Removable carbon and storage carbon of golden tides

Abstract

Due to ever-increasing global warming, ocean acidification, and inshore eutrophication, the outbreak of golden tides with Sargassum horneri has increased in the Yellow sea, where the biomass carbon enters three main carbon pathways: a. Removal of carbon from seawater by salvage, known as removable carbon; b. Biomass carbon is deposited to the seafloor through POC and RDOC through Biological Carbon Pump and Microbial Carbon Pump; c. Re-entering the carbon cycle through the food chain or re-entering the atmosphere through the action of microbes. Estimating carbon fixation (removable carbon) and storage (particulate organic carbon (POC) and refractory dissolved organic carbon (RDOC)) is vital in studying the global carbon cycle. In this research, it was observed that the C content of S. horneri was high, and the utilization rate of dissolved organic carbon (DOC), RDOC, and POC was also high in the eutrophication environment, where only 2.71 % of algal biomass carbon was converted to RDOC, and only 0.20 % converted to POC. The C + N + P combination has a restart effect on the seasonal accumulation of RDOC in relevant sea areas. It is suggested that the salvage and resource utilization should be strengthened to effectively control the golden tide and reduce the substantial economic losses to realize the win-win situation of carbon sink and environmental restoration.