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This study aimed to analyze the flux of CH4 gas in the sediments of mangrove and seagrass ecosystems in Tanjung Tiram, Ambon Bay. The research was conducted in May – June 2024. The mangrove and seagrass ecosystems at this location get inputs from the organic matter originating from litter production and domestic waste from people living around the ecosystem area. In each ecosystem, three observation points were determined based on the sediment type: sand, muddy sand, and sandy mud, each coded M1, M2, and M3 for mangrove and L1, L2, and L3 for seagrass ecosystems. Gas sampling was carried out by placing cylinder covers on each sediment type. Furthermore, 10ml of gas was taken seven times with an interval of 30s, namely 0, 30, 60, 90, 120, 150, and 180s. The gas was put into a vial, and then the gas concentration was analyzed using chromatography (GC-MS), flux, and global warming potential. The single factor ANOVA and t-test (α = 0.05) were carried out to determine the difference in each sediment's average gas concentration. The results showed that the average comparison of CH4 gas concentrations in mangrove and seagrass ecosystems (M:L) showed no significant difference with P = 0.0637 (P> 0.05). The average CH4 flux in mangrove sediments was 0.1476mg/ m ² / hour, more significant than that in seagrass sediments, which was 0.1424mg/ m 2 / hour. M1 and L1 recorded the most significant CH4 fluxes in each ecosystem sediment, which were 0.1794 and 0.1509mg/ m 2 / hour. Meanwhile, the most minor flux was found in M2, which was 0.1005mg/ m ² / hour, and L3, which was 0.1320mg/ m ² / hour. The GWP of mangrove sediments was 3.6907mg CO2e /m² / hour, more significant than the seagrass GWP of 3.5590mg CO2e/ m ² / hour. The flux of CH4 gas was significantly affected by the sediment type, especially in sandy sediments. It is related to the level of porosity of sediment, which acts as a circulating space for methane gas produced from the degradation process of organic matter contained in each type of sediment. The flux and GWP values of methane gas released from sediments of mangrove and seagrass ecosystems should not be ignored in climate change mitigation, especially in areas with very low-density levels and high organic waste inputs. [ABSTRACT FROM AUTHOR]

The Haruku Strait in the Central Moluccas is a potential marine resource located eastern Indonesia. Small pelagic fishes have been noted in abundance in the waters of this strait. Their abundance is mainly associated with the ample amount of plankton organisms serving as food for the former. To address the abundance of phytoplankton in Haruhu Strait, a study was carried out in September 2022. Sampling was achieved using a sample bottle from a depth of 1 meter. After that, the sample was filtered with a Kitahara net. Nineteen genera of phytoplankton were found in Haruku Strait during the study period. The phytoplankton abundance varied between 4,5 x 102 – 1,65 x 103 cells/l. Phytoplankton consists of Bacillariophyceae (Diatom) with 63% of the total genera, Dinoflagellata with 32 % of the total genera, and Cyanobacteria with 5%, while Chaetoceros, Rhizosolenia, Gonyaulax, Coscinodiscus, and Ceratium were the predominant phytoplankton genera in this area. The distribution pattern forms 8 groups. [ABSTRACT FROM AUTHOR]

Savu Sea waters are part of Indonesia waters which is located directly adjacent to Indian Ocean. The northern part of Savu Sea particularly in the south of Flores Strait, Lamakera Strait and the Strait of Alor waters are dynamic with changes in temperature and salinity of the surface which is significant at southeast monsoon season. The dynamics of these waters, especially in the surface layer is strongly influenced by the monsoon wind patterns. In June-July, the monsoon winds blowing from southeast with maximum strength in parts of Indonesia, including in the waters of the northern Sea Savu. The wind causes the movement of surface water masses tend to move westward. These circumstances would to bring deeper and colder waters to the surface layer in the northern part of Savu Sea. Sea surface temperature in the Flores Sea ranged from 27.45 to 27.79°C with a mean 27.62 ± 0.14°C, whereas the observation stations located in the south and deal directly with the Savu Sea, water temperatures in the range 25.25 to 26.75°C with a mean 25.90 ± 0.43°C. In general, the temperature distribution on the surface layer of the ocean at a depth of 0-5 m to the south indicates that the mass of sea water gets colder. Central mass concentration of water with the lowest temperature in the southern Strait of Alor range from 25.25 to 25.89°C. The cold waters of the northern part of the Savu Sea water mass indicates the possibility upwelling of water mass in the Savu waters. [ABSTRACT FROM AUTHOR]