Assessing the Carbon Sequestration Potential of Spirogyra Algae in Achieving Sustainable Development Goals (SDGs): Biomass Estimation and Microbial Interactions in the Chi River Basin, Thailand

Abstract

This study examined the carbon sequestration potential of Spirogyra algae in the Chi River Basin, Thailand, focusing on biomass, chemical composition, and interactions with sediment microorganisms. The average moisture and carbon content by dry weight were 97.3% and 36.8%, respectively, consistent with previous studies. Among the sampling sites, Spirogyra at Site 3 showed the highest carbon content, while Site 4 samples contained significantly higher nitrogen levels. Statistical analysis indicated a positive correlation between Spirogyra biomass, sediment organic carbon (SOC), and total organic matter (SOM). Principal component analysis confirmed carbon, biomass, and SOC/SOM as the key drivers of system variability. Microbial communities, particularly Rheinheimera and Flavobacterium sasangense, were found to play crucial roles in organic matter decomposition and nutrient cycling, enhancing carbon storage stability in freshwater ecosystems. Together, Spirogyra and sediment microorganisms act as an integrated carbon storage system that supports greenhouse gas reduction, ecosystem balance, and progress toward the Sustainable Development Goals (SDGs), especially SDG 13, SDG 14, and SDG 15.