The state of Oregon is sending out word that it wants to have more management options in dealing with the double-crested cormorants -- including shooting the big birds – to control impacts on hatchery-produced and wild juvenile salmon that stream into estuaries along the coast.
The cormorants based at the Columbia River estuary’s East Sand Island last year ate an estimated 22.6 million salmon that originated from hatcheries and spawning grounds upstream in Idaho, Oregon and Washington.
Back at the turn of the century only a few thousand double-crested cormorants nested at East Sand. But the number stair-stepped upward from about 5,000 in 1997 to nearly 14,000 in 2006 before leveling off, relatively. The population estimates in 2010 and 2011 were about 13,600, according to researchers.
Now federal entities are working with tribes and states to develop a management plan that would aim to reduce predation on salmon in the lower Columbia estuary. Any such plan would likely attempt to reduce the size of the colony, which stands in the way of 13 salmon and steelhead stocks that are protected under the Endangered Species Act.
Cormorant colonies along the Oregon coast are smaller. In 2009, an estimated 2,384 breeding pairs of double-crested cormorants nested at 22 colony sites along the Oregon coast, according to a research report prepared by Jessica Y. Adkins and Daniel D. Roby of the U.S. Geologic Survey’s Oregon Cooperative Fish and Wildlife Research Unit at Oregon State University. That was judged a modest increase from the 2003 and 2006 estimates of 2,216 and 1,903 breeding pairs at 24 and 21 colony sites, respectively.
Overall, breeding numbers during 2003-2009 in coastal Oregon are lower than the 1988-1992 estimate of 2,939 breeding pairs at 19 colony sites, the report says.
There has long been commentary, anecdotal evidence, from fishers about the birds plundering hatchery produced fish, as well as wild, listed stocks, emerging from such coastal streams as the Alsea River. But the fishery managers have no scientific data verifying the double-crested cormorants’ impact on salmon along the coast, according to Lindsay Adrean, ODFW’s avian predation coordinator.
For the first time this year ODFW obtained a permit for scientific purposes under the Migratory Bird Treaty Act to kill as many as 50 cormorants at coastal colonies in order to plumb their bellies “so we can learn for sure what these birds are eating.”
The idea is to build a baseline that describes population and diet trends. The diet data will help evaluations of hazing’s effectiveness, or if it is even needed at all. That baseline data will also help measure the ripple effect of management actions at East Sand. Researchers at both ends are expected to be monitoring the movements of cormorants that might be displaced from the estuary island.
The state is also preparing an application to the U.S. Fish and Wildlife Service, which is charged under the act with protecting he birds, for a depredation permit that would allow the lethal removal of up to 285 birds in total annually from cormorant colonies in the Tillamook, Rogue and Umpqua rivers. The application would request authority for the taking of up to 10 percent of the breeding population at any one colony.
Adrean said such a permit would serve as an additional tool to supplement hazing activities and control bird populations.
“It’s not birds against salmon. It’s about finding a balance” that would allow both fish and birds to flourish, Adrean said. The birds wing in each spring to nest and spend the summer and most of the fall.
Meanwhile Oregon has commented in a process aimed at scoping out the details for a “supplemental environmental impact statement” that would ultimately be prepared by the USFWS. That EIS would lead to revised regulations regarding double-crested cormorant management.
Under current regulations, cormorant damage management activities are conducted annually at the local level by individuals or agencies operating under USFWS depredation permits, the existing Aquaculture Depredation Order, or the existing Public Resource Depredation Order. The depredation orders are scheduled to expire on June 30, 2014.
The revision would update an order issued in 2003 that allows the control of double-crested cormorants without a permit by certain government agencies in 24 midwestern and eastern states.
“The ODFW requests that Western DCCO issues be included in the NEPA process,” according to comments signed by Oregon Department of Fish and Wildlife’s Wildlife Division Administrator Ron Anglin.
The April 5 letter said the “ODFW is highly concerned about the negative impacts of DCCOs on fish resources in Oregon, and would like to maximize the State’s ability to manage DCCO conflicts my improving the accessibility of lethal management tools.”
“There is also concern regarding economic impacts due to the loss of hatchery production and the loss of the contribution of angling to local economies.
“The ODFW invests more than $30 million annually in hatchery and habitat restoration programs to fuel healthy, sustainable wild and hatchery fish populations capable of supporting fisheries in Oregon,” the ODFW letter says.
“Past efforts to reduce DCCO impacts on fish resources using non-lethal management along has proved insufficient in Oregon,” Anglin said.