Ocean Carbon Removal Gets Its First International Rulebook — But the Market Already Left the Starting Line

The IMO adopted the first global framework for ocean geoengineering, but $500M+ in private capital is already deployed, and the rules are research-only guidelines with no enforcement teeth.

In October, the International Maritime Organization adopted the first international framework acknowledging three major ocean carbon removal techniques: ocean fertilisation, ocean alkalinity enhancement, and biomass sinking. The framework, adopted under the London Convention and Protocol — a treaty governing ocean dumping — urged caution and said further research is needed before anything beyond the research stage can be considered. It is the product of over a decade of negotiations among scores of countries.

The announcement arrives in a sector that has already moved. More than $500m has been invested in ocean carbon removal since 2021, according to Ocean Carbon Removal Watch, a Pulitzer Center-backed database. Planetary Technologies, operating out of a shipping container in Halifax harbour, runs ocean alkalinity enhancement five days a week, adding a proprietary alkaline slurry to a power company's cooling water, which is then discharged into the harbour. The company sells carbon-removal credits worth millions to JPMorgan Chase and Shopify through the Isometric registry. Nova Scotia has become the world's largest ocean alkalinity-enhancement centre. Planetary Technologies shares the waters with CarbonRun, pHathom Technologies, and a test site run by non-profit Carbon to Sea, all anchored by Dalhousie University's Ocean Frontier Institute and backed by Canadian government grants and international research partnerships from Germany and Australia. New field trials are proposed across the Gulf of Mexico, Saudi Arabia's Gulf coast, Norwegian rivers, and Singapore's harbours. The science underpinning these operations remains contested. Marine biologist Sam Dupont of the University of Gothenburg compares the sector's approach to skipping straight to clinical trials without pre-clinical steps. Nina Bednaršek of Slovenia's Jožef Stefan Institute warns that trace metals in cheaper alkaline feedstocks — particularly mining byproducts — can be toxic to zooplankton at very low concentrations, threatening the base of the marine food chain. Lisa Levin of Scripps Institution of Oceanography notes that most OAE research has examined ocean chemistry, not environmental risk. Bednaršek is working with the IPCC to develop carbon-accounting methodology for OAE that would include environmental safeguards. The regulatory gap is structural. Romany Webb of the Sabin Center for Climate Change Law warns that unclear jurisdiction over where existing maritime laws apply creates opportunities for bad actors. The IMO framework is guidance for research activities, not a binding enforcement regime for commercial operations. Government funding, particularly in the US where the sector originated, has increasingly dried up, leaving the private sector and academia to set standards on their own — a point Brad Ack of Ocean Visions calls insufficient. The core tension is temporal. Industry proponents like Planetary Technologies' Greg Rau argue the ocean is already warming and acidifying, and that conservation's instinct to fence off ocean activity is outdated. Scientists counter that rushing deployment with inadequate toxicology and no price on biological harm could damage marine ecosystems and undermine public trust in the entire sector before breakthroughs arrive. Fatima Candace Vahlsing of Ocean Conservancy frames the IMO framework as a signal that the global community prioritises getting the system right. What is emerging is a familiar pattern: private capital outrunning public governance. The carbon-credit revenue model creates incentives to scale operations before the science of ecological impact catches up. The IMO framework is a first step, but it explicitly applies only to research activities, and the line between research and commercial deployment in Halifax harbour — where credits are already being sold — is blurry at best.