Kansai Airports is pleased to announce that we have acquired additional J Blue Credit* certification on the acknowledgement of the CO2 absorption by the seaweed beds of the seawalls around the islands of Kansai International Airport (KIX).
Carbon stored in the water through the action of marine organisms is known as “blue carbon”, and it is attracting attention as a new source of CO₂ absorption. At the KIX airport islands, gently sloped rubble-mound seawalls were adopted for most of the shoreline, and efforts have been made to create a rich seaweed bed environment through seaweed seeding, protection and cultivation, and monitoring surveys.
In recent years, we have also actively worked on new initiatives such as protecting seaweed with protective nets and placing new substrates to promote the attachment of next‑generation seedlings, so as to maintain the stability of and expand the seaweed bed environment.
A survey we conducted in March 2025 confirmed that the seaweed bed area around the airport island seawalls had reached 66 hectares, with 58 species of seaweed growing there. With our continuous efforts, the seaweed bed area was the largest ever with an increase of about 20% compared to the previous survey in 2022. The seaweed beds also serve as habitats that nurture a diverse ecosystem, and various marine species—including red-spotted grouper and Asian sheepshead wrasse—were observed along the airport island seawalls.
In the process for this J Blue Credit certification, we assessed the seaweed bed area observed in the latest survey, collected baseline data not only on large seaweeds, such as wakame, but also small seaweeds, for more precise assessment of the CO₂ absorption of the seaweed beds where diverse seaweed species grow. As a result, a larger CO₂ absorption effect than the previous certification was recognized.
Kansai Airports Group will continue to promote all possible initiatives to reduce environmental impacts, aiming not only to achieve its long term vision of net zero greenhouse gas emissions by 2050 but also to coexist with nature by contributing to the conservation of healthy ecosystems.
*A credit that is certified, issued, and managed by JBE (Japan Blue Economy Technology Research Association). It is certified and issued after review and verification by a third‑party committee independent from JBE. Japan Blue Economy Technology Research Association
●Certification details (the third J Blue Credit certification and issuance for FY2025)
Absorption volume certified for the Credit: 103.2 t- CO2
Applicable period: 5 years (from FY2017 to FY2021)
