Coastal and Ocean Journal (COJ)

ESTIMATION OF CARBON STOCK IN SEAGRASS BIOMASS ON KEDINDINGAN ISLAND, EAST KALIMANTAN

Yusril M. Ambomasse — 2024-07-30

Kedindingan Island is a part of marine conservation area in East Kalimantan. This island has a seagrass ecosystem, which could potentially provide ecosystem service in climate change mitigation as a carbon sink. However, there is limited information on the carbon content of the seagrass ecosystem there. This study aimed to estimate the carbon stock in the seagrass biomass on Kedindingan Island. Field sampling activities for collecting seagrass biomass were done in September 2021. A PVC core with a 20 cm diameter, 3 mm thick, and 80 cm length was used to collect seagrass biomass. The loss on ignition (LOI) method was applied to determine the concentration of organic carbon in the biomass. The results of this study found 7 species of seagrass in the study area, which were dominated by Thalassia hemprichii. The organic carbon concentration in above-ground biomass and below-ground biomass ranged from 30.8-31.7% and 29.4-31.4%, respectively. The average biomass was 4.99 Mg/ha and its average carbon stock was estimated at 1.53 MgC/ha. Based on the total carbon stock analysis, the above-ground biomass stored more carbon (79.28%) than the below-ground biomass.

DOMINANCE AND ZONING PATTERN OF MANGROVE IN WEST PENTADU TOMINI BAY GORONTALO

Ditya Nanda Rahim — 2024-07-31

The purpose of this study is to discover the composition, dominance index value, and zoning pattern of mangrove plant in Pentadu Barat Village, Tilamuta Subdistrict, Boalemo Regency. This study was conducted from January to March 2023. The sampling method is purposive sampling using 10 × 10 cm linear transect for tree, 5 × 5 cm linear transect for saplings, and 2.5 × 2.5 cm linear transect for seedlings. The mangrove sample is descriptively and quantitatively analysed by identifying the species to calculate the type compositions and dominance index using Microsoft Excel. The result of the study reveals 12 species of 4 families from 3 study location (Avicennia alba, Avicennia officinalis, Bruguiera cylindrical, Bruguiera gymnorrhiza, Bruguiera parviflora, Ceriops decandraCeriops tagal, Rhizophora apiculata, Rhizophora mucronata, Rhizophora stylosa, Sonneratia alba and Xylocarpus granatum). The type composition value was 35% from Rhizophora mucronata. The average dominance index value was 0.0174. The zoning pattern was mixedbecause it grows mixed with each other among several species.

DEVELOPMENT OF A NEW CITY PATIMBAN AND SUISTAINABILITY OF THE MANGROVE FOREST IN PATIMBAN, SUBANG, WEST JAVA

Sharfina Elda Larasati — 2024-08-02

The focus of the development of the New City of Patimban(NCP) in Subang, West Java, lies in aligning with the city's aspirations and safeguarding the nearby mangrove forests. Guided by the West Java RTRW 2022-2042 and Subang Regent Regulation No. 38 of 2021, the development faces a challenge as allocating land for industrial purposes may adversely affect the mangrove ecosystems. Examining this situation through a Social-Ecological Systems (SES) lens reveals the need to comprehend the development's impact on mangrove forests.The research, titled "The Impact of the Development of the New City of Patimban on the Sustainability of Mangrove Forests," explores the interconnectedness of economic, social, and environmental factors. The New City of Patimban contend with environmental consequences, including habitat loss, mangrove ecosystem degradation, and greenhouse gas emissions. While infrastructure development holds economic promise, it concurrently poses risks to local livelihoods. To address these challenges, the study advocates for collaboration between the government, local communities, and stakeholders to restore and protect mangrove forests. It emphasizes the importance of ongoing assessment of regulations, such as the West Java RTRW 2022-2042 and Subang Regent Regulation No. 38 of 2021, to ensure the development aligns with desired principles without compromising the environment. The article underscores the historical significance of mangrove forests in supporting the socio-economic life of fishing communities for over 150 years. It suggests leveraging mangrove forests to sustain the social and economic well-being of these communities, emphasizing the need for responsible development that preserves both urban aspirations and ecological integrity.

CONCENTRATION AND EMISSION OF CARBON DIOXIDE (CO2) GAS IN MANGROVE ECOSYSTEM SEDIMENTS OF NANIA VILLAGE, AMBON CITY

Dhandi — 2024-08-02

Mangrove ecosystem is a type of coastal ecosystem that has many benefits from both ecological, social and economic aspects. The role of mangroves in absorbing carbon reaches 965 tons C/ha. The ability to store carbon is four times more than other ecosystems. Besides absorbing and storing carbon, mangroves also release carbon through litter production. The production of mangrove litter will then experience decomposition resulting in a flux of greenhouse gases. One of the greenhouse gases that triggers climate change is carbon dioxide (CO₂). The aim of this research was to determine the concentration and emission values of carbon dioxide (CO₂) in the sediments of the mangrove ecosystem of Nania Village, Ambon City. Gas sampling using a syringe through a syringe mounted on a hood. Analysis of gas concentrations used the gas chromatography method. Sediment sampling is carried out using a small shovel on the surface of the substrate under the mangrove canopy. Sediment samples will be analyzed using a sieving process. The results showed that the average concentration of CO₂gas with the highest value in the sandy mud substrate with a value of 701.61 ppm and the lowest in the sand substrate with a value of 561.48 ppm. The largest CO₂ gas emission in the mangrove ecosystem sediments of Nania Village was found in the sand sediment type of 75.0535 mg/m²/hour with an emission value, and the lowest was found in mud sediments, namely 30.1899 mg/m²/hour.