Methane Fluxes in Seagrass Beds of Inner Ambon Bay: A Comparison of Tanjung Tiram and Halong Coast

This study evaluates the concentration and emission of methane gas (CH₄) in seagrass ecosystems in the Inner Ambon Bay, especially in the Tanjung Tiram and Halong Coast areas. Methane, as one of the greenhouse gases, plays an important role in the global carbon cycle. Gas sampling was conducted using chambers at two research locations from June to September 2023. The analysis showed that the concentration of CH₄ in Halong Coast was higher (1.6893 ± 0.2076 ppm) than in Tanjung Tiram (1.4967 ± 0.1101 ppm) (P < 0.05). The flux of CH₄ gas also showed similar results, with the flux value at Pantai Halong (0.1010 mg/m²/hour) higher than in Tanjung Tiram (0.0521 mg/m²/hour) (P < 0.05). This difference is associated with a higher variation in the physicochemical conditions of the waters, thus affecting the more intense methanogens microbial activity on Halong Coast. Although the methane flux in this seagrass ecosystem is relatively low compared to mangrove ecosystems, the results of this study provide important insights into the role of seagrass in greenhouse gas emissions and its implications for climate change. This finding is expected to support conservation efforts and sustainable management of coastal ecosystems in the Inner Ambon Bay.