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Analisis Diagram T-S Berdasarkan Parameter Oseanografis di Perairan Selat Lombok Harvianto, Loecky; Parengkuan, Maxi; Koropitan, Alan F.; Agustiadi, Teguh
Surya Octagon Interdisciplinary Journal of Science and Technology Vol 1 No 1 (2015): SOIJST
Publisher : Surya University

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Abstract

Research of water masses by using conductivity temperature depth are conducted in the Lombok Strait during September 2014 under the Cruise SITE Leg II to Lombok Strait. The aim of the research is to investigate Temperature-Salinity Diagram based on oceanographic parameters in Lombok Strait. Temperature-Salinity Diagram shows the origin of the water masses across Lombok Strait. The results of this research shows water masses across Lombok Strait comes from North Pacific Subtropical Water (NPSW) on ~ 150 m depth and North Pacific Intermediate Water (NPIW) on ~ 400 m depth. The differences values of salinity reference and salinity measurement indicates the properties of NPSW and NPIW are dynamic, verified by the number of salinity reference is 34,55 Psu on ~ 150 m depth, whereas the salinity number of five station in order are  34,63 Psu; 34,65 Psu; 34,65 Psu; 34,57 Psu; 34,52 Psu. The difference of salinity number caused by strong vertical mixing in Indonesian waters.
A SEDIMENT CARBON STOCK OF WEST KALIMANTAN MANGROVE FOREST Nuraya, Tia; Koropitan, Alan F.; Wahyudi, A'an J.
Marine Research in Indonesia Vol 44 No 1 (2019)
Publisher : Research Center for Oceanography - Indonesian Institute of Sciences (LIPI)

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Abstract

The present study aims to investigate the influence of oceanographic factor and riverine input on  mangrove ecosystem and their ability in  absorbing carbon. The location of the study was conducted in two different locations in West Kalimantan, which are (1) Mempawah and (2) Bakau Besar. The sediment sampling was carried out using PVC pipes in the middle of the transect point and taken within ± 20 cm depth. After laboratory pre-treatment, we analyzed the carbon content using CHN Analyzer. The results showed that station 3 of Mempawah and station 2 of Bakau Besar have a high organic carbon content, i.e., 6.46 ± 0.23 ton C/ha and 14.93 ± 1.43 ton C/ha, respectively. We also found that input organic carbon in the river (location 2) and canal (location 1) were higher at high tide than low tide. Besides that, we also found that the sediment type at station 3 of Mempawah is categorized as silt (75%) and fine sand (± 0.24%). Whereas at station 2 of Bakau Besar, the sediment contains silt (68%) and fine sand (± 2%). In addition, those two stations have a total mangrove density up to 13519 individuals/ha and 9928 individuals/ha, respectively. According to this findings, we suggest that high organic carbon is influenced not only by high biomass density but also by the oceanographic factor that affects load of organic carbon in river and canal, and the difference of sediment types that are influenced by breaking wave height at the study site. Keywords: mangrove ecosystem, organic carbon, oceanographic factor, West Kalimantan
Model Pembentukan Eddy Akibat Interaksi Arus dan Topografi di Teluk Palu, Sulawesi Tengah Sabhan, Sabhan; Pranowo, Widodo Setiyo; Purba, Mulia; Koropitan, Alan Frendy
POSITRON Vol 10, No 1 (2020): Vol. 10 No. 1 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1027.043 KB) | DOI: 10.26418/positron.v10i1.37263

Abstract

Tofografi Teluk Palu unik dengan degradasi kedalaman yang tinggi sehingga membentuk kemiringan lereng yang curam. Tofografi teluk menyebabkan arus pusaran (eddy) membentuk siklonik dan antisiklonik sebagai salah satu penggerak upwelling. Penelitian ini menggunakan model hidrodinamika dengan pendekatan volume hingga dengan koordinat vertikal sigma. Model dibangkitkan oleh pasang surut dan angin. Hasil model menunjukkan korelasi pasang surut (r = 0,9937) yang baik dengan kondisi di Teluk Palu. Eddy Siklonik yang terbentuk mempunyai diameter yang berbeda untuk setiap kedalaman oleh efek dari tofografi aliran di Teluk Palu. Lokasi perpindahan vertikal massa air ke atas yang dikenal sebagai upwelling bersesuaian dengan eddy siklonik yang terbentuk.
Ecological Vulnerability of Coral Reef Ecosystem in Wakatobi National Park During Indian Ocean Dipole Event Hawis H. Madduppa; Alan F. Koropitan; Ario Damar; Beginer Subhan; Muhammad Taufik; La Ode Alam Minsaris; AM Azbas Taurusman; Agus Ramli; Arif Budi Purwanto
HAYATI Journal of Biosciences Vol. 27 No. 1 (2020): January 2020
Publisher : Bogor Agricultural University, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (700.326 KB) | DOI: 10.4308/hjb.27.1.57

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This research examines coral reefs vulnerability which threatening its existences and functions by climate change. The ecological vulnerability in Wakatobi (Wangi-wangi, Kaledupa, Tomia, and Binongko) was assessed during Indian Ocean Dipole (IOD) event in 2016. Climate exposure was determined using sea surface temperature, chlorophyll-a concentration, and wind speed magnitude; sensitivity was determined using coral susceptibility, fish susceptibility, and macroalgae primary productivity rate; then adaptive capacity was developed by hard coral cover, coral size distribution, coral richness, fish biomass, herbivore diversity, and herbivore grazing relative to algal production. The values of Exposure, Sensitivity, and Adaptive capacity in Wakatobi were 0.93±0.02, 0.42±0.18, and 0.44±0.10, respectively. Site specific vulnerability scores ranged from 0.52 to 1.60 (mean 0.92±0.26). Binongko was the least vulnerable than other islands. Tomia was observed as the least adaptive capacity and Wangi-wangi was the most bleaching incidents. These results could help coral reefs monitoring priority during the event and then when the event is gone by focusing on the marked islands and sites. Sites that were observed as more vulnerable is urgently need a management strategy to overcome the vulnerability status in the future, such as increasing site adaptability.
Modeling Mackerel Tuna (Euthynnus affinis) Habitat in Southern Coast of Java: Influence of Seasonal Upwelling and Negative IOD Alan F Koropitan; Ibrahim Kholilullah; Roza Yusfiandayani
HAYATI Journal of Biosciences Vol. 28 No. 4 (2021): October 2021
Publisher : Bogor Agricultural University, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.4308/hjb.28.4.271-285

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We used fishery catch data from Cilacap Fishing Port and Copernicus data set in July 2016-December 2017 to investigate the impacts of Indian Ocean Dipole (IOD) on upwelling and mackerel tuna distribution in the southern coast of Java. This study implemented a Generalized Additive Model (GAM) for habitat prediction of mackerel tuna in the waters. The present study showed that the extreme negative IOD in 2016 caused a weaker southeasterly wind and even a reversal to the northwesterly wind, as seen off Sumatra in September 2016. The situation produced vertically mixed layer thickening and no upwelling during the southeast monsoon event 2016, consequently resulted in warmer temperature and fewer Chlorophyll-a (Chl-a) compared to the southeast monsoon event 2017. The mackerel tuna production significantly dropped in 2016 and rose in 2017, particularly during the upwelling event. The high Habitat Suitability Index (HSI) was found in southern Central Java in July 2017, expanded bigger in August 2017, and decreased in September 2017. During July and August 2016, the high HSI covered only a less area in the region and disappeared in September 2017. The high HSI indicates that the oceanographic factor is consistent with the catch probability of mackerel tuna.
SEBARAN DAERAH TANGKAP IKAN TONGKOL (Euthynnus sp.) DI PERAIRAN SELATAN JAWA Ibrahim Kholilullah; Roza Yusfiandayani; Alan F Koropitan
Jurnal Teknologi Perikanan dan Kelautan Vol 9 No 2 (2018): NOVEMBER 2018
Publisher : Fakultas Perikanan dan Ilmu Kelautan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2421.491 KB) | DOI: 10.24319/jtpk.9.123-136

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Tingginya pemanfaatan masyarakat terhadap ikan tongkol kontradiksi dengan mayoritas armada kapal yang dimiliki nelayan di Selatan Jawa berupa gill net dan long line yang spesifikasi untuk menangkap tuna dan pelagis besar lainya. Peta daerah penangkapan ikan tongkol sangat dibutuhkan oleh nelayan, terutama ketika musim paceklik ikan berlangsung menjadi tulang punggung hasil tangkap nelayan. Raw data penangkapan diperoleh dari logbook penangkapan Pelabuhan Perikanan Samudera Cilacap (PPS Cilacap) sepanjang tahun 2017. Penelitian ini bertujuan (1) menganalisis sebaran daerah penangkapan ikan tongkol (Euthynnus sp.) untuk alat tangkap gill net dan long line di perairan selatan Jawa dan (2) menganalisis sebaran menegak lapisan rata-rata bulanan suhu dan salinitas perairan yang optimum untuk ikan tongkol. Hasil penelitian ini menunjukkan sebaran daerah penangkapan ikan tongkol (Euthynnus sp.) untuk alat tangkap gill net adalah 105,56⁰-110,78⁰ BT dan 7,48⁰-11,57⁰ LS serta untuk alat tangkap long line adalah 106,69⁰-109,46⁰ BT dan 7,84⁰-9,37⁰ LS. Sebaran daerah penangkapan ikan tongkol menggunakan gill net tertinggi pada bulan Agustus dengan perolehan hasil tangkap 76.634 kg, sedangkan menggunakan long line pada bulan Juli dengan perolehan hasil tangkap 18.741 kg. Sebaran menegak lapisan rata-rata bulanan suhu perairan untuk ikan tongkol optimum pada bulan Juli, Agustus, September untuk gill net dan bulan Juli serta November untuk long line yaitu 26-27⁰ C. Sebaran menegak rata-rata bulanan salinitas perairan untuk ikan tongkol juga optimum bulan Juli, Agustus, September untuk gill net dan long line sepanjang tahun kecuali bulan Januari merupakan kisaran optimum yaitu berkisar 34,0-43,3 %o.
Studi Dinamika Ekosistem Perairan Di Teluk Lampung: Pemodelan Gabungan Hidrodinamika-Ekosistem Alan Frendy Koropitan; Safwan Hadi; Ivonne M. Radjawane; Ario Damar
Jurnal Ilmu-Ilmu Perairan dan Perikanan Indonesia Vol. 11 No. 1 (2004): Juni 2004
Publisher : Institut Pertanian Bogor

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Abstract

Penelitian ini bertujuan untuk mengkaji dinamika ekosistem perairan di Teluk Lampung dengan menggunakan gabungan model hidrodinamika-ekosistem dengan pendekatan numerik. Secara umum, hasil simulasi pola arus residu M2 cenderung masuk dari mulut teluk sebelah barat, sebagian terus memasuki sampai kepala teluk dan sebagian keluar kembali dari mulut teluk bagian timur. Selain itu, terlihat pula adanya suatu eddy yang mengalir berlawanan arah jarum jam di sekitar kepala teluk. Pola penyebaran masing-masing kompartimen ekosistem hasil model memiliki kesamaan dengan hasil pengamatan di lapangan, serta konsisten dengan pola arus residu M2. Pengaruh suplai dari sungai, interaksi antara proses biologis seperti produktifitas primer, sekunder (pemangsaan), kematian alami plankton, serta proses dekomposisi oleh bakteri belum begitu berperan dalam neraca dan standing stock ekosistem di Teluk Lampung. Peranan suplai dari laut lebih dominan dibanding dengan proses-proses biokimiawi yang berinteraksi di dalam teluk. Hasil perhitungan tingkat efisiensi aliran energi dari proses dekomposisi dan produksi urine zooplankton ke produktifitas primer mengalami kehilangan sebesar 30.48 %, sementara dari produktifitas primer ke produktifitas sekunder (pemangsaan) mengalami penambahan 17.24 %.Kata kunci: dinamika ekosistem, Teluk Lampung, gabungan model hidrodinamika-ekosistem, arus residu M2.
WAVE PROPAGATION AND RESIDUAL CURRENT OF TIDE IN MAYALIBIT BAY: 2D HYDRODYNAMICS MODEL OF TIDE Asep Sandra Budiman; Alan F. Koropitan; I Wayan Nurjaya
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 7 No. 1 (2015): Elektronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1163.556 KB) | DOI: 10.29244/jitkt.v7i1.9802

Abstract

Study on tidal waves and residual currents in Mayalibit Bay was conducted by constructing the 2D numerical hydrodynamics to find the characteristics of tide and residual currents inside the Bay. The 2D hydrodynamic equations with non-linier terms were solved by finite difference methods explicitly. M2 and K1 wave propagations were observed and analyzed at 25 observation points. M2 and K1 residual currents were obtained and described spatially. Simulation results of tidal currents were validated with field measurements. The validation result showed that the tidal currents between the model results and field measurements were quite fit. Generally, simulation results showed the significant differences between the tide inside and outside the Bay. This was strongly explained by the simulation results of M2 and K1 wave propagations. The M2 and K1 amplitudes were 10 times lower inside  than outside the Bay with the phase lags of about 180°(M2) and 160°(K1). This result indicated that the tide inside and outside the Bay were in the opposite conditions. The tide had an ebb inside while the flood was outside and vice versa.  M2 residual currents was flowed into the Bay uniformly, while K1 residual currents flowed out to the open sea in the Northern part and it flowed into the Bay in the Southern part of the Bay. Eventually, both of them converged in the middle of the Bay. Keywords: tide, tide-induced residual current, numerical method
COHESIVE SEDIMENT TRANSPORT MODELING ON INNER AMBON BAY Yunita A. Noya; Mulia Purba; Alan F. Koropitan; Tri Prartono
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 8 No. 2 (2016): Elektronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2641.118 KB) | DOI: 10.29244/jitkt.v8i2.15834

Abstract

The presence of cohesive sediment in the water column can reduce light penetration and affect photosynthesis process, and it can be disrupted the primary productivity of aquatic, and sedimentation of coastal waters. The objective of this research was to determine the cohesive sediment distribution pattern and the relationship with sedimentation. MIKE 3 FM modeling was used to understand the process of sediment transport and sedimentation on Inner Ambon Bay. Sediment transport modeling method was divided into two stages: the hydrodynamic modeling (baroclinic) and sediment transport (mud transport) modeling. The model results indicate current patterns in the Inner Ambon Bay is influenced by the tidal factor. Suspended sediment dispersed vertically from the surface to a depth of 30 m with concentration of about 3.5-15 Kg/m3. The maximum consentration of the suspended sediment occurs at head of the bay (around Waiheru, Passo, and Lateri). Model simulations for 30 days showed the rate of erosion is about 1.04-6.15 Kg/m2/s, while in Inner Ambon Bay the erosion about 9.07x10-8Kg/m2/s only occurred in T1 station. Sedimentation associated with the cohesive sediment accumulation and it was shown by bed level. In addition, the simulation showed bed level in sill ranged at 0.01-0.19 cm and 0.47 mm/day on average, while in the Inner Ambon Bay it ranged from 1.75-10.01 cm, and the sedimentation rate was approximately 39.9 mm/day.
SEDIMENT ACCUMULATION PROFILE IN MANGROVE RESTORATION AREA OF LEMBAR BAY-LOMBOK ISLAND Mohammad Sumiran Paputungan; Alan Frendy Koropitan; Tri Prartono; Ali Arman Lubis
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 9 No. 1 (2017): Elektronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (548.965 KB) | DOI: 10.29244/jitkt.v9i1.17943

Abstract

Mangrove restoration is really needed for restoring its ecosystem functions, so that it could be able to support fisheries activity and to protect coastal by extreme weather. In addition, mangrove is able to accumulate sediment that important in protecting the coastal area from sea level rise. Therefore,  the aim of this study is to investigate sediment accumulation rate in mangrove area during post restoration. Sampling location were divided into three different stations based on estimated restoration ages, such as ≥ 15  years old (Station 1), 4 - 10 years old (Station 2) and 2 - 8 years old (Station 3). Sediment cores were carried out by inserting 7.6 cm diameter and 100 cm length of polyvinyl chloride pipes. Sedimentation rate is measured by using Pb-210 radionuclide analysis. The results show that the sediment accumulation rate in the last 20th years from all station ranges from 0.17 to 0.42 g/cm2/year. The highest accumulation rate is found at oldest year old station while the lowest accumulation rate is found at younger year old station of mangrove restoration area. Restoration process is clearly able to recover the mangrove’s role in trapping sediment in coastal region. Keywords: sediment accumulation, mangrove restoration, Lembar Bay-                   Lombok Island