Harmful algal blooms

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.

The Washington State Department of Ecology is responding to new legal rulings and public concerns with changes in planning and potentially future enforcement. We continue our occasional series on water quality and wastewater management in Puget Sound. Funding for the series is provided in part by King County.

A 2025 state of the knowledge report provides a technical background to support informed decision making and recovery planning focused on the Marine Water Quality Vital Sign.

Since 2011, the Puget Sound Ecosystem Monitoring Program has released the annual Puget Sound Marine Waters Overview report. The latest report combines a wealth of data from comprehensive monitoring programs and provides a concise summary of what was happening in Puget Sound’s marine waters during 2024. The report represents the collective effort of contributors from federal, tribal, state, and local agencies, academia, nonprofits, and private and volunteer groups.

Low dissolved oxygen levels put aquatic life in Puget Sound at risk – but not everywhere. A combination of careful monitoring efforts and powerful computer models are now enabling scientists to identify which areas of our regional waters are most prone to low oxygen levels, when, and why. This article is part of a series of reports funded by King County about the quest to define healthy oxygen levels in Puget Sound.

Chronic stress from lack of oxygen can make aquatic organisms more vulnerable to disease, pollution, or predation. Low oxygen can also result in reduced habitat for some species. Aquatic species may escape, acclimate, adapt, or die with exposure.