Skip to main content


July 13, 2023


Salish Sea Model tracks pollution, currents and climate change

This article is the latest in a series about computer models and their uses within the Puget Sound ecosystem. Today, we look at the Salish Sea Model, one of several models in the region helping to predict water circulation, water quality and food-web relationships. Read the full series: Where and how the water moves The […]

December 20, 2022


The quest continues for a nutrient reduction plan

The quest continues for a large-scale plan to reduce human sources of nitrogen and improve the health of Puget Sound. This article is part of the Puget Sound Institute’s effort to explore the technical uncertainties related to the science of Puget Sound water quality. The project, jointly funded by King County and PSI, includes online […]

September 12, 2022

An image of brackish water mixing in the Salish Sea as shown by the Salish Sea Model. Image courtesy of the Salish Sea Modeling Center.">

Upcoming workshops on tools to evaluate water quality and biological integrity 

New event: More than 130 researchers, scientists, modelers, and other experts attended our first workshop in July on The Science of Puget Sound Water Quality. The discussion continues with two interrelated workshops focusing on scientific tools for evaluating marine conditions and species health. Join us:  September 29th from 8 – 10 AM PT for Tools to […]

December 31, 2021


Ecology, EPA now under the gun to adopt new water quality criteria for aquatic creatures

Long delays in updating state water-quality standards to protect orcas, fish and other aquatic species appear to have finally caught up with the Washington Department of Ecology and its federal counterpart, the Environmental Protection Agency. In a court ruling this week, U.S. District Judge Marsha Pechman of Seattle found that Ecology has “abdicated its duties” […]

April 9, 2021


Washington’s Water Quality Assessment offers insights into status of pollution

More than 2,000 segments of streams, lakes and marine waters have been added to the state’s massive list of water-quality data, allowing more Washington residents to take stock of pollution levels near their homes. The latest Water Quality Assessment for Washington waters, released for public review this week, covers 9,279 miles of streams, 434 lakes […]

February 12, 2021


New sewage-treatment permit would be a step to curbing nitrogen in Puget Sound

In an effort to stem the flow of excess nitrogen into Puget Sound, Washington Department of Ecology has proposed a new type of permit for some 60 sewage-treatment plants operating throughout the region. The flexible permit, called the Puget Sound Nutrient General Permit, aims to hold nitrogen releases close to or below their current levels […]

September 5, 2019

Benthic invertebrates range in size from those easily seen with the naked eye to those that cannot be spotted without the use of a microscope. Photo: Christopher Dunagan">

Are some streams in Puget Sound getting cleaner?

Scientists are reporting some potentially good news about the health of Puget Sound’s streams. Ten years of data from 126 stream sites within King County have shown a slight improvement in water quality, according to the county’s Water and Land Resource Division. The study examined the variety of insects and other invertebrates that were collected […]

March 28, 2019

Screenshot from video.">

Video: Identifying sources of pollution in the Skagit Valley

A video produced by the University of Washington Center for Urban Waters shows how chemical tracers can identify sources of pollution affecting shellfish growers in Puget Sound’s Skagit Valley. Fecal coliform pollution is a widespread problem in Puget Sound, resulting in costly beach and shellfish bed closures whenever it is detected. Analytical techniques can now […]