Scientists are still trying to understand what caused the deaths of thousands of rhinoceros auklets in the Salish Sea in 2016. Some studies point to disease as a central factor in that incident and potentially other large seabird die-offs along the coast. That is prompting a deeper look at what makes these birds sick, and how local populations are faring. We followed a group of researchers as they gave a health checkup to a breeding colony of rhinoceros auklets on Protection Island.

The watersheds of Washington’s San Juan Islands were thought to be too small to support wild salmonid populations, and many streams flow only seasonally. But a 2019 article in the journal Conservation Genetics reports that at least five watersheds in the region support populations of coastal cutthroat trout (Oncorhynchus clarki clarki). Genetic analysis of the cutthroat trout in three of the watersheds suggest two support native populations. The findings are important for understanding the conservation status of these previously unknown populations. 

A new report from the Puget Sound Ecosystem Monitoring Program says climate change altered the base of Puget Sound's food web in 2018, diminishing microscopic phytoplankton necessary for marine life. Scientists also observed lower abundances of fish, seabirds, and marine mammals.

A 2019 article in the Journal of Wildlife Diseases looked at trace element concentrations of heavy metals in the livers of harbor seals that died and stranded in the San Juan Islands. The study indicated exposure to trace elements (naturally occurring, human-introduced, or both) in the Salish Sea; however, the study reports that trace element toxicity is not a major threat to harbor seal health.

A 2019 report from Oregon State University examines how community members, including non-property owners, value shorelines in Puget Sound. The report emphasizes the impacts of shoreline armoring on survey respondents' sense of place in the region.

Volunteer researchers are tracking the plastic and other debris washing up on Puget Sound's beaches. They hope the data can be used to protect sea creatures from the growing amounts of trash littering the world's oceans. [A version of this article first appeared in the COASST blog.]

Notes and biography about the history of the department of oceanography at the University of Washington (1903-1980) as reported by oceanagrapher Eugene Collias. Report courtesy of the Collias estate.

Spring and fall Chinook salmon were thought to be alike until researchers discovered a gene for early migration. Now, federal biologists and legal experts are struggling to decide if spring Chinook should be granted their own legal protection under the Endangered Species Act.

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

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.

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.

Pigeon guillemots have attracted relatively little scientific attention compared to other seabirds in Puget Sound. That may be because their population is generally stable, but a group of citizen scientists is helping to put guillemots on the conservation radar. They hope the birds can be used as an indicator of Puget Sound health.

A 2014 paper in the journal PLoS ONE examines differences between foraging behavior of harbor seals based on haulout site locations, seasons, sexes and times of day. The authors hypothesize that these factors may help explain the variability in diet among harbor seals observed at different haul-out site groups in the Salish Sea. 

An unintended consequence of the recovery of bald eagles (Haliaeetus leucocephalus) has been the impact on seabirds. The authors of a 2019 paper published in Ecology and Evolution suggest that the effects of bald eagle activity on a large glaucous-winged gull (Larus glaucescens) colony on Protection Island in the Strait of Juan de Fuca include the possibility of coexistence but also the possibility of gull colony extinction.

The Washington Department of Natural Resources is studying new ways of increasing ecologically important eelgrass habitat in Puget Sound. It is part of the state's effort to boost eelgrass 20% Sound-wide by 2020. So far, recovery of the species has fallen short of that goal, but transplanting efforts are showing promise. 

Eight aquatic reserves in Puget Sound are being studied by volunteers working under the direction of state experts. Washington Department of Natural Resources manages the reserves with guidance from nearby communities.

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 removal of shoreline armoring has become a priority for the state's Puget Sound recovery efforts. The Puget Sound Ecosystem Monitoring Program (PSEMP) is providing details on the effectiveness of armor-removal projects at 49 study sites.

The sunflower sea star (Pycnopodia helianthoides) is highly susceptible to sea star wasting disease. The authors of a 2019 paper published in Science Advances document the rapid, widespread decline of sunflower stars and discuss the ecological implications of losing this important subtidal predator species.

Puget Sound’s only native oysters were nearly wiped out in the 19th century from overharvesting. Now a network of scientists and advocates is working to restore them to their historical and cultural prominence.

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. 

New research shows that warmer and more acidic oceans could lead to shorter embryos and higher respiration in Pacific herring.

Scientists argue that herring managers should take a tip from stock market investors and diversify the population’s “portfolio.” 

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. 

The Puget Sound Coastal Storm Modeling System analyzes the potential impacts of sea level rise on nearshore areas of the Puget Sound region. 

Researchers are analyzing the harmful effects of creosote-treated wood pilings on Pacific herring and shellfish in Puget Sound. Studies show that piling removal projects can ease the impacts, but only if carefully done. 

The restoration of eelgrass (Zostera marina L.) is a high priority for Puget Sound ecosystem recovery. In 2011, the State of Washington set a restoration target to increase eelgrass abundance by 20% in Puget Sound by 2020. Locating areas to restore eelgrass effectively and efficiently has been challenging for researchers. A 2018 article in the journal Restoration Ecology reports on efforts to identify potential restoration sites using simulation modeling, a geodatabase for spatial screening, and test planting. 

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.

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. 

Ocean acidification could be up to twice as severe in fragile seagrass habitats as it is in the open ocean, according to a study published last April in the Proceedings of the National Academy of Sciences. The conditions may threaten Dungeness crabs by 2050 and will be especially pronounced in the winter, the study says.

New studies show that eelgrass wasting disease is more common in warmer waters, leading to concerns over the future effects of climate change on eelgrass populations in Puget Sound. We continue our series on science findings from the 2018 Salish Sea Ecosystem Conference.  

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.

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. 

A 2017 paper in the journal Northwestern Naturalist looks at distribution patterns for Glaucous-winged Gulls across associated habitats in the Salish Sea.  

Researchers are trying to determine which chemicals in stormwater are contributing to the deaths of large numbers of coho salmon in Puget Sound. It has prompted a larger question: What exactly is in stormwater, anyway?

A 2017 paper in the journal Aquatic Mammals reports that harbor seals in the Salish Sea are less concerned about predators when they become habituated to humans. 

Increased consumption of Chinook salmon by seals and sea lions in the Salish Sea “could be masking the success of coastwide salmon recovery efforts,” according to a new study published in the journal Scientific Reports. Endangered resident orcas are said to be declining in part due to a lack of available Chinook, the orcas' preferred prey.

Climate change could cause sea levels to rise more than four feet in some parts of Puget Sound, leaving shoreline residents with some tough decisions. Experts say fighting the waves with conventional seawalls may not be the answer.

The average worldwide sea level has increased more over the past 150 years than during the previous 1,500 years, experts say, and the seas continue to rise at an ever-increasing pace.

The Salish Sea Model is used to predict spatial and temporal patterns in the Salish Sea related to factors such as phytoplankton, nutrients and Dissolved Oxygen. It is a collaborative effort between the Pacific Northwest National Lab, the Washington State Department of Ecology and U.S. Environmental Protection Agency.

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.

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.

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.

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 2015 Puget Sound Fact Book produced by the University of Washington Puget Sound Institute. 

Scientists want to know why eelgrass is on the decline in some areas of Puget Sound and not others. The answer will affect future strategies for protecting one of the ecosystem’s most critical saltwater plants.

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. 

The Puget Sound Ecosystem Monitoring Program (PSEMP) is an independent program established by state and federal statute to monitor environmental conditions in Puget Sound. 

Vessel traffic is increasing in the Puget Sound region. A 2017 article in the journal Aquatic Mammals looks at the potential impacts that increasing vessel disturbance may have on resident harbor seal populations and how future management decisions may need to look at variable buffer zones related to level of human activity.

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. 

After a long struggle with pollution, Drayton Harbor has reopened to year-round commercial oyster harvesting for the first time in 22 years. Here’s how the community cleaned up its act, potentially showing the way for shellfish recovery throughout Puget Sound.

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.

A new study shows that increased populations of seals and sea lions are eating far more of Puget Sound’s threatened chinook than previously known, potentially hampering recovery efforts for both salmon and endangered killer whales. 

Eelgrass, a marine plant crucial to the success of migrating juvenile salmon and spawning Pacific herring, is stable and flourishing in Puget Sound, despite a doubling of the region’s human population and significant shoreline development over the past several decades. [Story reprinted from UW Today.]

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.

A 2016 article in the journal Conservation Letters makes policy recommendations to address shoreline armoring in the Salish Sea.

A September 2016 report from the University of Washington Puget Sound Institute summarizes and reviews 27 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 shoreline restoration and derelict net and fishing gear removal. 

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.

A study in the journal PLOS ONE uses volunteer diver surveys to assess the impacts of sea star wasting disease in the Salish Sea. Data shows that sunflower sea stars were especially hard hit and have all but disappeared from the region. 

Scientists are testing ways to use transplanted shellfish such as mussels to monitor toxic contaminants in Puget Sound. 

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.

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.

Another European green crab has been spotted in Puget Sound prompting concern that the species may gain a foothold in the region. 

Sand lance in parts of British Columbia are ingesting small pieces of plastic that may be passed through the food web.

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." 

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.

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.

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 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.

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.

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. 

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? 

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. 

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. 

A 2015 report from Snohomish County, King County and the Tulalip Tribes outlines protection strategies for salmon and salmon habitat within the Snohomish Basin. 

It turns out that a gooey substance known as biofilm is a big deal for Salish Sea shorebirds, providing critical food for some species. But could a proposed port expansion in Vancouver threaten this slimy resource?

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.

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.

Bulkhead removal is becoming an attractive option for many shoreline property owners as awareness spreads of their geological and ecological impacts, and as aging bulkheads come up for replacement. New state guidelines provide alternatives to hard armor.

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.

A significant number of Puget Sound property owners have been altering their shorelines without required permits. A new report suggests that state and local regulators should increase enforcement and make penalties more costly for violators.

By removing bulkheads where they can, property owners are improving shoreline habitat, one piece at a time. Officials from county and nonprofit groups have been offering assistance and finding new ways to connect with property owners.

Where shoreline bulkheads remain in place, the loss of spawning habitat used by surf smelt is likely to reach 80 percent.

Rising sea levels are expected to exacerbate habitat loss caused by bulkheads, according to studies in the San Juan Islands.

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.

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.

A 2016 paper in Environmental Pollution identifies dozens of pharmaceuticals and other compounds that are accumulating in Puget Sound fish such as salmon.

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.

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. 

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

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

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.

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.

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.  

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.

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 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.

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.

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.

The 2015 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.

A 2015 NOAA report creates an updated and comprehensive list of the fishes of 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. 

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.

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.

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.

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. 

Proceedings of the BC/Washington Symposium on the Marine Environment, January 13 and 14, 1994 

The symposium was held on September 12–14, 2012, at the University of Washington, Friday Harbor Laboratories campus. Sixty scientists, graduate students, and fisheries policy experts convened; showcasing ongoing research, conservation, and management efforts targeting forage fish from regional and national perspectives.

A 2015 paper in the journal Diseases of Aquatic Organisms examines potential causes of increased harbor porpoise strandings in Washington and Oregon.  

This 2008 report highlights the vision and accomplishments of ESRP in advancing an ecosystem restoration strategy in Puget Sound to restore the ecosystem processes that are essential for a self-sustaining coastal ecosystem.

This report highlights the vision and accomplishments of ESRP in advancing an ecosystem restoration strategy in Puget Sound to restore the ecosystem processes that are essential for a self-sustaining coastal ecosystem.

By the end of 2010, the PSP Science Panel’s efforts had reached the stage where an independent review by the WSAS (Washington State Academy of Sciences) was timely and useful to help guide its future indicator development efforts.

This report, Priority science for restoring and protecting Puget Sound: a Biennial Science Work Plan for 2011-2013, identifies priority science and monitoring questions needed to coordinate and implement effective recovery and protection strategies for Puget Sound.

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.

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.

Sound Science: Synthesizing Ecological and Socio-economic Information about the Puget Sound Ecosystem summarizes what we know about the greater Puget Sound ecosystem and what we think could happen in the future given present trajectories and trends.

This is the first annual report of the Puget Sound Ambient Monitoring Program (PSAMP); it briefly describes PSAMP, explains the significance of each type of measurement, and provides initial interpretation of the results.

This is the second annual Puget Sound Update. Findings from the first two years of the Puget Sound Ambient Monitoring Program (PSAMP) form the basis of this report. This report briefly describes PSAMP, explains the significance of each type of monitoring, and discusses the results. It provides some background on the workings of the Puget Sound ecosystem and the history of contamination problems in the Sound. 

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. 

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.

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.

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.

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.

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.

This is the Puget Sound Water Quality Action Team’s second report on key indicators of Puget Sound’s health. This report has been prepared in response to the Washington State Legislature’s request to evaluate efforts to protect Puget Sound. This second report includes updated information on the 12 indicators originally presented in 1998 as well as information on five new indicators.

The Washington Department of Fish and Wildlife has published a comprehensive set of guidelines for managing shoreline development such as bulkheads and seawalls.

The 2011 Salish Sea Ecosystem Conference was held October 25 to 27 at the Sheraton Wall Centre in Vancouver, British Columbia. This event brought together a diverse group of government officials, community leaders, First Nations and tribal members, environmental managers, scientists and academics to learn from each other about the state and threats to the shared ecosystem. Over 950 delegates attended.

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. 

With its striking plumage and brilliant orange bill, the Tufted Puffin is an iconic seabird well known to native peoples, fishermen, and coastal communities throughout its range in the temperate and sub-arctic North Pacific. Though pelagic in winter, puffins gather on islands and headlands during spring and summer to breed and raise their young. They are members of the auk family, with stocky bodies adapted to “flying” underwater as they dive in pursuit of a wide range of fish and invertebrate prey. Nesting Tufted Puffins range up to 100 km from their breeding colonies to forage for their nestlings, and are famed for carrying 20 or more small fish at one time, neatly lined up and carried crosswise in their large, brightly colored bills.

A 2015 paper in the journal Limnology and Oceanography presents new data on ocean acidification in the Salish Sea.

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). 

A 2000 report from the Washington Department of Fish and  Wildlife provides information on haulout sites for harbor seals, Steller sea lions, California sea lions, and northern elephant seals located in Washington waters. 

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. 

A December 2014 report from the University of Washington examines when and where climate change impacts will occur in the Puget Sound watershed.

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.

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.

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. 

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. 

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.

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.

This paper summarizes a 2014 report ranking the greatest human-caused threats to the Puget Sound ecosystem. 

A 2015 paper in Oikos Journal examines the impacts of great blue heron predation on species diversity in eelgrass meadows in British Columbia. 

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.

The Shoreline Monitoring Toolbox standardizes approaches to tracking the status and health of shoreline environments in Puget Sound.

A 2015 paper presented to the International Whaling Commission compares the impacts of kayaks and powerboats on killer whale populations.

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.

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.

A 2014 report by the Kitsap Public Heath District describes the goals and achievements of the Shellfish Restoration and Protection Project including: increasing harvestable shellfish growing areas, establishing a routine shoreline monitoring program, improving water quality, and increasing education of water quality and shellfish protection.

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. 

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.

This 2006 technical report for the Puget Sound Nearshore Partnership describes how shellfish have high ecological, economical, cultural, recreational value, however human activity is threatening their existence by altering their native habitat with changes in land use, shoreline modifications, stormwater, sewage and industrial discharge.

A December 2014 paper in the journal Aquatic Ecosystem Health & Management describes a project to identify transboundary ecosystem indicators for the Salish Sea. 

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.

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.

A 2014 literature review in the journal Ocean & Coastal Management suggests negative effects of nonnative eelgrass on the native species. 

Puget Sound herring reproduction is not limited by the amount of suitable spawning vegetation, according to a November 2014 paper in the journal Marine Ecology. The article points to terrestrial or marine variables as likely determinants of egg loss.

A report from the Tacoma-Pierce County Health Department describes the results of a project to address threats to water quality in Pierce County, focusing on shellfish areas most at risk.

The decaying seawall along Seattle’s waterfront is providing scientists with an opportunity to improve long-lost habitat for migrating salmon. It could also show the way for habitat enhancements to crumbling infrastructure worldwide. One University of Washington researcher describes the project.

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.

A 2014 San Juan County report addresses sustainable growth planning, pollution prevention, and mitigation actions in the Eastsound and Westcott Bay areas.

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.

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.

A summary of environmental conditions in Pacific Canadian Waters and the broader North East Pacific in 2013.

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.

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.

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.

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.

A 2014 article in the journal Northwestern Naturalist shows how Harbor Seal tissues can reflect regional and temporal trends in contaminants in Puget Sound.

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.

A 2014 report describes a research and monitoring study of Pigeon Guillemot conducted in and near the Nisqually Reach Aquatic Reserve. 

This paper appears in the July 2014 issue of the journal Coastal Management, which focuses on the role of social sciences in Puget Sound ecosystem recovery.

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.

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 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. 

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. 

A 2014 paper in the journal Aquatic Mammals examines coastal river otter predation on rockfish at three islands in the Salish Sea.

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. 

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.

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

Marine Protected Areas (MPAs) have been present in Puget Sound since the early 1900s, although most were established after the 1960s (Whitesell et al. 2008, Van Cleve 2009). 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 (Murray and Ferguson 1998).

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.   

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.

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.

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.

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 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)

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. The following text was written by Puget Sound Model co-creator John H. Lincoln (1915-2001) and is provided courtesy of the University of Washington School of Oceanography. 

A paper in the February 2014 journal Diseases of Aquatic Organisms examines the effect of leaf age on wasting disease in eelgrass across sites in the San Juan Archipelago. Co-author: Encyclopedia of Puget Sound topic editor Joe Gaydos. 

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.

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.

A January 2014 USGS report discusses approaches for measuring the effect of bivalves on nutrient availability in different regions of 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. 

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.

A November 2013 literature review by Washingtom Sea Grant synthesizes the state of the science of geoduck clams and the potential environmental impacts of geoduck aquaculture in the Puget Sound region.

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.

The Encyclopedia of Puget Sound spoke with Seattle Times reporter Lynda Mapes about the exhibit Elwha: A River Reborn, which opened at the University of Washington Burke Museum on November 23rd. The exhibit is based on the book of the same title by Mapes and photographer Steve Ringman, and tells the story of the largest dam removal in U.S. history.  

This paper describes a multi-year effort testing whether shoreline enhancements at the Olympic Sculpture Park in Seattle have improved conditions for fish and invertebrates as compared to armored shorelines.

This paper discusses the dietary habits of harbor seals (Phoca vitulina) in two estuaries in Puget Sound.

This page includes documents and links related to the status of Steller Sea Lion in Washington state and the Salish Sea region. 

Download presentations from the Study Panel on Ecosystem-based Management of Forage Fish held August 25, 2013 at the University of Washington’s Friday Harbor Lab, San Juan Island.

A new study provides strong evidence of substantial migration interference and increased mortality risk associated with the Hood Canal Bridge for aquatic animals, and may partially explain low early marine survival rates observed in Hood Canal steelhead populations.

The National Marine Fisheries Service has released a Draft Biological Report proposing designation of critical habitat for yelloweye rockfish, canary rockfish, and bocaccio in the Salish Sea. Download the full report and supporting data.

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.

In the 1970s and 1980s, research from a division of NOAA's Montlake Lab suddenly and irreversibly changed the way scientists and the public viewed the health of Puget Sound. Their discoveries 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.

Could recent declines in Puget Sound herring be linked to decreases in native eelgrass? Biologist Tessa Francis reports on a new study that may provide insight into the health of one of the region's most iconic forage fish.

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.

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.

This paper uses water quality data to examine the relationship between environmental condition and recreational use of parks in Puget Sound.

Sediment health in Central Puget Sound has shown a recent steep decline, according to a report by the Washington Department of Ecology. The report compares monitoring data over a ten-year period between 1998/1999 and 2008/2009.

Vern Morgas remembers the early days of scuba diving in Puget Sound.

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.

Browse a collection of shellfish photos provided by the Swinomish Tribe.

With funding from the EPA (EPA Interagency Agreement DW-13-923276-01), scientists at the Northwest Fisheries Science Center and the University of Washington used a field and quantitative modeling ‘source-transport-fate’ assessment approach to classify the vulnerability of shellfish growing areas to closures caused by watershed and marine-derived pathogens. Based on the historical prevalence of nutrient pollution, shellfish closures, and phytoplankton blooms in commercial and recreational shellfish growing area, the project focused on three nearshore sites--the Hamma Hamma (WRIA 16), Dosewallips (WRIA 16) and Samish (WRIA 3).

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. 

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.

This is the executive summary from a technical report produced for the Puget Sound Nearshore Partnership on Valued Ecosystem Components (VEC). The entire document is included as a PDF with this summary.

This technical report produced for the Puget Sound Nearshore Partnership on Valued Ecosystem Components (VEC) summarizes existing knowledge of salmon use of nearshore habitats in order to help protect and restore these habitats.

This is the executive summary from a technical report produced for the Puget Sound Nearshore Partnership on Valued Ecosystem Components (VEC). The entire document is included as a PDF with this summary.

Canadian and U.S. governments differ on special status for bocaccio in the Salish Sea. 

Harbor seal numbers were severely reduced in Puget Sound during the first half of the twentieth century by a state-financed population control program. This bounty program ceased in 1960, and in 1972, harbor seals became protected under the federal Marine Mammal Protection Act and by Washington State.

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.

Approximately 28 species of rockfish are reported from Puget Sound, spanning a range of life-history types, habitats, and ecological niches.

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.

Pinto abalone are the only abalone species found in Washington State.

Many types of bivalves, both native and non-native, flourish in Puget Sound. These species are a crucial part of the Puget Sound ecosystem and are also important for commercial fisheries.

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.

The State of Our Watersheds Report is produced by the treaty tribes of western Washington, and seeks to present a comprehensive view of 20 watersheds in the Puget Sound region and the major issues that are impacting habitat.

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

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.

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. 

Forage fish occupy every marine and estuarine nearshore habitat in Washington, and much of the intertidal and shallow subtidal areas of the Puget Sound Basin are used by these species for spawning habitat.

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:

Audio recordings of rhinoceros auklets on Protection Island.

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.

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.

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.

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. 

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.

"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.

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.