Hazing of double-crested cormorants is set to begin soon in several areas along the Oregon coast in an attempt to improve survival of juvenile salmon and steelhead as they migrate from inland waters out to the Pacific Ocean.
Double-crested cormorants are large, fish-eating waterbirds that gather throughout Oregon, and are particularly prevalent in the state’s estuaries during April through September. Research suggests that cormorants eat significant numbers of juvenile salmon and steelhead that migrate to the ocean during this time, thereby reducing the catch for commercial and recreational fishers.
To reduce threat to young fish, the Oregon Department of Fish and Wildlife is working with several nonprofit and local governmental organizations to haze cormorants in six coastal estuaries over the next two to four months, mainly in the morning and evening hours.
Hazing will begin as early as March 27 and continue in most areas through May 31 in the Nehalem, Nestucca, and Coquille river estuaries and in Tillamook and Alsea bays. The program may continue through July 31 in Astoria, where the Clatsop County Fisheries Project manages a salmon rearing program.
Hazing is designed to disrupt the birds’ feeding patterns long enough to give the young fish a chance to pass through the estuaries unharmed. The outbound migration of juveniles of several species of salmon and steelhead peaks in springtime. Some of these spring migrants, such as coho salmon, wild steelhead, and chum salmon, are listed by the state as sensitive species that are at some degree of conservation risk. Coho salmon are listed as “threatened” in Oregon under the Endangered Species Act. Cormorant hazing is expected to benefit both listed wild fish and hatchery fish, which are not listed but are vital to commercial and recreational fisheries on the coast.
In a separate but related project, ODFW staff will collect up to 50 double-crested cormorants each in Tillamook Bay and at the mouths of the Rogue and Umpqua rivers. This is part of an ongoing study that will assess the diet of double-crested cormorants in Oregon estuaries. Oregon has a permit from the U.S. Fish and Wildlife Service that allows for limited collection of double-crested cormorants, a protected species under the federal Migratory Bird Treaty Act.