Crews with the U.S. Department of Agriculture’s Wildlife Services have started killing cormorants on an island in the Columbia River, according to the U.S. Army Corps of Engineers.controversial plan to reduce the number of nesting cormorants on East Sand Island to protect salmon. The plan calls for cutting the number of birds on the island from 14,000 breeding pairs to 5,600 by 2018.
Environmental groups have sued the Corps to stop the management plan, arguing it is a distraction from the real threats to salmon from hydroelectric dams.
Corps spokeswoman Diana Fredlund said Wildlife Services crews started implementing the Corps’ plan over Memorial Day weekend. The management activities will continue through August when the cormorant nesting season ends, but they won’t be happening on a regular basis and the Corps is not disclosing when they will take place.
“We don’t know exactly. The time will vary based on weather, on tides, on a variety of different aspects,” she said. “But also for the safety and security of the people on the island that are doing the culling and for the public. We want to make sure everyone is safe while we’re doing these activities.”
Additional management may involve crews shooting birds with shotguns over the water, but so far the crews are using rifles on land, Fredlund said.
The Corps has a permit from the U.S. Fish and Wildlife Service to kill 3,489 double-crested cormorants and take 5,879 of their nests by January 2016.
Fredlund said she doesn’t know how many birds have been killed so far. The Corps will be providing regular updates on the number of birds killed and the number of eggs oiled on Thursdays at 9 am on their website, she said.
Scientists estimate cormorants on East Sand Island ate 18 million protected salmon and steelhead in 2013 and are regularly consuming 10 percent to 15 percent of the populations swimming through the Columbia River estuary.
Corps officials say research has found that alternatives to lethal removal such as shrinking the birds’ habitat hasn’t had an effect on the number of birds nesting on the island.
East Sand Island’s double-crested cormorant colony has grown from around 100 pairs in 1989 to 14,916 nesting pairs in 2013. That makes it the largest breeding colony of cormorants in North America.