State of Knowledge: Climate Change in Puget Sound

Can restoring the natural balance of the Nooksack River also reduce flood risks? Officials on both sides of the U.S.-Canada border are taking note as climate change raises the stakes. 

Warming waters threaten the recovery of salmon in Puget Sound. New findings about stream temperature could help salmon survive the threats of climate change.

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. 

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.

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.

It’s no secret that salmon and other Northwest fish populations are expected to shrink as a result of a warming Pacific Ocean. But a new study suggests that the resulting decline in commercial fishing by 2050 could be twice as great as previously estimated by climate scientists.

As officials struggle to track and contain the outbreak of the novel coronavirus known as COVID-19, ecologists say widespread impacts from viruses and other pathogens are also a growing threat to the species 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.

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.

About 80% of respondents to a 2022 human wellbeing survey reported some level of concern for environmental impacts affecting Puget Sound. The survey was funded by the Puget Sound Partnership and led by members in Oregon State University’s Human Dimensions Lab.

An estimated 70% of all the salmon in the North Pacific are pink salmon. Scientists say the extreme abundance of pinks could be causing a "trophic cascade" that is harming species across the food web.

The 2023 State of the Sound is the Puget Sound Partnership’s eighth biennial report to the Legislature on progress toward the recovery of Puget Sound. The document reports on both the status of the Partnership's recovery efforts and a suite of ecosystem indicators referred to as the Puget Sound Vital Signs.

All across the region, communities are finding that rising seas and rising rivers are two sides of the same coin. New research funded by the Environmental Protection Agency may help managers target their responses to climate-fueled flood risks in Puget Sound. The following article was commissioned by the Habitat Strategic Initiative Lead (HSIL), a cross-agency team co-led by the Washington Departments of Fish and Wildlife and Natural Resources.

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本區域各地的社區發現，海平面上升和河水上漲是一體兩面的問題。氣候變遷使得Puget 海灣面臨愈來愈高的洪水風險，環境保護局贊助的新研究可能有助於主管機關找出因應之道。

Trên toàn khu vực, các cộng đồng đang nhận thấy rằng tình trạng mực nước biển và mực nước sông dâng lên có mối liên hệ chặt chẽ. Nghiên cứu mới do Environmental Protection Agency (Cơ Quan Bảo Vệ Môi Sinh) tài trợ có thể giúp các nhà quản lý hướng các biện pháp ứng phó của họ vào các rủi ro lũ lụt do khí hậu tại Puget Sound.

En toda la región, las comunidades están descubriendo que el aumento del nivel del mar y los ríos son dos caras de la misma moneda. Una nueva investigación financiada por la Agencia de Protección Ambiental puede ayudar a los administradores a enfocar sus respuestas a los riesgos de inundaciones provocadas por el clima en el estrecho de Puget.

Were the islands half full of auklets or were they half empty? One scientist offers an insider's view of a newly published study of two Pacific seabird colonies. He says having good data for the paper was key, but finding the right title didn't hurt.

Researchers are compiling a strategic list of scientific uncertainties related to Puget Sound recovery. The list will be used to prioritize future funding and research to address critical knowledge gaps about the ecosystem.

The search goes on for a set of definitions and thresholds to represent low-oxygen concentrations that threaten various aquatic creatures. Over the years, ecologists have relocated, reshaped and revised the word “hypoxia” to describe these conditions. In part four of our series "Oxygen for life" we look at how scientists determine whether oxygen levels are low enough to be considered harmful to sea life. 

In time, lower dissolved oxygen worsened by climate change could increase the abundance of rare species in Puget Sound while putting populations of more common species into a tailspin. Part three of our series "Oxygen for life" looks at how warmer waters will gradually make it harder for many sea creatures to breathe. 

A 2023 paper in the journal Marine Ecology Progress Series examines seabird reproductive and dietary response to a severe marine heat wave affecting the California Current ecosystem from 2014 to 2016. The study involved rhinoceros auklet colonies on Destruction Island (California Current) and Protection Island (Salish Sea). The paper's first author Eric Wagner describes some of the findings from the study in this informal summary.

The Swinomish Indian Tribal Community has begun constructing the first known clam garden to be built in modern times. They hope that what was once an ancient way of cultivating shellfish can now be a hedge against climate change.

Puget Sound Restoration Fund has launched a network to track declining kelp populations in the Salish Sea. The three-year initiative aims to support and standardize underwater monitoring to improve kelp conservation in the region.

A pilot project to create a 'living dike' in Canada's Boundary Bay is designed to help a saltwater marsh survive rising waters due to climate change.

The marine heat wave that struck the Pacific Ocean in late 2013 also caused large changes in temperature in the Salish Sea, but scientists are still puzzling over the impacts of those changes on Puget Sound's food web. The so-called "blob" of warmer than average water was thought to have increased the production of plankton, which potentially benefits creatures like herring and salmon that feed on the tiny organisms. A new paper in the journal Frontiers in Marine Science calls that interpretation into question, pointing to a computer model that links the cause to higher-than-normal river flows in the region.   

Large plumes of methane bubbles have been discovered throughout the waters of Puget Sound prompting questions about the Puget Sound food web, studies of earthquake faults and climate-change research.

The year 2021 was generally drier and warmer including a heat wave in June. Higher river flows followed a rainy and cloudy fall. In 2021, EOPS aerial images continued to capture the diversity of phenomena on the water, with support from its wonderful contributors who documented visible water quality issues across the larger Puget Sound region. With our Artists Corner and story maps on critters in the mud, we hope to continue to inspire, educate, and motivate our community to keep curious and watchful eyes over the environment.

Raging wildfires can be an ecological disaster, especially as the planet warms due to climate change. But in small doses, some wildfires are actually beneficial. In prairie habitats, fires can enrich soils and maintain native plant species. In late September, state wildlife biologists oversaw several controlled burns near Joint Base Lewis-McChord (JBLM) as part of an effort to preserve habitat for the endangered Taylor's checkerspot butterfly. Less than 3% of Puget Sound's prairies now remain and are mostly concentrated along the region's southern edges, including land on the military base. Listen to a recording of some of the action, including comments from JBLM fire manager and biologist John Richardson.

Social Science for the Salish Sea (S4) provides a foundation for future research projects, accessible information for planning or management decisions, and synthesized content to inform ecosystem recovery.

The number of golden-crowned kinglets in the Puget Sound watershed has declined by more than 91% over a recent 50-year period, according to data from the North American Breeding Bird Survey. The data was reported by the Washington Department of Fish and Wildlife, which tracks the information for the Puget Sound Partnership’s terrestrial bird indicator. The indicator was established to monitor the health of Puget Sound’s species and food webs.

The Salish Sea Model is a computer model used to predict spatial and temporal patterns related to water circulation in the Salish Sea. It was developed at the United States Department of Energy's Pacific Northwest National Laboratory with funding from the Environmental Protection Agency. It is housed at the University of Washington Center for Urban Waters which is affiliated with the Encyclopedia of Puget Sound.  

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?

A new report from the Puget Sound Ecosystem Monitoring Program details the effects of a changing climate on Puget Sound in 2019, and documents how these changes moved through the ecosystem to affect marine life and seafood consumers.

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.

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.

Participants in this year’s Earth Day activities won’t be rallying in large groups, participating in environmental festivals or coming together to clean up the Earth. On the 50th anniversary of Earth Day — April 21st — the environmental movement will be uniquely digital, with many people celebrating from their home computers. [This story is reprinted from the Puget Sound Institute-sponsored blog 'Our Water Ways.']

When Cornell University ecologist Drew Harvell wrote her book "Ocean Outbreak," she couldn't have known that 2020 would be the year of COVID-19. But even as people around the world grapple with the effects of that disease, scientists are keeping watch on potential disasters from viruses and other pathogens for species in the world's oceans. As the oceans warm due to climate change, scientists expect incidences of disease to increase in marine ecosystems including the Salish Sea. We asked Harvell about her new book and the need to address this rising challenge.

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.]

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.

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

A 2019 paper in the Journal of Geophysical Research: Oceans outlines how the Salish Sea Model describes the impacts of climate change, sea level rise and nutrient loads on the region's nearshore environment.

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.   

A report from the Washington Coastal Resilience Project provides an updated assessment of projected sea level change for coastal Washington State and its relationship to coastal hazards such as flooding and erosion. 

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

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

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.  

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 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.

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.

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

Formerly known as “Red Tide”, harmful algal blooms are a health concern for both wildlife and humans. The following is a brief review of some of these algae and their effects.

Environmental samplers may provide early detection of harmful algal blooms (HABs) in Puget Sound. This toxic algae is expected to increase as the climate changes, bringing with it new and potentially more severe outbreaks of shellfish poisonings. 

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.

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

The Puget Sound Fact Book brings together statistics and other information about the health and makeup of the Puget Sound ecosystem. Areas of focus include climate change, geography, water quality, habitats, human dimensions and regional species. The fact book was prepared for the Encyclopedia of Puget Sound with funding from the Environmental Protection Agency and the Puget Sound Partnership.

A report from NOAA and the Puget Sound Ecosystem Monitoring Program provides an overview of 2014 marine water quality and conditions in Puget Sound from comprehensive monitoring and observing programs.

This report documents how Washingtonians have responded to the challenges of protecting and restoring salmon and steelhead to healthy status. It also serves as a tool to summarize achievements, track salmon recovery progress through common indicators, and identify data gaps that need to be filled.

The University of Washington Climate Impacts Group has been analyzing the potential effects of climate change in Puget Sound. The projections below represent some of their most recent reporting about expected conditions in the region over the next 50 to 100 years. Support for this article was provided by the Puget Sound Partnership.

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

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

When and where will we see the impacts of climate change in Puget Sound? A web-based tool factors in dozens of site-specific variables for watersheds throughout the Pacific Northwest. The resource was developed by the University of Washington Climate Impacts Group with support from the EPA, the US Army Corps of Engineers and the Center for Data Science, University of Washington-Tacoma.

A 2014 report by the North Cascadia Adaptation Partnership identifies climate change issues relevant to resource management in the North Cascades, and recommends solutions that will facilitate the transition of the diverse ecosystems of this region into a warmer climate.

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.

A 2014 report prepared by the Stillaguamish Tribe analyzes potential causes of changes in peak and low flows in the Stillaguamish River basin. 

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

A 2014 paper in the journal PloS One analyzes a large carbonate chemistry data set from Puget Sound as a basis for identifying control conditions in ocean acidification experiments for the region.

A December 2013 report by the University of Washington Climate Impacts Group projects wide reaching change for the Puget Sound ecosystem and the Pacific Northwest. Lead author: Encyclopedia of Puget Sound climate change topic editor Amy Snover.

Climate change is projected to result, on average, in earlier snowmelt and reduced summer flows, patterns that are not well represented in the historical observations used for planning and reliability analyses by water utilities.

A botanist believes Coast Salish tribes once favored small islands in the San Juan archipelago for growing camas, an important food staple. Her studies may also show the vulnerability of these relic gardens to climate change as sea levels rise.

The climate of Puget Sound is a product of the interaction between large-scale wind and weather patterns and the complex topography of the region. Seasonal changes in the movement of moisture-laden air that collides with the sudden barrier of the Olympic and Cascade mountains bring Puget Sound the record-breaking precipitation for which it is so famous. These circulation and topographic differences also lead to remarkable climate differences within Puget Sound itself, influencing the species and habitats that are found in the Sound.