When There's No Rock, Use the Ocean

pHathom raises $12M to store CO2 in seawater, no pipelines or geology needed

3 Jun 2026

pHathom Technologies, a Halifax-based startup founded in 2024, has closed a $4 million seed round to advance a carbon removal system that uses the ocean as its storage medium. Total committed capital now exceeds $12 million.

Propeller Ventures led the round, joined by the New Brunswick Innovation Foundation, Invest Nova Scotia, and Carmeuse Ventures, a Belgian industrial climate fund. A separate $16 million project grant through Canada's Ocean Supercluster adds federal weight to the private backing.

The context matters. Atlantic Canada lacks the geological formations that underpin Alberta's carbon capture corridor, leaving coastal industrial emitters with few viable sequestration options. pHathom's system targets this gap directly.

Designed for coastal bioenergy plants burning biomass such as wood chips, the technology captures CO2 at the point of emission and passes it through a limestone-seawater reactor. The output is bicarbonate, a compound already present in seawater at natural concentrations. Treated water returns to the ocean under closely matched conditions, requiring no pipeline, no geological injection, and no long-distance CO2 transport.

Two pilots are funded and scheduled. A summer 2026 study at the Huntsman Marine Science Centre will produce independent safety data on 13 marine species. A commercial-scale demonstration with a community college partner follows in 2027.

Frontier, the advance purchase program backed by Stripe, Shopify, and Google, has selected pHathom as a supplier. Foresight Canada named the company Atlantic Canada's Startup of the Year in 2025.

Verification standards for marine dissolved inorganic carbon storage remain less settled than those governing geological sequestration. Long-term monitoring frameworks are still being developed. pHathom has acknowledged this directly, committing to transparent data at each stage of its pilot programme.

Regulatory maturity will be the determining factor. For a coastline locked out of conventional carbon infrastructure, the commercial case hinges on whether monitoring standards catch up to the science.