Feast of the Cormorants

Do we really need to keep 30,000 cormorants on a 60-acre island made partly of dredge spoil while they annually consume up to 20 million salmon and steelhead smolts?

east sand island
Courtesy of U.S. Army Corps of Engineers

FRR Arrows2“We will not play nursemaid to the fish.” That was the official response of the US Army Corps of Engineers when the environmental community (such as it was in the late 1930s) asked it to install fish passage at its new Bonneville Dam.

But roles have reversed. Mandated by the Endangered Species Act, it is the Corps fighting to prevent extinction of five races of steelhead and eight races of salmon that cling to existence in the Columbia River system. And it is the environmental community fighting to let the extinction process proceed so that a modest cull of unnaturally abundant double-crested cormorants won’t happen.

Ninety-eight percent of all cormorants breeding in the Columbia River estuary nest on Oregon’s East Sand Island, 60 acres of natural terrain and dredge spoil near the river’s mouth. Each year they consume anywhere from 11 to 20 million steelhead and salmon smolts.

We know this from extensive studies of excreted passive integrated transponder (PIT) tags. PIT tags, similar to the ones placed under the skin of pet dogs, are encased in glass and are about the size of a grain of rice. Tagging crews inject them into hatchery smolts (and some wild smolts), recording species, race and origin. Then the PIT tags trip sensors as the fish pass by mainstem dams, allowing managers to estimate such information as travel times and survival rates.

As the Corps explains in its final EIS, cormorant nest sites on East Sand Island are littered with PIT tags. But not all tags are excreted on the island. Many fall into the water or are ruined during digestion, so predation is doubtless higher than reported estimates. Steelhead are more vulnerable than salmon because they swim higher in the water column. At least 6.7 percent of all wild steelhead smolts below Bonneville Dam, the lowest impediment on the Columbia River, wind up as cormorant scat.

The lost genes are sorely needed. These steelhead and salmon were the best of the best—the ones that made it past all the warm water, all the pathogens, all the turbines, all the spillways, all the predators proliferating in the impoundments, such as pike minnows, and alien smallmouth bass, channel catfish and walleyes.

 

The double-crested cormorant, one bird we most certainly are not running out of, proves that a species doesn’t have to be alien to be invasive. Catfish and baitfish farms in the South have caused a Biblical plague of cormorants along the mid-western migration route, particularly in the Great Lakes where the birds devastate gamefish, and wipe out island forests with their acidic guano.

In 1989 there were 100 breeding cormorant pairs on East Sand Island. By 2013 there were 15,000, making it the biggest double-crested cormorant colony on earth. All the Corps wants to do is trim the colony to between 5,380 and 5,939 breeding pairs so that smolt predation drops by about half—where it was a decade ago.

A four-year cull by the US Department of Agriculture’s Wildlife Services (with shotguns, and oil applied to eggs) began May 24. This followed denial of an injunction (and request for attorney fees) sought by the Audubon Society of Portland, the Center for Biological Diversity, Wildlife Center of the North Coast, Friends of Animals, Animal Legal Defense Fund and Earthrise Law Center. Now these plaintiffs are suing the Corps, the Fish and Wildlife Service and Wildlife Services.

This story is much bigger than just cormorants and salmonids. It is deeply revealing of the ecological illiteracy that blights our nation, and of society’s refusal to recognize our obligation to rebalance, where possible and to the extent possible, the predator-prey relationships we’ve thrown out of kilter. Few of us grasp the fact that “letting nature take its course” doesn’t mean standing back and watching man-made messes get worse.

Non-anglers don’t see or hear fish. Fish don’t have fur or feathers; they’re slimy and cold. Therefore, for the vast majority of Americans, fish don’t count as wildlife. Even some of the most effective and respected environmental groups are content to sacrifice them, especially when necessary culling of overpopulated wildlife provides fundraising opportunity. “Please make a donation to support our efforts to protect East Sand Island cormorants from horrific lethal control,” entreats the Audubon Society of Portland.

Consulting with the Corps under Section Seven of the Endangered Species Act, conducting much of the background research and issuing the Biological Opinion on the cull has been the National Marine Fisheries Service. And cooperating in the project with the Corps and Wildlife Services are the US Fish and Wildlife Service, the Oregon Department of Fish and Wildlife and the Washington Department of Fish and Wildlife. All data collected for decades by these agencies are dead wrong, according to virtually all comments on the Corps’ Draft Environmental Impact Statement, 98 percent (about 150,000) of which were submitted from two online petitions posted by CARE2 and the National Audubon Society.

Most of the comments are stunning in their mindlessness. For example: “The EIS fails to provide a legitimate discussion of ethics and the rights of wildlife,” and “Cormorants are vilified.”

Commentary on enviro Web sites is no better. The otherwise heroic Public Employees for Environmental Responsibility calls the plan “needlessly cruel” and claims that “cormorants do not need to be treated like terrorists simply because they eat fish.” Responding to an item on the online magazine TakePart one reader writes: “While we’re at it why don’t we kill 16,000 Christians to save a few more Islamists . . . you pathetic morons.”

Balanced reporting in the general media exists but is hard to find. A news item in the Portland Tribune refers to the cull as a “slaughter” and reports that the Corps only “alleges” an increase in cormorants. And the National Geographic recycles a favorite myth of the clueless, claiming that the feds are “killing one species of animal to protect another.” The feds are doing no such thing. They are killing individuals of a grossly overpopulated species to keep 13 imperiled races of steelhead and salmon on the planet.

“It has shocked us how much heat there has been over this issue,” says NMFS’s public affairs officer for Oregon, Washington and Idaho, Michael Milstein.

 

The Center for Biological Diversity—whose commitment to imperiled fish is best illustrated by its nearly successful campaign to cause the Paiute cutthroat to be hybridized into oblivion (see “Big Win for our Rarest Trout,” Winter 2014 FR&R)—accuses the Corps of “ignoring its own science” and that “scientists with the Fish and Wildlife Service concluded in a 2014 report that salmon and steelhead mortality due to cormorant predation is completely compensatory,” meaning that if cormorants don’t kill up to 20 million smolts a year, something else will. The Audubon Society of Portland goes so far as to accuse the Fish and Wildlife Service of “suppressing” the report.

The Fish and Wildlife Service didn’t ignore or suppress anything. The report (not by “scientists” but by a scientist, Dr. Steven Haeseker) is only a draft that has yet to undergo any kind of agency review, technical review or peer review. So the service can’t release it. What’s more, all kinds of other reviewed and completed studies indicate that much of the cormorant predation is additive (meaning it adds to other sources of mortality).

Miel Corbett, the service’s deputy assistant regional director for migratory birds, tells me this: “Haeseker’s paper focused on the mortality for Snake River steelhead and considers only adult return rates. It may contain valuable information, but it didn’t relate to the issue at hand. The role of the Fish and Wildlife Service was to analyze the Corps’ permit request [for take of migratory birds] to determine whether or not the proposed action of culling cormorants would reduce predation on salmonid smolts.” From all available data, the agency concluded the answer is yes.

“Of those fish swimming past East Sand Island, 96 to 98 percent are going to die before they return as adults,” says NMFS’s Ritchie Graves, chief of the Columbia River Power System Branch. “That’s just life. But the idea that fish the birds are eating are somehow different than fish the birds aren’t eating is where NMFS technical staff doesn’t see eye-to-eye with Haeseker.”

“Our feeling is there may be some compensatory mortality, but it’s not 100 percent,” adds Milstein. “These fish being eaten by cormorants in the estuary have already made it hundreds of miles down the mainstems of the Snake and Columbia, dodging predators the whole way. They’ve also made it past the dams. They’ve withstood a lot of challenges and are in relatively good shape. It just doesn’t seem reasonable to us that every one of them would have died anyway.”

The critics proclaim that the reason so many smolts are eaten is that they’re injured by dam passage. But the main symptom of such injury is scale loss; and smolts in the estuary show scarcely any descaling.

More can be done to reduce mortality at the dams, argue the critics; but it’s hard to imagine what. All manner of improvements have been implemented; and they’ve made possible the required 93- to 96-percent survival rate at each dam, depending on species; and some dams surpass this standard. Additional water is now spilled throughout the entire migration period, and the spills are shaped into safer flows. Gas-abatement structures at the bottom of spillways now shoot atmospheric nitrogen out over the surface so it doesn’t plunge into the water column where it used to cause gas-bubble trauma. Weirs allow smolts to pass over structures at normal migration depths, without having to dive to the bottom of the spillway gates. Fish-friendly turbines remove gas pressure and cavitation, sparing close to 99 percent of the smolts that pass through. Piscivorous birds that used to hang around the dams are hazed away. At Bonneville a screen system inside the powerhouse diverts fish into a tube that bypasses the dam; and an opening at the corner of the dam allows large numbers of fish to pass through without being screened from turbine intakes.

“We’re getting to the point with the dams where we’re tinkering with the last few tenths of a percent of survival,” remarks Milstein.

The critics also proclaim that the Corps, the Fish and Wildlife Service and Wildlife Services “ignored” non-lethal alternatives. They did not. When the cull is complete, terrain on the island’s west side will be modified to allow more frequent tidal inundation, reducing nesting habitat sufficiently to stabilize the population.

All other suggested “non-lethal” methods were tried and failed. As early as 2004 the Corps began trials to dissuade cormorants from nesting on East Sand Island. Techniques included hazing with lights and explosives, removal of nest structures prior to egg laying, removal of nesting material, and reduction of nesting habitat with fences. Between 2008 and 2013 1,961 cormorants were marked with color bands, 147 with satellite tags. With decoys and recordings the Corps succeeded in luring some cormorants to other nesting sites; but these were further upriver, where there were fewer marine fish. So smolt predation increased.

For three years Dr. Daniel Roby, head of the US Geological Survey-Oregon Cooperative Fish and Wildlife Research Unit, led a team investigating ways to kick nesting cormorants off East Sand Island. Hazing and habitat reduction seemed promising; and at one point all 15,000 breeding pairs were jammed onto just four acres. “Even though our attempts worked, the cormorants never had less habitat than they needed for the entire colony,” says Roby. He believes his team could have reduced habitat further if the cooperating agencies hadn’t pulled the plug on his research. “If you use that [hazing and habitat-reduction] approach,” he says, “those cormorants that can’t fit into the habitat are going to go look someplace else—probably upriver.”

While Roby understands that cormorants kill more smolts upriver than downriver, he says this: “Cormorants are very sensitive to hazing. My take is that if they nest somewhere you don’t want them, haze them there, too.”

When I ran Roby’s suggestion by Corps cormorant project leader Robert Winters he responded as follows: “That would require a constant effort. We’d have to be out there all the time hazing them off islands; that’s not feasible at all. And it wouldn’t reduce the number of cormorants. The biological opinion requires us to reduce the population to around 5,600 pairs. Just spreading them around the estuary and hazing them off islands would not achieve our goal.”

NMFS’s Graves adds this: “No hazing program was deemed by the federal parties to be sufficient. You’ve got literally all the salmon and steelhead in the river going right past East Sand Island. You’d have to cover the whole estuary in boats with cracker shells. The fish are too available. It’s just not practical.”

Caspian terns, also major smolt predators, breed on East Sand Island, too. Before the Corps started a reduction program (not a cull) the colony had numbered about 10,000 breeding pairs, the world’s largest by far. But, unlike cormorants, terns can be relocated to islands the Corps has constructed for that purpose and in areas where they won’t eat many smolts. “Lethal control is a last resort,” says Graves. “It’s not where any biologist would prefer to go. Luckily, Caspian terns are fairly picky about habitat. So that allows us to be more effective in pushing and pulling them to places they’d rather be.”

The number of breeding tern pairs (not yet available for 2015) probably remains above the goal of around 4,000; but tern eviction is definitely heading in the right direction. “This year we were able to reduce the tern habitat down to one acre,” says Winters. “At the same time we’re socially attracting them to other sites.”

 

The National Environmental Policy Act is an essential tool to keep federal agencies honest and on track and to allow the public to participate in decision making. But it is also ponderous, expensive and grotesquely time-consuming. Moreover, it frequently results in management by an ill-informed public as much as by fish and wildlife professionals. The Corps’ Final Environmental Impact Statement, an 1,100-page monstrosity, reflects the fretting of cormorant lovers that the cull originally proposed in the draft EIS was somehow dangerous to the western population, which has been expanding by more than two percent annually for the last 20 years. So the Corps worked with the Fish and Wildlife Service to reduce the cull adopted in the Final EIS by 40 percent.

The best fish-advocacy groups aren’t actively opposing cormorant reduction, but I wish they’d support it. Because Trout Unlimited and the Native Fish Society are two of my favorites I sought their input. TU’s senior scientist Dr. Jack Williams offered this: “It tends to be easy from a management perspective to go in and try to kill the predators without really addressing the big problems. The big problems on the Columbia are passage, warm temperatures, water quality. I can’t get too thrilled about those sorts of proposals. Maybe they’re needed at some level.”

The Native Fish Society’s director of science and conservation, Bill Bakke, is equally unenthused. “The states get revenue from non-native smallmouths, channel cats and walleye,” he declared. “So they’ve been reluctant to take limits off. But they’re not getting any revenue from the wild birds, and they’re out there killing them. The reason we have these huge bird colonies on the Columbia is that we’re releasing millions of hatchery smolts every spring. We’ve created a food source for them. They’re eating wild fish, too; but apparently they’re not as vulnerable. I have a hard time justifying killing cormorants when we’ve manufactured their food source and they have a nesting environment that was created by the Corps. The cormorants stage there before the smolt release. It’s a bird-training program.”

Nothing Williams and Bakke say is incorrect. But I’ll add this: We need to be practical and realistic. The dams aren’t coming down in the foreseeable future. East Sand Island isn’t going away. The torrent of hatchery smolts won’t cease anytime soon. Without culling, the unnatural cormorant irruption will only worsen. And, while Washington and Oregon have indeed conserved their alien bass, walleyes and channel catfish, they’ve recently found the courage to remove bag limits—Washington in 2013, Oregon in 2015. This despite the outrage and vicious lobbying of politically powerful bass clubs, walleye clubs and warmwater guides.

“These aren’t just run-of-the-mill hatchery fish that we’re trying to protect,” says NMFS’s Graves. “Our estimate is something like a million and a half of the smolts eaten by cormorants are ESA listed. It’s disturbing to me that people don’t seem to be concerned about these animals and just treat them as food for something else.”

And this from NMFS’s Milstein: “If you look at the whole life cycle of the steelhead and salmon and then look for major losses you can do something about, this seems like one that we really needed to take on.”

That’s the whole point. No one is claiming the cormorant cull is a solution. It’s just one of the few things we can still do now to save at least some imperiled salmonids. The ancient Snake River dams need to be breached. One day they will be, but the 13 stocks of wild fish listed as threatened and endangered may not have time to wait for that.

Ted Williams
About Ted Williams 665 Articles
Ted Williams is Fly Rod & Reel’s longtime Conservation Editor.

Be the first to comment

Leave a Reply

Your email address will not be published.