Species: Oncorhynchus tshawytscha

Pink salmon now comprise nearly 80 percent of all adult salmon in the North Pacific. This record abundance is coming at a cost to other salmon species such as threatened Chinook, which compete with pinks for spawning territory. A new study shows that the ecological toll may extend all the way to endangered southern resident killer whales.

The extensive loss or modification of estuaries throughout Puget Sound creates a significant challenge for adult salmon as they migrate to their natal streams to spawn. A 2024 report by University of Washington scientist Thomas Quinn looks at how different species of salmonids use estuaries to move from marine to freshwater environments. The report was commissioned by the University of Washington Puget Sound Institute with funding from the Environmental Protection Agency's National Estuary Program.

This overview describes the different ways that juvenile Pacific salmon and trout use estuaries, and why those differences are important for ecosystem recovery efforts. The report was commissioned by the University of Washington Puget Sound Institute with funding from the Environmental Protection Agency's National Estuary Program.

The Stillaguamish River is home to what may be the most imperiled stock of Chinook salmon in all of Puget Sound. What scientists are learning here at the Stillaguamish estuary on Port Susan Bay could help turn the tide for these fish and other salmon around the region. E

Tidal wetlands are crucial to Chinook salmon recovery but are among the most threatened habitats in Puget Sound. In 2012, The Nature Conservancy began restoring a 150-acre section of tidal marsh on Port Susan Bay at the mouth of the Stillaguamish River. That project is entering a new phase and may soon connect with other adjacent restoration efforts put forth by the Stillaguamish Tribe.

Zooplankton are critical to the marine food web, but until recently there have been few surveys of the zooplankton community in Puget Sound. Ongoing monitoring is now revealing a system full of complexity and surprises. The following article was commissioned by the Habitat Strategic Initiative Lead (HSIL), a cross-agency team co-led by the Washington Departments of Fish and Wildlife and Natural Resources.

Puzzling encounters between endangered killer whales and harbor porpoises point to questions about prey availability and whale culture, scientists say. Are the whales playing, practicing their hunting skills, or is something else going on? 

Following dam removal, migratory salmon have been free to swim into the upper Elwha River for the first time in 100 years. Their actual behaviors and reproductive success may well be driven by changes in their genetic makeup. Our seven-part series 'Returning home' examines how the fish are doing and whether the Elwha's genetic legacy remains intact. 

Our series 'Returning home: The Elwha's genetic legacy' continues with a look at the possible return of spring Chinook to the upper portions of the Elwha River. We bring you part three of seven.

How can Puget Sound generate more salmon? That question has been at the center of ecosystem recovery efforts for decades. But even as scientists and conservationists make progress on many fronts — from breaching dams to cleaning up the water — they have faced one especially complicated and frustrating limitation: Salmon need more estuaries. We look at how local tribes are working to restore this critical habitat.

This article provides an overview and a link to further information about the Chinook Salmon Implementation Strategy. Implementation Strategies (Strategies) are plans for accelerating progress toward the 2020 ecosystem recovery targets for the Puget Sound Vital Signs. The Strategies are developed collaboratively with technical, professional, and policy experts and with local and regional input. They are funded by the Environmental Protection Agency.

A 2021 paper in the journal PLoS ONE provides a clearer picture of what endangered southern resident orcas eat throughout the year. Chinook salmon make up the bulk of the whales' diet, but the paper suggests that other salmon species and non-salmonid fishes can also play important roles depending on the season.

Many creeks and waterbodies in Puget Sound may look pristine, but most face serious threats from stormwater pollution. A new study at Soos Creek shows how mud-dwelling bugs, traditional chemistry and digital "heatmaps" can be used to track stormwater impacts and identify the most polluted areas. Scientists and planners hope that this may one day lower the price tag on costly stormwater fixes. 

The Salish Sea’s endangered southern resident orcas travel freely across the U.S.-Canada border, unconstrained by political boundaries. But while they don’t require passports, they can still face differing policies and conditions as they go back and forth between nations. We look at some of the ways that the United States and Canada compare in their efforts to protect the whales.

Spring and fall Chinook salmon were thought to be alike until researchers discovered a gene for early migration. Now, federal biologists and legal experts are struggling to decide if spring Chinook should be granted their own legal protection under the Endangered Species Act.

This three-part series explores opportunities and challenges of using medical interventions to save Puget Sound's southern resident orcas from extinction. Part 1 looks at how scientists might treat endangered southern resident orcas that face starvation and risks of disease; Part 2 considers how veterinarians have intervened with other animals in the wild, and how this might apply to orcas in Puget Sound; and Part 3 explores a federally approved vaccination program designed to ward of a deadly virus among endangered Hawaiian monk seals.

The death of a young female orca in September has sparked a discussion of how and whether scientists should step in with medical care for distressed animals in the wild. Medical intervention has become routine for some endangered mammals, but scientists say Puget Sound’s resident orcas present a series of unique challenges and ethical questions. In part one of our two-part series The Orca Docs we look at how scientists are preparing to treat endangered southern resident orcas that face starvation and risks of disease.

Can scientists bring back the lost tidal forests of Puget Sound? It could take generations, but restoring this rare habitat will pay big dividends for Puget Sound’s salmon.   

Chemicals, disease and other stressors can increase a salmon's chance of being eaten or reduce its ability to catch food. We wrap up our series on the Salish Sea Marine Survival Project with a look at some of the lesser-known, but still significant factors contributing to salmon declines in the Salish Sea.

A recent influx of anchovies into Puget Sound may have saved some steelhead from predators, but researchers seek more evidence to prove the connection. Our series on the Salish Sea Marine Survival Project continues with a look at these and other potential impacts from predators on the region's salmon and steelhead.

An intensive research program in the U.S. and Canada is studying why so few salmon in the Salish Sea are returning home to spawn. They are uncovering a complex web of problems involving predators, prey and other factors that put salmon at risk as they migrate to the ocean. We begin a four-part series on the Salish Sea Marine Survival Project, including new findings presented at the 2018 Salish Sea Ecosystem Conference last spring in Seattle. 

As wildlife managers work to recover Puget Sound’s diminished Chinook population, a proposed white paper is expected to review the impacts of some of the salmon's chief predators. The study would include a section on potential management of seals and sea lions, prompting open discussion of a long taboo subject: Could officials seek to revise the Marine Mammal Protection Act — or even conduct lethal or non-lethal removal of seals and sea lions in some cases? Such actions are hypothetical, but we look at some of the ongoing discussions around the issue as prompted by a new resolution from the Puget Sound Leadership Council. 

Increased consumption of Chinook salmon by seals and sea lions in the Salish Sea “could be masking the success of coastwide salmon recovery efforts,” according to a new study published in the journal Scientific Reports. Endangered resident orcas are said to be declining in part due to a lack of available Chinook, the orcas' preferred prey.

In recent decades, hundreds of millions of dollars have been spent to restore habitat for Puget Sound salmon. In this article, we look at how scientists are gauging their progress. Are environmental conditions improving or getting worse? The answer may depend on where you look and who you ask.

A biennial report produced by the Governor's Salmon Recovery Office provides stories and data about salmon, habitat, and salmon recovery in Washington, including Puget Sound.

As threatened Chinook populations in Puget Sound continue to lose ground, the state is looking to new strategies to reverse the trend. In the Skagit watershed, the scientists — and the fish — are among those leading the way. 

A new study shows that increased populations of seals and sea lions are eating far more of Puget Sound’s threatened chinook than previously known, potentially hampering recovery efforts for both salmon and endangered killer whales. 

Drugs like Prozac and cocaine have been showing up in the region’s salmon. But these are just some of the potentially thousands of different man-made chemicals that escape into the Salish Sea every day, from pharmaceuticals to industrial compounds. Now the race is on to identify which ones pose the greatest dangers.

The Salish Sea Marine Survival Project has mobilized dozens of organizations in the U.S. and Canada to find an answer to one of the region's greatest mysteries. What is killing so many young salmon before they can return home to spawn? A series of talks at the 2016 Salish Sea Ecosystem Conference brought together some of the latest research. 

Many of Puget Sound's Chinook salmon spend their entire lives in local waters and don't migrate to the open ocean. These fish tend to collect more contaminants in their bodies because of the sound's relatively high levels of pollution. 

Researchers are proposing a shift in thinking about how some of the region’s most damaging pollutants enter Puget Sound species like herring, salmon and orcas.

The removal of shoreline armoring in Puget Sound has become a priority for state and federal agencies, but until recently there have been relatively few scientific studies of armoring's local impact. New research looks at the pronounced biological and ecological effects of these common shoreline structures, especially for tiny beach-dwelling creatures that make up the base of the food web.

For close to 100 years, Seattle's Ballard Locks has been one of the region's busiest waterways, drawing major boat traffic along with millions of tourists. But as it prepares to celebrate its centennial, the aged structure is also drawing the concern of engineers. They worry that an earthquake could cause the locks to fail, draining massive amounts of water from Lake Washington and Lake Union. In some scenarios, the two lakes could drop by as much as 20 feet, stranding boats, disabling bridges and causing big problems for salmon restoration.

Chinook, coho and sockeye salmon, along with steelhead trout, live in the Lake Washington watershed and navigate a treacherous route through the Ballard Locks on their way to Puget Sound.

Chinook, coho and steelhead populations in Puget Sound have declined dramatically over the past 30 years. In some cases, counts of fish returning to the rivers are just a tenth what they were in the 1980s. While many possible causes of this decline are under consideration, some researchers are focusing on the combined effects of predators and disease. This article continues our coverage of the ecological impacts of disease in Puget Sound.

Contaminants of Emerging Concern (CECs) range from pharmaceuticals, personal care products and food additives to compounds used in industrial and commercial applications. These compounds are not typically removed from wastewater and are flushed into waterways throughout the world in significant amounts. This article describes how scientists are measuring the presence of these contaminants along with their potential impacts in Puget Sound, the Columbia River and elsewhere.

This report documents how Washingtonians have responded to the challenges of protecting and restoring salmon and steelhead to healthy status. It also serves as a tool to summarize achievements, track salmon recovery progress through common indicators, and identify data gaps that need to be filled.

Salmon recovery demands both dedication among people with different interests, and sustained resources. This biennial report tells the story of the progress made to date and the challenges ahead.

The 2014 Salish Sea Ecosystem Conference took place April 30-May 2 at the Washington State Convention Center in downtown Seattle. Over 1200 delegates attended the conference.

King County conducted physical and biological monitoring between 2010 and 2013 in the Lake Washington/Cedar/Sammamish (WRIA 8) watershed using common survey protocols and a probabilistic survey design. Hydrologic monitoring was also conducted at several locations to supplement physical and biological monitoring. 

A 2015 article published in the Marine Ecology Progress Series identifies intraspecific differences in diet between harbor seals in the Salish Sea, suggesting implications for marine reserve management. 

The decaying seawall along Seattle’s waterfront is providing scientists with an opportunity to improve long-lost habitat for migrating salmon. It could also show the way for habitat enhancements to crumbling infrastructure worldwide. One University of Washington researcher describes the project.

The growth and survival of young salmon in streams, river deltas and floodplains are seen as crucial pieces of the salmon recovery puzzle. In part two of this two-part series, researchers at the Salish Sea Ecosystem Conference in Seattle say the complexities of the salmon life cycle require new coordination among scientists.

Scientists say Puget Sound’s salmon are dying young and point to low growth rates in the marine environment as a possible cause. In part one of this two-part series, scientists consider threats facing young salmon in the open waters of Puget Sound.

Lead Entities are local organizations in Puget Sound that develop salmon recovery strategies and priorities for the region on a watershed-based scale.

Download presentations from the Study Panel on Ecosystem-based Management of Forage Fish held August 25, 2013 at the University of Washington’s Friday Harbor Lab, San Juan Island.

A new Chinook monitoring framework is designed to build cooperation among managers and policymakers working across the Puget Sound watershed. The report, prepared by an independent team of scientists and released by NOAA, includes a regionally specific, common classification system for Chinook habitats and key ecological attributes. 

The Puget Sound Recovery Implementation Technical Team has released a draft of a NOAA technical memorandum describing frameworks for adaptive management and monitoring of Chinook salmon in Puget Sound. Download the report.

This technical report produced for the Puget Sound Nearshore Partnership on Valued Ecosystem Components (VEC) summarizes existing knowledge of salmon use of nearshore habitats in order to help protect and restore these habitats.

Fish in the family Salmonidae (salmon, trout, and charr) play potentially integral roles in the upland freshwater, nearshore and pelagic marine ecosystems and food webs of Puget Sound.