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April 15, 2005
BOISE — After a briefing from representatives of the U.S. Army Corps of
Engineers and the National Marine Fisheries Service Wednesday, the
Northwest Power and Conservation Council asked the agencies in a letter
"to immediately initiate all available actions under the Marine Mammal
Protection Act" to exclude salmon-eating seals and sea lions from the
Columbia River immediately below Bonneville Dam and from fish ladders at
the dam.
At least two sea lions have been seen in the fish ladders, which
adult salmon and steelhead use to pass the dam on their journey from the
ocean to spawn. While neither was seen attacking fish it is possible
that the 400-pound mammals could learn that the ladders provide easy
hunting. In recent years, seals and sea lions have had increasing
success in killing salmon and steelhead in the river just below the dam.
Their estimated take, which three years ago was less than 1 percent of
the annual spring and fall runs, now is estimated at 2 percent or more.
"A quick response is crucial, as safe passage for salmon and
steelhead at Bonneville Dam is essential to the health and improvement
of these species," said Council Chair Melinda Eden, one of Oregon's
two Council members.
Officials of the Corps and the Fisheries Service told the Council
that more than 100 marine mammals, primarily Stellar sea lions, have
been observed in the area immediately downstream of the dam. Mid-April
through mid-May is the peak of the annual return of spring Chinook
salmon. But this year the run is either delayed or drastically reduced
in numbers compared to recent years and historical averages, heightening
concern for the impacts of predation by seals and sea lions.
The federal officials told the Council they have a plan to harass the
marine mammals away from the dam and fish ladders using non-lethal means
such as blasts of underwater sound (the frequency is one salmon can't
detect) and the installation of bars at the ladder entrances that would
allow salmon to pass but exclude the mammals. Seals and sea lions are
protected under the Marine Mammal Protection Act of 1972. While the law
allows killing marine mammals that are killing threatened or endangered
salmon and steelhead, non-lethal means are the first resort.
The Council is an agency of the states of Idaho, Montana, Oregon and
Washington and is directed by the Northwest Power Act of 1980 to prepare
a program to protect, mitigate and enhance fish and wildlife of the
Columbia River Basin affected by hydropower dams while also assuring the
region an adequate, efficient, economical and reliable power supply.
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