Salmon have a new predator to avoid on the way from Idaho to the Pacific.
Just at the point that the Army Corps of Engineers and others have gotten Caspian terns under control, a new bird has flown into the picture and presents an even larger threat to struggling salmon.
The bird is the double-crested cormorant , which has moved into an island near the mouth of the Columbia northwest of Astoria Ore. Cormorant numbers have grown from less than 100 pairs in 1989 to about 14,000, which Michael Milstein of the Oregonian says is the largest population of the big, black water birds in the world.
The tern population exploded in the early 1990s in the Columbia, forcing federal agencies to spend millions of dollars to lure and harass them away from below Bonneville Dam, where barges released the salmon. They still eat 5 million salmon annually.
Now the cormorants eat 10 percent of all of the baby salmon that pass through Bonneville on their way to the sea, officials say. That would be tens of millions of fish.
You don’t have to like salmon to care about the cormorants. Controlling the new bird is going to add to the cost of salmon recovery, make it tougher and add to the constraints on the entire economy of the Pacific Northwest.