CHINOOK, Wash. (CN) – Heavy fog covered the dark waters of the Columbia River where it empties into the Pacific Ocean. Brown pelicans wound through the fog while a huge formation of double-crested cormorants glided and dipped. And the staccato bursts of shotguns echoed over the water.
“I don’t know how they can see what they’re shooting in this fog,” biologist Deborah Jaques said as she piloted a Boston whaler through the rolling water.
The shooting came from government-hired gunmen, charged with killing about 11,000 protected double-crested cormorants over four years at the species’ largest North American breeding colony.
A handful of government agencies hatched the plan to reduce the population of double-crested cormorants on a nearby island by nearly two-thirds, a controversial measure intended to reduce the birds’ predation of endangered steelhead salmon.
As of Oct. 1, the government has killed 1,707 adults and prevented eggs from hatching in 5,089 nests, according to a report on the U.S. Army Corps of Engineers website.
Double-crested cormorants, a native species protected by the Migratory Bird Act, have always nested on East Sand Island in the Columbia River Estuary. And they’ve always eaten young salmon. But their population has skyrocketed over the last quarter century, from 100 breeding pairs in 1989 to about 15,000 in 2013.
The birds are sleek and slender, an iridescent blue-black. They have glittering turquoise eyes, and two tufts that rise from their brows like a crown during mating season. They hunt in an unusual manner, diving into the water to swim and usually emerging with a fish in their bright blue mouths.
East Sand Island is home to 98 percent of the breeding pairs in the Columbia River Estuary, and about 40 percent of the western population of double-crested cormorants which spans breeding colonies from Canada to California and the Rocky Mountains to the Pacific Ocean.
The endangered salmon are a perfect food source for the birds, who must feed their hungry young chicks during the same months the fish pass East Sand Island on their way out to sea.
The birds have eaten 11 million young salmon each year for the last 15 years, or about 6.7 percent of the population of juvenile steelhead, according to Diana Fredlund with the U.S. Army Corps of Engineers.
“East Sand Island offers the perfect food source,” Fredlund said. “It has everything they need. How they talk to one another, I don’t know. But somehow word got out that this is a perfect place to raise a family. It’s a wonderful place to be if you’re a cormorant trying to raise your babies. There are no predators, there’s plenty of nesting materials, and you don’t have to look far for your food because it’s swimming right by.”
In 2004, the Corps tried to attract double-crested cormorants to other island nesting sites in the estuary.
Scientists successfully used decoys and recordings of bird calls to attract cormorants to Miller Sands Spit. But those efforts required constant work to keep the birds nesting there year after year.
And it turned out that the new sites actually increased the numbers of juvenile steelhead the cormorants ate because the nests were now further up river from East Sand Island, where fewer anchovies and other saltwater-loving fish meant juvenile steelhead made up a larger proportion of their diet.
That tactic was abandoned in 2008.
The Corps then tried luring the birds to nesting sites outside of the estuary. No takers.
In 2012, the Corps tried scaring the birds away from East Sand Island using hazing methods like erecting fences and flags as barriers to nesting and walking the island to scare the birds off. Despite those efforts, 98 percent of breeding pairs remained in the estuary during breeding season.
The Corps said those numbers demonstrated the birds’ “commitment” to breeding on East Sand Island – a commitment that it said left no choice but to begin reducing the population of the breeding colony.
“We didn’t want to move the population altogether because then they could go elsewhere, whether further up into the estuary where they’d find a higher population of juvenile salmon, or to Oregon or Washington, where the local agencies might not have resources to manage the problem,” Fredlund said. “We see this as a regional operation.”
So the plan was hatched: Reduce the population of double-crested cormorants on East Sand Island to around 5,600 breeding pairs between 2015 and 2018 and the survival rates of juvenile steelhead should rebound to historical levels from between 1983 and 2002, with about 3.5 percent of the fish still being eaten by the birds.
The plan calls for both shooting and killing adults and pouring vegetable oil on nests to suffocate the eggs and prevent them from hatching.
The U.S. Fish & Wildlife Service added rules intended to protect the long-term stability of the island’s cormorant colony. Hunters hired by the agency started shooting birds and oiling nests on the island in May. On-island killing stopped when the remaining eggs hatched, an effort to avoid killing parents who were working to feed their fledgling chicks. At that point, the hunters switched to shooting from boats, their shotguns mounted on the port and starboard of their metal skiffs.
The hunt continued into the fall, and the fledging chicks grew and started flying out over the estuary to find food on their own. The hunters are barred from killing the first-year juveniles, recognizable by their lighter coloring.
Miel Corbett with U.S. Fish & Wildlife stressed that the plan took pains to ensure the long-term survival of the island breeding colony. She said the whole plan has to be reevaluated each January, using cull numbers from the previous year’s hunt to determine how many birds should be killed in the current year.
“We would reevaluate if population numbers have dropped more significantly or rapidly than anticipated, Corbett said. “If there was an unexpected drop in numbers, we would have to take that into account. Like if there was an unanticipated loss of birds from another factor like weather.”
Theoretically, that reevaluation could result in the end of the culling operation.
“Each successive year is not guaranteed,” Corbett said.
Supporters and detractors
The fog had lifted by the time Jaques piloted her boat out to East Sand Island. She killed the engine about 100 meters away. The salty musk of guano filled the air. Hundreds of birds crowded the beach, bobbed in the water and swung through the air. A sea lion popped his head up out of the water and watched the boat curiously.
The 60-acre island is home to the largest breeding colony of double-crested cormorants in North America. It also hosts the largest breeding colony of caspian terms in the world, and the largest post-breeding roosting site for brown pelicans on the West Coast.
On Oct. 1, most of island’s double-crested cormorants had already left for their winter breeding grounds around the San Francisco Bay. But after scanning the island with her binoculars, Jaques estimated that there were still about 5,000 of the birds on the island that day.
“And some of those are definitely juveniles,” she said. “So those guys could be killing parents who are still feeding their chicks.”
Fredlund acknowledged the heated arguments inspired by the culling operation.
“It’s controversial, but at the same time it’s the best science we have and it’s combined science from all the different agencies, not just us,” Fredlund said.
Jeff Keightley, a fisherman who operates Astoria Fishing and Charters Service and takes tourists out to fish for salmon and sturgeon, said he was glad the government was killing the birds.
“It’s a good start,” Keightley said. “They’re a destructive, invasive species as far as I’m concerned.”
But not everyone thought killing all those birds was such a good idea.
In April, Audubon Society of Portland and four other environmental groups sued the federal agencies, claiming they were needlessly killing thousands of protected wild birds while glossing over the true cause of declining salmon numbers: habitat loss and the nearly 60 dams in the Columbia River watershed.
Dan Rohlf, an attorney for Audubon and professor at Lewis & Clark Law School, said the government made the birds a scapegoat – forcing them to bear responsibility for a salmon population that is in decline because of human changes to the environment, not because of a natural predator.
Rohlf said the government “had two choices: Reduce cormorant population back to 2008 levels or get increased juvenile and adult salmon survival by some other change. And that change would be changing dam operations, which none of the federal agencies want to do. So the only reason to kill all these birds is to balance out faulty math.”
“We’re shooting thousands of birds to make their math balance,” Rohlf said. “It has nothing to do with protecting salmon.”
Federal guidelines require a 96 percent passage-survival rate for juvenile steelhead and yearling Chinook salmon at dams.
Michael Millstein with National Oceanic and Atmospheric Administration Fisheries said most of the dams in the Columbia River watershed are “on track to meet those standards.”
The Corps said the birds kill more fish than the dams. The 4 percent mortality rate allowed at dams is lower than the 6.7 percent mortality rate caused by cormorant predation between 2003 and 2009, according to an environmental impact statement outlining the plan to reduce the cormorant population.
Cormorants eat as many young salmon as the dams chew up, and in some years cormorants kill three to four times as many young salmon as dams, according to the statement.
And the hazards are multiplied because the foraging range of cormorants nesting on East Sand Island overlaps the most dangerous stretch of the Columbia for young salmon and steelhead.
Other scientists emphasized the role of unintended consequences of human actions in bringing the current situation to a head.
Since 1873, the Corps has dredged shipping channels in the Columbia River. In the 1940s, the agency started piling sediment from its dredging operations on East Sand Island. It was both a dumping ground and a tool to control water flow around the island and improve navigability.
But the sediment ended up as piles of exposed sand – perfect nesting and breeding territory for double-crested cormorants. And the birds had no natural predators on the island, though coyotes and raccoons lived next door on West Sand Island.
Some said government hazing of the birds had backfired, and instead scared off predators that would help keep cormorant populations in check.
“Why would a coyote want to be on a little island with 10 people walking around every day?” Jaques asked.
If one thing won’t kill you, another thing will
And then there was the question of whether the fish eaten by birds would have died from other causes anyway.
Compensatory mortality is the idea that if one thing doesn’t kill juvenile steelhead, then something else will. For every 100 juvenile steelhead making their way to the Pacific Ocean, between one and three will return to spawn. And those 97 to 99 dead young fish could have been killed by dozens of factors.
“The percentage of juveniles killed by cormorants would still die of diseases or other predators,” Rohlf said. “The only thing that’s helpful is if you increase adult spawners. So if you are saving juveniles that are still going to die, that won’t do you any good.”
But while the concept holds water in some situations, it can’t account for all the juvenile salmon killed by cormorants, according to Ritchie Graves, a biologist with NOAA Fisheries.
“Some of the studies show that in a controlled situation, Caspian terns will eat more injured fish than non-injured,” Graves said. “So we know probably down in the estuary, compensatory mortality isn’t zero because if you can get an injured fish, you’ll take it – it’s just easier to catch. But we know it’s not 100 percent.”
Millstein said the argument hinged on the faulty idea that juvenile steelhead are at an increased risk for predation because they “are somehow weaker or less fit.”
“We don’t think that that’s correct because the fish that are making it to the estuary and being eaten by cormorants have survived a number of challenges to get there,” Millstein said. “They’ve survived numerous predators and several dams.”
“The fish that survived Bonneville are in pretty good shape,” Graves added. “So we don’t think we’ve got a bunch of injured fish down in the estuary. It’s not zero, but it’s also not 100 percent, as some people are claiming.”
Rohlf questioned the focus on juvenile salmon headed out to the ocean. He said it made more sense to focus on adults returning from sea. After all, they are the ones who will eventually spawn. And they still face a second round of passing through the more than 60 dams on the Columbia River watershed.
Graves disagreed, saying that the two segments of the population are connected.
“The goal is to get as many juveniles as we can to the ocean so, depending on ocean conditions, we can get as many adults returning as possible,” Graves said.
In August, the Fish & Wildlife Service released a report by one of its own biologists concluding that cormorant predation on young salmon had no bearing on the number of adult fish that later returned from the ocean to spawn.
In other words, compensatory mortality is 100 percent.
Rohlf claimed the agency buried its own analysis during consultation on the environmental impact statement for the cormorant culling plan in order to avoid the conclusion that the true danger to salmon is the dams.
Graves rejected that interpretation.
“What’s unstated in that claim is that this is just a draft,” Graves said. “The biologists at Fish & Wildlife never intended to publish an article. They just doubted the Corps’ claim that compensatory mortality is zero.”
Rohlf said the agencies’ dismissal of the report was unfair and politically motivated.
“Agencies use so-called draft material, or non-peer-reviewed material to make decisions all the time,” Rohlf said. “They use the best available information they have. And certainly the best available and the most timely info the Fish & Wildlife service has is the draft analysis from their own biologists saying that compensatory mortality is 100 percent. Instead, the service is putting its name on an EIS that says compensatory mortality is zero, which no one agrees with.”
Graves reiterated that the program called for an annual review by all of the cooperating agencies. The agencies will use data from the most current year and information from new studies to reevaluate the plan before moving forward.
“So if we find out that we were wrong, we can change direction,” Graves said.
- Cops to Face Trial in Shooting of Manic Man
- Judge Certifies Minor Leaguers’ Labor Class