Japan’s Environment Ministry Selects Five Blue Carbon Demonstration Projects for Subsidy Support

Japan’s Ministry of the Environment has announced the selection of five projects under a new subsidy scheme designed to scale up marine carbon-sink technologies toward the country’s 2050 net-zero target. Seven applications were received during a public solicitation that ran from late March through April 2026; five were approved following review by an expert committee. Although the broader programme covers blue carbon, biochar, and CO₂-absorbing concrete, this first funding round was restricted exclusively to blue carbon initiatives.

The five selected entities span a range of approaches to seaweed-based sequestration. ENEOS Holdings will run open-sea cultivation trials near Okushiri Island in Hokkaido, focusing on seaweed aquaculture expressly for greenhouse gas absorption. Okabe Co., Ltd. plans to establish a multi-tier aquaculture system reaching to approximately 18 metres depth, using vertical substrate arrays for multiple Arame (Eisenia bicyclis) and Kajime (Ecklonia cava) kelp species over a three-year period, aiming to reduce the frequency of seedling replenishment while enhancing CO₂ fixation. Green Co-op Community intends to demonstrate large-scale expansion of Akamoku seaweed (Sargassum horneri) in the Buzen Sea, develop a carbon credit methodology from the results, and subsequently roll the model out across 16 affiliated consumer co-operatives in western Japan in support of a self-declared 2027 net-zero operational target. Nippon Steel Corporation — in partnership with Hokkaido University’s Muroran Marine Station and Matsumae Town — will trial natural seaweed-bed restoration and Ma-kombu kelp (Saccharina japonica) cultivation in Matsumae, using a steel slag-derived marine fertiliser material to stabilise and expand blue carbon output. Finally, Riken Foods, together with Sumitomo Osaka Cement and Nichimo, will optimise nutritional, aquaculture, and propagation inputs across wakame and kombu cultivation sites, and develop a standardised biomass assessment method combining existing underwater drones and cameras to maximise measurable blue carbon effects.

The ministry frames the programme as bridging a gap where commercial returns alone are insufficient to accelerate deployment, with government co-funding intended to complement evolving domestic carbon-market infrastructure and hasten social implementation.