Salish Sea

The Salish Sea extends across the U.S.-Canada border, and includes the combined waters of the Strait of Georgia, the Strait of Juan de Fuca, Puget Sound Basin and the San Juan Islands.

Water Resource Inventory Areas (WRIA). Map: Kris Symer. Data source: WAECY.

OVERVIEW

Geographic boundaries of Puget Sound and the Salish Sea

The boundaries of Puget Sound and the Salish Sea are not always consistently defined by scientists and government agencies. This article clarifies the distinctions between oceanographic and watershed-based definitions of these geographic areas. 

RELATED ARTICLES

A man on a boat looking through a camera with a large lens.
1/3/2023

Remembering Ken Balcomb and his extraordinary life with killer whales

Environmental reporter Christopher Dunagan remembers the life and influence of pioneering orca researcher Ken Balcomb.  

A screenshot of an interactive map of the Salish Sea
4/6/2022

Interactive map of Puget Sound and the Salish Sea

Use our interactive map to determine if a geographic feature is within the boundaries of the Puget Sound or Salish Sea watersheds. The Puget Sound region includes the area within the United States while the Salish Sea region* encompasses the entire shaded area. Areas that influence circulation in the Salish Sea or eventually drain into the estuary are marked by broader boundaries.

Maps generated from the Salish Sea Model showing surface layer transport in the Northwest Straits (left) and sea surface salinity (right). Images: Pacific Northwest National Laboratory
5/18/2021

The Salish Sea Model

The Salish Sea Model is a computer model used to predict spatial and temporal patterns related to water circulation in the Salish Sea. It was developed at the United States Department of Energy's Pacific Northwest National Laboratory with funding from the Environmental Protection Agency. It is housed at the University of Washington Center for Urban Waters which is affiliated with the Encyclopedia of Puget Sound.  

Salish Sea map my Norm Maher. Courtesy of the SeaDoc Society.
4/2/2013

The Salish Sea

The Salish Sea extends across the U.S.-Canada border, and includes the combined waters of the Strait of Georgia, the Strait of Juan de Fuca, Puget Sound Basin and the San Juan Islands (see map).

The name Salish Sea was proposed by Bert Webber in 1989 to reflect the entire cross-border ecosystem. Both Washington State and British Columbia voted to officially recognize the name in late 2009. The name honors the Coast Salish people, who were the first to live in the region.

An adult elephant seal resting on the shore with water in the background.
12/4/2023

Northern elephant seals in Puget Sound and vicinity

Northern elephant seals were hunted heavily in the 19th century and believed to be extinct by 1892. However, a small remnant population (~50–100 animals) off the western coast of Mexico grew to populations in the United States and Mexico to at least 220,000 individuals as of 2010. Elephant seals are distributed in the central and eastern North Pacific Ocean, from as far north as Alaska down to southern Baja California. Sightings of elephant seals were once considered rare in the Salish Sea, but increasingly single individuals are known to haul out onto sandy beaches on Smith, Protection, and Whidbey Islands. In 2010, a local breeding population established itself along the lower west side of Whidbey Island in Puget Sound.

A grey and white harbor seal swimming in water
9/26/2023

Status and trends for harbor seals in the Salish Sea

Harbor seals were hunted from the 1870s to 1970s until they were protected in the United States by the 1972 Marine Mammal Protection Act and in Canada under the 1970 Marine Mammal Regulations in the Fisheries Act. The inland Washington harbor seal stock is estimated to be over 12,000, while the Strait of Georgia sustains approximately 39,000 harbor seals. Key threats include human disturbance, habitat degradation, loss of prey, and interaction with fishing gear and boats.

A much larger male Stellar sea lion sitting next to a male California sea lion on a rocky perch.
9/20/2023

Steller sea lions in Puget Sound and vicinity

Steller sea lions use Puget Sound as a feeding area from autumn through spring when they are not breeding in British Columbia and Alaska during summer. While the Western Stock of the species is considered Endangered under the US Endangered Species Act (ESA), the Eastern Stock, which occurs in Puget Sound, is increasing in numbers and not listed under the ESA.

Image of two California sea lions sitting on rocks.
9/20/2023

California sea lions in Puget Sound and vicinity

California sea lions have become common in Puget Sound in non-summer months. The overall trend for the population has been a dramatic increase in numbers since the species was protected in 1972. They are opportunistic feeders that often target herring and juvenile salmon and steelhead species in Puget Sound.

Cover of 2022 Salish Sea toxics monitoring synthesis: A selection of research
9/1/2023

2022 Salish Sea toxics monitoring synthesis: A selection of research

A 2023 report from the Puget Sound Ecosystem Monitoring Program presents an overview of selected recent monitoring and research activities focused on toxic contaminants in the Salish Sea. 

A single sea bird floating on the water with several thin silvery fish in its beak.
10/18/2022

Whir! Chunk! Capture! The art of tagging rhinoceros auklets on Protection Island

Where do Protection Island's rhinoceros auklets go to find their food? Scientists hope GPS tags will offer new insight into the bird's still mysterious foraging behavior. Biologist and science writer Eric Wagner reports from the field. 

A killer whale with a digital acoustic recording tag swimming in Puget Sound . Photo: NOAA/NWFSC (taken under NOAA research permit No.781-1824 and 16163).
6/16/2022

Placing microphones on orcas offers a point-of-whale perspective on underwater noise

Research on the sounds and feeding behavior of Puget Sound's southern resident orcas is providing new insight into how the whales respond to underwater noise. A recent online conference brought together some of these findings along with discussions on how to reduce the impacts of noise from vessel traffic.

A white beluga whale swiming near the surface of the water.
4/21/2022

Species account: A lone beluga whale visits the Salish Sea

A series of beluga whale (Delphinapterus leucas) sightings in southern Puget Sound in October 2021, added a new set of records for the species in this region. The 2021 event represents the longest period of time a beluga has been observed so far south of Alaska, in the eastern North Pacific. This may have just been an isolated event of a single extralimital individual. Alternatively, it may suggest a potential range expansion that could portend future increased visits by this species in the Pacific Northwest, especially if warming of Arctic waters continues.

Data image showing marine heatwave known as the Blob
2/27/2022

Model of heat wave 'blob' shows unexpected effects in the Salish Sea

The marine heat wave that struck the Pacific Ocean in late 2013 also caused large changes in temperature in the Salish Sea, but scientists are still puzzling over the impacts of those changes on Puget Sound's food web. The so-called "blob" of warmer than average water was thought to have increased the production of plankton, which potentially benefits creatures like herring and salmon that feed on the tiny organisms. A new paper in the journal Frontiers in Marine Science calls that interpretation into question, pointing to a computer model that links the cause to higher-than-normal river flows in the region.   

Salish Sea with Mt Baker in the background
9/2/2021

Social Science for the Salish Sea

Social Science for the Salish Sea (S4) provides a foundation for future research projects, accessible information for planning or management decisions, and synthesized content to inform ecosystem recovery.

Map of the Salish Sea & Surrounding Basin. Map: Stefan Freelan https://flic.kr/p/6adqMP (CC BY-NC 2.0)
8/30/2021

Salish Sea survey: Geographic literacy enhancing natural resource management

An article published in the journal Society & Natural Resources in 2021 describes the results of a geographic literacy survey which shows residents of Washington and British Columbia are largely unfamiliar with the name Salish Sea. The authors discuss the implications of their findings for ecosystem recovery of the region.

Western grebe (Aechmophorus occidentalis). Photo: Ingrid Taylar (CC BY-NC 2.0) https://flic.kr/p/7jmJHZ
8/30/2021

Effects of season, location, species, and sex on body weight and blood chemistry in free-ranging grebes

An article published in the Journal of Avian Medicine and Surgery in 2021 describes the results of study comparing the effects of season, location, species, and sex on body weight and blood chemistry for free-ranging western and Clark's grebes.

Minke whale ahead of a kayaker
7/28/2021

Solitary minke whales lurk in the waters of Puget Sound

A resident population of minke whales is catching the attention of scientists who want to learn if the elusive mammals are found here year-round. While small compared to their cousins the blue whales, minkes are still among the largest creatures in the Salish Sea.

An image from the LiveOcean model showing Salish Sea circulation patterns.
3/10/2021

Estuarine circulation, mixing, and residence times in the Salish Sea

A 2021 article in the journal JGR Oceans describes circulation and mixing in the Salish Sea. The findings are based on simulations produced by the LiveOcean computer model.

A woman standing on a rock in a river holding a long pole with a net on the end. Photo: Rachael Mallon
12/15/2020

Once hearty 'hooligans' declining in the Salish Sea

A river spawning species of forage fish known as the longfin smelt is rare and getting rarer in the Salish Sea. Biologists are looking into the mysterious decline of the ‘hooligans’ of the Nooksack.

Map showing a marine heat wave known as "the blob" which spread across the northeastern Pacific Ocean from 2014 to 2016. Image: Joshua Stevens/NASA Earth Observatory, Data: Coral Reef Watch
7/24/2020

'The blob' revisited: Marine heat waves and the Salish Sea

Years after the appearance of the devastating marine heat wave known as "the blob," scientists are still working to understand how it has affected the Salish Sea. In some ways, they say, it is like the blob never left.

Southern resident killer whales. Photo by Candice Emmons/NOAA Fisheries (CC BY-NC-ND 2.0)
7/16/2020

Orcas without borders

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.

Human-built clam gardens are found in the lower intertidal zone and characterized by a level terrace behind a rock wall. Photo: Amy S. Groesbeck
7/1/2020

How to plan a clam garden

The revival of an Indigenous aquaculture practice has come to the southern Salish Sea. Clam gardens could help First Nations in British Columbia and Washington state address issues of climate change and food sustainability. 

Locations of shellfish beds in the Salish Sea (left) compared to regions predicted by the Salish Sea Model to have high microplastic accumulation (right). Maps: PNNL
3/30/2020

Ecosystem models expand our understanding of the Salish Sea

Scientists are using computer models to address complex issues in the Salish Sea like the rise of harmful algal blooms and the movement of toxic PCBs. LiveOcean, Atlantis and the Salish Sea Model are three systems that are changing the game for ecologists and other researchers.

Harbor porpoise. Photo: Copyright Cindy R. Elliser, Pacific Mammal Research.
1/5/2020

Status and trends of harbor porpoises in the Salish Sea

Harbor porpoises declined dramatically in the Salish Sea in the 1970s but their populations have since rebounded, increasing by more than 10% per year in recent decades. A 2020 report for the Encyclopedia of Puget Sound examines harbor porpoise status and trends, natural history and recent policy considerations for the species.

Bigg's killer whales. Photo: copyright Monika Shields, with permission
10/24/2019

Status and trends for West Coast transient (Bigg’s) killer whales in the Salish Sea

Officially known as West Coast transients but increasingly referred to as Bigg’s killer whales, these marine mammal-eating orcas (Orcinus orca) are spending increasing time in the Salish Sea to consume their marine mammal prey including harbor seals, Steller sea lions, and harbor and Dall’s porpoise. They range from Southeast Alaska to California, but over the last 15 years more members of the population are spending increasing time in the inland waters of Washington State and British Columbia (Houghton et al. 2015, Shields et al. 2018). They have no predators (except perhaps occasionally other Bigg’s killer whales - see Towers et al. 2018), but are at risk from anthropogenic effects, including toxics and noise pollution (Ford et al. 2007).

Fishes of the Salish Sea book cover
9/24/2019

Of ratfish, Loch Ness monsters and stuffed sharks: A conversation with the authors of the book 'Fishes of the Salish Sea'

The first comprehensive guide to the fishes of the Salish Sea is the culmination of more than 40 years of research by University of Washington authors Ted Pietsch and Jay Orr. The new three-volume set includes descriptions and illustrations for every fish species known to have been documented within the Salish Sea, all gathered from an exhaustive search of libraries, aquariums, fish collections and even one restaurant.

An image from "Salish Sea Wild." Video courtesy of the SeaDoc Society.
6/6/2019

Video series features science and adventure in the Salish Sea

A new video series follows local scientists into the water, capturing the adventure behind the research. "Salish Sea Wild" is entering its second season and we interviewed the series host and producers. Among our burning questions: What's it like to have a Steller sea lion chew on your head? 

Salish Sea basin and water boundaries. The Salish Sea water boundary (blue) includes the Strait of Georgia, Desolation Sound, The Strait of Juan de Fuca, and Puget Sound. The larger watershed basin (green) is the area that drains into Salish Sea waters. WA Water Resource Inventory areas (WRIA) boundary lines are shown for reference. Map: Kris Symer. Data: Stefan Freelan; WAECY.
5/20/2019

Survey illustrates a lack of familiarity with the Salish Sea

Washington and British Columbia residents are largely unfamiliar with the Salish Sea. A recent study conducted by the SeaDoc Society and Oregon State University reveals a need to improve geographic literacy and familiarity with the Salish Sea among those communities who share and live alongside this integrated transboundary ecosystem. This summary was provided by two of the collaborators on the survey, David Trimbach of Oregon State University and Joe Gaydos, Science Director at the SeaDoc Society.

Cover of 2018 Salish Sea Toxics Monitoring Synthesis: A Selection of Research
3/31/2019

2018 Salish Sea toxics monitoring synthesis: A selection of research

A 2019 report from the Puget Sound Ecosystem Monitoring Program presents an overview of selected recent monitoring and research activities focused on toxic contaminants in the Salish Sea. 

Photo by Brandon Cole. All rights reserved. Courtesy of Explore the Salish Sea: A Nature Guide for Kids.
6/8/2018

New book helps kids discover the Salish Sea

Kids around the region are learning about the Salish Sea thanks to a new book that is being offered — in many cases free of cost — to Washington schools and libraries. Explore the Salish Sea by Joe Gaydos and Audrey Benedict inspires the next generation to appreciate and perhaps someday protect the environment close at hand. 

The shared marine waters of British Columbia and Washington report cover
7/28/2015

The shared marine waters of British Columbia and Washington

A scientific assessment of current status and future trends in resource abundance and environmental quality in the Strait of Juan de Fuca, Strait of Georgia, and Puget Sound 

Book cover for The Salish Sea: Jewel of the Pacific Northwest
4/20/2015

New book focuses on the natural history of the Salish Sea

The Salish Sea: Jewel of the Pacific Northwest brings together more than 230 extraordinary images of the Salish Sea. But don't call it a coffee table book. Its lush photos are backed by a serious scientific perspective on this complex and fragile ecosystem.

Screenshot of 2013 Health of the Salish Sea Ecosystem Report
7/19/2013

Report: 2013 Health of the Salish Sea Ecosystem Report

The 2013 Health of the Salish Sea Ecosystem Report was prepared jointly by the U.S. Environmental Protection Agency and Environment Canada. View the complete report, or read the Executive Summary below.