The Carbon Sink Potential of Marine Algae and Shellfish in China

Marine algae and shellfish are contributing positively to carbon sinks. As the world’s largest algae and shellfish producer, the carbon sinks potential in China is crucial. Here, the situation of algae and shellfish cultivation in China’s offshore from 2011 to 2020 was elaborated. The intensity of carbon sequestration by algae and shellfish annually was estimated. In 2020, the production of algae and shellfish in China has already reached to 2.62 million tons and 14.8 million tons, with an annual growth rate of 7.03% and 3.14%, respectively. Their annual productivity also maintained an increasing trend, while the rate of productivity increase decreased over ten years except for Porphyra haitanensis, Sinonovacula constricta, and Haliotis discus hannai. Crassostrea gigas and Ruditapes philippinarum were the highest fixed carbon shellfish, and Saccharina japonica was the dominant algae. Meanwhile, the relatively high carbon sink intensity was found in Shandong, Fujian, and Liaoning. In the last decade, the total carbon sink of algae and shellfish was 1.62 million tons and 7.16 million tons, with an increase of 90.55% and 31.73%, respectively. This created an economic value of 3.293 billion dollars. Results indicated that China’s offshore mariculture algae and shellfish assumed the considerable carbon sink capacity. Through rational utilization of the carbon sink resources in algae and shellfish, it provides potential ideas for China to pursue personalized carbon neutrality.