An estuarine habitat occurs where salty water from the ocean mixes with freshwater from the land. The water is generally partially enclosed or cut off from the ocean, and may consist of channels, sloughs, and mud and sand flats. River mouths, lagoons, and bays often constitute estuarine habitat. Within any estuary, there is a salinity gradient that determines to a large extent what plants and animals are present. In Puget Sound, it is difficult to differentiate between marine habitat and estuarine habitat, since salinity fluctuates with the seasons and tides. The Department of Natural Resources established a geographical boundary in 1990, drawing a line from Green Point, on Fidalgo Island, to Lawrence Point, on Orcas, and calling all waters to the east estuarine habitat, and water to the west marine (with some exceptions: Dungeness Bay, Sequim Bay, and various coastal estuaries such as Grays Harbor and Willapa Bay).
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.
What drives Puget Sound's 'underwater Amazon'?
In a new series we are calling Ask a Scientist we interview local researchers to get their thoughts on some of the important but lesser-known scientific facts about the Puget Sound ecosystem. Today, we speak with University of Washington oceanographer Parker MacCready about Puget Sound’s “underwater Amazon” and why it has profound implications for Puget Sound science and policy. It all begins, he says, with the mixing of fresh and salt water and something called the estuarine exchange flow.
How do you build an estuary? The answer lies in Puget Sound’s geologic history
Puget Sound is often referred to as the second largest estuary in the United States behind only Chesapeake Bay, but its overall size may be less important than its complexity. The place is defined by the mixing of saltwater from the ocean and freshwater from creeks and rivers that create an almost alchemical transformation of habitat. In this article, we look at the geologic forces that formed Puget Sound and made it the dynamic system that we understand today.
Making room for salmon
How can Puget Sound generate more salmon? That question has been at the center of ecosystem recovery efforts for decades. But even as scientists and conservationists make progress on many fronts — from breaching dams to cleaning up the water — they have faced one especially complicated and frustrating limitation: Salmon need more estuaries. We look at how local tribes are working to restore this critical habitat.
Puget Sound National Estuary Program Synthesis of Integrated Floodplain Management in Selected Puget Sound River Deltas
A 2021 synthesis report from the University of Washington Puget Sound Institute synthesizes leading integrated floodplain management approaches to support the EPA-funded Floodplains and Estuaries Implementation Strategy.
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 forests offer hope for salmon
Can scientists bring back the lost tidal forests of Puget Sound? It could take generations, but restoring this rare habitat will pay big dividends for Puget Sound’s salmon.
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.
Saving the last estuaries
When rivers spill into Puget Sound, they provide some of the most productive habitat in the ecosystem. The ebb and flow of the tides creates a perfect mix of fresh and salt water critical for young salmon. But over the past 100 years, the region’s tidal wetlands have declined by more than 75%. Now a coalition of state and federal agencies has a plan to bring them back.
Puget Sound: a uniquely diverse and productive estuary
Puget Sound is the second largest estuary in the United States. Today, we understand that estuaries—where freshwater and saltwater merge—are among the most productive places for life to exist.
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.
Eyes Over Puget Sound: Surface Conditions Report - March to June 2022
Low air temperatures, rain, and late snow accumulation pushed back the discharge of meltwater to Puget Sound this season. The water temperature in Puget Sound was mostly at expected levels, but cooler in South Sound by May. Central Sound saw more oxygenated conditions. This year, La Niña weather made flying for aerial photography challenging, but by June, sunny days made up for it, revealing a high number of schooling fish, unusually low tides, and a glimpse of macroalgae to come. Internal waves in Central Basin and Puget Sound, and the beauty of Puget Sound from the air, are a reminder of the unique place we live in.
'Invertebrate engineers' combat sea level rise
A pilot project to create a 'living dike' in Canada's Boundary Bay is designed to help a saltwater marsh survive rising waters due to climate change.
Rethinking flood control for the Nooksack River
Can restoring the natural balance of the Nooksack River also reduce flood risks? Officials on both sides of the U.S.-Canada border are taking note as climate change raises the stakes.
Eyes Over Puget Sound: Surface Conditions Report - February 25, 2022
The winter was cold and wet, resulting in a good snowpack in the mountains to sustain river flows into summer. In Puget Sound, saltier waters in summer transitioned to fresher conditions by fall 2021. Water temperatures in late winter 2022 are now colder and oxygen levels are high. From the air, Puget Sound looks spectacular, with few events to report. First signs of the spring bloom were visible in protected bays and passes. Port Susan and Carr Inlet already show sizable patches of drifting organic material. Small jellyfish patches were present in Eld Inlet.
Eyes Over Puget Sound - 2021 Year in Review
The year 2021 was generally drier and warmer including a heat wave in June. Higher river flows followed a rainy and cloudy fall. In 2021, EOPS aerial images continued to capture the diversity of phenomena on the water, with support from its wonderful contributors who documented visible water quality issues across the larger Puget Sound region. With our Artists Corner and story maps on critters in the mud, we hope to continue to inspire, educate, and motivate our community to keep curious and watchful eyes over the environment.
State of the Sound report 2021
The 2021 State of the Sound is the Puget Sound Partnership’s seventh biennial report to the Legislature on progress toward the recovery of Puget Sound. The document reports on both the status of the Partnership's recovery efforts and a suite of ecosystem indicators referred to as the Puget Sound Vital Signs.
Eyes Over Puget Sound: Surface Conditions Report - September 8, 2021
This summer river flows were generally lower than in 2020. And in August, high air temperatures and low precipitation continued, following a drought emergency declaration in mid-July that affected also marine conditions. The higher-than-normal salinity anomaly which persisted during summer in Puget Sound marine water is, however, eroding away, and lower-than-normal oxygen conditions developed in Central Sound in the month of August. Many blooms and organic material were reported by citizens throughout summer, and by September many colorful blooms in bays across the region continue to be active. Patches of macro-algae and organic debris are still numerous in South and Central Sound and in Padilla Bay. Jellyfish are occurring in unusual places. While we document water quality issues, we are also showcasing the natural beauty of Puget Sound through photography.
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.
Eyes Over Puget Sound: Surface Conditions Report - March 11, 2021
We are in a weakening La Niña, coastal downwelling has lessened and we are getting out of a cold and wet stretch, hurray. In March, rivers have almost returned to normal and carry clear water. It’s a good time to go diving if you don’t mind cold water. The productive season has only started in some places and patches of jellyfish are visible. Have a look at this edition and marvel about the secrets of the dead, or mysterious sediment clouds and the oil sheen spotted near Lummi Bay.
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.
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.
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.
Salish Sea Model looks at climate impacts on the nearshore
A 2019 paper in the Journal of Geophysical Research: Oceans outlines how the Salish Sea Model describes the impacts of climate change, sea level rise and nutrient loads on the region's nearshore environment.
Puget Sound River History Project
The Puget Sound River History Project at the University of Washington features historical topographic data for Puget Sound's river systems.
Policy pivot in Puget Sound: Lessons learned from marine protected areas and tribally-led estuarine restoration
A 2018 paper in the journal Ocean and Coastal Management examines and compares planning approaches used to develop marine protected areas and estuary restoration projects in Puget Sound. It finds that management policies can benefit from increasingly collaborative planning with a focus on multiple benefits such as flood control, salmon recovery, recreation and resilience to climate change.
Eyes Over Puget Sound: Surface Conditions Report – June 28, 2018
During June, near normal air temperatures and continued low precipitation have resulted in highly variable freshwater inputs to Puget Sound. A large Noctiluca bloom extends across the South Central Basin of Puget Sound. Coccolithophores are blooming in Hood Canal. Macroalgae is drifting as mats on the water in Port Madison, South Central Basin, and South Sound. They are also piling up on beaches in South and Central Puget Sound and Whidbey Basin. Juvenile fish are migrating out of the estuaries and meeting a complex thermal habitat. New infrared images tell the story. Meet our ocean acidification expert, Stephen Gonski.
Size means survival for young salmon
Getting bigger faster can help save juvenile Chinook salmon from a gauntlet of hungry predators ranging from birds and marine mammals to larger fish. We continue our series on the Salish Sea Marine Survival Project with a look at what helps salmon grow and prepare for life in the open ocean.
Opening the black box: What’s killing Puget Sound’s salmon and steelhead?
An intensive research program in the U.S. and Canada is studying why so few salmon in the Salish Sea are returning home to spawn. They are uncovering a complex web of problems involving predators, prey and other factors that put salmon at risk as they migrate to the ocean. We begin a four-part series on the Salish Sea Marine Survival Project, including new findings presented at the 2018 Salish Sea Ecosystem Conference last spring in Seattle.
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.
Monitoring helps to reveal hidden dangers in the food web
Toxic chemicals have been showing up in Puget Sound fish for more than a century, but consistent testing over the past 30 years has helped to reveal some unusual patterns of pollution.
Are we making progress on salmon recovery?
In recent decades, hundreds of millions of dollars have been spent to restore habitat for Puget Sound salmon. In this article, we look at how scientists are gauging their progress. Are environmental conditions improving or getting worse? The answer may depend on where you look and who you ask.
State of the salmon in watersheds 2016
A biennial report produced by the Governor's Salmon Recovery Office provides stories and data about salmon, habitat, and salmon recovery in Washington, including Puget Sound.
2016 Salish Sea Toxics Monitoring Review: A Selection of Research
A 2017 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.
Puget Sound Ecosystem Monitoring Program
The Puget Sound Ecosystem Monitoring Program (PSEMP) is an independent program established by state and federal statute to monitor environmental conditions in Puget Sound.
Finding a strategy to accelerate Chinook recovery
As threatened Chinook populations in Puget Sound continue to lose ground, the state is looking to new strategies to reverse the trend. In the Skagit watershed, the scientists — and the fish — are among those leading the way.
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.
Puget Sound marine and nearshore grant program results, final analysis report
A September 2016 report from the University of Washington Puget Sound Institute provides an overview of key products, results, and recommendations presented in three previous reports reviewing 50 projects from the first four years of the Puget Sound Marine and Nearshore Grant Program.
Concerns rise over rogue chemicals in the environment
Drugs like Prozac and cocaine have been showing up in the region’s salmon. But these are just some of the potentially thousands of different man-made chemicals that escape into the Salish Sea every day, from pharmaceuticals to industrial compounds. Now the race is on to identify which ones pose the greatest dangers.
Salish Sea snapshots: Invasive species and human health
Invasive species are considered a top threat to the balance of ecosystems worldwide. New discoveries of non-native green crabs in Puget Sound have highlighted that concern here at home, but invasive species can impact more than just the food web. Some introduced species can produce toxins that accumulate in shellfish or by directly infecting the human body.
2015 Puget Sound Marine Waters Overview
The Puget Sound Ecosystem Monitoring Program released its fifth annual Marine Waters Overview this week. The report provides an assessment of marine conditions for the year 2015 and includes updates on water quality as well as status reports for select plankton, seabirds, fish and marine mammals.
Second invasive green crab found in Puget Sound
Another European green crab has been spotted in Puget Sound prompting concern that the species may gain a foothold in the region.
Salish Sea snapshots: Plastics in fish may also affect seabirds
Sand lance in parts of British Columbia are ingesting small pieces of plastic that may be passed through the food web.
The return of the pig
After an almost complete collapse in the 1970s, harbor porpoise populations in Puget Sound have rebounded. Scientists are celebrating the recovery of the species sometimes known as the "puffing pig."
Green crabs could impair Puget Sound shellfish operations
Concerns over the potential arrival of the European green crab have inspired a small army of volunteers. A search is underway for early signs of an invasion.
Building a baseline of invasive species in Puget Sound
Almost twenty years ago, volunteer biologists began an intensive survey for invasive species in the marine waters of Puget Sound. In a little over a week of hunting, they found 39 such species, including 11 never before seen in the region.
Invasive marine species: Washington state priorities
The Washington Invasive Species Council evaluated more than 700 invasive species in and around Washington, considering their threats to the state’s environment, economy, and human health. They included terrestrial plants and animals, aquatic plants and animals (both freshwater and saltwater), insects and diseases. In the end, the council listed 50 “priority species” for action, including five marine animals and two marine plants, along with one virus that infects fish.
A review of Puget Sound marine and nearshore grant program results, Part 2
A July 2016 report from the University of Washington Puget Sound Institute summarizes and reviews 10 EPA-funded projects focusing on Puget Sound's marine and nearshore environments. The projects were conducted between 2011-2015 with support from the EPA's National Estuary Program. The report is an analysis of findings on invasive species, toxics, oil spill, and integrated risk assessment.
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.
Killer whale miscarriages linked to low food supply
New techniques for studying orcas have been credited with breakthroughs in reproductive and developmental research. Drones and hormone-sniffing dogs are helping scientists connect declines in food supply with low birth rates and poor health. Update: The research described in this 2016 article has now been published in the 6/29/17 issue of the journal PLOS ONE.
Salish Sea snapshots: Detecting harmful algal blooms
Environmental samplers may provide early detection of harmful algal blooms (HABs) in Puget Sound. This toxic algae is expected to increase as the climate changes, bringing with it new and potentially more severe outbreaks of shellfish poisonings.
Advances in technology help researchers evaluate threatened Puget Sound steelhead
New, smaller acoustic tags will allow scientists to track steelhead migrations in Puget Sound in ways that were once impossible. Will they provide answers to the mysterious decline of these now-threatened fish?
Mystery remains in deaths of young salmon
The Salish Sea Marine Survival Project has mobilized dozens of organizations in the U.S. and Canada to find an answer to one of the region's greatest mysteries. What is killing so many young salmon before they can return home to spawn? A series of talks at the 2016 Salish Sea Ecosystem Conference brought together some of the latest research.
Contaminants higher in resident 'blackmouth' Chinook
Many of Puget Sound's Chinook salmon spend their entire lives in local waters and don't migrate to the open ocean. These fish tend to collect more contaminants in their bodies because of the sound's relatively high levels of pollution.
New theory rethinks spread of PCBs and other toxics in Puget Sound
Researchers are proposing a shift in thinking about how some of the region’s most damaging pollutants enter Puget Sound species like herring, salmon and orcas.
The growing number of species of concern in the Salish Sea suggests ecosystem decay is outpacing recovery
The number of species of concern in the Salish Sea is growing at an average annual rate of 2.6%, according to a report published in the proceedings of the 2016 Salish Sea Ecosystem Conference in Vancouver, B.C.
Conference snapshot: The number of species of concern in the Salish Sea is growing steadily
The number of species of concern in the Salish Sea is growing at an average annual rate of 2.6%, according to a report published in the proceedings of the 2016 Salish Sea Ecosystem Conference in Vancouver, B.C.
Disappearance and return of harbor porpoise to Puget Sound
A 2016 technical report from the Washington Department of Fish and Wildlife and the Cascadia Research Collective details the decline of the harbor porpoise in Puget Sound in the 1970s and reports that species numbers have increased over the past twenty years likely due to outside immigration.
Contaminants of emerging concern in a large temperate estuary
A 2016 paper in Environmental Pollution identifies dozens of pharmaceuticals and other compounds that are accumulating in Puget Sound fish such as salmon.
Population diversity in Pacific herring of the Puget Sound
A 2016 paper in the journal Oecologia describes how individual herring populations in Puget Sound exhibit a portfolio effect, collectively influencing and stabilizing the region’s population as a whole.
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.
Will Ballard Locks withstand a major earthquake?
For close to 100 years, Seattle's Ballard Locks has been one of the region's busiest waterways, drawing major boat traffic along with millions of tourists. But as it prepares to celebrate its centennial, the aged structure is also drawing the concern of engineers. They worry that an earthquake could cause the locks to fail, draining massive amounts of water from Lake Washington and Lake Union. In some scenarios, the two lakes could drop by as much as 20 feet, stranding boats, disabling bridges and causing big problems for salmon restoration.
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.
Conjoined fetal twins in a harbor seal (Phoca vitulina)
This article describes the first known case of conjoined twins in a harbor seal. The case was documented in the Salish Sea region where harbor seals are often used as indicators of contaminant levels. However, researchers say their findings do not support that this anomaly was due to any common contaminants and hypothesize that the twinning was caused by disordered embryo migration and fusion.
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.
Are diseases playing a role in salmon decline?
Chinook, coho and steelhead populations in Puget Sound have declined dramatically over the past 30 years. In some cases, counts of fish returning to the rivers are just a tenth what they were in the 1980s. While many possible causes of this decline are under consideration, some researchers are focusing on the combined effects of predators and disease. This article continues our coverage of the ecological impacts of disease in Puget Sound.
Concerns rise over potential impacts of disease on the ecosystem
From orcas to starfish to humans, disease affects every living creature in the ecosystem. Scientists are increasingly alarmed by its potential to devastate already compromised populations of species in Puget Sound.
Evaluating threats in multinational marine ecosystems: A Coast Salish first nations and tribal perspective
A 2015 paper in the journal PLoS ONE identifies ongoing and proposed energy-related development projects that will increase marine vessel traffic in the Salish Sea. It evaluates the threats each project poses to natural resources important to Coast Salish first nations and tribes.
Birch Bay characterization and watershed planning pilot – taking action
A 2015 report from the Whatcom Conservation District and Whatcom County describes a pilot watershed characterization study focusing on the Terrell Creek and Birch Bay areas. The report and related appendices are available for download.
A review of Puget Sound marine and nearshore grant program results, Part 1
A 2015 report from the University of Washington Puget Sound Institute summarizes and reviews 14 EPA-funded projects focusing on Puget Sound's marine and nearshore environments. The projects were conducted between 2011-2015 with support from the EPA's National Estuary Program.
State of Knowledge: Climate Change in Puget Sound
A 2015 report from the University of Washington provides the most comprehensive assessment to date of the expected impacts of climate change on the Puget Sound region.
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
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.
Fishes of the Salish Sea: a compilation and distribution analysis
A 2015 NOAA report creates an updated and comprehensive list of the fishes of the Salish Sea.
Harbor porpoise in the Salish Sea
In the 1940s, harbor porpoise were among the most frequently sighted cetaceans in Puget Sound, but by the early 1970s they had all but disappeared from local waters. Their numbers have since increased, but they remain a Species of Concern in the state of Washington. This in-depth profile looks at harbor porpoise in the Salish Sea, and was prepared by the SeaDoc Society for inclusion in the Encyclopedia of Puget Sound.
2014 Puget Sound Marine Waters Overview
A report from NOAA and the Puget Sound Ecosystem Monitoring Program provides an overview of 2014 marine water quality and conditions in Puget Sound from comprehensive monitoring and observing programs.
2014 state of salmon in watersheds executive summary
This report documents how Washingtonians have responded to the challenges of protecting and restoring salmon and steelhead to healthy status. It also serves as a tool to summarize achievements, track salmon recovery progress through common indicators, and identify data gaps that need to be filled.
Evidence shows that gulls are shifting their diets from marine to terrestrial sources
A 2015 article in the journal Environmental Science and Technology presents additional isotopic evidence that glaucus-winged gulls in the Salish Sea are shifting their diets from marine to terrestrial sources due to human impacts. Scientists hypothesize that declining forage fish may be the cause.
Review of the marine environment and biota of Strait of Georgia, Puget Sound and Juan de Fuca Strait
Proceedings of the BC/Washington Symposium on the Marine Environment, January 13 and 14, 1994
Increased harbor porpoise mortality in the Pacific Northwest, USA: understanding when higher levels may be normal
A 2015 paper in the journal Diseases of Aquatic Organisms examines potential causes of increased harbor porpoise strandings in Washington and Oregon.
State of the physical, biological and selected fishery resources of Pacific Canadian marine ecosystems in 2014
An annual State of the Pacific Ocean meeting is held to review the physical, biological and selected fishery resources and present the results of the most recent year’s monitoring in the context of previous observations and expected future conditions. The workshop to review conditions during 2014 took place at the Institute of Ocean Sciences, Sidney, B.C. on March 10 and 11, 2015, with over 100 participants both in person and via webinar.
2012 state of salmon in watersheds executive summary
Salmon recovery demands both dedication among people with different interests, and sustained resources. This biennial report tells the story of the progress made to date and the challenges ahead.
Subsistence fishing in a 21st century capitalist society: From commodity to gift
A 2015 paper in the journal Ecological Economics evaluated “personal use” and subsistence use of seafood among commercial operators in Washington and California, as well as the extent, range, and species diversity of noncommercial wild ocean seafood subsistence harvests.
An inland sea high nitrate-low chlorophyll (HNLC) region with naturally high pCO2
A 2015 paper in the journal Limnology and Oceanography presents new data on ocean acidification in the Salish Sea.
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).
Spatial and temporal patterns in smolt survival of wild and hatchery coho salmon in the Salish Sea
Scientists say low marine survival rates threaten Puget Sound coho salmon populations. A 2015 article in the journal Marine and Coastal Fisheries reports that wild cohos in the Salish Sea had higher smolt survival rates over a 30 year period than hatchery coho salmon. Smolt survival in the Strait of Georgia during that time declined faster than it did in Puget Sound.
Time of emergence of climate change signals in the Puget Sound Basin
A December 2014 report from the University of Washington examines when and where climate change impacts will occur in the Puget Sound watershed.
Online resource identifies 'time of emergence' for Puget Sound climate impacts
When and where will we see the impacts of climate change in Puget Sound? A web-based tool factors in dozens of site-specific variables for watersheds throughout the Pacific Northwest. The resource was developed by the University of Washington Climate Impacts Group with support from the EPA, the US Army Corps of Engineers and the Center for Data Science, University of Washington-Tacoma.
Forty years of change in forage fish and jellyfish abundance across greater Puget Sound, Washington (USA): anthropogenic and climate associations
A 2015 paper in the Marine Ecology Press Series reports a trend toward more jellyfish and less of some forage fish species in Puget Sound. The paper analyzes more than 40 years of state data, and assesses potential human causes for the shift.
State of Washington status report for the tufted puffin
A 2015 report from the Washington Department of Fish and Wildlife reviews information relevant to the status of the tufted puffin in Washington and addresses factors affecting this status.
Foraging differences between male and female harbor seals present challenges for fisheries management
A 2015 article published in the Marine Ecology Progress Series identifies intraspecific differences in diet between harbor seals in the Salish Sea, suggesting implications for marine reserve management.
Status and trends for seagrasses in Puget Sound from 2010-2013
A 2015 report from the Washington State Department of Natural Resources summarizes the status and trends for native eelgrass and other seagrasses in Puget Sound from 2010-2013.
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.
Ranking the greatest threats to Puget Sound: A summary of the 2014 Puget Sound Pressures Assessment
This paper summarizes a 2014 report ranking the greatest human-caused threats to the Puget Sound ecosystem.
Top–down control by great blue herons regulates seagrass-associated epifauna
A 2015 paper in Oikos Journal examines the impacts of great blue heron predation on species diversity in eelgrass meadows in British Columbia.
Framework for prioritizing monitoring of CECs in the Pacific Northwest
The Puget Sound Ecosystem Monitoring Program (PSEMP), along with partners from the US EPA Columbia River Program and USGS Oregon Water Science Center, have developed a framework for prioritizing monitoring of Contaminants of Emerging Concern (CECs) in the Pacific Northwest.
Living in the fast lane: rapid development of the locomotor muscle in immature harbor porpoises (Phocoena phocoena)
A study in the Journal of Comparative Physiology shows that muscle development necessary for diving can take several years to mature in harbor porpoises. Scientists argue that this may make immature harbor porpoises more vulnerable than adults to impacts from boat traffic or other disturbances.
Stimulus-dependent response to disturbance affecting the activity of killer whales
A 2015 paper presented to the International Whaling Commission compares the impacts of kayaks and powerboats on killer whale populations.
Taxonomic guides to benthic invertebrates of Puget Sound
A 2014 Washington State Department of Ecology report provides a taxonomic guide for Puget Sound sediment-dwelling invertebrates (benthos). Surveys of these species are used to monitor the health of the foodweb, as well as levels of toxic contaminants in the seafloor.
Population structure and intergeneric hybridization in harbour porpoises Phocoena phocoena in British Columbia, Canada
A 2014 paper in Endangered Species Research suggests that harbour porpoises inhabiting coastal waters of southern British Columbia constitute a single genetic population, which should be reflected in management decisions.
Development of a stormwater retrofit plan for Water Resources Inventory Area (WRIA) 9: Comprehensive needs and cost assessment and extrapolation to Puget Sound
A 2014 King County report projects the capital and maintenance costs of the stormwater treatment facilities that would be needed, within WRIA 9 and the Puget Sound region, to fully comply with the Clean Water Act.
Gifts from the sea: shellfish as an ecosystem service
The region's famed mollusks provide more than just money and jobs. They offer what are called ecosystem services—a wide variety of benefits that humans derive from an ecosystem.
Health of the Salish Sea as measured using transboundary ecosystem indicators
A December 2014 paper in the journal Aquatic Ecosystem Health & Management describes a project to identify transboundary ecosystem indicators for the Salish Sea.
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.
Virus associated with sea-star wasting disease
A virus is the likely cause of sea-star die-offs on the Northeast Pacific Coast and in Puget Sound, according to a November 2014 paper published in the Proceedings of the National Academy of Sciences.
Ecological effect of a nonnative seagrass spreading in the Northeast Pacific: A review of Zostera japonica
A 2014 literature review in the journal Ocean & Coastal Management suggests negative effects of nonnative eelgrass on the native species.
Seeking higher calories for Puget Sound killer whales
A 2014 paper decribes how monitoring the energy density of key Pacific salmon species could affect the recovery of northern and southern killer whales through fisheries management.
Assessing ecological correlates of marine bird declines to inform marine conservation
Birds that dive for fish while wintering in the Salish Sea are more likely to be in decline than nondiving birds with less specialized diets, according to a 2014 study led by the School of Veterinary Medicine at the University of California, Davis. The study, published in the journal Conservation Biology proposes that long-term changes in the availability of forage fish are pushing the declines.
Citizens now the leading cause of toxics in Puget Sound
New research presented at the 2014 Salish Sea Ecosystem Conference shows that some of the greatest dangers to Puget Sound marine life come from our common, everyday activities. These pervasive sources of pollution are so woven into our lives that they are almost invisible to us, but it’s becoming impossible to ignore their effects.
State of the physical, biological and selected fishery resources of Pacific Canadian marine ecosystems in 2013
A summary of environmental conditions in Pacific Canadian Waters and the broader North East Pacific in 2013.
2013 Puget Sound Marine Waters Overview
A report from the Puget Sound Ecosystem Monitoring Program provides an overview of 2013 marine water quality and conditions in Puget Sound from comprehensive monitoring and observing programs.
No salmon left behind: The importance of early growth and freshwater restoration
The growth and survival of young salmon in streams, river deltas and floodplains are seen as crucial pieces of the salmon recovery puzzle. In part two of this two-part series, researchers at the Salish Sea Ecosystem Conference in Seattle say the complexities of the salmon life cycle require new coordination among scientists.
What is killing young salmon in Puget Sound?
Scientists say Puget Sound’s salmon are dying young and point to low growth rates in the marine environment as a possible cause. In part one of this two-part series, scientists consider threats facing young salmon in the open waters of Puget Sound.
Shedding new light on eelgrass recovery
Scientists say eelgrass, an unassuming flowering plant found just off shore in Puget Sound, is vital to the health of the ecosystem. They also say the plant is declining. New and increasingly urgent efforts to restore it brought a group of researchers to the 2014 Salish Sea Ecosystem Conference.
Age, region, and temporal patterns of trace elements measured in stranded harbor seals (Phoca vitulina richardii) from Washington inland waters
A 2014 article in the journal Northwestern Naturalist shows how Harbor Seal tissues can reflect regional and temporal trends in contaminants in Puget Sound.
Declines in marine birds trouble scientists
Why did all the grebes leave? Where did they go? And what does their disappearance say about the health of the Salish Sea? Seasonal declines among some regional bird species could hold important clues to the overall health of the ecosystem.
Pigeon Guillemot Foraging and Breeding Survey in and Near the Nisqually Reach Aquatic Reserve
A 2014 report describes a research and monitoring study of Pigeon Guillemot conducted in and near the Nisqually Reach Aquatic Reserve.
Collaboration within the Puget Sound marine and nearshore science network
A study published in the journal Coastal Management generates a broad description of the collaborative network among marine and nearshore researchers in Puget Sound and identifies incentives and barriers to collaboration.
Special issue of Coastal Management focuses on social sciences in Puget Sound recovery
The July 2014 issue of the journal Coastal Management focuses on the role of social sciences in Puget Sound ecosystem recovery. Articles range from political ecology to the development of human wellbeing indicators and directly address current Puget Sound restoration efforts. Guest editors include Encyclopedia of Puget Sound topic editor Kelly Biedenweg and Puget Sound Science Panel co-chair Katharine Wellman. The journal is co-edited by Patrick Christie of our editorial board. Extended abstracts of the articles will be available on these pages in coming weeks.
Harbor seal species profile
Harbor seals (Phoca vitulina) are the most commonly seen marine mammals in the Salish Sea and can be found throughout the region year round. They have been intensively studied within the Salish Sea and this species profile provides an overview of what is known about them. It was produced for the Encyclopedia of Puget Sound by the SeaDoc Society.
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.
Spatial and Temporal Variation in River Otter (Lontra canadensis) Diet and Predation on Rockfish (Genus Sebastes) in the San Juan Islands, Washington
A 2014 paper in the journal Aquatic Mammals examines coastal river otter predation on rockfish at three islands in the Salish Sea.
Species of Concern within the Salish Sea nearly double between 2002 and 2013
Approximately every two years, the SeaDoc Society prepares a list of species of concern within the Salish Sea ecosystem. The following paper found 119 species at risk and was presented as part of the proceedings of the 2014 Salish Sea Ecosystem Conference, April 30 – May 2, 2014, Seattle, Washington.
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.
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.
Nitrogen as an Eelgrass Stressor in Puget Sound
Although overall eelgrass abundance appears to be stable in Puget Sound, some local areas are showing declines. A 2014 report from the Washington State Department of Natural Resources looks at the potential impact of increased nitrogen on eelgrass health.
Videos: The Puget Sound Model
The Puget Sound Model was designed and built by the University of Washington School of Oceanography in the early 1950s to simulate the tides and currents of Puget Sound. A series of videos produced by the Encyclopedia of Puget Sound describes its construction and operation.
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.
Measuring Socio-Cultural Values Associated with Salmon in the Quinault Indian Nation
A 2014 report describes a study of socio-cultural values associated with blueback salmon in the Quinault Indian Nation. The blueback salmon (Oncorhynchus nerka) is a unique strain of sockeye that returns primarily to the Quinault river system.
Statement on Salish Sea Harbor Porpoise Research and Management Needs
Harbor porpoise (Phocoena phocoena) are one of the most frequently sighted cetaceans in the Salish Sea. Anecdotal information, possibly supported with stranding encounter rate data, suggests that harbor porpoise may have increased in Puget Sound, or have shifted their distribution back to Puget Sound relative to earlier decades.
Harbor Porpoise (Phocoena phocoena vomerina): Washington inland waters stock
Harbor porpoises were once common in Puget Sound, but had all but disappeared from local waters by the 1970s. Regular and numerous anecdotal sightings in recent years show that populations of these cetaceans are now increasing and may be approaching their former status. The attached document from NOAA Fisheries describes harbor porpoise numbers and their geographic range in Puget Sound as of 2011.
HARBOR PORPOISE (Phocoena phocoena vomerina): Washington Inland Waters Stock (NOAA Fisheries 2011)
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.
Defining and describing Puget Sound shore types
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.
Reducing the risk of PCBs in sediments
A 2014 paper in the journal Water Research sheds new light on a novel ‘in place’ treatment option that effectively lowers risk by reducing the activity of PCBs in sediment.
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.
Development of Puget Sound Benthic Indicators
A Washington State Department of Ecology report establishing benthic indicators for Puget Sound. Benthic macrofauna are known to be good indicators of the status of marine environments, and benthic indices are often used as an assessment tool.
Marine and terrestrial bird indicators for Puget Sound
A December 2013 report identifies marine and terrestrial bird species for use as indicators within the Puget Sound Partnership's "Vital Signs" for ecosystem health.
Making science useful in complex political and legal arenas: A case for frontloading science in anticipation of environmental changes to support natural resource laws and policies
Climate change impacts and adaptations in Washington State: Technical summaries for decision makers
A December 2013 report by the University of Washington Climate Impacts Group projects wide reaching change for the Puget Sound ecosystem and the Pacific Northwest. Lead author: Encyclopedia of Puget Sound climate change topic editor Amy Snover.
Puget Sound salmonid habitat monitoring inventory and recommendations
An October 2013 report released by the Puget Sound Ecosystem Monitoring Program inventories and assesses monitoring activities of Puget Sound's ESA-listed salmon and steelhead stocks and habitats.
Paper: Food habits of harbor seals (Phoca vitulina) in two estuaries in the central Salish Sea
This paper discusses the dietary habits of harbor seals (Phoca vitulina) in two estuaries in Puget Sound.
Reports: Steller Sea Lion status reports
This page includes documents and links related to the status of Steller Sea Lion in Washington state and the Salish Sea region.
2012 Puget Sound Marine Waters Overview
The Puget Sound Marine Waters 2012 Overview from the Puget Sound Ecosystem Monitoring Program synthesizes conditions measured in 2012 and has been expanded to include observations on seabirds that rely on marine waters. Read an excerpt below, or download the full report.
Puget Sound Voices: Don Malins interview
The audio files below are excerpts from a May 2013 interview with Donald Malins, former Director of the Environmental Conservation Division of NOAA Fisheries. Research by Malins and his colleagues in the 1970s and mid-1980s revealed high levels of industrial toxics in sediment-dwelling fish in Puget Sound, leading to the creation of Superfund sites in the Duwamish Estuary and Commencement Bay. Read a full profile of Donald Malins. The interview was conducted by Richard Strickland and Randy Shuman in cooperation with the Encyclopedia of Puget Sound as part of the Puget Sound Voices series. Additional assistance was provided by Jake Strickland.
Toxics research that changed Puget Sound history
In the 1970s and 1980s, research from a division of NOAA's Montlake Lab suddenly changed the way scientists and the public viewed the health of Puget Sound. Their discovery of industrial toxics in the region's sediment-dwelling fish led to the creation of two Superfund sites, and new approaches to ecosystem management across the Sound. The man at the forefront of this research was Dr. Donald Malins, featured here as part of the Puget Sound Voices series.
Paper: Citizen science reveals an extensive shift in the winter distribution of migratory Western Grebes
A June 19, 2013 paper in the journal PLoS ONE hypothesizes that regional declines in Western Grebe populations may be related to decreasing numbers of forage fish. Using citizen science data from 36 years of bird counts, researchers were able to look at population trends up and down the entire West Coast, finding that abundance of grebes decreased in the Salish Sea but increased in southern California. North American population declined by 52% overall.
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.
Puget Sound Voices: scuba pioneer
Vern Morgas remembers the early days of scuba diving in Puget Sound.
Influence of sex and body mass on harbor seal (Phoca vitulina) diving behavior
A master's thesis prepared at Western Washington University discusses the impact of harbor seals on fish stocks in the San Juan Islands, where the seals are a year-round predator.
NOAA report establishes Chinook monitoring framework
A new Chinook monitoring framework is designed to build cooperation among managers and policymakers working across the Puget Sound watershed. The report, prepared by an independent team of scientists and released by NOAA, includes a regionally specific, common classification system for Chinook habitats and key ecological attributes.
Puget Sound Chinook Salmon recovery: a framework for the development of monitoring and adaptive management plans
The Puget Sound Recovery Implementation Technical Team has released a draft of a NOAA technical memorandum describing frameworks for adaptive management and monitoring of Chinook salmon in Puget Sound. Download the report.
Eelgrass (Zostera marina L.) is an aquatic flowering plant common in tidelands and shallow waters along much of Puget Sound’s shoreline. It is widely recognized for its important ecological functions, and provides habitat for many Puget Sound species such as herring, crab, shrimp, shellfish, waterfowl, and salmonids.
Report: Stock assessment for Bocaccio in British Columbia waters for 2012
Canadian and U.S. governments differ on special status for bocaccio in the Salish Sea.
Report: The effects of salmon fisheries on Southern Resident Killer Whales
A recent report by an independent science panel reviewed data on the effects of salmon fisheries on Southern Resident Killer Whale populations. The report was released on November 30, 2012 and was commissioned by NOAA Fisheries and Oceans Canada.
Salmonids in Puget Sound
Fish in the family Salmonidae (salmon, trout, and charr) play potentially integral roles in the upland freshwater, nearshore and pelagic marine ecosystems and food webs of Puget Sound.
Bentho-pelagic fish in Puget Sound
Bentho-pelagic fish utilize both bottom habitats and shallower portions of the water column, often feeding in shallow water at night and moving to deeper water to form schools during the day.
Dungeness crabs in Puget Sound
Dungeness crabs are an important resource in Puget Sound for recreational, commercial, and tribal fisheries. They utilize a variety of habitats over the course of their lives, and are vulnerable to shifts in ocean temperature and water quality.
Sweetening the waters - the feasibility and efficacy of measures to protect Washington’s marine resources from ocean acidification
Washington State's ocean acidification initiative began with the launch of Governer Christine Gregoire's Blue Ribbon Panel on Ocean Acidification in December 2011. The initiative is the first of its kind in the country, and a report commissioned by the Global Ocean Health Program was released in November 2012. The report is a first step towards assessing and improving the tools at hand.
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.
2011 Puget Sound Marine Waters Overview
The Puget Sound Marine Waters 2011 report is now available. The report was produced by the Puget Sound Ecosystem Monitoring Program and assesses the condition and quality of the waters of Puget Sound.
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.
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.
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.
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.