A shellfish farm in Dachen town, Jiaojiang district, Taizhou, East China's Zhejiang province. [Photo/taizhou.com.cn]

Over 2,000 metric tons of blue carbon credits were recently auctioned off in Taizhou, East China's Zhejiang province, at a price of 45.2 yuan ($6.18) per ton. These credits were generated by shellfish farming on Dachen Island, located off the coast of the city's Jiaojiang district.

Zhejiang Crystal-Optech Co Ltd emerged as the winner after several rounds of competitive bidding, offering 100,500 yuan for the credits. The auctioned assets were created by all shellfish farmers in Dachen town, with a portion of the funds generated going back to the farming households. The remaining funds will be used to support marine ecological protection efforts and improve the marine ecosystem's overall quality on Dachen Island.

The concept of "blue carbon" was introduced in 2009 in a report called Blue Carbon: The Role of Healthy Oceans in Binding Carbon, published by the UN Environment Programme (UNEP) in collaboration with the UN Food and Agriculture Organization (FAO) and the UN Educational, Scientific and Cultural Organization (UNESCO).

Blue carbon refers to carbon absorbed from the atmosphere and stored in coastal and marine ecosystems. Mangroves, tidal marshes, and seagrasses are recognized as the three major blue carbon ecosystems that can sequester and store significant amounts of carbon in their plants and sediment. Fish, macroalgae, shellfish, and microorganisms also contribute to carbon fixation and storage.

The blue carbon credits are generated by these ecosystems based on the amount of carbon they absorb and store. These credits are then sold to buyers who wish to offset their carbon emissions.

Dachen Island was chosen as a pilot location for blue carbon trading due to its rich natural resources. With a forest coverage rate of 66 percent, it is the second-largest fishing ground in Zhejiang province.