Ocean Alkalinity Enhancement Trial Tests Carbon Capture
The LOC-NESS project released lye into the Gulf of Maine to measure atmospheric carbon dioxide absorption potential.
Updated on Oct. 16, 2026 in Environmental
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In August 2025, researchers conducted the LOC-NESS project in the Gulf of Maine, releasing 16,500 gallons of sodium hydroxide to test carbon dioxide sequestration. While the experiment successfully tracked an alkaline patch, seawater pH levels briefly exceeded the EPA-permitted limit of 8.7 during the operation.
Why it matters
Ocean alkalinity enhancement is being studied as a method to accelerate natural carbon absorption by raising seawater pH. Understanding the localized effects of such releases is critical for assessing the feasibility and safety of deploying this technology at scale.
The LOC-NESS trial released 16,500 gallons of sodium hydroxide in the Wilkinson Basin, where monitoring indicated that seawater pH exceeded the EPA limit of 8.7. The resulting patch, which measured 2,600 feet in diameter, was tracked for four days.
The players
LOC-NESS project
A research initiative focused on testing ocean alkalinity enhancement for carbon sequestration.
Environmental Protection Agency
The federal regulator that issued the permit for the Gulf of Maine field trial.
Research vessel Connecticut
The primary monitoring platform used to track the chemical patch in the Wilkinson Basin.
The details
The experiment used a support vessel to pump sodium hydroxide into the Wilkinson Basin, while the research vessel Connecticut monitored the chemical dispersion. The team used drifting buoys, gliders, and autonomous underwater vehicles—robotic systems that travel without human intervention—to track the patch for 96 hours. The project utilized Rhodamine Water Tracer—a fluorescent dye used to map water movement—to maintain visibility of the alkaline plume.
Timeline
2024: The EPA opened public comment periods for the project.
April 2025: The EPA approved the research permit for the trial.
August 13, 2025: The LOC-NESS project released 16,500 gallons of lye into the Gulf of Maine.
February 2026: Researchers presented preliminary findings at the Ocean Sciences Meeting.
The Tech Race
The LOC-NESS trial serves as a practical assessment of ocean alkalinity enhancement, a field currently competing against other direct carbon removal technologies for regulatory approval. This research specifically benchmarks the efficacy of lye-based methods against theoretical models of ocean-scale carbon absorption.
There is currently no direct impact on the public or commercial maritime operations. Future deployment of this technology would require long-term environmental certification and ongoing monitoring of local seawater chemistry.
The takeaway
This trial confirms that alkaline patches can absorb measurable amounts of carbon dioxide in open water settings. Observers should track upcoming longitudinal studies on marine life to determine if this sequestration method poses long-term risks to regional biodiversity.
Further reading
For broader context on these efforts, see the latest developments in Environmental research.
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