, except for one small detail: There was no actual island with the right conditions for Caspian tern nesting. So the Army Corps built an island. A square island.
Terns haven't nested before at Fern Ridge, but they have been spotted there. Kat Beal, an Army Corps wildlife biologist at Fern Ridge, says "failed breeders are what we have seen at Fern Ridge in the summer." Birds that fail at breeding disperse widely, she says.
The Fern Ridge site was chosen for its large body of water and food resources, says Portland-based Army Corps wildlife biologist Geoff Dorsey. These resources include non-native fish like bluegill, crappie, largemouth bass and goldfish. While there are endangered salmon within six miles of Fern Ridge, Dorsey says the terns "primarily forage where they nest."
Conveniently enough, Fern Ridge was created by a dam and is managed by the Army Corps. It's kept shallow in the wintertime, which allowed for the construction of the island. The island, when the reservoir is full, is about one mile from the shoreline, at the end of Royal Avenue. It's approachable on foot when the water is low, but now, during nesting season, the reservoir is filling, and the island really is an island.
But why a square?
For one thing, the island is located at the junction of Royal Avenue and Gibson Island Road, which is a 90-degree angle, so "it was convenient to put it as a square," says Dorsey. "Our objective is to provide the nesting habitat, and we've done that," he says.
"Square islands are cheaper to build," says fellow Army Corps biologist Beal. "They're simpler."
The one-square acre island is made of quarry waste, covered in fabric and then piled with pea gravel and surrounded with large rocks called "rip-rap." While terns prefer sand, Dorsey says the Army Corp experimented with pea gravel on East Sand Island, and the birds "didn't avoid it."
But how do you persuade a flock of birds to move to an island a hundred miles away?
No one is actually sure the terns will move in. "No one's ever tried to do this before," says Roby, who says most of terns he has relocated have moved "short distances away." He says, "If we're successful, it will be a first."
The idea is to attract a flock of terns through what OSU professor Roby calls a "four-pronged attack" that has been successful in other tern relocations like that on the Columbia. You create the desired habitat (in this case a square pea gravel island); protect the terns from predators; monitor the birds (the Corps constructed a hut for doing just that) and provide social attraction.
Social attraction, for terns anyway, involves using tern decoys and playing what Beal calls "Caspian tern attraction calls" through solar powered players and speakers.
For the Birds
Not everyone thinks that Tern Island, as it is called, or the whole tern relocation plan is a good idea.
"Terns are not a limiting factor on salmonids," says former USFWS biologist and current ecological consultant Brian Sharp. "The plan doesn't address the real problems facing the salmon."
"Caspian terns are a very small predator effect among a whole suite of predators on the Columbia River," he says. "The biggest problem," he says "is what's happening in the ocean itself."
Salmon and steelhead spend from two to five years in the ocean before returning upriver to spawn and die. Little is known about what happens to these fish while at sea, and once they head up river the endangered salmon and steelhead face obstacles like the Bonneville Dam.
Sharp points to the Environmental Impact Statement and says, "If you look at the EIS, most of the best biologists in the world disagree with the idea of trying to relocate the terns. It's not necessary, number one, and number two, it won't work."
"This kind of shoddy science is determining the management of the Columbia River," says Sharp, who says that the Caspian tern plan is "typical of the last seven or eight years of the Bush administration."
Of the terns he says, "They're being persecuted, if you want to use that word, for being successful."
He also questions what the terns will eat at Fern Ridge, "I don't know if a good analysis has ever been done of the food supply," he says.
Eugene artist Michael Randles hasobjected to the plan from the beginning, devoting a webpage to discussing the problems with Tern Island, from its square shape to the cost of building it (currently $757,749.18) and the effects of the construct-ion on county roads as well as whether the reservoir will be full enough to make Tern Island an actual island during nesting season. He calls the island "a pro-forma exercise to say 'look what we've done.'" The Army Corps, he says, "loves to move the earth."
Local enviros have taken a more wait-and-see approach to the terns and their quadrangular island. Doug Heiken of Oregon Wild says, "I really don't love the overall scheme." He worries about unforeseen effects like possible predation on baby threatened Western pond turtles. Beal and others at Fern Ridge have worked on a "headstart program" to help the turtles that nest at Fern Ridge. Dorsey and Beal say they don't anticipate this as a problem. The baby turtles hide in vegetation, and the terns are "an open-water fishing critter and are not going to be diving into the weeds," says Dorsey.
What Heiken finds humorous is that the whole problem was human-engineered in the first place. "They built a dam, which affected the salmon; dredged the river, which brought the terns; and now they built an island to fix the problem," he says, laughing.
Tern, Tern, Tern
Local bird watchers may be excited if the terns come to Lane County's very own square island to roost. Beal warns, however, "It's really important that people stay away," so the birds aren't disturbed.
Kevin Roth, an assistant manager and wildlife technician at Fern Ridge Wildlife says there are plans to "eventually build a viewing platform or area" for those curious to see the birds.
A recent article in the Columbia Basin Fish and Wildlife News Bulletin tells of a new twist in the tern tale: The double-crested cormorants of East Sand Island have also earned the designation "world's largest colony," and now that the terns are leaving, the cormorants are "champion consumers of Columbia juvenile salmonids."
Researchers are already working on the problem. The solution? Fern Ridge again. According to a report written by Roby and co-principal investigator Ken Collis, Fern Ridge Wildlife Area (which has restrictions on public use to protect the area) was chosen as a site for an experiment in attracting double-crested cormorants.
The scientists constructed a floating platform and placed 48 old tires filled with sticks and "woody debris" as nests and 40 painted cormorant decoys to attract the large, dark birds. They also played cormorant calls and anchored the floating cormorant encampment out in the waters of the Fern Ridge Wildlife Area. No cormorants nested in 2007, but the researchers will try again this year. Time will tell if the Army Corps decides to build an island for the double-crested cormorants too.
So the decoys are in place and the sexy tern sounds of karrr, kraa-ah, as well as the deep guttural grunts of the cormorants are wafting electronically over Fern Ridge. Now it's time to watch and wait, for the coming of the birds.
To learn more about the terns and other birds at Fern Ridge, check out the Wings and Wine Festival (www.wingsandwinefestival.com),coming May 10.