PANEL STUDIES OPTIONS FOR LETHAL TAKE OF
CALIFORNIA SEA LIONS
October 12, 2007
A panel of experts this week pondered which California sea lions
might be made to pay the ultimate price for plundering spring
chinook salmon returning to the Columbia River.
The 18-member task force is charged with recommending whether or
not the states of Idaho, Oregon and Washington should be
authorized for the "intentional lethal taking of individually
identifiable pinnipeds which are having a significant negative
impact on the decline or recovery of salmonid fishery stocks…."
If the group recommends the lethal take authorization, it must
define which sea lions can be taken, and where, when and how,
according to Section 120 of the Marine Mammal Protection Act.
Options mulled Tuesday and Wednesday ranged from allowing the
lethal take of California sea lions that are clearly identifiable
by brands or other physical markings and who are repeat visitors
to Bonneville Dam to an all-out effort to remove as many of the
animals as possible in the first year (as many as 170), marked or
The group this worked this week to apply Columbia River
definitions to the MMPA language, "individually identifiable
pinnipeds" and "significant negative impact."
"They're still not at a place where they are making decisions,"
said Donna Silverberg, whose firm is facilitating the process.
"They really respect the decision they have to make and take it
seriously," Silverberg said of the panel.
The task force mapped out a few non-lethal deterrent options that
could eventually be prerequisites to any lethal take
Researchers have told the panel that hazing methods employed at
the dam and downstream during the past two years have been futile
and few, if any, other non-lethal tools are in the toolbox.
During its initial meeting Sept. 4-5 in Portland, the group
reached a "near consensus" that sea lion predation does appear to
have a "significant negative impact" on the spring chinook salmon
run. Two main components of the run, Snake River and Upper
Columbia spring chinook, are listed under the Endangered Species
Act. The Upper Columbia stock is in the more tenuous condition,
holding "endangered" status, while the Snake River fish are
Researchers observed 3,859 fish being taken at the dam this past
spring with the vast majority being upriver spring chinook. That
observed sea lion predation in the waters immediately below the
dam alone accounted for an estimated 4.1 percent of the total
spring chinook return. No estimates are available regarding the
sea lions' predation in the 145 river miles between the dam and
the river mouth.
Researchers say that California sea lions were only occasional
visitors to the dam from the late 1930s, when Bonneville was
built, through most of the 1990s. Their growing presence in the
late 1990s and early this decade drew the attention of the NOAA
Fisheries Service, which triggered research by the U.S. Army Corps
of Engineers into the pinnipeds' eating habits.
The number of individual sea lions identified at the dam peaked in
2003 and 2004 at slightly more than 100. During the past three
years from 70-80 California sea lions have turned up at the dam,
for visits short and long. Many of the pinnipeds return year after
Researchers have charted, from 2002-2007, 151 "highly
identifiable" California sea lions. The most persistent of them
has been seen at the dam on 189 different days over the six years
and witnesses have seen him take 190 salmon. Researchers stress
witnessed predation represents only a part of any sea lions total
The states' application to Secretary of Commerce proposes legal
removal of California sea lions above Columbia River Navigation
Marker 85 (approximate river mile 139.5), annually from Jan. 1 to
June 30. Any lethal removal activity will be preceded by a period
of non-lethal deterrent activity (e.g., acoustic and tactile
harassment), followed by an evaluation period, according to the
"In addition to animals located above Marker 85, all individually
marked California sea lions that have been documented feeding on
salmonids at Bonneville Dam would be candidates for removal
without restriction to time or location in the river, according to
the application. Lethal removals in the first year of the proposed
authorization is expected to be less than 1 percent of the
Potential Biological Removal (PBR) level for California sea lions
(current PBR level is 8,333 animals out of an estimated population
of 237,000)." That PBR is an estimate of the annual mortality that
could occur without affecting the overall health of the California
sea lion population.
The task force this week formulated three potential lethal removal
scenarios, one of which shared the states' geographic definition
of individually identifiable and two that did not.
The product of one task force break-out group suggested a hard
charge at the beginning, the removal of as many California sea
lions as possible during a first year (up to 2 percent PBR).
Such a larger scale removal would have "no impact on the
reproductive efficiency of the (sea lion) population" and would
likely discourage the recruitment of Bonneville visitors in future
years, said task force member Bob Delong of NOAA Fisheries Service
National Marine Mammal Laboratory.
The other two options focused on Table 3.3, the list of 151 highly
identifiable pinnipeds. One proposed the lethal take of any of the
marine mammals on the list in the area immediately below the dam
in a first phase, and down to Navigation Marker 85 during a second
phase. So-called "notorious" pinnipeds -- those who have spent at
least seven days at the dam or that have been seen taking 12 or
more salmon -- could be killed anywhere, in the river or along the
The options and overall recommendations will be winnowed over the
next 2 1/2 weeks and a draft produced for the task force's Oct.
30-31 meeting in Portland. The two days will be spent finalizing
The report must be sent to the Commerce Department by Nov. 5. The
MMPA says that the task force must recommend whether or not to
approve the application and include a "description of the specific
pinniped individual or individuals, the proposed location, time
and method of such taking, criteria for evaluating the proposed
location, time and method of such taking, criteria for evaluating
the success of the action, and the duration of the intentional
lethal taking authority…."
Section 120 says that the secretary has 30 days from receipt of
the recommendations to either approve or deny the states'
"If such application is approved, the Secretary shall immediately
take steps to implement the intentional lethal talking, which
shall be performed by federal or state agencies, or qualified
individuals under contract to such agencies."
The panel's members come from government agencies, conservation
organizations, Indian tribes and science and fishing associations.
The task force includes:
-- Daryl Boness, Marine Mammal Commission;
-- Bruce Buckmaster, Salmon for All;
-- Jody Calica, Confederated Tribes of the Warm Springs
-- Robert Delong, NOAA Fisheries Service National Marine Mammal
-- Patricia Dornbusch, NOAA Fisheries Service Northwest Region
Salmon Recovery -- Division;
-- Doug Hatch, Columbia River Inter-Tribal Fish Commission;
-- Tom Loughlin, Independent Marine Mammal Scientist;
-- Debrah Marriott, Lower Columbia River Estuary Partnership;
-- Barry McPherson, Oregon Chapter, American Fisheries Society;
-- Guy Norman, Washington Department of Fish & Wildlife;
-- Joe Oatman, Nez Perce Tribes;
-- Dennis Richey, Oregon Anglers;
-- Carl Scheeler, Confederated Tribes of the Umatilla Indian
-- Tony Vecchio, Oregon Zoo;
-- Paul Ward, Confederated Bands of the Yakama Nation;
-- Steve Williams, Oregon Department of Fish & Wildlife;
-- Bob Willis, U.S. Army Corps of Engineers, and
-- Sharon Young, Humane Society of the United States.