Salish Sea Currents is an online magazine featuring the latest science from the 2014 Salish Sea Ecosystem Conference. Join us as we report on some of the key issues driving Puget Sound recovery.


A milky, turquoise, phytoplankton bloom in Hood Canal visible from space. Natural color MODIS image from Landsat 8 acquired July 24, 2016. Photo: NASA Earth Observatory

Does Puget Sound need a diet? Concerns grow over nutrients

As the region's population grows, scientists say we can expect to see increasing amounts of nitrogen and other elements flowing into Puget Sound. Known as “nutrients” these elements are naturally occurring and even necessary for life, but officials worry that nutrients from wastewater and other human sources are tipping the balance. That could mean big problems for fish and other marine life, gradually depleting the water of oxygen and altering the food web.

The Budd Inlet sewage treatment plant. Photo courtesy of LOTT Clean Water Alliance

Sewage treatment plant in Olympia a leader in nitrogen removal

A regional sewage-treatment system in Thurston County has helped contain  low-oxygen problems in Budd Inlet as the population continues to grow. The system cleans up some of the effluent for replenishing groundwater supplies.

The rapid growth of a red-orange algae, Noctiluca scintillans, dramatically colors the waters of Puget Sound near Edmonds on May 16, 2013. Such algae blooms have been seen more frequently in recent years. Photo: Jeri Cusimano via WA Ecology (CC BY-NC 2.0)

Dead plankton leave clues to a food-web mystery

High amounts of elements such as nitrogen can cause blooms of phytoplankton that sometimes trigger perturbations throughout the food web. This occurs most often in the spring and summer after the long, dark, cloudy days of winter begin to fade.

A sharp boundary appears as sediment-laden freshwater is discharged from British Columbia's Fraser River into the Salish Sea. Fresh water, which is less dense than salt water, spreads in a shallow (approximately 1 m deep) plume at the sea surface. Photo: Ed McNichol, Ocean Networks Canada (CC BY-NC-SA 2.0)

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.

Harbor Seals sunning on intertidal rocks of Puget Sound. Photo: Tony Cyphert (CC BY-NC-ND 2.0)

Study would explore changes to protections for seals and sea lions

As wildlife managers work to recover Puget Sound’s diminished Chinook population, a proposed white paper is expected to review the impacts of some of the salmon's chief predators. The study would include a section on potential management of seals and sea lions, prompting open discussion of a long taboo subject: Could officials seek to revise the Marine Mammal Protection Act — or even conduct lethal or non-lethal removal of seals and sea lions in some cases? Such actions are hypothetical, but we look at some of the ongoing discussions around the issue as prompted by a new resolution from the Puget Sound Leadership Council. 

A dying female coho salmon in the Lower Duwamish spotted by Puget Soundkeeper volunteers in October 2017. Photo: Kathy Peter

What is killing the coho?

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 young resident killer whale chases a chinook salmon in the Salish Sea near San Juan Island, WA. Sept 2017. Photo: (CC BY-SA 2.0)

Seals and sea lions may be slowing salmon recovery, hurting orcas

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.

The Vechey residence and bulkead (circa 2013) before the restoration project. Photo courtesy: John Vechey

With sea-level rise, waterfront owners confront their options

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.

Olympia high tide, Dec 28, 2010. Photo: Johanna Ofner (CC BY-NC-SA 2.0)

Average high tides are creeping higher in Puget Sound

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.

GIS is used to illustrate sea-level rise scenarios in downtown Olympia. Story map by City of Olympia:

Local governments begin to plan for higher tides

Planning for rising seawater in Puget Sound has often focused on public property such as roads, buildings and utilities. Now local governments are looking more closely at private property despite regulations based on traditional flooding history.

English Sole (Parophrys vetulus) in Puget Sound. Photo: biodiversityguy

PCBs in fish remain steady while other toxics decline

A new study shows a surprising decline in some toxic chemicals in Puget Sound fish, while levels of PCBs increased in some cases. Scientists say the study shows that banning toxic chemicals can work, but old contaminants remain a challenge as they continue to wash into Puget Sound.

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

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

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.

Eelgrass at Alki Beach, Seattle. Report cover photo: Lisa Ferrier

Eelgrass declines pose a mystery

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.

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

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.

The University of Washington Tacoma has spurred sustainable urban development including re-purposing of historic buildings, new housing, a museum and retail district, multi-use trails, and light rail transit. Photo courtesy: UW Tacoma

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.

2016 aerial view of completed Calistoga Reach levee project in Orting, WA. Image courtesy: CSI Drone Solutions and Washington Rock Quarries, Inc. Video:

Floodplain projects open doors to fewer floods and more salmon

A new approach to flood control is taking hold across Puget Sound. Rivers, scientists say, can be contained by setting them free. Conservationists hope this is good news for salmon recovery.

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

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. 

Celebrating a community harvest at Drayton Harbor. Photo: Jack Kintner

Bringing the shellfish back: How Drayton Harbor overcame a legacy of pollution

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.

Sea lion sunbathing between meals in Seattle's Eliott Bay. Photo: Johnny Mumbles (CC BY 2.0)

Study says predators may play major role in chinook salmon declines

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. 

Benthic invertebrates range in size from those easily seen with the naked eye to those that cannot be spotted without the use of a microscope. Photo: Christopher Dunagan

Healthy stream, healthy bugs

Many groups have been formed around the goal of saving salmon, but few people talk about a concerted effort to save microscopic creatures. Whether or not a pro-bug movement catches on, future strategies to save salmon are likely to incorporate ideas for restoring streambound creatures known as benthic invertebrates.

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

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.]

Heartbeat line overlays Seattle Skyline from Alki Beach. Graphic: Puget Sound Institute w/ copyrighted images

Implementation Strategies will target Puget Sound ‘Vital Signs’

New EPA-funded Implementation Strategies are designed to target Puget Sound recovery in the most direct and coordinated way ever conducted by state and federal agencies. We report on how these strategies will affect Puget Sound’s Vital Signs for years to come, and why you should care (a lot).

Fluoxetine hydrochloride. Photo: Meg (CC BY-NC-ND 2.0)

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.

Industrial plant. Photo: Gray World (CC BY 2.0)

New law will increase testing of chemicals

New federal legislation, approved overwhelmingly by the U.S. Congress in December 2015 and signed into law by President Obama in June 2016, is designed to make sure that people and the environment are not harmed by new and old chemicals on the market.

Before and after composite view at the site of a 2013 bulkhead-removal project on the shore of Penrose Point State Park in Pierce County. Composite: Kris Symer, PSI; original photos: Kristin Williamson, South Puget Sound Salmon Enhancement Group

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.

Bay Mussels (Mytilus trossulus) on Edmonds Ferry Dock. Photo [cropped]: brewbooks (CC BY-SA 2.0)

Salish Sea snapshots: Mussel memory

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

Toxic algal blooms are sometimes associated with invasive plankton. Photo: Eutrophication&Hypoxia (CC BY 2.0)

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.

Carcinus maenas. Photo: Brent Wilson (CC BY-NC-SA 2.0)

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.

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)

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." 

2013 Swinomish Tribe clam bake. Photo: Copyright Northwest Treaty Tribes

Clam hunger

Social scientists around the Salish Sea are predicting the effects of environmental change through the lens of culturally important foods.

Pacific sand lance at rest on sand. Photo: Collin Smith, USGS.

The secret lives of forage fish: Where do they go when we aren’t looking?

Some of the most important fish in the Salish Sea food web are also the most mysterious. Researchers have only begun to understand how many there are, where they go, and how we can preserve their populations for the future. A University of Washington researcher describes how scientists are looking into the problem.

A state inspector boards a container ship at the Port of Seattle to check on ballast water and determine whether procedures were followed to reduce the risk of invasive species being released into Puget Sound.  Photo: WDFW

Invasive stowaways threaten Puget Sound ecosystem

Gaps in regulations could allow invasive species to hitch a ride on ships and boats. We report on some of the potential impacts, and how state and federal agencies are trying to solve the problem. 

Carcinus maenas. Photo: Brent Wilson (CC BY-NC-SA 2.0)

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)

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

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. 

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

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.

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

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

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

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. 

Studies suggest that western sandpipers depend on biofilm for close to 60% of their diet. Storey's Beach, Port Hardy, BC. Photo:  Nicole Beaulac (CC BY-NC-ND 2.0)

Salish Sea 'slime' vital for shorebirds

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?

Puget Sound's orcas are among the most contaminated marine mammals in the world. Photo: Minette Layne (CC-BY-2.0)

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.

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

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.

Bulkhead in Puget Sound. Photo by Christopher Dunagan

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. 

Killer whales and boat in Puget Sound. Photo courtesy of NOAA.

Conference snapshot: Listening to the Salish Sea

Scientists are realizing that underwater noise in the Salish Sea affects a broad range of species, even plankton. Read a Q & A with the organizers of the session 'From plankton to whales: underwater noise and its impacts on marine life.'

A 6-year-old killer whale from L pod, known as L-73, chases a Dall’s porpoise in this historical photo taken in 1992. Photo: Debbie Dorand/Center for Whale Research

Resident killer whales sometimes attack porpoises but never eat them

The mysterious practice of killing porpoises may have a useful function, but it has yet to be fully explained, according to orca researcher Deborah Giles.


Perception is the key to a better future, says Canadian astronaut

Dr. Roberta Bondar opens the three-day Salish Sea Ecosystem Conference in Vancouver, B.C., by challenging people to see things in different ways.