Thu, 26 Jun 2014 10:33:17 PDT
The Army Corps of Engineers has proposed an unusual and controversial plan to save endangered coho salmon and steelhead trout in Oregon: The Corps wants to kill 16,000 double-crested cormorants that are eating the rare fish. Most of the birds would be dispatched with shotguns. The Corps would also smash cormorant eggs in their nests or treat them with oil so they don't hatch.
All of this would take place at East Sand Island near the mouth of the Columbia River. The site is one of the most important migration points for coho, but it is also the primary breeding site for double-crested cormorants. About 15,000 pairs of cormorants breed on the island, up from 100 pairs in 1989. The Corps would like to keep that number at fewer than 6,000 pairs.
The plan has sparked outrage from bird lovers.
Bob Sallinger, conservation director for Audubon Oregon, said that just because double-crested cormorants are thriving on East Sand Island doesn't mean they are doing well elsewhere. "Cormorants are being persecuted throughout their range," he said "Colonies are winking out left and right."
Not only are they removed in other places to protect various fish, Sallinger noted, but they are still recovering from contamination by the pesticide DDT a half century ago.
Sallinger called East Sand Island a haven for a large number of bird species and characterized the Corps' plan as horrific. The island is home to 39 percent of the double-crested cormorants west of the Northern Rockies, and he said the killing could jeopardize the species.
Oregon is no stranger to the conflict between cormorants and endangered juvenile fish, which have often just been released from hatcheries. The state has been "hazing" cormorants in one way or another since 1988, according to Lindsay Adrean, species strategy coordinator for the Oregon Department of Fish and Wildlife.
This usually involves trying to scare the birds away from juvenile salmon by using agricultural pyrotechnics called "screamer shells," which send a loud, piercing sound over a range of up to 300 feet. Other times volunteers use loud motorboats to drive the birds downstream toward other fish. Similar techniques have been deployed against sea lions, which also eat the salmon.
But hazing only works in certain conditions. "A narrow river that leads right to the ocean is much easier because there is less water for the birds," Adrean said. That's not the case around East Sand Island, which sits in a large, wide bay, making it more difficult to control where the birds go.
The Corps, which manages the fish recovery program in the Columbia River Basin, has already tried another tactic on East Sand Island. It first attempted to reduce the amount of available nesting habitat. "It was not very successful," said Adrean. The island is attractive to the birds because it has "many acres of open sand and is relatively free from predators."
According to the Corps, the cormorants eat an estimated 11 million juvenile salmon and trout every year, representing about 3.6 percent of the local population. These numbers are based on a study begun in 2012 in which a small number of cormorants were killed to examine their stomach contents.
Sallinger said focusing on numbers alone is the wrong approach because the birds may be eating fish that would not survive anyway. He points out the fish have already gone through dams managed by the Corps, and he suspects the process may have injured them and made them vulnerable to cormorants, although he doesn't have evidence of this.
There have been other high-profile cases where endangered species have been protected by killing animals that were eating them, such as barred owls being shot to preserve spotted owls and sea lions being killed to shield the same Columbia River salmon. Sallinger said the cormorant plan takes it to a new scale.
"We're now talking about manipulating entire populations of species, thousands—tens of thousands—of birds, not just shooting one or two animals,” he said. “In an age of climate change, where birds are going to be changing their range and we're going to see all kinds of new interactions, the idea that we can manage these species with a shotgun doesn't make any sense."
The proposal by the Army Corps of Engineers, which will cost an estimated $1.5 million over four years, is not final. The Corp will hold two public meetings in Oregon next month and is seeking public comment on the proposal. Comments are due by Aug. 4.
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Original article from TakePart