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's Grand Uncertainties Matrix
Researchers are compiling a strategic list of scientific uncertainties related to Puget Sound recovery. The list will be used to prioritize future funding and research to address critical knowledge gaps about the ecosystem.
Circulation in Puget Sound (infographic)
Estuaries around the world including Puget Sound perform an amazing feat of continuous water mixing called estuarine exchange flow.
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.
Scientists look for answers in methane bubbles rising from bottom of Puget Sound
Large plumes of methane bubbles have been discovered throughout the waters of Puget Sound prompting questions about the Puget Sound food web, studies of earthquake faults and climate-change research.
Eyes Over Puget Sound: Surface Conditions Report - April 1, 2021
After a wet winter/spring transition it has been noticeably drier, warmer and sunnier. River flows are near normal levels and in Puget Sound and coastal bays salinity is increasing above normal. The spring bloom is developing but not very pronounced, yet, Noctiluca is already visible in southern Hood Canal. Suspended sediment near rivers and creeks, failing bluffs, and shellfish activities are frequent. Capturing herring spawning from the plane is informative; pilots share their observations.
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.
Eyes Over Puget Sound: Surface Conditions Report - February 3, 2021
Rivers are flowing higher than normal since 2020. Winter weather has been warmer and wetter. In marine waters, temperatures have become too cool for Northern Pacific anchovies to tolerate in North Sound. From patches of jellyfish and snow geese, to sediment and early blooms, there is more happening in the winter than you might expect. Puget Sound has many species worth showcasing such as the heart crab – a shy critter that wears its heart on its shell.
2019 Puget Sound Marine Waters Overview
A new report from the Puget Sound Ecosystem Monitoring Program details the effects of a changing climate on Puget Sound in 2019, and documents how these changes moved through the ecosystem to affect marine life and seafood consumers.
Eyes Over Puget Sound: Surface Conditions Report - October 26, 2020
After a relatively warm summer and fall, and La Niña forming in the tropics, stream flows in the Puget Sound region are now relatively normal. Summer in Puget Sound produced lots of algal and organic material in the water and on beaches, which by October have disappeared. Kelp beds look strong in northern Puget Sound and the Straits; and the harvest of the annual chum salmon run is in full swing in Hood Canal. Jellyfish aggregations are visible in Budd and Sinclair Inlets — and some of the jellyfish might conceal a beast of another kind within. Oil sheens on the water are currently numerous.
Puget Sound National Estuary Program land development and cover base program analysis
A 2020 Base Program Analysis from the University of Washington Puget Sound Institute presents an overview of the programs, policies and initiatives that support the Puget Sound Partnership’s Land Development and Cover Implementation Strategy.
Seawall removal reaps benefits of Elwha recovery
The Elwha River has become famous as the site of the largest dam removal project in U.S. history. Several years ago, scientists began knocking down another barrier about a mile away from the river's delta. They removed a large seawall along the Salish Sea shoreline and discovered that sediment from the dam removal had huge benefits for their project.
Eyes Over Puget Sound: Surface Conditions Report - March 16, 2020
After a wet January, precipitation has been low and air temperatures have been cooler. As a result, rivers gages are lower than expected, a pattern that has continued since last year. In March we approached the coldest water temperatures of the year. Herring are spawning in Port Madison. Although these cool temperatures are good for herring, temperatures are close to the survival limits for anchovies. If you can handle these temperatures, now is a good time to go diving to benefit of good underwater visibility, just avoid windy days near wave-exposed beaches. If you are lucky, you might see the kelp humpback shrimp, a master of camouflage.
Puget Sound's 'warm snow’ makes region vulnerable to climate shifts
Climate models project that if carbon emmisions continue as they are now, the vast majority of watersheds feeding Puget Sound will receive more rain and far less snow by 2080, causing increased flooding and other dramatic changes to the freshwater ecosystem. We look at the past and possible future of the region's snowpack and what this might mean for salmon and other species — including humans.
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.
Story map: Seeking softer shores on Puget Sound
A 2019 story map produced by the University of Washington Puget Sound Institute in collaboration with the Washington Department of Fish and Wildlife shows how shoreline armoring can often be replaced by softer, shore-friendly features.
Puget Sound tides
This article provides a general overview of tidal patterns in Puget Sound.
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.
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.
Puget Sound circulation triggers low-oxygen conditions at different times and in different places
The amount of oxygen in the Salish Sea is dependent on water circulation which distributes chemical elements such as nitrogen through the system.
Urban lifestyles help to protect the Puget Sound ecosystem
The state of Washington estimates that the Puget Sound area will grow by more than 1.5 million residents within the next two decades. That is expected to have profound effects on the environment as more and more people move to undeveloped areas. The race is on to protect this critical rural habitat, but planners say what happens in the cities may be just as important.
Hitting a wall: Can we fix Puget Sound’s beaches?
New numbers show progress in the state’s efforts to remove shoreline armoring, but they don’t tell the whole story.
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.
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.
Suspended marine pollutants more likely to enter food web
Researchers are studying how persistent pollutants such as PCBs avoid settling to the bottom of Puget Sound. This article continues our coverage of new theories on the spread of toxic chemicals in the food web.
Conference snapshot: Long-term study looks at impacts of shoreline armoring
A new peer-reviewed study reports significant findings on the impacts of shoreline armoring in the Salish Sea.
Sources of sand: maps show crucial “feeder bluffs”
For more than a hundred years, property owners have seen shoreline erosion as the enemy. But it turns out that in many cases erosion is actually a good thing — crucial, according to scientists — because it provides the sand and gravel needed for healthy beaches.
Shoreline and Coastal Planners Forum: Shoreline stabilization
Proceedings of the March 31, 2016 WA Shoreline and Coastal Planners Group Spring Forum. Shoreline Stabilization: Using the Permit Process to Protect Shoreline Habitat and Property with a Focus on Single Family Residential Properties
Spawning habitat for forage fish being lost to rising tides
Where shoreline bulkheads remain in place, the loss of spawning habitat used by surf smelt is likely to reach 80 percent.
Forage fish are losing places to lay their eggs
Rising sea levels are expected to exacerbate habitat loss caused by bulkheads, according to studies in the San Juan Islands.
Shoreline armoring's effect on the food web
The removal of shoreline armoring in Puget Sound has become a priority for state and federal agencies, but until recently there have been relatively few scientific studies of armoring's local impact. New research looks at the pronounced biological and ecological effects of these common shoreline structures, especially for tiny beach-dwelling creatures that make up the base of the food web.
Transfer of nutrients in the ecosystem
Decaying organic matter plays an important role in marine ecosystems.
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.
Salmon live in a topsy-turvy world upstream of the Ballard Locks
Chinook, coho and sockeye salmon, along with steelhead trout, live in the Lake Washington watershed and navigate a treacherous route through the Ballard Locks on their way to Puget Sound.
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.
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.
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.
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.
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.
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.
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.
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
The temperature and salinity characteristics of Puget Sound and Strait of Juan de Fuca based on the M. V. CATALYST observations of 1932 to 1942
A 1956 thesis submitted in partial fulfillment ot the requirement for degree of Master of Science, University of Washington
Chemistry of Puget Sound waters and influencing factors
This 1954 report present the results of a geochemical investigation, based on existing data, of the waters of Puget Sound. Rivers draining into the Puget Sound and upwelled water moving in at depth from Juan de Fuca Strait are the chief sources of the chemical constituents in Puget Sound.
The surface winds over Puget Sound and the Strait of Juan de Fuca and their oceanographic effects
This 1954 report accumulates all available wind report summaries have been in the form of monthly wind roses for each reporting station and makes a determination of the frequency and maximum duration of surface winds of above average velocity at selected stations over a three year period.
Hansen Creek alluvial fan and wetland restoration project
Habitat restoration was undertaken in 2009-2010 on lower Hansen Creek, Washington. The project converted 140 acres of isolated floodplain into 53 acres of alluvial fan and 87 acres of flow-through wetlands.
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.
1992 Puget Sound Update
The 1992 Puget Sound Update is the third annual report of the Puget Sound Ambient Monitoring Program (PSAMP). It reports the results of sampling undertaken in 1991, the most current year for which the data have under gone analysis and quality assurance tests.
1993 Puget Sound Update
The 1993 Puget Sound Update—the fourth annual report of this program—evaluates the data collected by PSAMP in 1992 (the most recent year for which the data have undergone quality assurance review and interpretation) and compares these data to past information on Puget Sound water quality.
1994 Puget Sound Update
The 1994 Puget Sound Update—the fifth annual summary report of this program—evaluates the data collected by the PSAMP in 1993 (the most recent year for which the data have undergone quality assurance review and interpretation) and compares these data to past information on Puget Sound.
1998 Puget Sound Update
This is the sixth Puget Sound Update, a report for residents of the region about the overall health of Puget Sound. The conclusions in the Update are based mainly on scientific results of the Puget Sound Ambient Monitoring Program (PSAMP).
2000 Puget Sound Update
This seventh Puget Sound Update is based primarily on the findings of the Puget Sound Ambient Monitoring Program (PSAMP). The PSAMP is a long-term effort to investigate environmental trends, improve decision-making and prevent overlaps and duplication in monitoring efforts. The results of the PSAMP are supplemented by the findings of many other efforts to evaluate the condition of Puget Sound’s waters, sediments, nearshore habitats and biological resources.
2002 Puget Sound Update
This Puget Sound Update is the eighth report of the Puget Sound Ambient Monitoring Program (PSAMP) since the program was initiated in 1988 by the State of Washington.
2007 Puget Sound Update
The Puget Sound Update is a technical report that integrates results of PSAMP and other scientific activities in Puget Sound focused on marine life and nearshore habitat, marine and freshwater quality, and toxic contamination.
Marine shoreline design guidelines
The Washington Department of Fish and Wildlife has published a comprehensive set of guidelines for managing shoreline development such as bulkheads and seawalls.
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).
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.
Influence of climate and land cover on river discharge in the North Fork Stillaguamish River
A 2014 report prepared by the Stillaguamish Tribe analyzes potential causes of changes in peak and low flows in the Stillaguamish River basin.
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.
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.
Suspended-sediment concentrations during dam decommissioning in the Elwha River, Washington
This document was prepared by the U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency and the National Park Service. Download the entire report, or read the Introduction below. Portions of this document were originally published in June 2013 and were updated in February 2014.
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.
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.