Turning Ocean Chemistry into Climate Action: How Carbon Removal Is Supporting Coastal Economies and Marine Health

As the climate crisis intensifies, the world’s oceans are absorbing a growing share of atmospheric carbon dioxide, taking up roughly a quarter to a third of global emissions. While this natural process slows warming, it comes with a hidden cost: as CO₂ dissolves in seawater, it forms carbonic acid, gradually increasing ocean acidity and altering marine chemistry in ways that can threaten ecosystems and coastal economies.

This shift in ocean chemistry reduces the availability of carbonate ions, a key building block used by shell-forming organisms such as oysters, corals and certain plankton. Without sufficient carbonate, these species struggle to build and maintain their shells and skeletons, with consequences that ripple through entire marine food webs. Scientists warn that these changes are no longer distant projections but are already being observed in aquaculture systems and coastal environments.

In Maine, where shellfish farming plays a central economic and cultural role, the effects have been particularly tangible. The Damariscotta River Estuary alone accounts for a significant share of the state’s oyster production, supporting a local industry that is both economically valuable and deeply embedded in community life. Yet rising acidity levels in incoming seawater have disrupted oyster hatcheries, at times causing severe losses during sensitive early growth stages.

In response, researchers at MIT, working in collaboration with the University of Maine Darling Marine Center and local aquaculture operators, have been developing an innovative approach that turns ocean chemistry itself into a tool for carbon removal and ecosystem restoration. Rather than adding chemicals to buffer seawater, the system uses electrochemical processes to directly extract dissolved carbon dioxide while restoring the water’s natural alkalinity.

The method operates by using electrically charged reactive electrodes that draw protons into controlled chambers, triggering a sequence of reactions that separate dissolved inorganic carbon from seawater. The carbon dioxide is then captured as a gas under vacuum conditions, while the treated water is returned to the ocean in a rebalanced, less acidic state. In effect, the system removes CO₂ from seawater while simultaneously correcting pH levels that are critical for marine life.

Early trials have shown that this approach is not only biocompatible but also beneficial for shellfish development. Oysters exposed to treated seawater demonstrated improved shell formation compared with those grown in untreated or chemically buffered conditions. Importantly, the process produces no harmful chemical by-products, instead operating as a closed-loop system in which seawater enters, carbon dioxide is extracted, and restored water is returned to the marine environment.

The captured carbon dioxide itself may also have downstream uses, including applications in algae cultivation for aquaculture feed, creating potential links between carbon removal and sustainable food production systems.

Researchers involved in the project describe the work as both a climate intervention and a form of ecosystem support. By improving seawater conditions for shellfish growth while removing carbon dioxide, the technology effectively aligns environmental restoration with economic resilience in coastal communities.

Beyond its technical aspects, the project is also being viewed through a broader socio-economic lens. Coastal regions such as Maine are increasingly exposed to climate-driven changes in ocean chemistry, and aquaculture industries are among the first to feel the impacts. By stabilising local marine conditions, the technology could help safeguard jobs and maintain productivity in regions that depend heavily on shellfish farming.

The research team emphasises that the system is still in development and will require further scaling before broader deployment becomes viable. Current efforts are focused on improving system durability, efficiency and performance in real-world marine environments. Funding support from US research programmes has enabled continued development and expansion of pilot trials in partnership with aquaculture operators.

What distinguishes this approach from many other carbon removal strategies is its integration with existing marine industries. Rather than operating as a separate industrial system, it is designed to work alongside aquaculture, potentially creating a mutually reinforcing relationship in which carbon removal improves water quality, and aquaculture provides operational deployment environments.

Researchers suggest that this integration could form the foundation of a new type of “blue economy”, where climate mitigation, marine restoration and economic activity are closely linked. In this model, aquaculture is not only a food production system but also a potential platform for environmental repair and carbon management.

While challenges remain in scaling the technology and ensuring long-term operational stability, the work represents a shift in how ocean systems are being considered in climate strategies. Rather than viewing the ocean solely as a passive carbon sink, this approach actively engages with marine chemistry as a controllable system that can be tuned to support both ecological and economic outcomes.

As one researcher involved in the project noted, the goal is not only to remove carbon dioxide but also to sustain the coastal communities that depend on healthy marine ecosystems. In that sense, the project sits at the intersection of climate science, engineering innovation and regional economic resilience, suggesting a future where carbon removal and aquaculture may evolve together rather than separately.