How the J-Blue Credits enabled funding for coastal communities to recover their ecosystems
In this series we explore Japan’s blue carbon credit system by diving into case studies highlighting how coastal restoration is being turned into a financial mechanism that funds itself. In this article, we highlight the Miyagi Blue Carbon Project, where seaweed is used to rebuild a sustainable industry from disaster.
Devastation and recovery
With all fishing ports gone and over a third of fishermen unwilling to return to the water, the Great East Japan Earthquake had not only destroyed an industry, but also threatened the stability of an entire coastal community in Miyagi (McCurry, 2017). The magnitude 9.0 earthquake struck off the Pacific coast of Japan in March of 2011, becoming the largest ever recorded in its history. Thirty minutes later a tsunami arrived, causing widespread devastation across Tōhoku in the northeast region of Japan. The disaster led to an estimated 18,000 dead or missing, destroyed 123,000 homes, and caused an estimated €190 billion EUR in damage, breaking another record as the most expensive natural disaster in history (NOAA, 2021).
The prefecture of Miyagi, closest to the earthquake’s epicentre, was among the most severely affected regions with nearly half of all those lost or missing coming from the area (Rafferty and Pletcher, 2026). For the fishing industry, the tsunami was catastrophic. 90% of fishing vessels were lost and all aquaculture facilities for seaweed, including cultivation of wakame, one of the most widely consumed species of kelp in Japan, were completely destroyed (Delaney, 2012). Even thriving coastal ecosystems which the industry relied on showed a reduction in marine vegetation in some areas to a tenth of the levels seen before the tsunami (Jiji Press, 2024).
Despite the enormous challenges, Japan’s response was nothing short of remarkable. The Japanese government allocated the equivalent to a €60 million EUR supplementary budget for fishery reconstruction and established a temporary work programme paying fishers to clear debris (Delaney, 2012). Through the programme, local fishers and citizens met and began discussing ways they could build more local resilience and contribute to recovery efforts as survivors. What emerged was a range of community-driven recovery efforts, such as sharing boats and dividing profits, which no policy could have planned for (Takakura, 2021).
The combined recovery efforts from governments, organisations, and locals have led to wakame seaweed production rebounding to among the highest volumes in Japan (FAO 2026), offering a productive base from which the Miyagi Blue Carbon Project emerged. As wakame farming is now expected to produce stable profits annually, the initiative extends the industry’s recovery through a blue carbon credit framework which generates additional funding for restoration projects that sequester carbon and deliver co-benefits for biodiversity and local communities. The restored ecosystems in turn create healthy seaweed beds that act as nurseries for fish and other marine life, increasing ecological stability and building a more resilient, sustainable future for the fisheries which the industry depends on.
Kelp is central to the Miyagi Blue Carbon Project, which aims to restore a seaweed forest spanning multiple kelp species, other seaweeds, and cultivated wakame, together generating blue carbon and restoring coastal ecosystems. As kelp stores carbon in its biomass through photosynthesis, some is naturally exported into the ocean when detached, with a fraction sinking to deep ocean reservoirs for long-term storage. Kelp also releases dissolved organic carbon when alive, over half of which persists over long timescales and can contribute to long-term carbon storage (Lie et al., 2022). It is these pathways which make kelp a valuable asset to the Miyagi Carbon Project.
Japan’s pioneering blue carbon credit system
So, what is blue carbon? When we talk about blue carbon, we are referring to the carbon dioxide (CO2) sequestered in the oceans by coastal ecosystems, including mangroves, seagrass beds, tidal flats, and seaweed forests, all with distinct carbon removal mechanisms. Despite only covering 2% of the ocean, coastal habitats disproportionately contribute to the carbon cycle by accounting for approximately 50% of all carbon buried in ocean sediments (The Blue Carbon Initiative, 2026). For decades, their climate value went largely unrecognised, with seaweed in particular overlooked in both blue carbon research and policy to this day.
Japan began to change this narrative. In 2020, Japan developed the world’s first government-approved, voluntary blue carbon credit system, J-Blue Credit, operated by the Japan Blue Economy Association (JBE). The system measures and verifies the CO2 removed through blue carbon restoration activities, converting it into tradable credits which can be purchased and retired by businesses, creating a financial mechanism which funds and raises awareness of ocean conservation projects.
Two years later, Japan made history again by being the first nation to officially recognise seaweeds like kelp as part of their blue carbon ecosystem by including seaweed-based carbon in its national emissions inventory submitted to the United Nations. The Miyagi Blue Carbon Project is included as a mechanism within this framework, giving scientific and financial credibility to its recovery initiatives and business model.
For the purchasers of these credits, J Blue Credits also offers companies an opportunity for a genuine partnership by directly supporting local fishermen and, in Miyagi’s case, the resurgence of a local economy and ecosystem. Corporate involvement can also raise environmental awareness among employees and their families, driving broader behavioural changes and mindset shifts across society. Changing behaviour in employees has been reported by Tokyo Gas, whose engagement with restoration activities boosted employee morale as public awareness of blue carbon grew (Miyagi Blue Carbon Project, 2026). These are unique features of the J-Blue Credit system. It creates an environment for real collaboration between industry and community, and in doing so, has the potential to bring about systemic change.
Kelp is central to the Miyagi Blue Carbon Project, which aims to restore a seaweed forest spanning multiple kelp species, other seaweeds, and cultivated wakame, together generating blue carbon and restoring coastal ecosystems. As kelp stores carbon in its biomass through photosynthesis, some is naturally exported into the ocean when detached, with a fraction sinking to deep ocean reservoirs for long-term storage. Kelp also releases dissolved organic carbon when alive, over half of which persists over long timescales and can contribute to long-term carbon storage (Lie et al., 2022). It is these pathways which make kelp a valuable asset to the Miyagi Carbon Project.
The Miyagi Blue Carbon Council: the people behind the project
The Miyagi Blue Carbon Council, established in 2021, brings together a mixture of academics, government officials, industry representatives, and fishers. As the control centre for the Miyagi Blue Carbon Project, the Council sets targets, manages progress, and verifies results. Its main goal is to create a sustainable fishing industry by growing a seaweed forest of both cultivated and wild seaweed, generating blue carbon credits which funds the project further and offsets CO2 emissions from the industry itself. The Council says it aims to generate 250 tonnes of CO2 in blue carbon credits per year, reaching 2500 tonnes of CO2 over its 10-year target period.
The establishment of the Council also created a shift in how restoration was understood and valued in the area. Fishers could now create and conserve seaweed habitats knowing that it would create opportunity. Rather than restoration potentially coming at a cost, the blue carbon credit system turned it into something that was economically rewarded. This provided an incentive and funding for fisheries to further invest in recovery efforts from the earthquake and restore their marine ecosystem and productivity.
To achieve it aims, the Council works within three parallel pathways. Research and Technology provide the groundwork for the initiatives, mapping how much seaweed exists across the Miyagi Sea and calculating how much carbon is absorbed by different species alongside how much is released by the industry. Practice in Model Districts tests and optimises cultivation and planting methods under local conditions, while refining survey protocols for carbon credits. Finally, Raising Awareness and Education ensures community ownership of the project by bringing together fishermen, industry, and local representatives, and educating younger audiences through interactive events. Community engagement is essential to the maintenance of the Miyagi Blue Carbon Project, ensuring long-term sustainability and transparency of its initiatives.
At the heart of the Miyagi project is its sustainable cycle. Initially, fishermen cultivate wakame through their normal aquaculture activities. The carbon absorbed by that kelp is quantified by the Council and verified through the J Blue Credit scheme and when these credits are sold, the profits will be reinvested into further cultivation and creation of seaweed beds. More seaweed means more credits, and so the cycle continues. The growth of seaweed beds for purposes besides aquaculture creates an additional opportunity to profit from co-benefits such as increased catches, species conservation, and other environmental benefits which the J-Blue System allows to increase the unit price of each credit if proven. As the health of kelp ecosystems increase, so does the wealth of the industry.
The beginning stages of the cycle have already begun. Cultivated wakame generated 20.8 tCO2 of certified J Blue Credits from the 2023 season, which was officially issued by JBE in 2025. The purchasers of these first credits reflect the breadth of corporate interest in the project, ranging from a historic seaweed wholesaler and Sanyo Techno Marine, a marine environment consultancy, to a renewable energy firm and regional construction corporation, Maruhon Gumi. All are either Miyagi-based or have strong regional ties, suggesting the project has so far attracted buyers motivated by both environmental commitment and the community’s future, making each purchase a genuine partnership in supporting the local economy and ecosystem.
A roadmap for the future
The Miyagi Blue Carbon Project demonstrates how a blue carbon initiative can be more than a restoration or offsetting tool. The J-Blue Credit System also provides opportunity to raise additional funds for industry, support local communities, and foster meaningful partnerships between organisations and the communities they invest in. In Miyagi’s case, this has contributed to the recovery and resurgence of local fisheries by developing a sustainable, self-funding industry. Ultimately, this shows that significant ecosystem restoration will occur when it is genuinely rewarding for everyone involved and generates lasting value. Miyagi is one example of this, and as blue carbon frameworks continue to develop globally, it offers a model for how kelp-based blue carbon can deliver positive environmental and socioeconomic outcomes.
A self-sustaining future
At the heart of the Miyagi project is its sustainable cycle. Initially, fishermen cultivate wakame through their normal aquaculture activities. The carbon absorbed by that kelp is quantified by the Council and verified through the J Blue Credit scheme and when these credits are sold, the profits will be reinvested into further cultivation and creation of seaweed beds. More seaweed means more credits, and so the cycle continues. The growth of seaweed beds for purposes besides aquaculture creates an additional opportunity to profit from co-benefits such as increased catches, species conservation, and other environmental benefits which the J-Blue System allows to increase the unit price of each credit if proven. As the health of kelp ecosystems increase, so does the wealth of the industry.
The beginning stages of the cycle have already begun. Cultivated wakame generated 20.8 tCO2 of certified J Blue Credits from the 2023 season, which was officially issued by JBE in 2025. The purchasers of these first credits reflect the breadth of corporate interest in the project, ranging from a historic seaweed wholesaler and Sanyo Techno Marine, a marine environment consultancy, to a renewable energy firm and regional construction corporation, Maruhon Gumi. All are either Miyagi-based or have strong regional ties, suggesting the project has so far attracted buyers motivated by both environmental commitment and the community’s future, making each purchase a genuine partnership in supporting the local economy and ecosystem.
References
Delaney, A.E. (2012) “A Report from One Miyagi Fishing Community,” Asia Pacific Journal, 10(3).
FAO (2026) “Undaria pinnatifida. Cultured Aquatic Species Information Programme,” Fisheries and Aquaculture [Preprint]. Edited by S.J. Pang, X. Li, and T. Chopin.
Jiji Press (2024) “Seagrass bed restoration work spreading in Miyagi,” Yomiuri.co.jp. The Japan News, 26 December. Available at: https://japannews.yomiuri.co.jp/science-nature/environment/20241226-229895/ (Accessed: March 9, 2026).
Li, H., et al. (2022). Carbon sequestration in the form of recalcitrant dissolved organic carbon in a seaweed (kelp) farming environment. Science of the Total Environment, 838, 15615
McCurry, J. (2017) Tohoku: the fishing industry, The World from PRX. Available at: https://theworld.org/stories/2017/05/13/tohoku-fishing-industry (Accessed: March 12, 2026).
NOAA (2021) On This Day: 2011 Tohoku Earthquake and Tsunami, National Centres for Environmental Information (NCEI). Available at: https://www.ncei.noaa.gov/news/day-2011-japan-earthquake-and-tsunami (Accessed: 15 March 2026).
Rafferty, J.P., Pletcher, K. (2026) Japan earthquake and tsunami of 2011. Encyclopedia Britannica. Available at: https://www.britannica.com/event/Japan-earthquake-and-tsunami-of-2011.
Takakura, H. (2021) “Individualism and collectivism in small-scale fisheries post-3.11 Japan,” Disaster Prevention and Management, 30(6), pp. 26–38.
The Blue Carbon Initiative (2026). The Blue Carbon Initiative. Available at: https://www.thebluecarboninitiative.org (Accessed: March 19, 2026).
The Miyagi Blue Carbon Project (2026.) “令和7年度 宮城県ブルーカーボン・シンポジウムを開催しました！,” note, 29 January. Available at: https://note.com/blue_carbon/n/n4a5a31d37e42 (Accessed: March 24, 2026).
