A 2021 paper in the journal PLoS ONE provides a clearer picture of what endangered southern resident orcas eat throughout the year. Chinook salmon make up the bulk of the whales' diet, but the paper suggests that other salmon species and non-salmonid fishes can also play important roles depending on the season.

The recently approved HEAL Act requires the state of Washington to address issues of environmental justice within its agencies. The Act is expected to be signed by the governor and focuses on inequities in environmental health conditions for disenfranchised populations.

Researchers are looking at the forces of discrimination that worsen the environmental health risks for some communities.

Years of struggle have led to reduced pollution and a stronger sense of community in the Duwamish Valley. As cleanup efforts there continue, environmental justice has come front and center for the area's diverse populations.

An update to state rules regarding the cleanup of toxic pollution is expected to bring more attention to factors like race, ethnicity and income within populations that live near contaminated sites.

Close to 30% of Puget Sound's shoreline is armored with seawalls and other structures meant to protect beaches against rising tides and erosion. But science increasingly shows that these structures are ineffective and cause significant harm to salmon and other creatures. State and federal agencies have been encouraging private property owners to remove armoring in a race to improve habitat, but why did so much of it start appearing in the first place?

Collisions with boats and other interactions with humans are "significant" causes of death for killer whales in the northeastern Pacific, a recent study says. The findings come from one of the most comprehensive looks at killer whale pathology to date, but scientists say determining how a killer whale may have died is often notoriously difficult.

A river spawning species of forage fish known as the longfin smelt is rare and getting rarer in the Salish Sea. Biologists are looking into the mysterious decline of the ‘hooligans’ of the Nooksack.

The search for why large numbers of spawning coho salmon have been dying in Puget Sound's urban streams goes as far back as the 1980s and culminated this year with the discovery of a previously unidentified chemical related to automobile tires. We offer a detailed timeline for the discovery. 

Environmental engineers and chemists at the University of Washington Tacoma have identified a mysterious compound implicated in the deaths of large numbers of coho salmon in Puget Sound. The chemical is linked with a rubber additive commonly used in tires and is thought to kill more than half of the spawning coho that enter the region's urban streams every year. 

Modern automobile tires are a complex mixture of chemicals, all used together in different ways to give tires their structure and properties, including riding comfort, safety and long life. Chemicals from tire wear particles are now thought to be responsible for the deaths of large numbers of coho salmon returning to spawn in Puget Sound streams. 

Many creeks and waterbodies in Puget Sound may look pristine, but most face serious threats from stormwater pollution. A new study at Soos Creek shows how mud-dwelling bugs, traditional chemistry and digital "heatmaps" can be used to track stormwater impacts and identify the most polluted areas. Scientists and planners hope that this may one day lower the price tag on costly stormwater fixes. 

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. 

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. 

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 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 those in 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.

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.

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.

New technology is helping to remove deadly “ghost nets” that have been lost in the depths of Puget Sound. It is part of an effort that saves millions of animals every year, but managers say better reporting of these lost nets by fishermen is still needed.    

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.

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.

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.   

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.

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.

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.

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.

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.

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.

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.

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 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.

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.

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. 

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.

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).

A "learn and adjust" strategy known as adaptive management plays a central role in state and federal Puget Sound recovery efforts. It is an approach that is gaining traction for ecosystem management worldwide. A December 2016 article from the Puget Sound Institute provides an overview of the concept and how it is being applied locally.