We first covered the Loc-Ness OAE trial when initial results emerged in March. Now the Woods Hole Oceanographic Institution team has presented detailed findings at the Ocean Sciences Meeting 2026, and the data is more complete. The picture is encouraging.
The Experiment
The Loc-Ness project (named for its combination of Loring Air Force Base logistics and the Ness of monitoring) ran a six-day field trial in August 2025 in the Gulf of Maine. The setup:
- 65,000 liters of sodium hydroxide dispersed over approximately 1 km² of open ocean
- Three research vessels tracking the alkalinity plume
- Four autonomous underwater vehicles (AUVs) monitoring water chemistry and biology
- NASA’s PACE satellite providing remote sensing of the dispersal pattern from above
This was the first precision-tracked OAE experiment conducted in an open marine environment, as opposed to laboratory tanks or enclosed mesocosms.
The Results
The provisional findings presented at Ocean Sciences Meeting 2026:
CO₂ capture: 2-10 tonnes of atmospheric CO₂ absorbed during the 4-day active monitoring period. The range reflects measurement uncertainty across different monitoring methods and spatial coverage. Extended modeling suggests the same alkalinity addition would drive approximately 50 tonnes of CO₂ absorption over a full year as the enhanced seawater chemistry continues to equilibrate with the atmosphere.
Ecosystem impact: None detected. The team monitored phytoplankton abundance, zooplankton populations, fish behavior, and lobster larvae. No statistically significant negative effects across any trophic level. This aligns with a recent PLOS One study showing that the zooplankton species Oikopleura dioica exhibited resilience to OAE conditions in controlled experiments.
Plume tracking: The AUV fleet and satellite imagery successfully tracked the alkalinity plume as it dispersed. This is a technical achievement in its own right: one of the hardest problems in marine CDR is knowing where your intervention went and what it did. The Loc-Ness monitoring architecture demonstrated that precision tracking is feasible.
Why This Matters for OAE’s Future
The ocean holds approximately 38,000 gigatonnes of carbon, roughly 40 times the atmospheric reservoir. Seawater is naturally alkaline, which causes it to absorb CO₂ from the atmosphere. But as oceans take up more anthropogenic CO₂, their pH drops (ocean acidification), which weakens their capacity to absorb additional carbon.
OAE reverses this by adding alkaline materials to seawater, restoring and enhancing the ocean’s natural CO₂ absorption capacity. The chemistry is well-understood. The open questions have been: does it work at meaningful scale in real ocean conditions, and what are the ecological risks?
Loc-Ness provides data on both questions. The capture numbers are modest in absolute terms, but the experiment was designed for precision monitoring, not maximum removal. The ecological monitoring found no harm. Together, these results support the case for scaling up to larger field trials.
The MRV Challenge Remains
Measuring OAE’s effectiveness is fundamentally harder than measuring DAC output. In DAC, you meter the CO₂ coming out of a pipe. In OAE, you are measuring changes in ocean chemistry across a dispersing plume in an environment with natural variability in temperature, salinity, biology, and circulation.
The Loc-Ness approach, using multiple vessels, AUVs, and satellite monitoring simultaneously, is expensive and logistically complex. Scaling OAE to millions of tonnes per year will require cheaper, more automated monitoring approaches. Proxy methods, permanent buoy networks, and machine learning models trained on trial data are all being explored.
Microsoft and Google have both signed agreements with Ebb Carbon for OAE-based carbon removal, signaling corporate confidence in the pathway. But buyer confidence depends on MRV confidence, and that requires more trials like Loc-Ness.
What Comes Next
The AUVs remain deployed at the Loc-Ness test site for long-term impact monitoring. The team will track whether any delayed ecological effects emerge over months, not just days.
Meanwhile, other OAE research groups at the University of Tasmania, University of Southampton, and commercial operations like Planetary Technologies and Reefal are running parallel trials. The equatic seawater alkalinization study published last month added another data point on electrochemical OAE approaches.
The field is building a body of evidence. Loc-Ness is one of the most important contributions so far.
Source: Chemistry World, reporting on Loc-Ness results presented at Ocean Sciences Meeting 2026.