Puget Sound Institute

08/28/2026

Now is the time to witness a momentous occasion: fall migration of Chinook salmon. Many Chinook are returning from their ocean sojourns north as far as Alaska and south into Oregon. But did you know that a portion of Chinook salmon in Puget Sound never leave for the ocean at all?
These so called “residents” complete their entire marine life in Puget Sound estuaries near the mouths of rivers that enter Elliott Bay including the Duwamish River. In fact, according to University of Washington biologist Thomas Quinn, the “resident” portion is so large it may account for the majority of Chinook in Puget Sound. Estuaries provide important feeding habitat for young and mature chinook alike.

To learn more about the critical role of estuaries in the life juvenile and adult Chinook in Puget Sound, check out our report written by Quinn.

https://www.eopugetsound.org/article/chinook-salmon-and-estuary-use-in-puget-sound

08/19/2026

Check out the new Shore Friendly Synthesis report by Puget Sound Institute's Aimee Kinney and Sydney Fishman of Washington Sea Grant. It includes a comprehensive executive summary. Download the report at https://www.eopugetsound.org/article/synthesis-shore-friendly-program-2019-2025

08/11/2026

How much does low oxygen reduce habitat for species in Puget Sound? A new report from the Puget Sound Institute and the UW School of Aquatic and Fishery Sciences measures habitat compression species by species — for Dungeness crab, English sole, and Chinook salmon.

Researchers used a metric called the metabolic index, which accounts for both oxygen levels and water temperature, to model habitat compression for three case studies: Dungeness crab, English sole, and Chinook salmon. The approach goes beyond the standard hypoxia threshold, which doesn't hold equally for every species — salmon need more oxygen than that threshold assumes, while crabs can tolerate less of it in cold water than in warm.

The findings: nutrient pollution from human sources is responsible for a real but comparatively small share of the habitat species lose to low oxygen, even during the worst conditions of the year. But the effects aren't evenly spread — Hood Canal stands out as a location where both Chinook salmon and Dungeness crab lose a substantial share of their habitat on their worst days.

Read the full story in Salish Sea Currents: https://tinyurl.com/low-oxygen-case-studies

07/31/2026

Just after this week's southern resident orca census news, here's another look at these endangered whales — this time, after dark.

"There's no rest for these endangered whales. They are attempting to find food day and night."

That's NOAA Fisheries Service biologist Marla Holt, describing new research that offers the first published look at what southern resident killer whales do after dark. Researchers attached acoustic recording tags to 10 whales and found they're diving and hunting almost as much at night as during the day.
But not evenly. Females are far less likely to attempt a catch at night than during the day, and the drop-off is stark: on deep dives, females had an 88% probability of attempting a catch during the day, but just 21% at night. The findings add to earlier evidence that vessel noise disrupts female foraging more than males' during the day, reinforcing the case for measures that reduce daytime vessel traffic noise in the Salish Sea.

Full story, video of a tagging in action, and audio of orca echolocation clicks: https://tinyurl.com/orcasatnight

07/30/2026

Southern resident orca population up by two? Pending one final check, it appears that this year’s census of the endangered southern resident killer whale population will show a positive increase of two orcas — an annual increase equaled only four times in the past 20 years. Check out Salish Sea Currents to learn more about results of the annual orca census conducted by the Center for Whale Research.

https://www.eopugetsound.org/article/annual-census-could-show-increase-two-killer-whales-among-southern-residents

07/20/2026

Untangling chemical names and looking back over 200 years of 6PPD history

The tire chemical 6PPD is known worldwide for its deadly effect on salmon, but it also has a complex history. Our senior writer Christopher Dunagan looks back at the chemical's origins, from its connection to a life-saving malaria drug to its ever-present use as a rubber preservative.

https://www.eopugetsound.org/article/history-and-chemical-structure-tire-chemical-6ppd-q

07/06/2026

New on the PSI blog: environmental social science — the study of how people and ecosystems shape each other — has quietly built out major infrastructure in Puget Sound over the past decade-plus, from the Human Wellbeing Vital Signs to a Social Sciences Advisory Committee running since 2010. A new introduction to a special issue of Coastal Management, co-authored by PSI's Rob Anderson and Allison Morgan along with twelve others, argues the field has outgrown its "helpful but secondary" reputation and makes the case for treating it as essential to ecosystem recovery. As Anderson puts it, most environmental issues are as much about people and politics as they are about nature itself.

07/01/2026

With a worldwide market valuation somewhere around $1 billion a year for the single chemical 6PPD, tire companies and their chemical suppliers are working overtime to find a safe and effective replacement for the toxic tire additive. Our senior writer Christopher Dunagan reports on which companies are in the hunt.

With a worldwide market valuation somewhere around $1 billion a year for the single chemical 6PPD, tire companies and their chemical suppliers are working overtime to find a safe and effective replacement for the tire additive. The financial stakes are enormous, since virtually every tire on the mar...

06/17/2026

The northern right whale dolphin is one of the most unusual marine mammals of the North Pacific Ocean and it can sometimes be spotted in the Salish Sea. It is one of only two dolphin species in the world without a dorsal fin, and its slender and streamlined shape make it appear almost eel-like. We have published a new overview of this species in the Encyclopedia of Puget Sound. https://www.eopugetsound.org/article/northern-right-whale-dolphins-salish-sea

06/15/2026

Hatchery production is a key tool for supporting vulnerable Pacific salmon stocks, but it comes with tradeoffs. When salmon reproduce in artificial versus natural habitats, different environments can select for different traits — and those genetic effects may carry long-term fitness costs for integrated stocks.

Join Tim Healy of Fisheries and Oceans Canada at the next Salish Sea Science Roundtable to learn about recent findings from the Pacific Salmon Strategy Initiative on heritable effects of hatchery production in British Columbia.

Tuesday, June 30 | 12:30 – 1:30 pm
Free. Registration required. https://tinyurl.com/June30-SSSR