Salish Sea Currents is an online magazine focusing on the science of ecosystem recovery. Browse individual stories below or visit the Salish Sea Currents magazine homepage to see them organized by topical series.
We regularly compile stories into printed yearbooks intended as special reports for Puget Sound policymakers. These are also available for viewing as PDFs:
- Salish Sea Currents: 2014 special report for Puget Sound Policymakers (themes from the 2014 Salish Sea Ecosystem Conference)
- Salish Sea Currents: 2016-17 special report for Puget Sound Policymakers (themes from the 2016 Salish Sea Ecosystem Conference)
- Salish Sea Currents: 2017-18 special report for Puget Sound Policymakers (on implementation strategies)
Tiny bone samples show that seals alter their diets as conditions change. The findings could help scientists understand whether seals are contributing to local salmon declines.
Last month's federal authorization to kill more than 700 sea lions to protect salmon runs along the Columbia River is prompting discussions of similar actions for harbor seals in Puget Sound. But experts say the situations are very different with many unanswered questions.
We have published a yearly round-up of stories from our magazine Salish Sea Currents. The 2020 edition focuses on the impact of climate change on the Salish Sea and includes a special section on the effect of global warming on infectious diseases in the ecosystem.
Few environment problems in the Salish Sea have been studied more than the steep decline in salmon populations. But one potential contributor to these declines has gained less attention. Scientists say infectious disease may play a wider role than previously understood.
Years after the appearance of the devastating marine heat wave known as "the blob," scientists are still working to understand how it has affected the Salish Sea. In some ways, they say, it is like the blob never left.
The Salish Sea’s endangered southern resident orcas travel freely across the U.S.-Canada border, unconstrained by political boundaries. But while they don’t require passports, they can still face differing policies and conditions as they go back and forth between nations. We look at some of the ways that the United States and Canada compare in their efforts to protect the whales.
The Elwha River has become famous as the site of the largest dam removal project in U.S. history. Several years ago, scientists began knocking down another barrier about a mile away from the river's delta. They removed a large seawall along the Salish Sea shoreline and discovered that sediment from the dam removal had huge benefits for their project.
The revival of an Indigenous aquaculture practice has come to the southern Salish Sea. Clam gardens could help First Nations in British Columbia and Washington state address issues of climate change and food sustainability.
Identifying kelp stocks that are tolerant of warmer waters could help the Salish Sea’s iconic underwater forests survive climate change.
Design innovations at the new seawall along Seattle's waterfront could inspire improvements for other shoreline structures around Puget Sound. They may even encourage broader regulatory changes that enhance habitat for migrating salmon and other species.
The pinto abalone was a popular sport catch for divers in the Salish Sea until its numbers plummeted to near extinction. Now, the delicious marine snail is on the endangered species list and the focus of an ambitious hatchery and replanting program. A broad coalition of partners has released more than 20,000 young pintos into the wild with the hope that the population will start to rebound.
The state's stay-at-home order has halted much of the field research that would normally be underway in Puget Sound this spring, but a small group of scientists and volunteers have been able to continue their search for an invading marauder along the shoreline. Their work has been classified as critical by the state.
Historically, the eastern part of the state has seen the largest impacts from fires, but climate change is now increasing the risk west of the Cascades. That could have big implications for many rural communities throughout Western Washington, including the Puget Sound region.
The geoduck has earned an honored place as Puget Sound's largest and most distinctive native clam, but how much do we really know about it? Often seen as a culinary curiosity, the geoduck has only been commercially harvested on a large scale since the 1970s, and the clam's current popularity is based mostly on demand from Asian markets. Nevertheless, this deep-burrowing mollusk has always been a signature part of the Salish Sea ecosystem.
Climate models project that if carbon emmisions continue as they are now, the vast majority of watersheds feeding Puget Sound will receive more rain and far less snow by 2080, causing increased flooding and other dramatic changes to the freshwater ecosystem. We look at the past and possible future of the region's snowpack and what this might mean for salmon and other species — including humans.
High levels of mercury and other toxic chemicals are showing up in seemingly remote and pristine parts of the Puget Sound watershed, the result of atmospheric deposition. Scientists talk about a “dome” of pollution hanging over urban areas, leading to a never-ending cycle of persistent compounds working their way through the air, onto the land and into the water.
Last summer, scientists met at the University of Washington to address alarming findings concerning the rapid acidification of the world's oceans. Experts at that symposium warned that wildlife in the Salish Sea, from salmon to shellfish, may start to see significant effects from changing water chemistry within the next 10 to 20 years. This article summarizes the symposium's key findings and was commissioned and edited by the Washington Ocean Acidification Center which hosted the gathering. Funds for the article were provided by the Washington state legislature. [A version of this article was originally published by the Washington Ocean Acidification Center.]
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.
They rival tropical forests in their richness and diversity, but Puget Sound's kelp beds have declined steeply in recent decades. Scientists are just starting to understand the extent of these losses. What they are finding is bringing kelp to the forefront of Puget Sound's environmental concerns.
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.]
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.
Scientists believe that herring have been a staple of Salish Sea food and culture since humans first arrived here at least 12,500 years ago. That importance has continued into modern times, even as herring numbers have declined in parts of the region.
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.
Each winter and spring, researchers survey the sometimes spectacular spawning events of Puget Sound's Pacific herring. They have found wide swings in the fish's population and an overall decline in herring numbers since the 1970s, but little is known about the cause or what this might mean for the health of the food web. We spent a day with a biologist spotting herring eggs and considering the future of one of our region's most ecologically and culturally important fish species.
Understanding the social networks and family bonds of Puget Sound's southern resident orcas may be critical to keeping the endangered whales from extinction. A healthy population is about more than numbers, scientists say. It's about connections.
This three-part series explores opportunities and challenges of using medical interventions to save Puget Sound's southern resident orcas from extinction. Part 1 looks at how scientists might treat endangered southern resident orcas that face starvation and risks of disease; Part 2 considers how veterinarians have intervened with other animals in the wild, and how this might apply to orcas in Puget Sound; and Part 3 explores a federally approved vaccination program designed to ward of a deadly virus among endangered Hawaiian monk seals.
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.
For critically endangered animal populations, experts worry that a highly infectious disease could be the final nail in the coffin, forcing the species into extinction. That’s one reason why federal authorities approved the development and deployment of a new vaccine to ward off the deadly morbillivirus among Hawaiian monk seals. The vaccination program raises the possibility of using vaccines to prevent disease among Puget Sound's southern resident killer whales, but no specific steps have been taken so far.
As the plight of Puget Sound’s southern resident orcas becomes increasingly desperate, with the population dropping from 98 to 75 in just 22 years, scientists are weighing the options of medical intervention. In part two of our two-part series The Orca Docs we look at how veterinarians have intervened with other animals in the wild, and how this might apply to the situation here in Puget Sound. [Part one, "When should medical experts intervene to save a killer whale?" is also available.]
The death of a young female orca in September has sparked a discussion of how and whether scientists should step in with medical care for distressed animals in the wild. Medical intervention has become routine for some endangered mammals, but scientists say Puget Sound’s resident orcas present a series of unique challenges and ethical questions. In part one of our two-part series The Orca Docs we look at how scientists are preparing to treat endangered southern resident orcas that face starvation and risks of disease.
Can scientists bring back the lost tidal forests of Puget Sound? It could take generations, but restoring this rare habitat will pay big dividends for Puget Sound’s salmon.
Puget Sound's rockfish have declined by 70% over the past few decades, prompting state and federal protection efforts. We look at some of the ways that scientists are working to reverse the fish's downward trend.
With a population growth of about 10 percent per year in inland waters, harbor porpoises are having an undetermined but growing effect on food dynamics in Puget Sound.
As critically important eelgrass declines in some parts of Puget Sound, scientists are trying to plant more of it. The health of the ecosystem may be riding on their efforts, but what they are finding is something that farmers have known for thousands of years: Getting something to grow may be harder than you think.
More than 70 percent of the seabird population of Puget Sound nests on a single island in the Strait of Juan de Fuca. That includes a massive colony of rhinoceros auklets that has drawn the interest of scientists and birders alike. Our writer Eric Wagner visited the island this summer and reports on a long-term study of the auklets that is revealing new information about the health of seabirds in the Salish Sea.
The reasons for the surprise visits are unknown, but changes in environmental conditions here or elsewhere are one possibility.
Recent images of a mother orca appearing to grieve for her dead calf have brought worldwide attention to the plight of Puget Sound’s endangered Southern Resident orcas. As orca numbers decline, we look at how the effects of toxic chemicals on the whales are magnified even as the residents slowly starve from a general lack of Chinook salmon, their chief source of food.
An intensive research program in the U.S. and Canada is studying why so few salmon in the Salish Sea are returning home to spawn. It is uncovering a complex web of problems involving predators, prey and other factors that put salmon at risk as they migrate to the ocean. We present a four-part series on the Salish Sea Marine Survival Project, including new findings presented at the 2018 Salish Sea Ecosystem Conference last spring in Seattle.
A recent influx of anchovies into Puget Sound may have saved some steelhead from predators, but researchers seek more evidence to prove the connection. Our series on the Salish Sea Marine Survival Project continues with a look at these and other potential impacts from predators on the region's salmon and steelhead.
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.
An intensive research program in the U.S. and Canada is studying why so few salmon in the Salish Sea are returning home to spawn. They are uncovering a complex web of problems involving predators, prey and other factors that put salmon at risk as they migrate to the ocean. We begin a four-part series on the Salish Sea Marine Survival Project, including new findings presented at the 2018 Salish Sea Ecosystem Conference last spring in Seattle.
Kids around the region are learning about the Salish Sea thanks to a new book that is being offered — in many cases free of cost — to Washington schools and libraries. Explore the Salish Sea by Joe Gaydos and Audrey Benedict inspires the next generation to appreciate and perhaps someday protect the environment close at hand.
A high-profile salmon escape led to a ban on salmon farms in Washington earlier this year. But just across the border, scientists say salmon farms in British Columbia expose migrating fish from Puget Sound to potential maladies like parasites, bacteria and dangerous viruses. They say simply getting rid of salmon farms in Washington does not put the potential impacts to rest.
Ocean acidification may be twice as extreme in Puget Sound’s seagrass habitats, threatening Dungeness crabs
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.
Pacific herring exposed to stormwater in Puget Sound show some of the same effects as fish exposed to major oil spills. Symptoms include heart and developmental problems.
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.
Genetic testing shows that invasive European green crabs in Puget Sound likely did not come from the Sooke Basin in British Columbia as previously thought. New findings on the crab's origins were presented at the 2018 Salish Sea Ecosystem Conference in Seattle.
State agencies tracking pollution levels in Puget Sound have discovered traces of oxycodone in the tissues of native bay mussels (Mytilus trossulus) from Seattle and Bremerton area harbors. The findings were presented at the 2018 Salish Sea Ecosystem Conference in Seattle.
Scientists are trying to learn how to restore Puget Sound’s diminishing kelp forests in an effort to stave off habitat loss for rockfish and other threatened species.
Bridging the gap between nature and technology might be a challenge for the Puget Sound region, but tech leaders could play an important role in protecting and restoring the ecosystem, according to a panel of experts at last week’s Salish Sea Ecosystem Conference in Seattle.
Gov. Jay Inslee joined former Interior Secretary Sally Jewell to open three days of science talks at the Salish Sea Ecosystem Conference in Seattle. The conference includes about 700 scientific presentations on topics ranging from orcas to habitat restoration, from climate change to toxic chemicals.
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.
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.
The amount of oxygen in the Salish Sea is dependent on water circulation which distributes chemical elements such as nitrogen through the system.
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.
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?
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.
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.
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.
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.
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.
New numbers show progress in the state’s efforts to remove shoreline armoring, but they don’t tell the whole story.
Social scientists around the Salish Sea are predicting the effects of environmental change through the lens of culturally important foods.
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.
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.
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.
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.
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?
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.
Researchers are studying how persistent pollutants such as PCBs avoid settling to the bottom of Puget Sound. This article continues our coverage of new theories on the spread of toxic chemicals in the food web.
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.
A new peer-reviewed study reports significant findings on the impacts of shoreline armoring in 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.'
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.
Dr. Roberta Bondar opens the three-day Salish Sea Ecosystem Conference in Vancouver, B.C., by challenging people to see things in different ways.
About 4,600 miles of coastline wind from southern Puget Sound to northern British Columbia along what is known as the Salish Sea. It is a land of connections and contradictions. Snowmelt from three national parks feeds more than a thousand creeks and rivers that in turn flow to the rich floodplains and estuaries of places like the Skagit and Nisqually deltas. It is one of the most diverse and spectacular ecosystems in the world, a fact made even more incredible because it is also home to 8 million people.
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.
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.
Chinook, coho and sockeye salmon, along with steelhead trout, live in the Lake Washington watershed and navigate a treacherous route through the Ballard Locks on their way to Puget Sound.
Pacific herring have long been considered an essential part of the Puget Sound food web. Now, studies are beginning to reveal how diseases in herring could be reverberating through the ecosystem, affecting creatures large and small. We continue our coverage of the ecological impacts of disease in Puget Sound with this look at the region's most well-known forage fish.
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.
How does one of the West's busiest airports deal with extreme stormwater, and what does that mean for water quality standards in the rest of the state?
Pollution from stormwater has been called one of the greatest threats to Puget Sound. How much will it cost to hold back the rain? A new EPA-funded study says the price could reach billions per year, a figure that dwarfs current state and federal allocations.
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.
Scientists are rethinking floodplain management in Puget Sound. Can we have our farms and salmon too?
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.
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.
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.
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.