Judul: Cannibalism rate and production performance of cantang grouper nursery in floating net cages with multilevels shelter
Abstrak: Tingkat kanibalisme yang tinggi pada pendederan kerapu cantang disebabkan oleh tingginya frekuensi pertemuan antar ikan. Hal ini dapat diatasi dengan menggunakan selter bertingkat pada wadah. Tujuan penelitian ini adalah mengetahui pengaruh selter bertingkat terhadap tingkat kanibalisme dan kinerja produksi pendederan kerapu cantang pada karamba jaring apung di laut. Perlakuan yang digunakan adalah jumlah tingkat yang berbeda, yaitu perlakuan K (tanpa selter) sebagai kontrol, A (2 tingkat, dasar + 1 tingkat), dan B (3 tingkat, dasar + 2 tingkat). Benih ikan ditebar sebanyak 100 ekor/m3 pada wadah jaring high density polyethylene berukuran 1 × 1 × 1 m3 (MS: 5 mm) dan diberi pakan sebanyak 4 kali sehari secara at satiation selama 30 hari. Hasilmenunjukan adanya pengaruh positif dengan adanya selter bertingkat terhadap tingkat kanibalisme dan kinerja produksi. Hasil terbaik diperoleh pada perlakuan B dengan tingkat kanibalisme sebesar 32,67%, tingkat kelangsungan hidup sebesar 67,33%, laju pertumbuhan panjang dan bobot sebesar 0,174 cm/hari atau 2,57%/hari dan 0,547 g/hari atau 8,09%/hari, rasio konversi pakan sebesar 1,09, High rate cannibalism in cantang grouper nursery are caused by high frequency of fish fingerling encounters. This problem can be solved by using multilevel shelter in cage. The aim of this study was to find out the influence of multilevel shelter on cannibalism rate and production performance of nursery cantang grouper in sea floating net cage. The treatment which has been used is K (without shelter) as a control, A (two levels, base + 1 level), and B (three levels, base + 2 levels). Fish fingerling are stocked as much as 100 fish/m3 in floating net cage made of high-density polyethylene with 1 × 1 × 1m3 (MS: 5 mm) and feeded as much as 4 times a day as fully as needed for 30 days. The results show that there is a positive influence with the existence of multilevel shelters on cannibalism rate and production performance. The best results were obtained in treatment B with a cannibalism rate is 32.67%, survival rate is 67.33%, growth rate of length and weight are 0.174 cm/day or 2.57%/day and 0.547 g/day or 8.09 %/day, and feed conversion ratio is 1.09
Keyword: cannibalism, cantang grouper, multilevel shelter, nursery, production performance

Judul: Kinerja Produksi Pendederan Ikan Kerapu Cantang dalam Keramba Jaring Apung di Laut dengan Pencahayaan Teduh dan Terang
Abstrak: Ikan kerapu bersifat nokturnal dan memiliki sifat kanibalisme tinggi pada pemeliharaan dengan pencahayaan terlalu terang. Pendederan ikan kerapu dalam keramba jaring apung (KJA) di laut telah diaplikasikan, namun intensitas cahaya tidak terkontrol. Penelitian ini bertujuan untuk menganalisis pengaruh kondisi pencahayaan teduh dan terang melalui penggunaan penutup KJA dengan kerapatan yang berbeda terhadap kinerja produksi pendederan ikan kerapu cantang di laut. Rancangan Acak Lengkap digunakan dalam penelitian ini dengan perlakuan pencahayaan teduh (kedalaman 1 m 1472 lux dan permukaan 2405 lux) dan terang (kedalaman 1 m 3633 lux dan permukaan 16.552 lux) dan setiap perlakuan diulang tiga kali. Ikan kerapu cantang (bobot 7,18±0,17 gram dan panjang 7,06±0,051 cm) dipelihara dalam KJA selama 32 hari dengan padat tebar 100 ekor/m³ dan diberi pakan buatan berupa pelet tenggelam dengan metode ad-satiation pada 08.00, 12.00, dan 16.00 WIB. Oksigen terlarut, suhu, pH, dan salinitas air dalam KJA diukur setiap 7 hari, sedangkan ammonia setiap 2 minggu. Nilai koefisien keragaman panjang dan tingkat kanibalisme pada perlakuan teduh lebih tinggi dari perlakuan terang., Groupers are nocturnal and have high cannibalism in rearing with too bright light. Nursery of grouper in floating net cages (KJA) in the sea has been applied, but the light intensity is uncontrolled. This study aims to analyze the effect of shady and bright lighting conditions through the use of KJA covers with different densities on the nursery production performance of cantang grouper in the sea. Completely randomized design was used in this study with shady (depth 1 m 1472 lux and surface 2405 lux) and bright lighting (depth 1 m 3633 lux and surface 16.552 lux) and each treatment was three replications. Cantang grouper (weight 7,18±0,17 grams and length 7,06±0,051 cm) was reared in KJA for 32 days with a stocking density of 100 fish/m³ and given artificial feed in the form of sinking pellets by ad-satiation method at 08.00, 12.00 and 16.00 WIB. Dissolved oxygen, temperature, pH, and salinity of water in KJA were measured every 7 days, while ammonia every 2 weeks. The coefficient of length variation and the level of cannibalism in the shade treatment were higher than in the light treatment.
Keyword: floating net cages (KJA), grouper, nuersery, shady and light

Judul: Utilization of terra/MODIS L1B data for analysis of horizontal wind profile in the troposphere
Abstrak: This study was concerned with horizontal wind derived from data collected with the Moderate-resolution Imaging Spectroradiometer (MODIS) on board the NASA’s Earth Observation System (EOS)-Terra satellite. The aim of this study is to develop a method for the estimation of horizontal wind movement in the troposphere based on Navier-Stokes equation. The method was applied to a calibrated and geolocated Terra/MODIS L1B 1 km data set. The data inputs to estimate surface temperature are retrieved from TIR (Thermal Infrared) bands 31 (10.780 μm to 11.280 μm) and 32 (11.770 μm to 12.270 μm). The obtained surface temperatures were later used to approximate geopotential height on a constant-pressure surface by using the modified Poisson equation. The main assumptions used are the hydrostatic equilibrium, ideal gas law, constant lapse rate and constant acceleration of gravity. Based on the distribution of geopotential height, the pressure gradient force is measured by the gradient of geopotential on an isobaric coordinate to present the horizontal wind profile. For certain topographic areas especially in the mountain ranges, there was a disadvantage of using pressure as a vertical coordinate which lead to inaccuracy. In spite of that, Terra/MODIS L1B data with 1 km spatial resolution can be used to estimate the horizontal wind movement in the troposphere.
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