Trend of fishery carbon sink in Chinese bivalve aquaculture from 2004 to 2023.

Abstract

Climate change is a global issue that requires immediate attention. In order to achieve carbon neutrality as outlined in the Paris Agreement of 2015, in addition to reducing carbon dioxide (CO₂) emissions, promoting blue carbon sinks is equally important. Fishery carbon sink (FCS), especially from bivalve aquaculture, have received increasing attention as bivalves not only store carbon in their flesh and shells, but also promote carbon storage in the aquaculture environment. Unlike previous studies that focused on localized assessments or used outdated carbon budget models, this study was conducted to analyze the trend of fishery carbon sinks from bivalve aquaculture in China (the largest producer of farmed bivalves) over the past two decades using the refined carbon budget model that integrates both carbon removal (flesh and shells) and carbon storage (biodeposits and excretion). In general, the results of this study revealed that the contribution of bivalve aquaculture to FCS has increased significantly with rising bivalve production. Oysters and clams are the most farmed bivalves, with Shandong and Fujian provinces being the largest farmed bivalve producers. From 2004 to 2023, bivalve aquaculture in China contributed to 15 million tonnes of net carbon sink, and is expected to produce over 1 million tonnes of net carbon sink per year from 2024 onwards. The findings of this study not only advance our knowledge of the current trend of FCS in China, but also provide important information to promote the development of carbon trading.