Estuarine habitat

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 east marine (with some exceptions: Dungeness Bay, Sequim Bay, and various coastal estuaries such as Grays Harbor and Willapa Bay).

Sources:

http://www.dnr.wa.gov/Publications/amp_nh_marine_class.pdf

http://www.ecy.wa.gov/programs/sea/shellfishcommittee/mtg_may08/Salmon_Recovery_Report.pdf

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

OVERVIEW

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.

RELATED ARTICLES

WDFW biologists sorting and measuring fish from PSEMP's index sites in the Duwamish River and near the Seattle Waterfront. Photo: WDFW
8/25/2017

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.

Dean Toba, a scientific technician with the Washington Department of Fish and Wildlife, operates the agency’s screw trap on the Skagit River. The trap helps biologists estimate the number of juvenile salmon leaving the river each year. Photo: Christopher Dunagan, PSI
8/4/2017

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.

Salmon smolts. Photo courtesy of Governor's Salmon Recovery Office
7/20/2017

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.

The Qwuloolt estuary hydrology restored by breaching a century old levee. WRP easement land in the foreground. Photo: USDA
5/26/2017

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.

Harbor seals at haulout site. Photo courtesy of WDFW: http://wdfw.wa.gov/wildwatch/sealcam/.
4/10/2017

Harbor seal (Phoca vitulina) tolerance to vessels under different levels of boat traffic

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.

Fir Island Farms habitat restoration monitoring in Skagit County. Project provides rearing habitat for young threatened Chinook salmon along with other wildlife. Copyright: Bob Friel
3/30/2017

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. 

Map image of Puget Sound and surroundings. Courtesy of USGS.
2/6/2017

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.

An eelgrass bed near Bainbridge Island, Washington. David Ayers/USGS
1/6/2017

Eelgrass in Puget Sound is stable overall, but some local beaches suffering

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.]

report cover: Synthesis of 2011-2014 results and key recommendations for future recovery efforts: Final analysis report
12/6/2016

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.

Fluoxetine hydrochloride. Photo: Meg (CC BY-NC-ND 2.0) https://www.flickr.com/photos/disowned/1125134972
11/9/2016

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.

Toxic algal blooms are sometimes associated with invasive plankton. Photo: Eutrophication&Hypoxia (CC BY 2.0) https://www.flickr.com/photos/48722974@N07/5120831456
10/4/2016

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.

Puget Sound Marine Waters 2015 report cover
9/27/2016

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.

Carcinus maenas. Photo: Brent Wilson (CC BY-NC-SA 2.0) https://www.flickr.com/photos/59048895@N06/5409329320/
9/23/2016

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. 

Rhinoceros Auklet carrying sand lance. Photo by Peter Hodum.
9/20/2016

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.

Harbor Porpoise (Phocoena phocoena). Bellingham Bay, WA. Photo: Andrew Reding (CC BY-NC-ND 2.0) https://www.flickr.com/photos/seaotter/9509722373/
9/13/2016

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." 

Carcinus maenas. Photo: Brent Wilson (CC BY-NC-SA 2.0) https://www.flickr.com/photos/59048895@N06/5409329320/
8/2/2016

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.

The orange-striped Asian anemone (Diadumene lineata) was commonly observed in Shelton during the 1998 Puget Sound Expedition. Photo: James Koh (CC BY-NC-SA 2.0) https://www.flickr.com/photos/jameskoh/3835201631/
8/2/2016

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.

A clump of cordgrass (Spartina alterniflora) Photo: USDA-NRCS PLANTS Database
8/2/2016

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. 

report cover: Analysis of invasive species, toxics, oil spill, and integrated risk assessment findings
8/1/2016

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.

Due to the 'Red Tide' misnomer, blooms of red-colored algae, like this Noctiluca sp. (a dinoflagellate) seen here in Eastsound, Washington (July 2016), can cause undue public concern about harmful algal blooms. Photo: Jordan Cole
7/26/2016

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.

Photogrammetry image of an adult female Southern Resident (J16) as she’s about to surface with her youngest calf, born earlier in 2015, alongside. Photo: NOAA Fisheries, Vancouver Aquarium
7/20/2016

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. 

Monitoring devices deployed by NOAA for detecting harmful algal blooms. Photo by Rachael Mueller.
7/12/2016

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. 

A steelhead (Oncorhynchus mykiss) in the Cascade River, WA, 2014. Photo: © Morgan Bond http://www.morganhbond.com/
6/30/2016

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? 

Key hypotheses include bottom-up and top-down processes and additional factors such as toxics, disease, and competition.  Graphic: Michael Schmidt, Salish Sea Marine Survival Project
6/29/2016

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. 

Chinook salmon (Oncorhynchus tshawytscha). Photo: WDFW
6/17/2016

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. 

Puget Sound's orcas are among the most contaminated marine mammals in the world. Photo: Minette Layne (CC-BY-2.0) https://en.wikipedia.org/wiki/Killer_whale#/media/File:Orca_porpoising.jpg
5/18/2016

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 Tufted Puffin is among 125 species of concern found in the Salish Sea. Photo: Peter Hodum.
4/20/2016

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.

Black Scoter (Melanitta negra), one of seven new birds added to a Salish Sea-wide list of species of concern. Photo courtesy of USGS.
4/16/2016

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.

Close up of Phocoena phocoena. Photo: AVampireTear (CC BY-SA 3.0) https://commons.wikimedia.org/wiki/File:Daan_Close_Up.PNG
3/8/2016

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.

Salmon. Photo: Dan Hershman (CC BY-NC 2.0) https://www.flickr.com/photos/hershman/497293505
2/29/2016

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.

Algal bloom. Photo: Eutrophication&Hypoxia (CC BY 2.0) https://www.flickr.com/photos/48722974@N07/5120831456
2/26/2016

Harmful algal blooms in Puget Sound

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

Young adult herring from Puget Sound.Margaret Siple/University of Washington
2/25/2016

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. 

Puget Sound. Photo: S.N. Johnson-Roehr (CC BY-NC 2.0) https://www.flickr.com/photos/snjr22/4095840433
2/18/2016

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. 

Ballard Locks from the air. Photo: Jeff Wilcox (CC BY-NC 2.0) https://www.flickr.com/photos/jeffwilcox/4805933588
2/18/2016

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.

Waves crashing on the Puget Sound Photo: MikeySkatie (CC BY-SA 2.0) https://www.flickr.com/photos/mikeyskatie/5473869676
2/17/2016

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.

FIGURE 2. Dorsoplanar computed tomography image of conjoined fetal twins in a harbor seal (Phoca vitulina) from San Juan County, Washington, USA. The arrow points to the fusion of the spines.
2/2/2016

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. 

Stormwater flowing into catch basin carries contaminants to our waterways. Photo: Ben McLeod (CC BY-NC-SA 2.0) https://www.flickr.com/photos/benmcleod/420158390
2/1/2016

Stormwater facts

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

Steelhead (Oncorhynchus mykiss). Photo: Eric Engbretson, U.S. Fish and Wildlife Service
1/13/2016

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.

Mist from the breath of killer whales is collected at the end of a long pole then tested for dozens of different types of bacteria. Photo: Pete Schroeder
1/13/2016

Going viral: 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.  

Fig 1. The six projects assessed are located on both sides of the Canadian / United States border, which bisects the Salish Sea and its watershed.
1/4/2016

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. Photo by Jeff Rice
12/21/2015

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. 

report cover: Analysis of  Effective Regulation and Stewardship Findings
12/17/2015

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.

Report cover for State of Knowledge: Climate Change in Puget Sound
11/16/2015

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.

11/3/2015

2015 State of the Sound

The 2015 State of the Sound is the Puget Sound Partnership’s fourth biennial report to the Legislature on progress toward the recovery of Puget Sound by 2020. The document reports on both the status of the Partnership's recovery efforts and the status of a suite of ecosystem indicators.

Lower Duwamish Waterway dredging on Superfund site. Photo: Gary Dean Austin (CC BY-SA 2.0) https://www.flickr.com/photos/49648789@N08/17069420399/
10/5/2015

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.

2015 Puget Sound Fact Book report cover
10/2/2015

2015 Puget Sound Fact Book

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.

Fishes of the Salish Sea report cover
9/30/2015

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 surfacing. Photo: Erin D'Agnese, WDFW
9/25/2015

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.