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California sea lion eating a salmon

Non-lethal hazing is primarily done from a boat (sled) near the Willamette Falls. Willamette River

California sea lion eating a salmon
California sea lion eating a salmon
Willamette Falls
Willamette Falls
California sea lion eating a salmon
California sea lions have been feeding on threatened and endangered salmon and steelhead in the waters below Willamette Falls.

Video of sea lion predation at Willamette Falls.

California Sea Lion Management

Restoring balance between predators and salmon

Columbia and Willamette river salmon and steelhead face serious threats from California sea lions that prey on fish waiting to move up the fish ladders at Bonneville Dam and Willamette Falls. Since the 1990’s, a small number of habituated sea lions have consumed tens of thousands of migrating fish at these two locations, many from threatened and endangered runs protected under the federal Endangered Species Act (ESA).

The federal Marine Mammal Protection Act (MMPA) of 1972 specifies the actions States can/cannot take to manage California sea lions. Recognizing that predation by a growing sea lion population can jeopardize salmon and steelhead stocks at risk of extinction, the US congress amended the MMPA in 1994 to allow States to apply for limited lethal removal authority under a narrow set of circumstances (Section 120 of the MMPA).

In March 2008, Fish and Wildlife agencies in Washington, Oregon, and Idaho received federal authorization under Section 120 of the MMPA to remove California sea lions that have been observed preying on salmon and steelhead below Bonneville Dam under a specific set of qualifications. The federal authorization allows wildlife managers to use lethal measures to remove sea lions that meet specific criteria, although NOAA’s first priority has been to place them in zoos and aquariums.

In December 2018, the Oregon Department of Fish and Wildlife was granted authorization, with a different set of qualifying criteria, to begin removing California sea lions preying on threatened salmon and steelhead below Willamette Falls.

Removal of problem sea lions has proven to be the most effective means of protecting fish from predation. Other methods attempted included exclusion gates keep sea lions out of the fishways, multiple years of hazing including pyrotechnics and rubber buckshot, and even long-distance relocation only result in temporary mitigating effects. Wildlife managers from Washington and Oregon and federal and tribal partners have been deterring predatory sea lions in the area immediately below Bonneville Dam for over a decade. Unfortunately, all of these efforts have not proven effective in curbing salmon predation by robust populations of California sea lions.

Population Impacts of Removing California Sea Lions

The California sea lion population along the West Coast (the ‘U.S. Stock’) is no longer considered at risk. According to experts at NOAA, the U.S. Stock of California sea lions has likely reached its “optimum sustainable population”- also known as Carrying Capacity- with an estimated 250-300,000 individuals, a drastic increase from <75,000 individuals when the Marine Mammal Protection Act was adopted back in 1972. Female California sea lions do not migrate north as far as Oregon or Washington, so all California sea lions in these regions are generally subadult or adult males. Removing the relatively few habituated sea lion males posing an immediate risk to salmon and steelhead at Bonneville Dam and Willamette Falls (less than 0.1% of the population) will not negatively affect the U.S. California sea lion population. ODFW pinniped biologists believe California sea lions are now expanding their upriver range beyond historic use to include Willamette Falls, where the first documented sighting was in the 1950s.

The Consequences of Inaction

Recent decades have seen unprecedented effort and collaboration among Northwest states, federal agencies, tribes, and private citizens to protect and recover salmon and steelhead. These efforts equate to hundreds of millions of dollars invested annually, and billions of dollars over the past several decades. The ongoing imperiled status of these culturally and economically important fish is not only costing the region millions in direct investments, but also in opportunity costs associated with lost fisheries, restricted power generation, and constraints on land and water use. If predation by sea lions at these environmental pinch points is not addressed as a tipping point, there is a high risk that these investments will fail, many efforts will be negated, and additional and irreplaceable native fish runs will be extirpated at increasing rates.

Ports, Marinas, Private Property Owners and Vessels Actively Fishing have the right to deter sea lions to protect personal property and safety. NOAA has established guidelines for this deterrence that can be found here:
NOAA’s Guidelines for Sea Lion Deterrence

Managing Pinnipeds on the Willamette River

California sea lion predation on native Upper Willamette River salmon and steelhead stocks has been a growing threat to these fish populations in recent years, and has now reached a crisis point.

The upper Willamette River Winter Steelhead Population Viability Study, completed by ODFW scientists in 2017, concluded that upper Willamette River native steelhead are at significant risk of extinction due to predation by California sea lions. Sea lions are not native to the Willamette River and are preying on native runs of steelhead and salmon that are listed as threatened under the federal Endangered Species Act. In addition, California and Steller sea lions are preying on native populations of white sturgeon and lamprey in the Willamette River.

In October 2017, ODFW submitted an application to NOAA Fisheries for authorization to remove California sea lions from below Willamette Falls under Section 120 of Marine Mammal Protection Act. On Nov. 14, 2018, NOAA Fisheries approved ODFW’s application and authorized the agency to remove and euthanize up to one percent of the population’s “potential biological removal” level, a metric that translates to a maximum of 93 animals a year on the lower Willamette. ODFW must verify that each animal is individually-identifiable (has defining marks, tags, or brands) and meets one or both of two federally-mandated criteria to qualify for removal:

  1. the sea lion must be observed in the area between Willamette Falls and the mouth of the Clackamas River for two calendar days, or
  2. be confirmed in the act of eating salmon or steelhead in this area. Those qualifying sea lions captured on the Willamette by agency biologists and staff are transported to a secure indoor facility and humanely euthanized under supervision of veterinary staff.

ODFW’s Section 120 authorization for lethal removal of California sea lions comes after 20 years of intermittent monitoring, multiple relocation efforts, and years of non-lethal efforts by staff to reduce sea lion predation at Willamette Falls. The lengthy period of monitoring that preceded this action will continue into the foreseeable future to assess predation rates, individual identification, and to measure effects of removal efforts. All MMPA authorizations are re-evaluated every five years to determine renewal criteria and approval.

Video of sea lion predation at Willamette Falls

Willamette Falls is a natural barrier to salmon migration found 26 miles (42 km) upstream from the confluence of the Willamette and Columbia Rivers. Therefore, animals must travel 128 miles (206 km) from the ocean just to reach this relatively isolated destination. Most of this is learned behavior, resulting from animals following others upstream to this location.

California sea lions are returning from their breeding ground in Southern California to Willamette Falls earlier every year in summer, resulting in longer consecutive stays at this area. Individuals are now arriving as early as August, well before the first of the ESA-listed upriver wild Willamette winter steelhead are showing up at the Falls. A larger number of animals naturally results in increased probability that other animals will find their way to the Falls. For example, in 2017, the single day maximum number of California sea lions was 41, up from 2-4 individuals observed in the late 1990s and early 2000s. ODFW estimates sea lions consumed an estimated 25 percent of the Willamette River wild winter steelhead population in 2017.

Hazing and Monitoring Programs

ODFW conducted non-lethal hazing of sea lions at Willamette Falls in 2010, 2011, and 2013 in an attempt to deter sea lions from foraging near the fish ladder entrances. After hazing proved to be unsuccessful, ODFW began a rigorous monitoring program, tracking sea lion abundance and predation to document the extent of the problem. The results of these monitoring efforts can be found in these reports: 201420152016 , 2017 and 2018. Monitoring resumes annually in January through May.

Removing sea lions is the latest attempt by ODFW to reduce pinniped predation on the lower Willamette in order to prevent Oregon’s iconic Upper Willamette native steelhead from going extinct.

ODFW now considers sea lion predation one of the greatest threats to the survival of wild winter Willamette steelhead as well as native Chinook, lamprey and sturgeon. In 2017, the number of wild steelhead that crossed Willamette Falls fell to an all-time low of just 512 adult fish, while marine mammals were responsible for taking an estimated 25 percent of the run. 2018 and 2019 steelhead numbers are tracking slightly better but are still far below the ten-year average.

ODFW is trying to avert a situation similar to the one at Ballard Locks in Seattle in the 1980s where a small group of California sea lions wiped out the Lake Washington native steelhead population by preying on them while they congregated in a concentrated area that made them susceptible to predation.

Sea Lion Trapping Below Willamette Falls

In February 2018, ODFW began relocating California sea lions from the lower Willamette River to the Oregon Coast in an attempt to reduce extinction risk to wild Willamette steelhead.

On Wednesday, Feb. 7, 2018 ODFW biologists captured the first California sea lion on the Willamette. The captured male had been traveling to Willamette Falls to feed almost every year since 2009, including every year from 2013 to 2018. Following his release at South Beach near Newport, he had returned to Willamette Falls within three days, a swim of more than 200 miles. A second sea lion was relocated Thursday, Feb. 8 and returned in six days.

With federal authorization in hand, ODFW began lethal removal of California sea lions in December of 2018 when two animals were removed. ODFW plans to continue the Willamette sea lion trapping operation for subsequent seasons.

California Sea Lion Removal Summaries 2018-2019

Removals at Willamette Falls conducted/permitted via ODFW MMPA §120 Authorization
Removals at Bonneville Dam conducted/permitted via ODFW, WDFW, IDFG MMPA §120 Authorization


Individuals Removed
Month Of Willamette Falls Bonneville Dam

December 2018

3 California sea lions


January 2019 3 California sea lions N/A
February 2019 3 California sea lions N/A
March 2019 5 California sea lions N/A
April 2019 14 California sea lions 10 California sea lions
May 2019 6 California sea lions 9 California sea lions
TOTAL REMOVALS 2018-19 33 total 19 total

Since 2008, the Oregon Department of Fish & Wildlife and Washington Department of Fish & Wildlife have staffed a branding and removal program to reduce predation at Bonneville Dam problem California sea lions. The Idaho Department of Fish and Game also began assisting with this program in 2019.

From 2008 to present, a total of 232 California sea lions have been removed from the Columbia River: 15 were placed in permanent captivity, 7 died in accidents incidental to trapping, and the remainder were chemically euthanized.

Learn more about why California sea lions are being removed from the Columbia River (pdf)

See above table for 2019 operations at both Bonneville and Willamette Falls.

Annual report: Pinniped monitoring at Willamette Falls 2018-2019 (pdf)
Annual report: Pinniped management at Willamette Falls 2018-2019 (pdf)
Annual report: Pinniped management at Bonneville Dam 2019 (pdf)

Summary of 2018 California sea lion trapping operations at Bonneville Dam (pdf)
Summary of 2017 California sea lion trapping operations at Bonneville Dam
Summary of 2016 California sea lion trapping operations at Bonneville Dam (pdf)
Summary of 2015 California sea lion trapping operations at Bonneville Dam (pdf)
Summary of 2014 California sea lion trapping operations at Bonneville Dam (pdf)
Summary of 2013 California sea lion trapping operations at Bonneville Dam (pdf)

Current Section 120 Authority to Remove Sea Lions

In March 2012, NOAA Marine Fisheries issued a letter authorizing (pdf) the States of Oregon, Washington and Idaho to remove individually-identifiable California sea lions that are eating threatened salmon and steelhead in at Bonneville Dam. That original authorization expired in June 2016, and was renewed for another five years until June 30, 2021. The authorization allows the states to remove up to 93 California sea lions a year. These animals must meet the following criteria:

  1. Must be individually identifiable through natural or applied features (usually a brand) AND
  2. Have been observed eating salmonids in the Bonneville Dam area between Jan. 1 and May 31 of any year OR
  3. Have been observed on a total of any five days (consecutive days, days within a single season, or days over multiple years) between Jan. 1 and May 31  AND
  4. Have been subjected to but not responded to non-lethal hazing

Visit the NOAA Marine Fisheries Website for more information about the Section 120 application and authorization.
Pinniped Branding on the West Coast (pdf)

Media Contact: Rick Swart,, 971-673-6038.


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