The U.S. Army Corps of Engineers’ Walla Walla District is expanding its current nonlethal avian hazing program at five Corps dams, including McNary Lock and Dam, to incorporate limited lethal “take” of certain piscivorous or fish-eating birds.
The expanded efforts, designed to protect endangered salmon and steelhead, will focus specifically on ring-billed gulls, California gulls and, to a lesser extent, double-crested cormorants within the Walla Walla District.
This expanded effort is in conjunction with the Corps’ existing nonlethal hazing program to manage piscivorous birds, which uses pyrotechnics and other noisemaking devices, water-spray cannons, and passive deterrent structures to dissuade birds away from certain areas at Corps dams where they prey on salmonids. Lethal removal will be used only if nonlethal methods are not successful.
Seasonal avian hazing by U.S. Department of Agriculture (USDA) Wildlife Services (WS) personnel is scheduled to begin March 30 at McNary Lock and Dam near Umatilla, and April 1 in Washington state on the Lower Snake River at Ice Harbor Lock and Dam, Lower Monumental Lock and Dam, Little Goose Lock and Dam, and Lower Granite Lock and Dam.
The purpose of the expanded program is to further reduce predation by piscivorous birds on downstream-migrating juvenile salmonids protected by the Endangered Species Act (ESA). The 2008/2010 Federal Columbia River Power System (FCRPS) Biological Opinion, as supplemented in 2014, directs the Corps to “continue to implement and improve avian deterrent programs at all lower Snake and Columbia River dams” in its Reasonable and Prudent Alternative (RPA) Action 48. Research studies have shown that piscivorous birds consume significant numbers of juvenile salmonids at dams.
The Corps’ expanded program will allow removal of a maximum total of 650 ring-billed gulls, 1200 California gulls and 150 double-crested cormorants each year at the five dams.