Cage doors slammed shut
on two California sea lions this week during the initial 2009
effort by Oregon and Washington to trap and remove the big
marine mammals from the area below the Columbia River's
One of the captured animals was euthanized
Thursday after a health examination revealed the animal had
lesions of a viral origin. Research has shown that the
condition is often linked to cancer and is potentially
contagious to other animals in captivity, according to state
officials. The decision to euthanize the animal was made by an
attending state veterinarian.
The second captured sea lion has the same fate. The results
of medical tests received this morning (Friday) "conclude this
animal is suffering from the same viral condition," said Rick
Hargrave, Oregon Department of Fish and Wildlife spokesman.
"Our primary goal is to place healthy animals in the
approved facilities that have asked to receive them," Hargrave
said. "This animal had an infectious disease that was
potentially contagious and could not be placed in a zoo or
aquarium without endangering other animals."
The animals, had they been given a clean bill of health,
would have been transported to Chicago to take up residence at
the Shedd Aquarium.
The states have said their first choice is to relocate
captured animals to facilities such as zoos or aquariums. So
far this year they have eight animals spoken for – two to
Shedd Aquarium and six to the Gladys Porter Zoo in
"They wanted six last year and we weren't able to provide
them," Guy Norman, director of the Washington Department of
Fish and Wildlife's Southwest Region, said of Gladys Porter.
This year the zoo balked at first because of the economic
situation but ultimately decided it could afford the animals,
The states were authorized to remove, lethally or
otherwise, as many as 85 California sea lions annually during
a five-year period in an effort to reduce the animals' impact
on protected fish. The marine mammals have largely ignored
non-lethal efforts, such as hazing, to deter them from preying
Those efforts continue. Boat-based crews from ODFW, WDFW
and the Columbia River Inter-Tribal Fish Commission began
hazing sea lions within the Bonneville Dam boat restricted
zone and in downriver areas in January, and plan to continue
through the end of May. The U.S. Department of Agriculture
Wildlife Services, contracted by the Corps, began to haze sea
lions from dam structures and adjacent lands last week and
will continue seven days per week, eight hours per day, during
daylight hours through the end of May.
Trapping and removal operations at Bonneville Dam will
continue through mid-May. Animals that are trapped and cannot
be placed will be lethally removed, according to state
officials. Remote gate closing mechanisms have been added to
the traps to assure they are not closed inadvertently or by
anyone other than those involved in the trapping.
An increased number of California sea lions have in recent
years been making the 146-mile trip from the Pacific Ocean to
the dam. The attraction apparently is salmon, which are easy
prey as they stall and search for a path up and over the hydro
project – via the dam's fish ladders.
One of the California sea lions was trapped late Tuesday
and the other early Wednesday. They were taken from the traps
to a holding facility at the dam for a medical screening.
"They've got to be acceptable from a health standpoint" to
qualify for relocation, Norman said.
Trapping began this week as more salmon, and more sea
lions, have begun to appear at the dam. As of two weeks ago
only about nine California sea lions had been spotted at the
dam. By this week, that number had swelled to at least 21
individuals, according to Robert Stansell, who heads a U.S.
Army Corps of Engineers' research project at the dam. As many
as 106 (in 2003) California sea lions have stationed
themselves below the dam in any one year.
Salmonid passage has also in recent days increased to
double digits in daily counts at the fish ladders, with 301
steelhead and 17 chinook having passed since Jan. 1, which is
the second lowest to date total since the sea lion research
begin in 2002.
"However, more Chinook have been observed taken by
California sea lions than have passed the dam yet, so they are
present and will likely push on through soon," according to
the Corps weekly research update.
The researchers since 2002 have been documenting sea lion
predation at the dam. Through that research a list has been
compiled that links predation to individual sea lions, which
are identified by body markings or by brands affixed elsewhere
as part of other research efforts.
"They both are on the list and they both have been observed
as extremely predatory," Hargrave said of the two sea lions
captured this week.
The euthanized sea lion, branded with a C265, has gained
some notoriety over the years. The male California was trapped
and weighed near Astoria, Ore., near the river mouth on March
6, 2007, tipping the scales at 560 pounds. After 2 ½ months
spent mostly below the dam, C265 appeared again at Astoria,
where he was trapped and weighed again. The result -- 1,043
pounds, a gain of 483 pounds.
C265 has been spotted at the dam during all eight years of
the ongoing Corps study. Through 2007 observers had documented
C265's take of 102 salmon, the second most among the 151
California sea lions on an initial list of animals qualifying
for removal. During his first six annual trips upriver he was
spotted at the dam on 147 different days.
Last year spring observers saw C265 at the dam on 50 days
and he was seen to take at least 82 salmonids (plus one
unknown and one lamprey).
The big pinniped is unusual in that he left Bonneville in
the late spring, as all of the sea lions do, but returned at
the end of the summer. The visiting animals are all males that
forage northward before returning southward for the summertime
breeding season on the Channel Islands off the Southern
Many return to Astoria at the mouth of the river at
summer's end but few travel back up to the dam before late
C265 was seen last year at Bonneville on Sept. 19, and was
present on at least 41 of 46 days observed between then and
Dec. 31. During that time, he was seen to take at least 19
salmonids plus six coho plus two steelhead plus five fish of
unknown species. Since Jan. 1, he was seen on 16 days and seen
to taking four steelhead, two shad, and on fish of unknown
species, according to researchers. His is the first documented
take of fall chinook salmon at the dam.
The other captured animal, C635, has been observed at the
dam in the springtime for five straight years. He was observed
taking 67 salmon during his first three visits. He was spotted
at the dam on 83 different days from 2005-2007.
C635 was present at the dam for 35 days last year and seen
taking 37 salmonids and five unknown fish. This year, he has
been at the dam for 35 days and was seen to take six.
Stansell notes that the predation totals represent only
observed take. And many times observers cannot attribute a
specific catch to a specific individual if they do not show
the brands or move so far downstream with the catch that they
cannot be identified. So take totals are minimums only.
Washington, Oregon and Idaho, late in 2007 applied to the
federal government for authority to remove some of the
California sea lions because of growing impacts on migrating
salmon and steelhead. Five of the steelhead and chinook salmon
stocks forging upriver to spawn in springtime are listed under
the Endangered Species Act.
NOAA Fisheries Service in March 2008 granted the authority
under Section 120 of the Marine Mammal Protection, which
allows the lethal removal of "individually identifiable
pinnipeds which are having a significant negative impact on
the decline or recovery of salmonid fishery stocks."
The section was added to the act in 1994 in response to a
situation at Ballard Locks in Seattle, where California sea
lions had been documented taking up to 65 percent of the
annual return of adult winter steelhead in the Lake Washington
Section 120 authority was granted to the WDFW to capture
three predatory sea lions and transfer them to Sea World in
May 1996. No sea lions were lethally removed from the locks.
C265 is the first sea lion to be lethally removed under
Section 120 authority. Last spring Washington and Oregon
wildlife managers captured seven California sea lions for
relocation to zoological facilities. Six sea lions have been
flown to SeaWorld facilities in Orlando, Fla., and San
One of the animals died when it failed to resume breathing
after being sedated for a health examination. The sea lion
dubbed B198 weighed 1,452 pounds, a record among California
sea lions catalogued by researchers and nearly double the
average weight of an adult male. He exhibited the same viral
infection as the two animals trapped this year.
Trapping efforts were ended when six marine mammals were
found May 4 in two closed floating traps below dam. The traps
doors had been accidentally triggered overnight, trapping the
animals inside. A necropsy performed on the animals concluded
that the sea lions died of overheating.
The NOAA decision granting Section 120 authority has been
challenged in federal court by the Humane Society of the
United States. A U.S. District Court in November upheld the
decision. Briefing in an appeal of the district court opinion
is about to begin. HSUS asked the United States Court of
Appeals for the Ninth Circuit for a stay the trapping
activities while the appeal is being heard, but the request
was denied Feb. 26.