PORT ANGELES HARBOR – WASHINGTON STATE
Help shape the future of
Project Macoma
A unique ocean-climate research site in Port Angeles Harbor is evolving. We’re asking the people who live, fish, work, play, and conduct science here to help guide what happens next.
About this page
Why we’re asking for your input
Project Macoma is a small-scale ocean research site in Port Angeles Harbor where scientists have been studying ocean alkalinity enhancement (OAE), a method of removing carbon dioxide (CO2) from the atmosphere and storing it in the ocean caused by slight, temporary adjustments in the chemistry of seawater. Researchers want to determine whether OAE is a durable solution to the ocean-climate crisis and whether at larger-scale it can be done safely for fish, shellfish, and the broader ecosystem.
The organization that built and operated the site, Ebb Carbon, has found that making small amounts of seawater less acidic can draw down legacy carbon pollution from the atmosphere, without measurable adverse effects on species or their habitat. Ebb Carbon is relocating their engineering equipment due to a scheduled stormwater construction project at their land-based facility at the Port of Port Angeles. The research and monitoring infrastructure is still in place, a careful and well constructed research permit is established, and there is a lot of science still left to be done.
We believe this research site has significant potential — for the local community, regional ocean science, and Washington State’s coastlines, which face one of the highest risks of ocean acidification in the world. As we at Carbon to Sea consider the next phase of science at the site, we want to hear from you.
Who we are: Carbon to Sea is a philanthropic initiative that funds and coordinates scientific research on marine carbon dioxide removal. We are not a commercial enterprise, we do not sell carbon credits, and our research findings are published openly. Our goal for this site is to establish it as a nonprofit, independently-governed research hub, and shaped by your input.
Who is this page for?
Everyone with a connection to this place
Indian Tribes
Local residents
Fishers & shellfish farmers
Nature lovers & climate advocates
Boaters & beachgoers
Scientists & researchers
Educators & students
And you!
The location
Where is the research site?
Project Macoma is situated within the industrial Port of Port Angeles and adjacent to Tse-whit-zen, a significant ancestral village site of the Lower Elwha Klallam Tribe, on Washington state’s Olympic Peninsula. (Photo courtesy of Ebb Carbon)
Project Macoma is located in Port Angeles Harbor on Washington’s Olympic Peninsula, hosted at the Port of Port Angeles – an active industrial working harbor. Project Macoma sits adjacent to Tse-whit-zen, a significant ancestral village site of the Lower Elwha Klallam Tribe and within the usual and accustomed fishing and harvesting waters of several Coast Salish Tribal nations with treaty rights and cultural ties to these waters.
Like other areas in the Pacific Northwest, the harbor is at the front lines of ocean acidification, driven by natural upwelling of deep ocean waters and land-based runoff.
Port Angeles Harbor and Project Macoma are uniquely positioned to explore the role ocean carbon management may play in meeting the State’s dual goals of mitigating ocean acidification and reaching Washington’s net-zero targets by mid-century.
The Science
What is ocean alkalinity enhancement?
To avoid the worst effects of climate change, we must reduce carbon dioxide (CO₂) emissions and also remove carbon dioxide already emitted into the atmosphere.
Nature’s own carbon removal systems, such as oceans, forests, soils and wetlands, are valuable and should be protected and restored. Scientists also agree these systems alone cannot absorb carbon fast enough to offset what has already been accumulated over a century of industrial emissions without support. That’s why researchers around the world are working to develop new approaches, and why carefully conducted field science is so important.
Seawater naturally emits and absorbs CO₂ from the atmosphere through a process called air-sea gas exchange. Unfortunately, the ocean has absorbed so much man-made carbon that it’s becoming more acidic. That process, called ocean acidification, is already threatening shellfish, salmon, and the entire marine food web that Pacific Northwest communities depend on.
Ocean alkalinity enhancement (OAE) is a way of mimicking and expanding the ocean’s natural capacity to absorb CO₂ through the careful addition of alkaline compounds — similar to the minerals that dissolve from rocks into rivers and eventually reach the sea, without increasing acidity. That additional, absorbed CO2 ends up dissolved in the ocean in the form of bicarbonate, a naturally occurring and stable ion already present in the ocean in immense quantities.
OAE stands out as one of the most promising carbon dioxide removal (CDR) approaches because it builds on the ocean’s natural, vast capacity for storing carbon in safe and stable forms. Further, by shifting the ocean’s carbon chemistry into less acidic forms, OAE may help to locally combat ocean acidification.
Why this research matters for Washington State: Washington has some of the most acidic nearshore waters in the country, driven by a combination of CO2 emissions, upwelling ocean currents and land-based runoff. Local shellfish hatcheries have already suffered real economic damage from these changes; in fact, many hatcheries already add dissolved alkaline minerals to seawater to protect larvae, a small-scale version of what OAE aims to do at scale. Focused research here could help determine whether and how OAE could one day help improve the marine environment and help coastal communities — including shellfish growers and Tribal harvesters — to mitigate and adapt to climate change.
Research to date
What has been studied so far?
Locally sourced juvenile mussels and oysters – donated by Taylor Shellfish Farms – were deployed throughout research site waters and monitored over several months for survival and shell growth. No differences have been observed to date between exposed and control groups. (Photo courtesy of Ebb Carbon)
Project Macoma was established by Ebb Carbon and operated from 2024 to early 2026. It grew from years of research at Stony Brook University and a scientific partnership with Pacific Northwest National Laboratory–Sequim, which tested the safety of OAE on local oysters and species that live on eelgrass. In addition to the R&D goals of Ebb Carbon, the site hosted collaborations with over a dozen partners including: universities, national laboratories, environmental consultancies, local community centers, lifecycle analysis and technoeconomic analysis researchers, and the Lower Elwha Klallam Tribe. The work conducted so far provided an example of how this site could be formalized into a community-led research effort, with additional funding support.
Anchor QEA
[C]Worthy
Ebb Carbon
Feiro Marine Center
Google X
Lower Elwha Klallam Tribe
Monash University
NOAA PMEL
NREL
Oregon State University
Pacific Northwest National Laboratory
Spheros
Stony Brook University
Submarine Scientific
UC San Diego
University of Chicago
University of Washington
This is a small but representative selection of completed and ongoing work at Project Macoma. A full research overview and publication list is available here.
Complete
Baseline habitat & water quality surveys
Comprehensive baseline surveys identified marine habitats, vegetation, and benthic communities in the project area. Sampling and in-situ sensors tracked water quality and seawater carbonate chemistry parameters including pH, dissolved oxygen, temperature, and alkalinity for a period of nine months before any alkalinity release. Monitoring continued throughout all operations, showing measurable changes were confined to the immediate outfall zone, as expected based on modeling studies.
Ebb Carbon
Complete
Carbon removal quantification
A combination of in-water sensors, nearfield dilution models, and regional ocean models are being used to demonstrate that alkalinity addition to the ocean results in the additional uptake and storage of CO2 into the ocean. Alkalinity released into Port Angeles Harbor is rapidly diluted and distributed. Ongoing research is refining calculations of how much CO2 the Harbor absorbed as a result of alkalinity additions.
Ebb Carbon – [C]Worthy – PNNL – Submarine Scientific
Complete
Salmon safety studies (phase 1 & 2)
Juvenile coho salmon – donated by the Lower Elwha Klallam Tribe – were exposed to alkaline conditions simulating the near-field zone around the outfall. At both routine and scientific operating pH levels, no differences in physical or behavioral outcomes were observed compared to control fish.
Ebb Carbon – Lower Elwha Klallam Tribe – Ringham et al., 2026 EcoAnalysts report PG2280.02 submitted to WA Department of Ecology
Ongoing
Y-maze salmon behavior study
A study led by the University of Washington is testing whether juvenile coho, steelhead and chinook salmon can detect and navigate around alkalinity gradients in the water. The salmon were donated by the Lower Elwha Klallam Tribe and Washington Department of Fish and Wildlife, and will provide insight about salmon navigation in the context of ocean alkalinity enhancement projects.
Ebb Carbon – University of Washington – Lower Elwha Klallam Tribe – Washington Department of FIsh & Wildlife
Ongoing
In-water shellfish monitoring
Locally sourced juvenile mussels and oysters – donated by Taylor Shellfish Farms – were deployed throughout research site waters and monitored over several months for survival and shell growth. No differences have been observed to date between exposed and control groups.
Ebb Carbon – University of Washington – local aquaculture partners
Ongoing
Microbial community responses
A combination of incubation experiments and seawater samples collected before, during, and after alkalinity releases are being analyzed for changes in bacterial community composition and gene expression. These results will be used to understand effects of alkalinity addition at the base of the marine food web.
University of Chicago – Oregon State University – PNNL
Future research at the site could prioritize near-field biological observations and in-situ studies, expanded nearfield model validation, air-sea gas exchange research and testing novel sensors for monitoring, reporting and verification (MRV) of carbon removal. Project Macoma can also serve as an effective blueprint and case study for collaborative research across the region and provide a tangible asset from which the community can explore the impacts of climate change and progress towards real world solutions.
What’s next?
Where we are in the transition process
Here is where things stand today and next steps for the coming months.
Due diligence completed — Feb to Apr 2026
Carbon to Sea evaluated the scientific potential, existing infrastructure, permit status, and funding requirements. Our due diligence showed significant scientific and field-building potential, enough to pursue additional input from the broader community.
Input gathering period — May to August 2026 You are here
Carbon to Sea is seeking community input on future research priorities through this website, community events around Seattle and Olympia, and through an interactive exhibit at the Feiro Life Marine Center (led by University of Washington). To be notified about our events or to reach out to our team with questions, send an email to: macoma@carbontosea.org.
Governance & permit transition — Summer to Fall 2026
Carbon to Sea will initiate and establish an independently-governed, nonprofit entity to hold the permit and steward the site, informed by input gathered during the community input phase.
Research resumption — timing depends on your input
Building on your input, the site would resume scientific operations under a new nonprofit governance. The specific research agenda would be shaped by what we hear during this input phase.