Caspian terns, much maligned for feasting on declining salmon runs on the Columbia River, just got a wing up.
Displaced by development along the Pacific Coast, the world's largest tern colony settled several years ago on an island composed of dredging material disposed of by the Army Corps of Engineers. There, near the mouth of the Columbia River, the 20,000 birds eat millions of migrating juvenile salmon and steelhead (HCN, 2/28/00: Tern terror). In an effort to help endangered fish, in 1999, the Army Corps began destroying habitat on Rice Island and planned to haze birds with noise. But a coalition of four conservation groups sued the agency, demanding it prepare an environmental-impact statement before evicting the birds, which are protected by the federal Migratory Bird Treaty Act.
Now, a settlement agreement allows the Army Corps to develop tern habitat on a new island closer to the mouth of the Columbia, where the water is deeper and the young salmon are less accessible to the birds. The Corps is clearing grass to provide new nesting habitat for the terns, which like to lay eggs on open beaches where they can watch for predators, and using decoys and recordings of tern calls to attract the birds to their new home.
Both sides call the agreement a major victory.
"This is a less costly alternative to taking down the dams," says Matt Rabe of the Army Corps. "But it's something that has a definite impact on the survivability of fish."