Predation on salmon was reduced through the removal of 40 California sea lions from the lower Columbia River during 2008-2010, but a renewed and strengthened effort is needed to protect fish stocks that are listed under the Endangered Species Act, according to an Oct. 4 report produced by the states of Oregon and Washington and the Columbia River Inter-Tribal Fish Commission.
The “Field Report: 2011 Pinniped Research and Management Activities at and Below Bonneville Dam” recommends that the states “increase removal efforts to regain lost ground from the 2011 season. Tangible gains made in 2008-2010 were potentially reversed by allowing the pool of experienced, predatory sea lions to increase unchecked in 2011.”
Following that path would require that the states’ application for lethal removal authorization be granted by NOAA Fisheries Service. The states gained such authority in 2008 but, after a series of legal skirmishes, the authority was unavailable this year. The states removed 40 California sea lions during the they had federal authority.
The report also recommends that boat-based hazing of the California and Steller sea lions be reduced so that more staff time can be devoted the predation observation effort.
“Given the relative ineffectiveness of hazing to deter pinnipeds, and the overlap in coverage between boat-based hazing and dam-based USDA hazing, a better use of limited staff time would be to quantify predation immediately below the tailrace observation areas. Many predation events are known to occur in this area that cannot be seen by the USACE dam-based observers,” the report says. Most of the data about sea lion predation impacts on salmon and steelhead comes from a long-running study involving observations from atop Bonneville Dam.
The Oregon-Washington report, as well as the U.S. Army Corps’ 2011 field report on marine mammal predation at Bonneville Dam, can be found online at:
The report was developed by Robin Brown, Steven Jeffries, Doug Hatch, Bryan Wright and Sandra Jonker. Brown and Wright represent the Oregon Department of Fish and Wildlife, Hatch the Columbia River Inter-Tribal Fish Commission and Jeffries and Jonker the Washington Department of Fish and Wildlife.
That web site includes information about the Pinniped-Salmon Interaction Task Force. The panel will meet Monday in Portland to discuss the latest available information about marine mammal predation on salmon in the Columbia River. It will recommend to NOAA Fisheries Service whether or not a new federal authorization should be provided to allow states to lethally remove individually identifiable California sea lions that each spring gather below Bonneville Dam to prey on, principally, salmon and steelhead. The authorization would come under terms of the Marine Mammal Protection Act.
On Sept. 12, NOAA Fisheries accepted for a second time a joint application from the states of Idaho, Oregon and Washington regarding sea lion removal authority. Included among those fish stocks are wild fish protected under the Endangered Species Act. The California sea lions are protected under the MMPA but not the ESA. NOAA is charged with enforcing both acts. The MMPA’s Section 120 outlines a process for exempting the MMPA’s protections in special instances.
A public comment period on the application closed Oct. 12.
NOAA Fisheries on Oct. 6 announced that a task force would be convened to review the application, public comments, and other relevant information. The task force is composed of NOAA Fisheries staff, independent scientists, representatives from affected conservation and fishing communities, tribes, states and others.
The task force will then develop a recommendation that will inform the federal determination to approve or deny the states' application.
A previous application submitted by the states in November 2006 was approved by NOAA Fisheries in March 2008. Seventeen of the 18 members of a task force convened for two-day meetings in both September and October 2007 supported lethal removal of California sea lions while one member from the Humane Society of the United States opposed the states’ application and any lethal removal.
But that authorization was deemed invalid late last year by the U.S. Court of Appeals for the Ninth Circuit. The HSUS and Wild Fish Conservancy were plaintiffs in the litigation.
NOAA Fisheries in May reissued the authorization, saying it had corrected legal flaws noted by the appeals court. But in July the federal agency revoked the authorization and invited the states to apply again.
The new state report says that “The estimated benefit in 2011 from removing California sea lions was due largely to previous removals since only a single animal was removed this year. It is estimated that approximately 1,000-3,000 additional salmonids would have been consumed in 2011 had these animals not been removed.” Corps researchers estimate that 3,970 adult salmonids (salmon and steelhead) were gulped down from Jan. 1-May 31 this year in the area immediately below the dam.
To get the estimates the researchers evaluated how many days a particular sea lion had spent at the dam in the past, and how many pounds of fish each animal would need per day.
“The median estimated daily individual salmonid biomass requirement based on a bioenergetics model was 14.2 kg (95 percent confidence interval was 7.8 to 27.1 kg/day), which translated into a median of 3 chinook/day (95 percent confidence interval was 2 to 6 chinook/day),” the report says.
“The median estimated seasonal salmonid requirement for each sea lion was 57 salmonids (95 percent confidence interval was 6 to 216 salmonids/season). The predicted number of salmonids that would have been required from 2008 to 2011 by the 39 eligible California sea lions that were removed from the Columbia River was between 2283 and 8738 fish.”
“Overall, the 2011 field season was successful from a research standpoint but unsuccessful from a management standpoint,” the report says. “New research efforts in 2011 (e.g., GPS-phone tags, river-wide pinniped surveys) provided an unprecedented level of information on pinniped abundance, distribution, and foraging behavior in the Columbia River.
“Management, however, was hampered by continued litigation and a lack of removal authority for the majority of the season, and a continued lack of effective non-lethal deterrent methods,” the report says. Only one California sea lion was removed this year before the authority was withdrawn.
“As in previous years, the purpose of non-lethal, boat-based deterrent activities was two-fold. First, it attempts to disrupt sea lion foraging behavior and reduce sea lion abundance immediately below Bonneville Dam, thereby increasing salmonid survival. Second, it fulfills the LOA requirement that predatory California sea lions be exposed to hazing prior to subjecting them to permanent removal efforts.
“Observations and GPS tag data suggest that these activities only cause a short-term disruption in foraging behavior and fail to deter the majority of sea lions from the dam,” according to the report. “The continued lack of effective non-lethal deterrents that can be used in this situation without having potentially negative impacts on fish passage remains a problem.”