General descriptions of topics of interest (such as ROVs or Major Ports in Puget Sound, fact sheets, tribes of the Salish Sea, etc.).


Report cover

Habitat protection and restoration in Puget Sound: An overview of Strategic Initiative Lead investments 2016-2023

Between 2016 and 2021, $21 million provided by the Environmental Protection Agency (EPA) funded 100 different projects to protect, restore, and study critical habitats in Puget Sound. This publication presents an overview of many of the key accomplishments and lessons learned from these efforts. It is a catalog of some of the ‘big ideas’ presented by the scientists and conservationists involved, and it is meant to inform and guide future Puget Sound recovery efforts. This overview is based on the full synthesis report, “Synthesis of Habitat Strategic Initiative Lead 1.0 2016-2023 Investments for Puget Sound Recovery," published by the Puget Sound Institute.

Weather map of the northwestern United States.

Six things that people should know about ecosystem modeling and virtual experiments

It’s hard to overstate the importance of mathematical models to science. Models show how planets move and how diseases spread. They track the paths of hurricanes and the future of climate change. Models allow scientists to look at systems or scenarios that they could never view otherwise. Increasingly, mathematical models are also helping scientists understand Puget Sound. In this series of articles, we look at some of the ways that models are being used in ecosystem recovery efforts. We start with the basics. What are mathematical models and which types are most common?

A physcial model of Puget Sound shown without water.

Before supercomputers, a structural model helped scientists predict currents in Puget Sound

One of the first working models of Puget Sound was a scaled-down concrete reproduction, with actual water running through channels, around islands and into bays, inlets, and harbors. Motors, pumps and timing gears are part of an elaborate mechanism that replicates tides and river flows in the still-functioning model.

Hand holding an oyster.

Researchers use a qualitative network model to test ways to boost production at shellfish farms

The skeletal beginnings of nearly all models is a conceptual understanding of the basic workings of the system being studied: Who are the important actors, and what are their roles within the system?

Underwater view of shark and several smaller yellow and white fish swimming in coral reef.

Quantitative models, including Ecopath, take food web studies to a higher level of analysis

The Ecopath model, designed to describe the flow of energy through a food web, as evolved since it was first developed in the early 1980s in Hawaii. This article is part of a series focused on different models and their uses within the Puget Sound ecosystem.

Massive die-offs of Dungeness crab off the Pacific Northwest Coast have been attributed to dangerously low oxygen levels. Once dead, the aquatic crabs often wash up on beaches, as seen here on Kalaloch Beach on June 14, 2022. Photo: Jenny Waddell/NOAA

Hypoxia (fact sheet)

The following fact sheet provides an overview of low oxygen conditions in Puget Sound. It addresses some of the related causes and concerns that have been identified by scientists in the region. The overview was prepared in conjunction with a series of workshops on hypoxia and nutrient pollution presented by the University of Washington Puget Sound Institute. 

View of bright green, segmented, phytoplankton with spines under microscopic magnification.

Phytoplankton and primary productivity (fact sheet)

In many parts of Puget Sound, hypoxic waters are thought to be at least in part due to overgrowth of microscopic algae, which is triggered by excess nitrogen. That means it’s important to understand the dynamics of primary productivity – the rate at which those microscopic algae, known as phytoplankton, produce organic matter through photosynthesis and in this way provide the base of the food web. Researchers are investigating different types of phytoplankton and rates of primary productivity throughout the Salish Sea, and seeking to understand how primary productivity is likely to change as climate change alters patterns of coastal upwelling and freshwater flow into the Sound.

A woman wearing blue gloves standing on a boat sorting through sediment in a collection box. Water and clouds in the background.

The role of sediment in nitrogen cycling and hypoxia (fact sheet)

How do marine sediments affect oxygen and nutrient levels in the water?

A 1924 photo titled "Treaty trees" shows the site of the 1854 Medicine Creek Treaty. The photo is used by permission of the Washington State Historical Society (photo catalog no. 1943.42.30562) and was retrieved from HistoryLink.org.

Legal milestones for Indigenous sovereignty and salmon co-management in the Puget Sound region

Treaty rights are critical to the sovereignity of Puget Sound area Tribes and are deeply connected to natural resource management. Five landmark treaties in our region were signed during a three-year period from 1854 to 1856 and continue to drive policy to this day.  

: Underwater view of a person in scuba diving gear holding a clipboard and grasping a stalk of brown kelp.

Underwater monitoring of kelp forests

Puget Sound Restoration Fund has launched a network to track declining kelp populations in the Salish Sea. The three-year initiative aims to support and standardize underwater monitoring to improve kelp conservation in the region.

Ecology's Marine Sediment Monitoring Team in action.

Eyes Under Puget Sound

The Washington State Department of Ecology’s Marine Sediment Monitoring Program, initiated in 1989, is one component of the Puget Sound Ecosystem Monitoring Program, a collaborative effort dedicated to monitoring environmental conditions in Puget Sound. The Marine Sediment Monitoring Team collects sediments from the bottom of Puget Sound twice a year and tests them to determine their physical, chemical, and biogeochemical characteristics; and to determine the condition of the invertebrate communities that live in them.  They report their findings in agency reports and story maps, and in Eyes Under Puget Sound (EUPS) blog posts.

Golden-crowned kinglet (Regulus satrapa). Photo: Minette Layne (CC BY-NC 2.0)

Golden-crowned kinglets in Puget Sound have seen a steep decline since 1968

The number of golden-crowned kinglets in the Puget Sound watershed has declined by more than 91% over a recent 50-year period, according to data from the North American Breeding Bird Survey. The data was reported by the Washington Department of Fish and Wildlife, which tracks the information for the Puget Sound Partnership’s terrestrial bird indicator. The indicator was established to monitor the health of Puget Sound’s species and food webs.

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

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.  


Marine Water Quality Implementation Strategy

This article provides an overview and a link to further information about the Marine Water Quality Implementation Strategy. Implementation Strategies (Strategies) are plans for accelerating progress toward the 2020 ecosystem recovery targets for the Puget Sound Vital Signs. The Strategies are developed collaboratively with technical, professional, and policy experts and with local and regional input. They are funded by the Environmental Protection Agency.


Implementation Strategy for Puget Sound’s Shellfish Beds Recovery Target

This article provides an overview and a link to further information about the Shellfish Implementation Strategy. Implementation Strategies (Strategies) are plans for accelerating progress toward the 2020 ecosystem recovery targets for the Puget Sound Vital Signs. The Strategies are developed collaboratively with technical, professional, and policy experts and with local and regional input. They are funded by the Environmental Protection Agency.


Chinook Salmon Implementation Strategy

This article provides an overview and a link to further information about the Chinook Salmon Implementation Strategy. Implementation Strategies (Strategies) are plans for accelerating progress toward the 2020 ecosystem recovery targets for the Puget Sound Vital Signs. The Strategies are developed collaboratively with technical, professional, and policy experts and with local and regional input. They are funded by the Environmental Protection Agency.


Land Development and Cover Implementation Strategy

This article provides an overview and a link to further information about the Land Development and Cover Implementation Strategy. Implementation Strategies (Strategies) are plans for accelerating progress toward the 2020 ecosystem recovery targets for the Puget Sound Vital Signs. The Strategies are developed collaboratively with technical, professional, and policy experts and with local and regional input. They are funded by the Environmental Protection Agency.


Floodplains and Estuaries Implementation Strategy

This article provides an overview and a link to further information about the Floodplains and Estuaries Implementation Strategy. Implementation Strategies (Strategies) are plans for accelerating progress toward the 2020 ecosystem recovery targets for the Puget Sound Vital Signs. The Strategies are developed collaboratively with technical, professional, and policy experts and with local and regional input. They are funded by the Environmental Protection Agency.

Tidal marsh at the Nisqually National Wildlife Refuge in Puget Sound. Photo courtesy of USFWS.

Types of estuaries in Puget Sound

An estuary is a place where saltwater from the ocean mixes with freshwater from rivers and streams. Technically, this defines all of Puget Sound, but scientists have identified several types of "sub-estuaries" within the water body. These include pocket estuaries (or embayments), tidally-influenced rivers and wetlands and other areas near the shoreline connected with freshwater sources. This summary provides descriptions of these estuaries from the Washington State Department of Natural Resources, the Puget Sound Nearshore Partnership and others.  

In 2014 and 2019, sea surface temperatures across a broad area warmed to well above average (0 in the middle of the key). On map, 3° C = 5.4° F // Map: NOAA Fisheries

Warm-water ‘blobs’ significantly diminish salmon, other fish populations, study says

It’s no secret that salmon and other Northwest fish populations are expected to shrink as a result of a warming Pacific Ocean. But a new study suggests that the resulting decline in commercial fishing by 2050 could be twice as great as previously estimated by climate scientists.

“The Blue Marble,” photo taken by the crew of Apollo 17 in 1972, two years after the first Earth Day

Earth Day events go online because of virus

Participants in this year’s Earth Day activities won’t be rallying in large groups, participating in environmental festivals or coming together to clean up the Earth. On the 50th anniversary of Earth Day — April 21st — the environmental movement will be uniquely digital, with many people celebrating from their home computers. [This story is reprinted from the Puget Sound Institute-sponsored blog 'Our Water Ways.']

Freshwater habitat in King County. Photo by Jeff Rice. All rights reserved.

Connections between terrestrial, freshwater, and marine habitats

Freshwater habitat in the Puget Sound region consists of rivers, marshes, streams, lakes and ponds that do not have any saltwater input. Many species depend on these freshwater resources, including salmon, salamanders, frogs, and beavers.

Location of eight aquatic reserves in Washington. Map: WA DNR

Washington state aquatic reserves

Eight aquatic reserves, managed by the Washington Department of Natural Resources, have been established to protect important ecosystems on state aquatic lands.

In most reserves, area residents work with state, local and tribal officials and nonprofit groups to develop and carry out management plans, including scientific research.

The aquatic reserves in the order they were established include: 

  • Maury Island 2004
  • Cypress Island  2007
  • Fidalgo Bay 2008
  • Cherry Point 2010
  • Protection Island 2010
  • Smith and Minor Islands 2010
  • Nisqually Reach 2011
  • Lake Kapowsin 2016
The Puget Sound Partnership's list of Puget Sound 'Vital Signs'

Toxics in Fish Implementation Strategy

The Toxics in Fish Implementation Strategy is a recovery plan that will guide funding and activities to reduce the impacts of toxics contaminants on marine fish and the humans that consume them. A final version of the plan was published in May 2021.

Water drop image courtesy of Bureau of Ocean Energy and Management

Ten things to understand about the Clean Water Act

The federal Clean Water Act of 1972 was designed as a logical step-by-step approach to clean up the nation's waterways. Most people acknowledge that the law has been effective in reducing pollution, but industrial and environment groups tend to be on opposite sides when discussing whether regulations and permits adequately protect water quality. These 10 elements of the Clean Water Act (CWA) focus on how the law applies to Puget Sound.

A screenshot of tidal fluctuations in Puget Sound. Image courtesy of University of Washington Coastal Modeling Group

Puget Sound tides

This article provides a general overview of tidal patterns in Puget Sound. 

This diagram shows how housing, health, transportation, environment and other factors interact in creating sustainable and equitable communities. Courtesy of U.S. Environmental Protection Agency

Environmental justice

Environmental justice is the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income, with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies.

An orca show at Miami Seaquarium featuring southern-resident orca Lolita. Photo by Marc Averette. Avaiable through a Creative Commons Attribution 3.0 Ported license. https://commons.wikimedia.org/wiki/File:Miamiseaquariumlolita.jpg

Orca captures for aquariums

Between 1962 and 1973, at least 263 killer whales were caught or killed in the waters of British Columbia and Washington (Bigg and Wolman 1975). Twelve of these died during capture and fifty were kept for display in aquariums. The remainder of the captured animals escaped or were released. Twenty-seven of the whales kept as captive were taken from the population now designated as endangered southern-resident killer whales (Balcomb 2018). Of those captive whales, all but one have since died. The sole living whale, nicknamed Lolita, remains in captivity at the Miami Seaquarium.

Balcomb, Ken. (2018). Center for Whale Research. Personal correspondence. 

Bigg, M. A., & Wolman, A. A. (1975). Live-capture killer whale (Orcinus orca) fishery, British Columbia and Washington, 1962–73. Journal of the Fisheries Board of Canada, 32(7), 1213-1221.

A large river delta in Puget Sound. Photo courtesy of Puget Sound Nearshore Ecosystem Restoration Project

The mosaic of deltas and other estuarine ecosystems in Puget Sound

The diversity and complexity of estuarine ecosystems is vital to the overall health of Puget Sound. This summary fact sheet focuses on the current state of these ecosystems in Puget Sound—large river deltas, embayments, their interconnecting beaches, and rocky coasts—and the historical changes that have occurred since the development of the Puget Sound coastline. Additional emphasis is placed on the historical losses of tidal wetlands within these estuaries. 

Pacific herring (Clupea pallasii). Image courtesy of NOAA.

Pacific herring distribution in Puget Sound

Pacific herring are a pelagic fish species found from northern Baja California to northern Honshu Island, Japan. They are found throughout the Puget Sound basin and are a mix of “resident” and “migratory” stocks. 

Puget Sound Partnership Vital Sign wheel

Puget Sound Vital Signs

The Puget Sound Vital Signs are measures of ecosystem health that guide the assessment of progress toward Puget Sound recovery goals. They were adopted by the Puget Sound Partnership at the state of Washington to help guide local, state and federal ecosystem recovery efforts. Each of the six Puget Sound recovery goals are expressed with one or more Vital Signs. Vital Signs represent an important component of the ecosystem (e.g. marine water, economic vitality). Each component is, in turn, represented by one or more indicators. The indicators are specific measures of Puget Sound conditions, including human wellbeing, while ecosystem recovery targets are policy statements that express desired future conditions for human health and quality of life, species and food webs, habitats, water quantity, and water.

Giant Kelp (Macrocystis pyrifera). Photo by Claire Fackler. Courtesy of NOAA.


Kelps are large seaweeds in the order Laminariales that form dense canopies in temperate rocky intertidal and subtidal habitats less than 30 m in depth. The kelp flora of the Pacific Northwest is one of the most diverse in the world.

Image describing low oxygen "dead zones"; image courtesy of NOAA

How the state assesses low oxygen in Puget Sound

Under the federal Clean Water Act, states are required to assess the quality of their surface waters and compile a list of polluted water bodies. The law mandates cleanup plans to address pollution and other water-quality problems. This article describes how this process works in Washington state for dissolved oxygen. 

Spiny Dogfish (Squalus acanthias), a species typically found in Puget Sound marine waters. Image courtesy of NOAA.

The pelagic (open water) food web

The marine habitat of Puget Sound can be divided up into nearshore, benthic (associated with the sea floor), and pelagic (open water) habitats. This article focuses on the pelagic habitat within the Puget Sound. This article was prepared as part of the 2015 Puget Sound Fact Book produced by the University of Washington Puget Sound Institute. 

Dead salmon. Photo: Boris Mann (CC BY-NC 2.0) https://www.flickr.com/photos/boris/3037705761

The nearshore food web: Detritus

Detritus, or dying or decaying matter, is a central component of the nearshore food web in Puget Sound. This article was prepared as part of the Puget Sound Fact Book produced by the University of Washington Puget Sound Institute. 

Puget Sound basins. The oceanographer’s definition of Puget Sound is limited to the following marine basins: Hood Canal, Main Basin (Admiralty Inlet and the Central Basin), South Basin, and Whidbey Basin. Map: Kris Symer. Data source: WDFW.

Puget Sound's physical environment

The Puget Sound ecosystem is shaped by its physical environment. This article looks at Puget Sound's geologic history as well as dynamic factors such as the flow of its rivers and currents.

Room fire simulation shows burned furniture. Photo: Kecko (CC BY 2.0) https://www.flickr.com/photos/kecko/3648477592/

Flame retardants

Efforts to reduce fire hazards over a half century ago have left an unintended trail of persistent environmental contaminants from flame retardant chemicals known as PBDEs. Bans and substitutes are still evolving.

Due to the 'Red Tide' misnomer, blooms of red-colored algae, like this Noctiluca sp. (a dinoflagellate) seen here in Eastsound, Washington (July 2016), can cause undue public concern about harmful algal blooms. Photo: Jordan Cole

Harmful algal blooms in the Salish Sea

Formerly known as “Red Tide”, harmful algal blooms are a health concern for both wildlife and humans. The following is a brief review of some of these algae and their effects.

Algal bloom. Photo: Eutrophication&Hypoxia (CC BY 2.0) https://www.flickr.com/photos/48722974@N07/5120831456

Harmful algal blooms in Puget Sound

An algal bloom is a rapid increase or accumulation in the population of algae in a water system. While most are innocuous, there are a small number of algae species that produce harmful toxins to humans and animals.

Common starfish feeding on mussels. Photo: James Lynott (CC BY-ND 2.0) https://www.flickr.com/photos/jlynott/11715880653

Food web dynamics: competition and invasive species

Competition occurs when individuals of different species struggle to obtain the same resource in an ecosystem (such as food or living space). Adaptations, such as physical mutations and behavior modifications, can help an organism outcompete its competitors. 

Early morning meal. Photo: jdegenhardt (CC BY-NC-ND 2.0) https://www.flickr.com/photos/jdegenhardt/2771107305

Food web connections beyond the marine areas of Puget Sound

Food webs are natural interconnections of food chains and depict what-eats-what in an ecological community. While Puget Sound represents a specific food web, the organisms that reside within that web often travel outside the region. In this way, one community's food web can be drastically affected by a change in a neighboring ecosystem.

Dead salmon. Photo: Boris Mann (CC BY-NC 2.0) https://www.flickr.com/photos/boris/3037705761

Transfer of nutrients in the ecosystem

Decaying organic matter plays an important role in marine ecosystems. 

Puget Sound. Photo: S.N. Johnson-Roehr (CC BY-NC 2.0) https://www.flickr.com/photos/snjr22/4095840433

Water and nutrient circulation in Puget Sound

Complex physical processes such as hydrology, nutrient cycling, and sediment transport are linked to water circulation patterns in Puget Sound. 

Waves crashing on the Puget Sound Photo: MikeySkatie (CC BY-SA 2.0) https://www.flickr.com/photos/mikeyskatie/5473869676

Climate and ocean processes

This overview discusses the processes that control ocean and climate characteristics. Topics include atmospheric forcing, precipitation patterns, oscillation trends, coastal upwelling, and climate change.

2003 Seattle Marathon - Seward Park Photo: J Brew (CC BY-SA 2.0) https://www.flickr.com/photos/brewbooks/1282527696

Cleaning up Lake Washington

Lake Washington was heavily contaminated by untreated sewage until extensive pollution controls by the city of Seattle. 

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

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. 

Bear eats salmon. Photo: Robert Voors (CC BY-NC-ND 2.0) https://www.flickr.com/photos/robert_voors/1303192433

Food webs

The health of an ecosystem is tied closely to the health of its food webs. This article provides an overview of the concept, origin, and characteristics of a food web and how predator and prey relationships are shaped in the Salish Sea.  

The Puyallup River outside Orting, WA. Photo: Lindley Ashline (CC BY-NC-ND 2.0) https://www.flickr.com/photos/91625873@N04/22035924720

Land cover conversion and ecosystem decline

Land cover conversion through human development was listed as a leading cause of ecosystem decline in the 2014 Puget Sound Pressures Assessment, a document supported by the Environmental Protection Agency and prepared by more than 60 of the region's scientists. 

Salmon fishing at Fauntleroy. Photo: Washington State Dept of Transportation (CC BY-NC-ND 2.0) www.flickr.com/photos/wsdot/3999467495

Human dimensions

This content initiates a description of the social dimensions of the Puget Sound system with a short list of facts about population growth trends, how humans interact with and depend on the Puget Sound ecosystem for their wellbeing (in the broadest sense), and the large-scale policies and individual human activities that have the greatest potential impact on the Puget Sound ecosystem. 

Stormwater flowing into catch basin carries contaminants to our waterways. Photo: Ben McLeod (CC BY-NC-SA 2.0) https://www.flickr.com/photos/benmcleod/420158390

Stormwater facts

Runoff from rain and melting snow is one of the leading causes of pollution in Puget Sound. Here are selected facts related to stormwater, its prevalence, how it affects the Puget Sound ecosystem, and its environmental and economic impacts.

Sucralose, an artificial sweetener, is a good tracer of wastewater. It is present at low levels throughout the Puget Sound [1].

Contaminants of emerging concern (CECs) in the waters of the Pacific Northwest

Contaminants of Emerging Concern (CECs) range from pharmaceuticals, personal care products and food additives to compounds used in industrial and commercial applications. These compounds are not typically removed from wastewater and are flushed into waterways throughout the world in significant amounts. This article describes how scientists are measuring the presence of these contaminants along with their potential impacts in Puget Sound, the Columbia River and elsewhere.

Lower Duwamish Waterway dredging on Superfund site. Photo: Gary Dean Austin (CC BY-SA 2.0) https://www.flickr.com/photos/49648789@N08/17069420399/

Persistent contaminants in Puget Sound: Overcoming a toxic legacy

The Lower Duwamish Waterway in Puget Sound was designated a Superfund cleanup site in 2001. Its legacy of contamination predates World War II and the waterway continues to pollute Puget Sound through stormwater runoff.

Puget Sound Fact Book report cover

Puget Sound Fact Book

The Puget Sound Fact Book brings together statistics and other information about the health and makeup of the Puget Sound ecosystem. Areas of focus include climate change, geography, water quality, habitats, human dimensions and regional species. The fact book was prepared for the Encyclopedia of Puget Sound with funding from the Environmental Protection Agency and the Puget Sound Partnership.


Tribes of the Puget Sound and Salish Sea regions

The following list includes Native American tribes and First Nations of the Salish Sea region.

Puget Sound portion of a 1798 chart showing "part of the coast of N.W. America : with the tracks of His Majesty's sloop Discovery and armed tender Chatham / commanded by George Vancouver, Esqr. and prepared under his immediate inspection by Lieut. Joseph Baker." Credit: Library of Congress, Geography and Map Division.

Puget Sound: A uniquely diverse and productive estuary

Puget Sound is the second largest estuary in the contiguous United States. Today, we understand that estuaries — where freshwater and saltwater merge — are among the most productive places for life to exist.

All scenarios project warming for the 21st century. The graph shows average yearly temperatures for the Pacific Northwest relative to the average for 1950-1999 (gray horizontal line). The black line shows the average simulated temperature for 1950–2011, while the grey lines show individual model results for the same time period. Thin colored lines show individual model projections for two emissions scenarios (low: RCP 4.5, and high: RCP 8.5)[ ], and thick colored lines show the average among models projecti

Future scenarios for climate change in Puget Sound

The University of Washington Climate Impacts Group has been analyzing the potential effects of climate change in Puget Sound. The projections below represent some of their most recent reporting about expected conditions in the region over the next 50 to 100 years. Support for this article was provided by the Puget Sound Partnership.


Dissolved oxygen and hypoxia in Puget Sound

Hypoxia, defined as dissolved oxygen (DO) concentrations less than 2 mg / L, has become widespread throughout estuaries and semi-enclosed seas throughout the world (Diaz 2001). 

Clam gardens, while all being characterized by a level terrace behind a rock wall in the lower intertidal, are diverse in their shapes and sizes. Photo: Amy S. Groesbeck.Clam gardens, while all being characterized by a level terrace behind a rock wall in the lower intertidal, are diverse in their shapes and sizes.

Ancient clam gardens of the Northwest Coast of North America

Northwest Coast First Peoples made clam garden terraces to expand ideal clam habitat at tidal heights that provided optimal conditions for clam growth and survival, therefore enhancing food production and increasing food security.

Amphipholis squamata (Phylum Echinodermata, Class Ophiuroidea) – This is a brittle star, commonly known as the “brooding snake star”. (Sandra Weakland, Brooke McIntyre photo)

Benthic Invertebrates of Puget Sound

A list of over 1800 benthic infaunal invertebrates is now available on the Encyclopedia of Puget Sound. The list was prepared as part of the Washington State Department of Ecology’s Marine Sediment Monitoring Program (MSMP).  This program, initiated in 1989, is one component of the Puget Sound Ecosystem Monitoring Program, a collaborative effort dedicated to monitoring environmental conditions in Puget Sound. 


Regional investigations into the effects of CECs

Several research groups in the region are investigating biological markers and/or impacts of Contaminant of Emerging Concern (CEC) exposure in different organisms.  An abstract describing each study is included below.  Also included are links or contact details for further information about each project.


Regional monitoring of CECs in the Salish Sea

Several studies have been performed to determine the occurrence of selected Contaminants of Emerging Concern (CECs) in the environment.

The view from the shore of Brackett's Landing, a Marine Protected Area in Puget Sound. Photo by Jeff Rice. Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Marine Protected Areas in Puget Sound

Marine Protected Areas (MPAs) have been present in Puget Sound since the early 1900s, although most were established after the 1960s. By 1998 there were at least 102 intertidal and subtidal protected areas in Puget Sound, created and managed by at least 12 different agencies or organizations at the local, county, State and Federal level.

CECs include pharmaceuticals and thousands of other commonly used chemical compounds. Photo courtesy of EPA.

Contaminants of emerging concern in the Salish Sea

Thousands of different compounds are produced and used as part of our daily lives.  Examples include pharmaceuticals (NSAIDs, birth control pills, etc), personal care products (sun screen agents, scents, preservatives, etc), food additives (artificial sweeteners) and compounds used in industrial and commercial applications (flame retardants, antibiotics, etc).  Advances in analytical methods have allowed the detection of many of these compounds in the environment.

Tidal turbines like this one developed by OpenHydro, Ltd. will be installed in Puget Sound in mid 2015 as part of a demonstration project. Sustainable, large-scale development of tidal energy will require studying and learning from these early-stage projects. Image source: OpenHydro, Ltd./DCNS

Tidal energy in Puget Sound

Scientists have identified the strong underwater currents of Puget Sound's Admiralty Inlet as a potential source of electricity for nearby utilities. The following article describes some of the basic principles and mechanisms of tidal energy.  

Cover page for A Marine and Estuarine Habitat Classification System for Washington State

Defining and describing Puget Sound shore types

Species and their habitats are a foundation of the ecosystem framework, but there is currently no generally agreed upon habitat classification system for Puget Sound. The closest thing for its marine and nearshore environments may be Dr. Megan Dethier’s 1990 resource A Marine and Estuarine Habitat Classification System for Washington State. Much of the work for that document was done in the general vicinity of Puget Sound, and it has been an influential resource for major habitat mapping efforts in the region, such as Shorezone.
The Puget Sound Model at the UW School of Oceanography

The Puget Sound Model

The Puget Sound Model was designed and built in the early 1950s at the University of Washington School of Oceanography as a research and teaching tool for understanding Puget Sound circulation patterns.

Salish Sea Hydrophone Network locations and 2011
 orca sightings from the Orca Network Whale Sightings Network. Source: Salish Sea Hydrophone Network and Orca Network.

Salish Sea Hydrophone Network and Orca Network

The Salish Sea Hydrophone Network and Orca Network are two citizen science projects dedicated to furthering our understanding of abundance, distribution, behavior, and habitat use by the endangered population of Southern Resident Killer Whales, also called orcas. The Hydrophone Network lets the public listen for orcas through their computers and phones, while the Orca Network gathers and disseminates sightings of orcas as they move between Puget Sound, the Fraser River, and the Pacific Ocean.


The IEA framework in the Puget Sound Partnership Biennial Science Work Plan

The 2009-2011 Biennial Science Work Plan specifies the use of the IEA framework by the Puget Sound Partnership "to


Salish Sea Natural Area Conservation Plan

The Salish Sea Natural Area Conservation Plan is a project of the Natural Areas Conservation Program (NACP) established in 2007 by the Canadian government, which helps non-profit, non-government organizations protect sensitive areas. The process involves selecting biodiversity targets and determining measures of conservation success.

Friday Harbor, San Juan Island. Photo courtesy of NOAA and the Pacific Tides Party.

San Juan County Best Available Science Synthesis

A summary of data on ecosystems designated as Critical Areas (formerly Environmentally Sensitive Areas) in San Juan County, including recommendations for management.


Envision Skagit

Envision Skagit is a partnership between Skagit County and various local and regional organizations. The county is using a land use model as a tool to engage the community about natural resource planning and decisions. 

Chinook salmon. Image courtesy of NOAA.

Lead Entities for salmon recovery in Puget Sound

Lead Entities are local organizations in Puget Sound that develop salmon recovery strategies and priorities for the region on a watershed-based scale.

Submerged marsh in Fisher Slough. Image courtesy of NOAA.

Floodplains by Design

Floodplains by Design identifies floodplains in Puget Sound with multiple benefit potential and use information on flood risk to inform ecosystem restoration. 


The Willamette Valley-Puget Trough-Georgia Basin Ecoregional Assessment

The Willamette Valley-Puget Trough-Georgia Basin Ecoregional Assessment considers 833 conservation targets identified by expert teams, proposing that if those targets are represented in an ecoregion, a majority of species, including those which lack data, will be included.


Puget Sound Nearshore Ecosystem Restoration Project

The Puget Sound Nearshore Ecosystem Restoration Project (PSNERP) works to assess the health of Puget Sound nearshore environments and provides strategies for their protection and restoration. 

Puget Sound drainage area. Image courtesy of the Washington Department of Ecology.

Puget Sound Watershed Characterization Project

This project is a coarse-scale, systematic characterization of different areas within the Puget Sound watershed, aimed at providing a framework for land use discussions.

A bald eagle in Padilla Bay National Estuarine Research Reserve. Photo courtesy of NOAA.

West Coast Governors' Alliance Integrated Ecosystem Assessment

The West Coast Governor's Alliance on Ocean Health, a regional collaboration to protect and manage U.S. West Coast ocean and coastal resources, was launched in September of 2006. This collaboration began an integrated ecosystem assessment (IEA) covering the entire coast, comprised of six regional IEAs (R-IEAs) in Washington, Oregon, and California. The R-IEAs evaluate a range of management objectives and establish “a harmonized set of standards and indicators for ocean health, including metrics for ecological integrity, ecosystem services, and socioeconomic conditions.” 

Graphic of the IEA loop. Credit: NOAA

Ecological assessments in the Salish Sea

Ecological assessments (sometimes referred to as "conservation assessments") typically identify and evaluate the ecological attributes of an ecosystem. There is no single type of ecological assessment, but the following list includes an informal inventory of related efforts in the Salish Sea. This list does not include Ecological or Environmental Impact Assessments, which are targeted to specific land uses. This is a living document and will be updated as more information becomes available and as needs arise. 

The Seaeye Falcon used by the Washington Department of Fish and Wildlife. Photo courtesy WDFW.

Remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs) in Puget Sound

Remotely Operated Vehicles (ROVs) and Autonomous Underwater Vehicles (AUVs) are underwater robotic vehicles used for a variety of ocean surveys and operations. Both are used for deep-sea observation, mapping of underwater environments, and surveys of biodiversity and water quality trends. While ROVs are tethered to the user by a cord called the umbilical, which provides power as well as control and video signals, AUVs are programmed for a specific course and then set loose, operating without a tether.

The float plane prepares to take off. Photo by Jeff Rice for the Encyclopedia of Puget Sound.

About the Eyes Over Puget Sound monitoring program

Once a month, Washington State Department of Ecology marine scientists take to the air to obtain high-resolution aerial photo observations and gather water data at the agency's monitoring stations and via state ferry transects. This provides a visual picture of the health of Puget Sound, which they call Eyes Over Puget Sound or EOPS.

Image courtesy of NOAA.

Major ports in Puget Sound: fact sheet

The following fact sheet represents economic and environmental activities of major ports in the Puget Sound region. This is a living document and may be updated as new information becomes available. 

A view from the San Juan Islands. Photo: Bureau of Land Management

San Juan Islands National Monument

The San Juan Islands National Monument was established on March 25, 2013 by the Obama administration. 

MoSSea snapshot of sea surface temperature over the full model domain around May 15, 2006; image courtesy of PRISM

Water quality model development and application in Puget Sound and Georgia Basin

A recent summary includes information compiled in Winter 2013 by the modeling workgroup of the Puget Sound Ecosystem Monitoring Program (PSEMP). It describes several ecosystem modeling efforts in the region.

Salish Sea map my Norm Maher. Courtesy of the SeaDoc Society.

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.


Ecosystem-based management

Ecosystem-based management (EBM) is an integrated, science-based approach to the management of natural resources that aims to sustain the health, resilience and diversity of ecosystems while allowing for sustainable use by humans of the goods and services they provide.


Native American tribes of the Puget Sound watershed

This page includes links to information for Native American tribes with tribal lands found within the boundaries of the Puget Sound watershed.

Photo credit: Biopix, Caddisfly, Limnephilus politus CC BY-NC

Indicator species

An indicator species is an organism whose presence, absence or abundance reflects a specific environmental condition. Indicator species can signal a change in the biological condition of a particular ecosystem, and thus may be used as a proxy to diagnose the health of an ecosystem. For example, plants or lichens sensitive to heavy metals or acids in precipitation may be indicators of air pollution. Indicator species can also reflect a unique set of environmental qualities or characteristics found in a specific place, such as a unique microclimate.


Salish Sea tribes in Canada

This page includes links to information for First Nations living along the Salish Sea in Canada. First Nations peoples occupied what is now Canada prior to the arrival of Europeans and Americans, and over 50 cultural groups and unique languages are represented across the country.


Puget Sound watershed hydrologic units

There are many ways of defining the boundaries of the Puget Sound watershed. Hydrologic unit codes (HUCs) are nationally standardized divisions that are often used by conservation agencies and national organizations.

Protection Island. Image courtesy of NOAA.

Protection Island

Protection Island, a National Wildlife Refuge in the Strait of Juan de Fuca, provides important habitat for seabirds and marine mammals.

Open Standards Project Management Cycle. Graphic courtesy of Conservation Measures Partnership

Open Standards

Open Standards seek to build a common language and framework for decision making and prioritization of conservation issues.

Map of the Hood Canal Action Area; courtesy Puget Sound Partnership

Review finds minimal evidence for human impacts on Hood Canal hypoxia

An independent review conducted by the Puget Sound Institute (PSI) is featured in findings by the Environmental Protection Agency and the Washington State Department of Ecology that there is currently “no compelling evidence” that humans are the cause for recent trends in declines in dissolved oxygen in Hood Canal.


Upper Skagit Tribe

The Upper Skagit tribe includes descendants from 11 villages in the Upper Skagit and Samish watersheds. Although the tribe signed the treaty of Point Elliott, no reservation was established, and members refused to leave the region. Today, the tribe's population is scattered among different towns, including Sedro-Woolley, Mount Vernon, and Newhalem.

Upper Skagit Area of Concern:


Tulalip Tribes

The Tulalip reservation is located near Marysville, Washington. It was created after the Point Elliott Treaty of 1855, and currently has a population of 2,500 members. The entire tribal population is approximately 4,000 and growing. 

Tulalip Tribes Area of Concern:


Swinomish Indian Tribal Community

The Swinomish Indian Tribal Community is descended from Coast Salish people that lived in and around the Skagit and Samish Rivers. Their reservation, about 15 square miles, is located on Fidalgo Island, between Skagit Bay, Padilla Bay, and the Swinomish channel.

Swinomish Area of Concern:


Suquamish Tribe

The Suquamish Tribe, whose ancestors have lived in the region for approximately 10,000 years, has 950 enrolled members. About half of them live on the Port Madison reservation, established in 1855 by the treaty of Point Elliott.

Suquamish Tribe Area of Concern:


Stillaguamish Tribe

The Stillaguamish Tribe is descended from the Stoluck-wa-mish River Tribe, who signed the treaty of Point Elliott in January 1855. Some tribal members moved to the Tulalip reservation, while others remained along the Stillaguamish River. The headquarters for the tribe are in Arlington, Washington.

Stillaguamish Area of Concern:


Squaxin Island Tribe

The Squaxin Island tribe is made up of several tribes from Squaxin Island and the surrounding inlets. Although no members of the tribe currently live on Squaxin Island year-round, it unites past and future generations and is still an important destination. The tribal headquarters are located in Kamilche.

Squaxin Island Area of Concern:


Skokomish Tribe

The Skokomish Tribe began as the Twana Indians, made up of nine communities living in and around the Hood Canal drainage basin.

Skokomish Area of Concern:


Sauk-Suiattle Tribe

The original homeland of the Sauk-Suiattle tribe covered the entire drainage area of the Sauk, Suiattle, and Cascade rivers. A village of eight traditional cedar longhouses at Sauk Prairie was destroyed by settlers in 1884. From a tribe of 4,000 in 1855, numbers dropped until 1924, when only 18 members remained. Currently, the tribe has around 200 members.

Sauk-Suiattle Area of Concern:


Quinault Indian Nation

The Quinault Indian Nation includes the Quinault and Queets tribes, as well as descendants of five other coastal tribes. The tribe's headquartes are located in Taholah, Washington.

Quinault Area of Concern:


Quileute Tribe

The Quileute live along the Pacific Coast, in La Push, Washington. The tribe's historical territory stretched up and down the coast.

Quileute Area of Concern:


Puyallup Tribe

The Puyallup Tribe lives in one of the first areas in Puget Sound that was settled by Euro-Americans. For years, they were unable to exercise their fishing rights, until the U.S. vs. Washington court decision, which allowed them access to the usual and accustomed areas.

Puyallup Tribe Area of Concern:


Port Gamble S'Klallam Tribe

The Port Gamble S’Klallam reservation covers 1,340 acres. Over half of the nearly 2,000 enrolled tribal members live on the reservation. Port Gamble Bay, the tribe’s ancestral home, has proven to be more resilient than other nearby water bodies, but it still carries a load of toxins from the Pope & Talbot sawmill, which operated on the bank for over 150 years.

Port Gamble S'Klallam Area of Concern:


Nooksack Tribe

The Nooksack are a tribe of about 2,000 members. After signing the Point Elliott Treaty in 1855, they lost ownership of much of their land in exchange for fishing and hunting rights. They were expected to move to the Lummi Reservation, but most refused, and they were eventually granted some homestead claims. Currently, around 2,400 acres remain in trust, administered by the Bureau of Indian Affairs. After the 1855 treaty, the tribe remained unrecognized until 1973. The tribe's name translates to "always bracken fern roots".

Nooksack Tribe Area of Concern:


Nisqually Tribe

The Nisqually tribe has over 650 enrolled members. Most live on or near the reservation, which was established by the Medicine Creek Treaty in 1854. According to legend, the Nisqually people migrated from the Great Basin thousands of years ago, crossing the Cascades and settling in what is now Skate Creek. The tribe is one of the largest employers in Thurston County.

Nisqually Tribe Area of Concern:


Muckleshoot Tribe

The Muckleshoot Indian Tribe is named after the prairie where the Muckleshoot reservation was established in 1857. The tribe’s members are descended from the Duwamish and Upper Puyallup people.

Muckleshoot Tribe Area of Concern:


Makah Nation

Makah tribal headquarters are located in Neah Bay, Washington. In the 1800s, the tribe numbered between 2,000 and 4,000, spread between five permanent villages on the Washington Coast. The Makah have a strong whaling tradition and close ties to the ocean.

Makah Area of Concern:


Lummi Indian Tribe

The Lummi tribe is one of the largest in Washington State, with over 5,000 members.

Lummi Tribe Area of Concern:


Lower Elwha Klallam Tribe

The Lower Elwha Klallam Tribe lives on the north coast of the Olympic Peninsula, west of Port Angeles, in the lower Elwha River valley. The land was proclaimed the Lower Elwha Reservation in 1968, and the current tribal lands include approximately a thousand acres. Currently, the tribe has 985 enrolled members, with 395 living on the reservation.

Lower Elwha Klallam Area of Concern:


Jamestown S'Klallam Tribe

The Jamestown S’Klallam tribe is one of several communities originating from the S’Klallam tribe (“strong people”), a cultural and linguistic group in the Salish Sea. The S’Klallam signed the treaty of Point No Point in 1855, which entitled them to a payment of $60,000 over 20 years and fishing rights at the “usual and accustomed places.” In 1874, a band of S’Klallams paid $500 for a 210-acre piece of land near Dungeness, which became the Jamestown community.


Hoh Indian Tribe

The Hoh River (chalak'At'sit, or "the southern river") is central to the history, economy and culture of the tribe. Established in September of 1893, the Hoh Indian Reservation covers 443 acres of land on the west side of the Olympic Peninsula. The tribe shares a language with the Quileute. In 2010, additional land was transferred to the tribe under the Hoh Indian Tribe Safe Homelands Act, in order to allow the tribe to move to land outside the tsunami zone if necessary.

Hoh Tribe Area of Concern:

Coast Salish Canoe Journey 2009 landing in Pillar Point; photo by Carol Reiss, USGS

Traditional Ecological Knowledge

Traditional Ecological Knowledge (TEK), sometimes called Indigenous Knowledge, refers to cumulative knowledge and experience that indigenous cultures have of their environment. In the last thirty years, there has been growing interest in TEK as a resource for restoration and conservation projects.

Benthic macroinvertebrates are visible to the naked eye. Photo by Jo Wilhelm, courtesy King County.

Featured resource: Puget Sound Stream Benthos

Puget Sound Stream Benthos is a data management project which monitors benthic invertebrates in streams and rivers in the Puget Sound region. The system is maintained and operated by King County and was the result of a joint effort between King, Pierce, and Snohomish Counties.

Moss Lake, part of a bog wetland complex in Moss Lake Natural Area. Photo by Jennifer Vanderhoof.

King County wetland habitat

Wetlands are recognized as critical ecosystems for biodiversity because of their disproportional use by wildlife and exceptional habitats for plants. It is their unique combination of shallow aquatic habitats and adjacent terrestrial conditions extending over a wide range of geomorphic and elevational settings that accounts for their ecological complexity and resultant richness. Because of their landscape setting, each wetland tends to exhibit unique habitat types and characteristic arrays of species adapted to idiosyncratic conditions, products of each wetland’s ecological and evolutionary history.

Mountain goats are commonly found in alpine habitat. Photo by Jennifer Vanderhoof.

King County subalpine and alpine habitat

Except for a very small area in the SE corner of the County, the subalpine and alpine habitats are located in the North Cascades Ecoregion that occupies the NE quarter of King County. This ecoregion is composed of steeply dissected valleys that rise precipitously to the subalpine (montane) forests, meadows, and parklands and, in a short distance more, to the alpine ridges and peaks of the Cascade Crest. The habitats that typify this high-elevation zone are among the most undisturbed habitats remaining in King County.

The Snoqualmie River. Photo copyright King County.

King County rivers and streams

The diversity of streams in the county is a reflection of the diversity of its geography. From the small rivulets that begin high in the Cascade Mountains, to the brooks that flow gently across the lowlands, to the five major rivers of the county, there are over 4,800 kilometers (3,000 miles) of perennial streamcourses in King County.

A section of Griffin Creek. Photo copyright King County.

King County riparian habitat

Riparian habitats are often characterized by particular trees and shrub species that line the banks of most rivers and streams in the lowlands and foothills of King County.

Seagrass meadows provide valuable habitat. Photo by Randy Shuman.

King County marine habitat

King County contains four major marine habitats: backshore, intertidal and shallow subtidal, deep subtidal, and riverine/sub-estuarine. Descriptions of each of these habitats and the types of flora and fauna associated with them are provided below.

Red alder, a deciduous species that often grows in disturbed areas. Photo copyright King County.

King County lowland habitat

The history of land use in King County has produced a lowland and foothill landscape of bewildering variety. The once continuous forest of western hemlock, Douglas-fir, and redcedar has given way to a patchwork of lawns, parks, playgrounds, woodlots, greenbelts, old fields, croplands, tree farms, and remnant forests set amid a landscape of urban, suburban, rural, and commercial uses, all joined and, at the same time, separated by a vast network of roads and communication corridors.

Canada geese, commonly seen in Lake Washington. Photo by Jennifer Vanderhoof.

King County lake habitat

The natural biodiversity of the lakes of King County is strongly influenced by geography. The county runs from the Cascade mountain crest to the shores of Puget Sound, covering all three different Level III ecoregions (Puget Lowland, North Cascade, and Cascade). The geology, elevation, climate, and ecology in these three ecoregions are all different, and these differences in environmental factors determine the natural biodiversity of the lakes and also influence the risks, vulnerability, and impacts to that biodiversity.

Aerial view of the Vashon Island shoreline.

The Puget Lowland ecoregion

Ecoregions provide a useful framework and background for the discussion of marine, freshwater, and terrestrial environs of the county. The discussion of ecoregions is based on U.S. Environmental Protection Agency (EPA) ecoregion conventions, which result in units similar to European biogeographical regions because they denote areas of general similarity in ecosystems.

King County map, showing incorporated land and major water bodies. Copyright King County.

The North Cascades ecoregion

Ecoregions provide a useful framework and background for the discussion of marine, freshwater, and terrestrial environs of the county. The discussion of ecoregions is based on U.S. Environmental Protection Agency (EPA) ecoregion conventions, which result in units similar to European biogeographical regions because they denote areas of general similarity in ecosystems.

King County map, showing incorporated land and major water bodies. Copyright King County.

The Cascades ecoregion

Ecoregions provide a useful framework and background for the discussion of marine, freshwater, and terrestrial environs of the county. The discussion of ecoregions is based on U.S. Environmental Protection Agency (EPA) ecoregion conventions, which result in units similar to European biogeographical regions because they denote areas of general similarity in ecosystems.


Pollution control strategies for Puget Sound

Pollution of the rivers, creeks, bays, and open waters of Puget Sound comes from a variety of sources and travels along many pathways. Spilled oil products and fuel, deposition of air pollutants, legacy toxic pollutants, disease-bearing and illness-causing organisms from failing and poorly maintained on-site sewage treatment systems, fertilizers, erosion, and the runoff from roads and parking lots all find their way into the waters of Puget Sound, where they harm fish and wildlife and create direct health risks to people. Polluted waters reduce ecosystem services – shellfish closures, beach closures, impacts to recreation, impairments to sources of drinking water, loss of cultural resources, consumption warnings for fish, and low oxygen conditions that kill marine species. Increasing numbers of people, cars, and pavement mean more pollutants enter our waterways in higher concentrations, and at a faster rate. Pollutants also enter waterways directly through point source discharges from commercial and industrial sites.


Restoration strategies for Puget Sound

In the course of building homes, businesses, roads, and infrastructure, the lands and waters of Puget Sound have been drastically modified. Levees, dams, and toxic deposits are obvious and have site-specific impacts. But less obvious are the cumulative changes from human land use activities, such as bulkheads, docks, permanent removal of native vegetation, and loss of native habitat in marine and upland areas. These activities have damaged the underlying processes that form beaches, keep rivers, estuaries, and forests healthy, and support species. Historically, the actions that led to ecosystem degradation were intended to improve the quality of life for Puget Sound residents, but with closed shellfish beds, flooding, species decline, and other impacts it is clear that ecosystem rebuilding efforts are needed.


Protection strategies for Puget Sound

Puget Sound has been dramatically altered during the past 150 years. One-third of the shoreline has been armored, large areas of forestland and farmland have been paved or otherwise converted to other uses, and river systems have been altered by dams and levees. These actions were undertaken to produce other benefits, but they cumulatively damage and destroy the underlying ecological processes that enable Puget Sound to be healthy and productive. Human population growth and a changing climate in Puget Sound will exacerbate the threats to ecosystem health. To maintain or restore the structure and function of the Puget Sound ecosystem, it is imperative to identify and retain the important features of the ecosystem that still function well.

Seaglider in the open water. Photo courtesy of Seaglider Fabrication Center

Seagliders in Puget Sound

They are sometimes called Autonomous Underwater Vehicles (AUVs), or submersible drones. They glide like airships through the deeper channels of Puget Sound, and have become an important tool for a wide array of open ocean applications, including detection of marine mammals, military reconnaissance and the monitoring of environmental disasters like the Deepwater Horizon oil spill. Puget Sound is the birthplace and key testing area of the Seaglider.

Shoreline armoring along railroad

An overview of Shoreline armoring in Puget Sound

More then 700 miles of Puget Sound shoreline is considered to be "armored," and as much as four miles of new armoring is added each year.

WRIA boundaries in Puget Sound area

Water Resource Inventory Areas in Puget Sound

The Washington State Department of Ecology and other state natural resources agencies have divided the Washington into 62 "Water Resource Inventory Areas" or "WRIAs" to delineate the state's major watersheds.

Satellite image of Western Washington

Climate change impacts on water management in the Puget Sound region

Climate change is projected to result, on average, in earlier snowmelt and reduced summer flows, patterns that are not well represented in the historical observations used for planning and reliability analyses by water utilities.

Chief Sealth, known to settlers as Chief Seattle. Photo: E.M. Sammis/MOHAI.

Modern Puget Sound timeline

The Puget Sound region has a long history that has shaped the culture and environment we experience today. View a timeline describing key events in the Puget Sound region dating from Washington statehood to the present.


Marine fecal bacteria

Fecal bacteria are found in the feces of humans and other homeothermic animals. They are monitored in recreational waters because they are good indicators of harmful pathogens that are more difficult to measure. 

Bluff failures contribute sediment to beaches

Shoreline formation in Puget Sound

Puget Sound has over 4,000 km (2,500 miles) of shorelines, ranging from rocky sea cliffs to coastal bluffs and river deltas. The exchange of water, sediment, and nutrients between the land and sea is fundamental to the formation and maintenance of an array of critical habitat types.


Puget Sound's climate

The climate of Puget Sound is a product of the interaction between large-scale wind and weather patterns and the complex topography of the region. Seasonal changes in the movement of moisture-laden air that collides with the sudden barrier of the Olympic and Cascade mountains bring Puget Sound the record-breaking precipitation for which it is so famous. These circulation and topographic differences also lead to remarkable climate differences within Puget Sound itself, influencing the species and habitats that are found in the Sound.

Whale watching boat in Puget Sound.

Ecosystem services in Puget Sound

Ecosystem services are the “outputs” and experiences of ecosystems that benefit humans, and are generated by the structure and function of natural systems, often in combination with human activities. The Millennium Ecosystem Assessment, a global effort to catalog and assess ecosystem status and functions, offers a useful classification scheme.

Great blue heron fishing. Photo: Leo Shaw, The Seattle Aquarium.

Food Web

Puget Sound hosts more than 100 species of seabirds, 200 species of fish, 15 marine mammal species, hundreds of plant species, and thousands of invertebrate species. These species do not exist in isolation, but rather interact with each other in a variety of ways: they eat and are eaten by each other; they serve as vectors of disease or toxins; they are parasitic; and they compete with each other for food, habitat, and other resources.


Habitats of the Puget Sound watershed

"Habitat" describes the physical and biological conditions that support a species or species assemblage and refers to conditions that exist at many scales. An oyster shell provides habitat for some algae and invertebrates, whereas cubic miles of sunlit water in Puget Sound comprise the habitat for many planktonic species.


Herbivores and detritivores in Puget Sound

Many consumer organisms in Puget Sound are both herbivores and detritivores. Zooplankton and benthic invertebrates that are scavengers, herbivores, or detritivores are considered jointly in this article. Some of these organisms can be predatory as well. Hundreds of invertebrates and fish species have a planktonic larval stage that eats plants and occupies the nearshore and offshore pelagic waters of Puget Sound.

Photo: Leo Shaw, The Seattle Aquarium.

Mid-level consumers in Puget Sound

A variety of animals, including invertebrates, fish, mammals, and birds, consume the suspension-feeders, filter-feeders, grazers, and detritivores that serve as a link between the primary producers and detrital pathways and the upper levels of the food web.

sea lions

Top-level predators in Puget Sound

Fishes, birds, and mammals (including humans) serve as top-level carnivores in the Puget Sound ecosystem. With the exception of humans, these organisms have a diet that consists almost entirely of fish or other vertebrates.

The invasive tunicate Styela clava. Photo: WDFW

Intentional and unintentional introduction of invasive and non-native species

Non-native species are those that do not naturally occur in an ecosystem. A non-native species is considered invasive when it is capable of aggressively establishing itself and causing environmental damage to an ecosystem. Plants, animals, and pathogens all can be invasive.