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A group of five gray whales swimming in the same direction seen from above.

Gray whale safe haven in Puget Sound takes on new significance amid population decline

Almost 200 gray whales have washed up dead along the West Coast in 2026. A small group of gray whales who feed in Puget Sound is surprisingly central to understanding the crisis.
Graphical illustration of circulation pattern in Puget Sound of deep and surface waters

Marine circulation in Puget Sound

Water circulation in Puget Sound is important for flushing out nutrients and affects dissolved oxygen. This overview describes Puget Sound's two-layer circulation process where fresher surface water flows out to sea while saltier ocean water flows in along the bottom. Dissolved oxygen in Puget Sound basins varies by location and season, and is influenced by ocean water entering at the Strait of
Underwater view of bull kelp against a blue-green background with sunburst above and behind it

Nitrogen and carbon cycling in the marine system

This overview describes how nitrogen in the marine environment changes depending on oxygen levels and can be lost from the system as nitrogen gas. In spring and summer, nitrogen near the surface of the Salish Sea may become low enough to limit primary production, and organic carbon that settles into sediments can reduce dissolved oxygen.
Aerial view of a river flowing through farmland buffered on both sides by trees and other vegetation, with islands and Puget Sound in the distance.

Controlling nutrients in the watershed

A state plan calls for reductions in nutrients across 163 distinct watersheds in Puget Sound, including non-point-source pollution. Agencies and restoration practitioners are looking at ways to measure the problem and hope to work with a broad slew of landowners and other partners to help control it. This article is part of an occasional series on nutrient pollution in Puget Sound.
An adult and juvenile harbor seal hauled out on a dock on a sunny day.

Congress debates lethal removal of seals and sea lions in Puget Sound

A proposed amendment to the Marine Mammal Protection Act has renewed a debate over the merits of killing seals and sea lions to protect salmon. Proponents say it will help some endangered salmon populations while opponents say the legislation is misguided and likely to be counterproductive.
Two pilot whales, one surfacing with a visible spray, the other in the background with only a dorsal fin showing.

Short-finned pilot whales in the Salish Sea

Short-finned pilot whales occur around the world as distinct populations, but records of their occurrence in the Salish Sea are rare. Pilot whales are highly social, with some of the strongest bonds known among cetaceans. Unfortunately this makes them vulnerable to mass strandings and hunting.
Puget Sound Marine Waters 2025 Overview report cover with image of a beach with driftwood and trees in the background on a sunny day.

Puget Sound Marine Waters 2025 Overview

The 15th annual Puget Sound Marine Waters Overview combines summaries of monitoring data for marine conditions occurring in 2025. It represents the collective work of federal, tribal, state, and local agencies, academia, nonprofits, and private and volunteer groups.
A group of sperm whales breaking the surface together in gray water.

Sperm whales: A rarity in the Salish Sea

Described as ‘ocean nomads,’ sperm whales range widely throughout the world’s oceans. In Puget Sound and the Salish Sea, there has been only one documented record of a sighting in Haro Strait in 2018.
English sole camouflaged against sandy seafloor, both eyes visible on its upward-facing side

Case studies provide new details on impacts of low oxygen on Puget Sound species

A new report from the Puget Sound Institute and the University of Washington School of Aquatic and Fishery Sciences examines a species-level approach to oxygen risks in Puget Sound. Case studies of Dungeness crabs, English sole, and Chinook salmon provide new details on when and where individual species may be most vulnerable. Funding for this article is provided in part by King County.
An adult and a juvenile killer whale swimming next to each other

Annual census could show an increase of two killer whales among southern residents

The news of two new southern resident orca calves this year marks the 50th anniversary of whale counts from the Center for Whale Research.