Yulianto Suteja, Yulianto
Program Studi Ilmu Kelautan, Fakultas Kelautan dan Perikanan, Universitas Udayana, Bukit Jimbaran, Bali 80361

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TURBULENT MIXING IN OMBAI STRAIT Suteja, Yulianto; Purba, Mulia; Atmadipoera, Agus S.
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol 7, No 1 (2015): Elektronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Jurnal Ilmu dan Teknologi Kelautan Tropis

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Abstract

Ombai Strait is one of the exit passages of Indonesian Throughflow (ITF) which conveys hotspot of strong internal tidal energy. Internal tide is the one of main energy which causes mixing processes in the oceans and could lead to changes in water mass characteristics. The purpose of this research was to estimate the turbulent mixing by using Thorpe analysis. Nine CTD cast were obtained for one tidal cycle (24 hours) in Ombai Strait. The results showed the average value of the turbulent mixing is 833.5 x 10-4 m2s-1, the highest found in deep homogeneous layer (2383.4x 10-4 m2s-1), followed by mixed surface layer (103.0 x 10-4 m2s-1) and thermocline (14.2 x 10-4 m2s-1). This Turbulent mixing value is much higher than the previous measurement in Indonesian Sea. This is presumably due to the strong internal tidal energy and its interaction with existing deep sill in Ombai Strait. Keywords: Indonesian throughflow (ITF), Ombai Strait, turbulent mixing
Beban Pencemar Dan Kapasitas Asimilasi Amonium dan Nitrat Saat Pucak Musim Barat di Teluk Jakarta Suteja, Yulianto
Journal of Marine and Aquatic Sciences Vol 2, No 1 (2016)
Publisher : Fakultas Kelautan dan Perikanan Universitas Udayana

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Abstract

Jakarta Bay is a bay that has an important role in Jakarta, but the activity in this area lead to the potential for pollution mainly ammonium and nitrate. Pollution peaks generally occur during the rainy season (west monsoon). Pollution that enters the bay can be neutralized naturally by water as long as the amount does not exceed the asimilation capacity. This study aims to calculate the total input (load), assimilation capacity, and residence time of ammonium and nitrate in Jakarta Bay in the rainy season. Data from this study is derived from secondary data. For the total input of pollutants are calculated from the input stream, the atmosphere and the boundary. From the research found that the Jakarta Bay had a total load of pollutants NH4 at 115.8 x 109 mmol N /month and NO3 46.5 x 109 mmol N/month. The biggest contributor to the pollution comes from the boundary NH4 is 56.9% and NO3 from the river 70.1%. Load from Citarum river for NH4 around 3.8 x 1010 mmol N/month and NO3 around 3.0 x 1010 mmol N/month higher than Marunda, Priok and Angke the rivers. Assimilation capacity of Jakarta bay  for NH4 around 25.7 x 109 mmol N /month and NO3 of 24.1 x 109 mmol N /month. It shows the total load of pollutants entering the Jakarta Bay is greater than the assimilation capacity. The residence time of water in the Bay of Jakarta is 13.3 days longer than the residence time of NH4 and NO3 which were only 8.6 and 9.2 days.
Penilaian Pengkayaan Logam Timbal (Pb) dan Tingkat Kontaminasi Air Ballast di Perairan Tanjung Api-Api, Sumatera Selatan Agustriani, Fitri; Purwiyanto, Anna Ida Sunaryo; Suteja, Yulianto
Journal Omni-Akuatika Vol 12, No 3 (2016): OmniAkuatika special edition Kripik SCiFiMaS
Publisher : Fisheries and Marine Science Faculty - Jenderal Soedirman University

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Abstract

Tanjung Api-api sebagai pelabuhan sedikit banyak memiliki kontribusi dalam perubahan lingkunga peraiaran, termasuk perubahan konsentrasi logam timbal (Pb). Hal ini karena terjadinya peningkatan volume dan frekuensi pelayaran yang memberikan sumbangan logam Pb melalui buangan air ballast kapal. Penelitian ini bertujuan untuk mengetahui kontribusi pembuangan air ballast kapal terhadap penambahan logam berat Pb di perairan pelabuhan Tanjug Api-Api. Penelitian dilakukan dengan mengambil sampel air ballast pada beberapa kapal (feri, speedboat, pompong) dan sampel permukaan perairan pada saat surut untuk dianalisis kandungan Pb. Pengkayaan logam Pb pada perairan dianalisis menggunakan concentration factor (Cf), Degree of contamination/Cd, dan Pollution load index/PLI.Hasil analisis menunjukkan bahwa pada perairan Tanjung Api-Api terjadi penambahan logam berat Pb secara antropogenik, dimana salah satu sumber pencemarnya adalah buangan air ballast kapal. Hal ini ditunjukkan oleh konsentrasi logam Pb lebih tinggi dibanding perairan dan adanya korelasi positif antara logam Pb perairan dan air ballast. Konsetrasi logam Pb di perairan telah melampaui ambang batas baku mutu KepmenLH No. 51 tahun 2004, sedangkan konsentrasi logam Pb di air ballast untuk kapal feri masih berada di bawah baku mutu, namun untuk speedboat dan kapal pompong telah melampaui batas baku mutu KepmenLH No. 51 tahun 1995.Keywords : pengkayaan, logam Pb, air ballast, tingkat kontaminasi, tanjung api-api
Detection of Eutrophication In Benoa Bay - Bali Suteja, Yulianto; Dirgayusa, I Gusti Ngurah Putra
Journal Omni-Akuatika Vol 14, No 3 (2018): Omni-Akuatika November
Publisher : Fisheries and Marine Science Faculty - Jenderal Soedirman University

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Abstract

Eutrophication is an increase of organic material caused by the increase of nutrients in aquatic ecosystem by human activities. One effect of eutrophication is Harmful Algae Blooms (HABs) that are very harmful to the environment and humans. The Purpose of this study were determine spatial distribution of nutrient based on total nitrogen (total N) and total phosphate (total P), ratio of total N, and trophic level in Bay Benoa. Nutrient measurements were using spectrophotometric method. The Spatial distribution of total N and P show a generally pattern concentration increases in waters near the mainland. The highest concentrations of total N and P were found in Loloan River estuary closed to the floating net cages (FNC). Ratio of total N showed generally that the waters in Benoa Bay were dominated by Nitrate. High ammonia concentration was found in all rivers and Loloan River estuary. Benoa Bay is mostly in Oligotrophic conditions based on total N, while eutrophic conditions were only found in the Loloan River estuary. Based on total P, Benoa Bay was generally in hypertrophic level.
Distribusi Spasial Kerapatan Mangrove Menggunakan Citra Sentinel-2A Di TAHURA Ngurah Rai Bali Pratama, I Gede Merta Yoga; Karang, I Wayan Gede Astawa; Suteja, Yulianto
Journal of Marine and Aquatic Sciences Vol 5 No 2 (2019)
Publisher : Fakultas Kelautan dan Perikanan Universitas Udayana

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Abstract

Hutan mangrove TAHURA Ngurah Rai merupakan salah satu ekosistem mangrove di Bali yang mengalami kerusakan dan perubahan kerapatan karena faktor alam dan aktivitas manusia. Penginderaan jauh adalah salah satu teknologi yang dapat digunakan untuk estimasi kerapatan tajuk mangrove TAHURA Ngurah Rai. Tujuan dari penelitian ini adalah untuk mengetahui indeks vegetasi terbaik dalam mengestimasi kerapatan tajuk mangrove dan memetakannya secara spasial menggunakan citra Sentinel-2A. Metode penelitian ini adalah menggunakan indeks vegetasi NDVI, EVI dan mRE-SR untuk estimasi kerapatan tajuk mangrove. Pengambilan data lapangan dilakukan menggunakan metode Stratified Random dan Proporsional Sampling dengan mengambil foto kerapatan tajuk menggunakan kamera dengan lensa Fish Eye pada 34 plot. Hasil penelitian ini menunjukkan uji satistik dari model linier indeks vegetasi dengan nilai kerapatan tajuk mangrove pada indeks NDVI (r = 0.8165, R2 = 0.6667, RMSE = ± 8.1508), EVI (r = 0.8597, R2 = 0.7390, RMSE = ± 7.8117), dan mRE-SR (r = 0.9277, R2 = 0.8607, RMSE = ± 4.9571). Kesimpulan dari penelitian ini adalah indeks vegetasi mRE-SR mampu memetakan kerapatan tajuk mangrove lebih baik dari indeks vegetasi NDVI dan EVI dengan akurasi mencapai 86.07 %. Distribusi spasial mangrove yang dihasilkan dari model mRE-SR adalah seluas 1002.22 Ha dengan kerapatan tajuk kategori sangat rapat adalah 3.24 Ha, kerapatan tajuk kerapatan tajuk kategori rapat seluas 94.82 Ha, kerapatan sedang seluas 333 Ha, kerapatan jarang seluas 402.38 Ha dan kategori kerapatan sangat jarang seluas 168.78 Ha.
Konsentrasi Klorofil-a dan Hubungannya dengan Pasang Surut di Selat Lombok Gianie, Annassita; Suteja, Yulianto; Karim, Widiastuti
Journal of Marine Research and Technology Vol 2 No 2 (2019): AGUSTUS 2019
Publisher : Department of Marine Sciences, Faculty of Marine Science and Fisheries, Udayana University

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Abstract

Lombok Strait is a strait located between Bali Island and Lombok Island that has a strong current and crossed by the main trajectory of Indonesian Throughflow (ITF). ITF is a current system that connects the Pacific and Indian Ocean. When mass water ITF passes through Indonesian waters, it mixes with other water masses, resulting in a mix of two water masses from two different oceans. These differences in water mass characteristics include temperature, salinity, DO, chlorophyll, and other tracers that can be used as an indicator of productivity. This can be determined based on the availability of chlorophyll-a concentrations. Chlorophyll-a is an active pigment in phytoplankton cells that has an important role on photosynthesis process. It is essential to know the temporal fluctuations of the chlorophyll-a concentrations at both high and low tide, and the correlation between chlorophyll-a and the water quality in the Lombok Strait. This research used primary data on chlorophyll-a and water quality parameter (DO, temperature, and salinity) and secondary data regarding tides on Port of Lembar. This research used CTD SBE 911+ as a measurement of instrument. The concentration of chlorophyll-a on CTD measurement of 0 m (0.011mg/l and 0.005) and for 10m of chlorophyll-a concentration (0.014mg/l and 0.006). The fluctuations of chlorophyll-a pattern during the tides showed that at low tide, the chlorophyll-a concentration is high, and vice versa. The chlorophyll-a was situated on a depth of 0 m and 10 m and was not affected by the water quality.
Pemodelan Distribusi Nitrat di Kawasan Perairan Teluk Benoa Raharja, I Made Dharma; Hendrawan, I Gede; Suteja, Yulianto
Journal of Marine Research and Technology Vol 1 No 1 (2018): AGUSTUS 2018
Publisher : Department of Marine Sciences, Faculty of Marine Science and Fisheries, Udayana University

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Abstract

Teluk Benoa merupakan perairan yang dipengaruhi oleh kondisi lingkungan perairan. Nitrat adalah salah satu parameter perairan yang sangat penting bagi kelangsungan hidup biota di laut. Dari penelitian sebelumnya terkait beban pencemaran nitrat di Teluk Benoa, kondisi nitrat telah melampui kondisi baku mutu yang ditetapkan melalui Peraturan Gubernur Bali Nomor 16 Tahun 2016 tentang Baku Mutu Lingkungan Hidup dan Kriteria Baku Kerusakan Lingkungan Hidup yaitu 0,008 mg/L. Penelitian yang telah dilakukan sebelumnya masih terbatas pada analisis nitrat pada bagian permukaan perairan sehingga dari  hal  tersebut penting  halnya melakukan kajian lebih lanjut terkait  kondisi nitrat di kolom perairan Teluk Benoa. Kajian konsentrasi nitrat pada kolom perairan dapat dilakukan dengan observasi secara langsung dilapangan, namun membutuhkan waktu yang cukup lama dan biaya yang tinggi. Sehingga pada penelitian ini digunakan pemodelan numerik. Pemodel numerik yang digunakan dalam penelitian ini adalah Finite Volume Coastal Ocean Model (FVCOM) yang dimodelkan secara 3-D. Dalam analisis distribusi nitrat pada studi ini digunakan persamaan momentum dan persamaan adveksi-difusi. Dari hasil model diketahui pada setiap kondisi pasang surut konsentrasi nitrat pada bagian permukaan perairan Teluk Benoa cenderung tinggi pada daerah bagian barat Teluk Benoa dan timur Teluk Benoa. Sementara pada kolom perairan di Teluk Benoa konsentrasi nitrat cenderung dipengaruhi oleh keadaan elevasi pasang surut. Kondisi nitrat paling tinggi berada pada kondisi surut terendah dan paling rendah berada pada kondisi pasang tertinggi. Konsentrasi nitrat secara vertikal memiliki konsentrasi yang relatif sama.
KONDISI NITRAT, NITRIT, AMONIA, FOSFAT DAN BOD DI MUARA SUNGAI BANYUASIN, SUMATERA SELATAN Putri, Wike Ayu Eka; Purwiyanto, Anna Ida Sunaryo; Fauziyah, .; Agustriani, Fitri; Suteja, Yulianto
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol 11, No 1 (2019): Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Bogor Agricultural University

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Abstract

ABSTRAKPesisir Banyuasin merupakan salah satu sentra perikanan tangkap di Provinsi Sumatera Selatan. Kawasan ini menyimpan potensi sumber daya perikanan yang harus dijaga kelestariannya. Banyak nelayan yang menggantungkan hidupnya di kawasan ini, hanya saja ragam pemanfaatan di sepanjang aliran Sungai Banyuasin seperti pemukiman, industri, pertanian dan transportasi telah mempengaruhi kualitas perairan. Penelitian ini bertujuan untuk mengkaji bagaimana kondisi nitrat, nitrit, amonia, fosfat dan BOD di Pesisir Banyuasin. Pengambilan sampel dilakukan pada bulan September 2017 meliputi 22 stasiun penelitian, analisa sampel dilakukan di Laboratorium Balai Riset dan Standardisasi Industri (Baristand) Palembang merujuk pada SNI. Hasil penelitian menunjukkan konsentrasi nitrat selama penelitian berkisar antara 0,025-3,21 mg/L, nitrit 0,002-0,093 mg/L, amonia 0,002-0,031 mg/L, fosfat 0,011-0,231 mg/L dan BOD 2,14-8,73 mg/L. Konsentrasi nitrat dan fosfat telah melebihi baku mutu yang ditetapkan, adapun untuk parameter nitrit, amonia dan BOD masih dibawah baku mutu. ABSTRACTCoastal of Banyuasin is one of the centers of capture fisheries in South Sumatra Province. This area had the potential of fisheries resources that must be preserved. Many fishermen are depend their lives on this area, but some activity along Banyuasin River such as settlement, industry, agriculture and transportation has affected the quality of water. This study aims to examine the conditions of nitrate, nitrite, ammonia, phosphate and BOD in the Coastal of Banyuasin. Sampling was conducted in September 2017 covering 22 research stations, sample analysis conducted at Palembang Institute for Industrial Research and Standaritation Laboratory refers to SNI. The results showed that the concentration of nitrate during the study ranged from 0.025-3.21 mg.L-1, nitrite 0.002-0.093 mg.L-1, ammonia 0.002-0.031 mg.L-1, phosphate 0.011-0.231 mg.L-1and BOD 2.14-8.73 mg.L-1. The concentration of nitrate and phosphate in Banyuasin River estuary were exceeded quality standards while nitrite, ammonia and BOD were still below specified quality standards.