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Utilization of the coastal area of Miangas Island as the outermost small island of Indonesia Jamaluddin Jamaluddin; Achmad Nagi; Gandhi Napitupulu; Isdradjad Setyobudiandi; Mujizat Kawaroe
Akuatikisle: Jurnal Akuakultur, Pesisir dan Pulau-Pulau Kecil Vol 7, No 1 (2023)
Publisher : Sekolah Tinggi Ilmu Pertanian Wuna

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29239/j.akuatikisle.7.1.85-92

Miangas Island is one of the outer islands of Indonesia. Determining policies for optimal and sustainable spatial use of coastal areas on Miangas Island requires a deep understanding of the people who live there. Observation survey and interview methods were used to collect primary data. The analysis used is the Analytical Hierarchy Process (AHP) to formulate solutions to land use conflicts in coastal and marine areas. The results of the analysis of conflict resolution on the use of coastal space using AHP show that the criteria that have a large influence on the purpose of conflict resolution analysis are land availability and suitability, and the first priority for alternative spatial development for the coastal area of Talaud Islands Regency is the development of fishery areas.

Utilization of the coastal area of Miangas Island as the outermost small island of Indonesia Jamaluddin Jamaluddin; Achmad Nagi; Gandhi Napitupulu; Isdradjad Setyobudiandi; Mujizat Kawaroe
Akuatikisle: Jurnal Akuakultur, Pesisir dan Pulau-Pulau Kecil Vol 7, No 1 (2023)
Publisher : Sekolah Tinggi Ilmu Pertanian Wuna

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29239/j.akuatikisle.7.1.85-92

Miangas Island is one of the outer islands of Indonesia. Determining policies for optimal and sustainable spatial use of coastal areas on Miangas Island requires a deep understanding of the people who live there. Observation survey and interview methods were used to collect primary data. The analysis used is the Analytical Hierarchy Process (AHP) to formulate solutions to land use conflicts in coastal and marine areas. The results of the analysis of conflict resolution on the use of coastal space using AHP show that the criteria that have a large influence on the purpose of conflict resolution analysis are land availability and suitability, and the first priority for alternative spatial development for the coastal area of Talaud Islands Regency is the development of fishery areas.

Pemetaan Zona Potensial Penangkapan Ikan Tongkol di Perairan Teluk Banten Achmad Nagi; Gandhi Napitupulu; Ivonne Milichristi Radjawane; Susanna Nurdjaman; Dedi Supriadi; Dewi Nurhayati
Buletin Oseanografi Marina Vol 12, No 3 (2023): Buletin Oseanografi Marina
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/buloma.v12i3.50374

Ikan Tongkol (Euthynnus affinis) adalah komoditas di perairan Teluk Banten yang memiliki nilai produksi tinggi. Potensi ini bisa dimanfaatkan secara maksimal melalui pengetahuan tentang Zona Potensial Penangkapan Ikan (ZPPI). Penelitian ini bertujuan untuk menganalisis hubungan antara parameter oseanografi (suhu permukaan laut (SPL) dan klorofil-a) dan hasil tangkapan Ikan Tongkol, serta membuat pemetaan ZPPI Ikan Tongkol pada tahun 2014-2019. Prediksi ZPPI dilakukan melalui pendekatan parameter oseanografi berdasarkan citra satelit dan data hasil tangkapan Ikan Tongkol. Rata-rata tertinggi produksi Ikan Tongkol tahun 2014-2019 di Teluk Banten diperoleh selama musim peralihan I dengan SPL 29,92C – 30,98C dan konsentrasi klorofil-a 0,99 – 1,13 mg/m³. Analisis pengaruh SPL dan klorofil-a pada tangkapan dilakukan dengan regresi berganda. Pengaruh SPL dan klorofil-a terhadap hasil tangkapan dinilai cukup kuat berdasarkan dari koefisien korelasi () 0,743 dan koefisien determinasi () sebesar 0,551. Nilai dapat memberikan penjelasan bahwa SPL dan klorofil-a mempengaruhi hasil tangkapan sebesar 55,1%. Melalui Analisis Wavelet diperoleh persebaran klorofil-a dominan dipengaruhi faktor monsun sedangkan pengaruh IOD (Indian Ocean Dipole) dan ENSO (El Niño–Southern Oscillation) lemah, sehingga pemetaan ZPPI disusun berdasarkan empat musim. ZPPI yang memiliki potensi lokasi terbanyak diperoleh pada musim barat sejumlah 13 titik. Selanjutnya, berkurang pada musim peralihan I sebanyak 10 titik, musim peralihan II sebanyak 6 titik, dan musim timur sebanyak 4 titik. Mackarel Tuna (Euthynnus affinis) is a commodity in Banten Bay waters that has high production value. This potential can be maximally utilized through knowledge of the Potential Fishing Zone (). This study aims to analyze the relationship between oceanographic parameters (sea surface temperature (SST) and chlorophyll-a) and the catch of Mackarel Tuna, and create PFZ mapping of Mackarel Tuna in 2014-2019. The prediction of PFZ is done through the approach of oceanographic parameters based on satellite imagery and catch data. The highest average production of Mackarel Tuna in 2014-2019 in Banten Bay was obtained during transitional season I with a SST of 29.92°C - 30.98°C and a chlorophyll-a concentration of 0.99 - 1.13 mg/m³. Analysis of the effect of SST and chlorophyll-a on catch was done with multiple regression. The influence of SST and chlorophyll-a on catch was considered quite strong based on the correlation coefficient () of 0.743 and the coefficient of determination () of 0.551. The value can provide an explanation that SST and chlorophyll-a affect the catch by 55.1%. Through Wavelet Analysis, it is obtained that the distribution of chlorophyll-a is dominantly influenced by monsoon factors while the influence of IOD (Indian Ocean Dipole) and ENSO (El Niño-Southern Oscillation) is weak, so that mapping is organized based on four seasons. The that has the most potential locations is obtained in the west season with 13 points. Furthermore, it decreases in the first transition season with 10 points, the second transition season with 6 points, and the eastern season with 4 points.

Impact of Climate Change on Coral Reefs Degradation at West Lombok, Indonesia Susanna Nurdjaman; Muhammad Ikram Nasution; Ofri Johan; Gandhi Napitupulu; Ejria Saleh
Jurnal Kelautan Tropis Vol 26, No 3 (2023): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v26i3.18540

Coral reefs are one of the ecosystems that provide economic and environmental benefits to coastal communities in Indonesia. However, coral reef ecosystems are also one of the ecosystems threatened by climate change at the local scale. The waters of North Sekotong, West Lombok, Indonesia, are a tropical coastal system with beautiful coral reefs and marine ecosystems. Coral reef damage has been widespread in this area due to increased water temperatures. Increased water temperature results in coral reef degradation. Field surveys were conducted on May 23-28, 2016, in collaboration with the Marine and Coastal Resources Research and Development Center, Ministry of Marine Affairs and Fisheries, and coral reef mapping using Landsat 7 and Landsat 8 during 2002 - 2016 as well as processing monthly sea surface temperature (SST) data from the AquaModis and Oi SST V2 satellites and daily SST data from the NOAA Coral Reef Watch satellite. Changes in coral cover area were compared with temperature changes due to climate change. The increase in temperature creates a hotspot phenomenon in the coral reef ecosystem, resulting in coral reef degradation. The results showed that coral reefs in this area have degraded by 17.55% or 78.21 Ha from 455.68 Ha (2002) to 367.46 Ha (2016), with a degradation rate of 2.8 Ha/year in 2002 - 2014; 8.1 Ha/year (2014 - 2014) and 36 Ha/year (2015 - 2016) caused by an increase in SST which caused a hotspot phenomenon with a high enough intensity that there was an increase in temperature in 2016 which reached 9.77oC.

The One-Dimensional (1D) Numerical Model: An Application to Oxygen Diffusion in Mitochondria Cell Gandhi Napitupulu; Achmad Nagi; Mutiara Rachmat Putri; Ivonne Milichristi Radjawane
ComTech: Computer, Mathematics and Engineering Applications Vol. 14 No. 2 (2023): ComTech
Publisher : Bina Nusantara University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21512/comtech.v14i2.9705

The first model of oxygen transport was formulated by August Krogh. However, the investigations conducted have yet to yield a complete analytical model and a widely applicable solution for One-Dimensional (1D) network construction. The research sought to provide numerical and analytical solutions for the oxygen transfer model in mitochondrial cells to enable researchers to estimate the molecular dynamics and diffusion characteristics in mitochondrial cells. The oxygen diffusion process in mitochondria was modeled with ID numerical models. The numerical models used to solve the equations were explicit and implicit. The explicit model consisted of Forward Time Center Space (FTCS) and DuFort-Frankel. Meanwhile, the implicit model had Crank-Nicholson and Laasonen. The numerical solutions of the explicit and implicit were divided into four scenarios with a variation of Δt and compared with the analytical solutions. The results show that the Laasonen method is the best in describing the diffusion process. The best scenario with the lowest slope value and small Root Mean Square Error (RMSE) value is scenario 2 (Δt = 3,33E-4 s and Δx = 2,00E-5 cm). The numerical model and analytical solution show that the time required to reach a steady state is 0,7 s. It indicates oxygen exchange in two sides of the mitochondrial cell after 0,7 s.

VARIABILITY ANALYSIS OF SIGNIFICANT WAVE HEIGHTS AND WIND WAVES IN RIAU ARCHIPELAGO SEA PART ALKI 1 Gandhi Napitupulu; Ayi Tarya; I Gede Merta Yoga Pratama; Ignatius Sonny Winardhie
JURNAL PESISIR DAN LAUT TROPIS Vol. 10 No. 3 (2022): JURNAL PESISiR DAN LAUT TROPIS
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jplt.10.3.2022.55019

The Riau Archipelago Sea is part of the Indonesian Archipelago Sea Lane (ALKI) 1, with a very high intensity of crossing ships. Analysis of surface wind speed and significant wave height is the most important for the safety and performance of offshore shipping. This research aims to study wave characteristics and wind speed by identifying the main factors that affect significant wave height and surface wind speed. Dominant factors that affect significant wave height and wind speed are needed to decide on the safest path and the best time before crossing in ALKI-1. Temporal and spatial analysis of the seasonal variability of significant wave height and wind speed using ECMWF data for 18 years. The data used are significant wave height data and wind speed every 6 hours during the period 2000 – 2018. Three observation points are used for temporal analysis, it is found that significant wave height and wind speed are influenced by two main factors, namely MJO and Monsoon. Maximum significant wave height and wind speed that occurs in the SON period for points 3 and the DJF period at points 1 and 2. MJO affects directly from phases one to eight for observation points 1, 2, and 3. The 4, 7, and 8 MJO phases affect the value of wave height and wave speed significantly, and the 1, 2, and 5 MJO phases affect wave height and wind speed weakly. Keywords: ALKI 1, MJO, MJO phase, Monsoon, Significant wave height, Wind speed.

Pelacakan Mundur Partikel Sampah dengan Metode Euler-Lagrange di Pelabuhan Ratu Ivonne Milichristi Radjawane; Ilyas Nurfadhil Basuki; Gandhi Napitupulu
Limits: Journal of Mathematics and Its Applications Vol 20, No 3 (2023)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/limits.v20i3.18676

Masalah yang sering dijumpai pada daerah pesisir adalah banyaknya sampah terapung. Salah satu Kawasan pesisir yang akan menjadi daerah kajian studi ini adalah daerah pariwisata Pelabuhan Ratu yang terletak di bagian Barat Daya pulau Jawa. Tujuan studi ini adalah untuk melakukan pelacakan mundur untuk mencari sumber sampah laut yang berada di Teluk Pelabuhan Ratu. Model hidrodinamika 2 dimensi horizontal digunakan untuk simulasi arus laut dan melacak masing-masing sampah laut sebagai partikel secara mundur terhadap waktu dengan metode Euler-Lagrange. Data input model berupa data batimetri, posisi sampah, kecepatan angin, dan elevasi pasang surut. Hasil trayektori (lintasan) menunjukkan kesesuaian antara hasil pelacakan maju dan pelacakan mundur di mana sebagian besar partikel yang dilacak mundur berakhir di posisi yang dekat dengan posisi awal pelacakan maju. Hasil simulasi juga menunjukkan kesesuaian dalam perpindahan partikel dengan perhitungan manual dan pola trayektori partikel yang berbentuk elips juga sesuai dengan teori arus pasang surut (pasut). Hasil pelacakan mundur partikel di dalam Teluk Pelabuhan Ratu menghasilkan trayektori yang sangat pendek akibat arus yang sangat kecil yang mengindikasi sampah di dalam teluk berasal dari daerah pesisir teluk. Partikel yang bergerak ke arah timur akan diperpanjang trayektorinya pada musim barat dan pada musim timur, partikel yang bergerak ke arah barat diperpanjang trayektorinya.

Seasonal Variability of Sea Surface Chlorophyll-a at West Borneo Island Radjawane, Ivonne Milichristi; Saleh, Ejria; Napitupulu, Gandhi; Abdillah, Muhammad Rais; Hassan, Mohd Azamuddin Mohd
Indonesian Journal of Geography Vol 56, No 1 (2024): Indonesian Journal of Geography
Publisher : Faculty of Geography, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijg.87713

The optimization of marine fisheries activities can be achieved through an understanding of the timing of fishing, access to good information, and knowledge of oceanographic conditions. These conditions often lead to significant nutrient enrichment in the surface layer of the ocean, which in turn increases the sea surface chlorophyll-a (SSC). In the context of the west Borneo Island region, seasonal variability in SSC plays a crucial role in determining potential fishing grounds. The objectives of this study are examining the seasonal variability of SSC, identifying upwelling and downwelling processes through analysis of sea surface wind (SSW), and determining the climatological distribution of Sea Surface Temperature (SST) and sea surface height (SSH) within the water off Labuan Island, Malaysian Borneo, and the Karimata Strait, West Kalimantan, Indonesia. Remote sensing data spanning from 2007 to 2021 were analyzed, encompassing SSC, SST, SSH anomalies, SSW, wind stress curl, and Ekman pumping. Additionally, rainfall and river discharge were examined as supplementary indicators of these oceanographic processes. The findings indicate that SSW plays a pivotal role in driving upwelling and downwelling processes, which in turn influence SSC variability. In Labuan waters, upwelling occurs primarily from November to February, while downwelling predominates from June to September. In contrast, in the Karimata Strait, upwelling is identified from July to September, with downwelling prevalent between March and May. Upwelling events in both regions are characterized by increasing SSC, accompanied by decreasing SST and SSH, while the opposite trends are observed during downwelling events. The peak of rainfall and river discharge in December is noted to potentially enhance SSC variability in the Karimata Strait compared to Labuan Island waters.

PENGELOLAAN DAN PEMANFAATAN KAWASAN PESISIR PULAU MIANGAS SEBAGAI PULAU KECIL TERLUAR INDONESIA Nagi, Achmad; Jamaluddin, Jamaluddin; Napitupulu, Gandhi; Nurdjaman, Susanna; Setyobudiandi, Isdradjad; Radjawane, Ivonne Milichristi
Jurnal Kebijakan Perikanan Indonesia Vol 15, No 1 (2023): (Mei) 2023
Publisher : Pusat Riset Perikanan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15578/jkpi.15.1.2023.%p

Pulau Miangas merupakan salah satu pulau terluar yang berbatasan dengan negara Filipina dan terletak di wilayah administratif Kabupaten Kepulauan Talaud di Provinsi Sulawesi Utara. Sumber daya alam yang ada memiliki potensi yang besar untuk pemanfaatan wilayah pesisir dan laut yang dimilikinya. Tujuan dari penelitian ini adalah menganalisis potensi, kelayakan dan prioritas komersial untuk pemanfaatan sumber daya pesisir Pulau Miangas. Survei dengan pengamatan secara langsung dan metode wawancara digunakan untuk mengumpulkan data dan informasi. sedangkan metode analisis sistem informasi geografis (SIG) digunakan untuk mengevaluasi kelayakan penggunaan lahan di wilayah pesisir. Melalui empat tahapan analisis yang meliputi penyusunan peta wilayah, matriks cakupan per kategori, pemberian bobot dan scoring, serta analisis spasial. Hasil analisis kesesuaian lahan dengan menggunakan SIG menunjukkan bahwa kawasan pesisir Pulau Miangas memiliki potensi untuk berbagai program pembangunan terkait pengelolaan dan pemanfaatan pesisir, seperti kawasan pemukiman, kawasan budidaya rumput laut, kawasan penangkapan ikan, kawasan budidaya keramba jaring apung, budidaya mutiara dan konservasi terumbu karang.Miangas Island is one of the outermost islands bordering the Philippines and is located in the administrative area of the Talaud Islands Regency in North Sulawesi Province. The existing natural resources have great potential for the utilization of coastal and marine areas. The purpose of this study was to analyze the potential, feasibility and commercial priorities for the utilization of coastal resources of Miangas Island. Direct observation surveys and interview methods were used to collect data and information, while geographic information system (GIS) analysis methods were used to evaluate the feasibility of land use in coastal areas. Through four stages of analysis that include the preparation of area maps, coverage matrix per category, weighting and scoring, and spatial analysis. The results of the land suitability analysis using GIS show that the coastal area of Miangas Island has the potential for various development programs related to coastal management and utilization, such as residential areas, seaweed cultivation areas, fishing areas, floating net cage cultivation areas, pearl cultivation and coral reef conservation.

Pengaruh Sirkulasi Arus Geostropik dan Ageostropik Terhadap Upwelling di Perairan Selatan Jawa Radjawane, Ivonne Milichristi; Yusarita, Alvi; Kuswardani, Anastasia Rita Tisiana Dwi; Napitupulu, Gandhi
Buletin Oseanografi Marina Vol 13, No 3 (2024): Buletin Oseanografi Marina
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/buloma.v13i3.62368

Perairan selatan Jawa merupakan lokasi dengan fenomena upwelling yang signifikan. Penelitian bertujuan untuk memahami kecepatan dan pola arus geostropik serta ageostropik orde dua musiman dari permukaan hingga kedalaman 600 m. Nilai Ekman pumping velocity (EPV) yang dibangkitkan oleh angin menunjukkan upwelling mulai bulan Juni, mencapai puncaknya dari Juli hingga September, dan menurun mulai Oktober, hampir menghilang pada November. Nilai EPV antara perairan Jawa Barat dan Timur menunjukkan tingkat upwelling yang lebih tinggi di sebelah barat. Data CTD menegaskan bahwa upwelling terjadi selama musim Timur (Juni-Agustus), ditandai dengan penurunan suhu air, dangkalnya termoklin, dan peningkatan salinitas terhadap kedalaman. Pada musim barat (Desember-Februari), arus geostropik cenderung ke timur di sepanjang pantai Jawa Barat karena arus selatan Jawa (ASJ), sementara di selatan Jawa Tengah dan Jawa Timur, arah arus ke barat disebabkan oleh arus lintas Indonesia (Arlindo) dan arus ekuator selatan (AES). Pada musim timur, ASJ melemah, dan arah arus geostropik berubah ke barat, memperkuat ASJ dan Arlindo. Sirkulasi Sekunder Ageostropik, diperkirakan melalui metode C-Vektor, memainkan peran dalam pergerakan massa air vertikal, meningkatkan intensitas upwelling di perairan selatan Jawa. Wilayah sekitar Jawa Timur memiliki komponen C-Vektor positif yang berdampak pada peningkatan intensitas upwelling di daerah tersebut. The southern waters of Java are a location with significant upwelling phenomena. The study aimed to understand the velocity and pattern of seasonal second-order geostropic and ageostropic currents from the surface to 600 m depth. Wind-generated Ekman pumping velocity (EPV) values show upwelling starting in June, peaking from July to September, and decreasing from October, almost disappearing in November.. The EPV values between western and eastern Java waters show higher levels of upwelling in the west. CTD data confirms that upwelling occurs during the East season (June-August), characterized by decreasing water temperature, shallow thermocline, and increasing salinity with depth. In the West season (December-February), geostropic currents tend to be eastward along the West Java coast due to the South Java Current (SJC), while south of Central Java and East Java, the current direction is westward due to the Indonesian Throughflow ( ITF ) and the South Equatorial Current (SEC). In the eastern season, the SJC weakens, and the direction of the geostropic current changes to the west, strengthening the SJC and ITF. The Ageostropic Secondary Circulation, estimated through the C-Vector method, plays a role in the vertical movement of water masses, increasing the intensity of upwelling in the waters south of Java. The region around East Java has a positive C-Vector component which has an impact on increasing the intensity of upwelling in that area.

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