Judul: Biomass and Carbon Stock Mangrove and Pandan Laut Ecosystems (Pandanus tectorius) on North Pari Island, Seribu Islands, DKI Jakarta
Abstrak: Kenaikan suhu atmosfer saat ini telah menjadi isu hangat bagi seluruh dunia yang di sebabkan karena peningkatan konsentrasi karbon dioksida (CO2) dan berdampak pada perubahan iklim. Analisis nilai biomassa stok karbon yang tersimpan dilaksanakan pada 20 November – 26 November 2023 di Utara Pulau Pari, Kepulauan Seribu DKI Jakarta dari 5 titik pengamatan yang berbeda, yaitu 3 pengamatan di ekosistem mangrove dan 2 pengamtan di ekositem pandan laut. Pengambilan sampel dilakukan dengan menggunakan metode plot lingkaran. Pengukuran stok karbon dan biomassanya hanya didasarkan atas diameter batang. Nilai biomassa yang di dapat dibandingkan untuk menentukan lebih banyak manakah CO2 yang diserap untuk mengurangi emisi CO2 di kedua ekosistem pesisir. Ekosistem mangrove memiliki serapan karbon CO2 lebih besar daripada ekosistem pandan laut yaitu sebesar 1407 ton CO2/ha dan 10 ton CO2/ha, dikarenakan jumlah diameter dan jenis spesies yang ditemukan saat dilokasi lebih banyak dan mendominasi ekosistem mangrove daripada pandan laut yaitu sebesar 163 ind dan 26 ind., The rise in atmospheric temperature has now become a hot issue for the whole world caused by an increase in carbon dioxide (CO2) concentrations and an impact on climate change. Analysis of the value of stored carbon stock biomass will be carried out on November 20 – November 26, 2023 in the North of Pari Island, Seribu Islands DKI Jakarta from 5 different observation points, namely 3 observations in mangrove ecosystems and 2 observations in pandan laut ecosystems. Sampling is carried out using the circular square transect method. The measurement of carbon stocks and biomass is based only on the diameter of the rod. Biomass values can be compared to determine where more CO2 is absorbed to reduce CO2 emissions in both coastal ecosystems. Mangrove ecosystems have greater carbon CO2 absorption than pandan laut ecosystems, which are 1407 tons CO2/ha and 10 tons CO2/ha, because the number of diameters and types of species found when located is more and dominates mangrove ecosystems than sea pandanus, which is 163 ind and 26 ind.
Keyword: biomassa, mangrove, stok karbon, pandan laut, Pulau Pari

Judul: Carbon Storage Potential on Seagrass Bed in Pari Island, the Seribu Islands, Jakarta
Abstrak: Optimalisasi ekosistem blue carbon adalah salah satu strategi dalam memitigasi perubahan iklim yang mengancam keseimbangan ekosistem dunia. Salah satu ekosistem blue carbon adalah lamun yang dapat menyerap karbon selama proses fotosintesis dan menyimpannya dalam bentuk biomassa sekaligus dapat menjaga pesisir dan meningkatkan hasil perikanan. Meski demikian, belum banyak yang menyadari dan mengabaikan keberadaan ekosistem lamun. Penelitian bertujuan menghitung nilai karbon yang tersimpan pada padang lamun sebagai komponen blue carbon dalam menyimpan karbon di Pulau Pari, Kepulauan Seribu, Jakarta. Terdapat empat stasiun pengamatan dengan penutupan lamun sedang. Hasil analisis biomassa menunjukkan bahwa biomassa bawah substrat lebih besar dibandingkan dengan biomassa atas substrat. Total stok karbon ekosistem lamun sebesar 8627,21 tonC dengan stok karbon pada biomassa lamun sebesar 329,55 tonC dan total stok karbon sedimen sebesar 8297,66 tonC. Stok karbon pada sedimen lebih besar dari biomassa lamun., The blue carbon ecosystem would help mitigate climate change. Seagrass is a part of this ecosystem and has the ability to absorb carbon during photosynthesis, storing it as biomass. Seagrass also plays a role in protecting coasts and boosting fisheries yields. However, many people are unaware of the importance of seagrass ecosystems. A research project is underway to determine the value of carbon stored in seagrass beds on Pari Island, Seribu Islands, Jakarta. Four observation stations have been set up to study seagrass cover. The analysis shows that below-ground biomass is greater than above-ground biomass. The total carbon stock of seagrass bed is 8627,21 tonC with carbon stock in biomass is found to be 329,55 tonC, while the total carbon stock of sediment is 8297,66 tonC. The lower carbon stock in biomass.
Keyword: Pulau Pari, blue carbon, lamun, blue carbon, Pari Island, seagrass

Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
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