At Ocean Exchange, we see this dynamic play out each year as entrepreneurs bring forward bold, sometimes untested, ideas. Many of these concepts are not ready to scale today. Some will need years of development before they make a measurable impact. But taken together, they point toward the portfolio of solutions that will drive a lower-carbon ocean economy.
RETHINKING PROPULSION
One such solution is the search for alternative fuels for propulsion. Startups are experimenting with ways to make shipping less dependent on heavy diesel. Blaze Energy is pursuing ammonia-hydrogen blends that could provide a carbon-free alternative for hard-to-electrify industries. CarbonBridge is turning waste gases into ultra-low-carbon methanol, a fuel gaining traction among shipowners looking for compatibility with existing infrastructure. Sweden’s Zparq is rethinking propulsion altogether with compact electric motors designed for both commercial and recreational vessels. Flux Marine is growing its recreational electric motor business and raising new capital for expansion.
MATERIAL MATTERS
Another wave of innovation is emerging in materials. Today’s plastics and textiles are deeply intertwined with fossil fuels, and replacing them at scale will take time. Still, entrepreneurs are laying critical groundwork. Sway uses seaweed to create compostable replacements for plastics, like retail bags, polybags for clothing from factory to doorstep. The company has early pilots and sales with several major retail brands. US-based Soarce is developing seaweed-derived fabrics and leathers that are not only sustainable but also high-performing, with fire resistance and UV stability built in. Another past finalist, Kintra Fibers, is creating a bio-based and biodegradable polyester alternative. While these companies are small compared to the trillion- dollar plastics and polyester industries, they provide a glimpse of how the future might look.
CARBON SEQUESTRATION
A third frontier, marine carbon dioxide removal (mCDR), is attracting significant attention, though it is still in its earliest stages. Unlike fuels or materials, no approach has yet been proven at the scale that will be required to have significant ocean impact. A central challenge is the lack of fully commercially vetted MRV (measurement, reporting, and verification)— tools that would allow markets to value and finance ocean-based carbon sequestration. Some sequestration/removal methods may raise concerns about unintended ecological impacts, habitat disruption, and other long-term consequences. Uncertainties and perceived risk can be mitigated with more science, more data, and more test beds.
For now, investors are watching carefully while some philanthropies and public sector funds are stepping in to keep the science advancing. What is clear is that ocean carbon removal will need more research, robust MRV frameworks, and significant funding before it becomes a major pillar of decarbonization. Startups and researchers working in this space may not yet offer ready-to-deploy scaled solutions, but they are laying necessary groundwork.
Decarbonizing the Blue Economy will not happen with one breakthrough technology, nor with one bold investment. It will require persistence, diversity of ideas, and willingness to take risks on solutions that may not yet be fully proven. That is the role startups will play, and the role Ocean Exchange is proud to support—elevating innovations that point the way forward.
This spotlight appeared in ON&T Magazine’s 2025 September Edition, Decarbonizing the Blue Economy, to read more access the magazine here.
