Johannes Hutabarat

Oithona sp. merupakan salah satu copepoda yang dapat digunakan sebagai pakan alami untuk larva ikan ataupun udang laut. Oithona sp. memiliki nilai nutrisi yang hampir sebanding dengan Artemia. Oithona sp. memiliki kandungan protein sebesar 69,24%. Tujuan dari penelitian ini untuk mengkaji pengaruh perbedaan kandungan protein pada pakan organik terhadap performa pertumbuhan Oithona sp., dan mengetahui perlakuan dari kandungan protein pakan organik yang memberikan performa pertumbuhan Oithona sp. terbaik. Penelitian dilakukan dengan metode eksperimen menggunakan Rancangan Acak Lengkap (RAL) dengan 4 perlakuan dan 4 kali ulangan. Perlakuan yang dilakukan yaitu pemberian pakan organik dengan kandungan protein 25% (A), 30% (B), 35% (C) dan 40% (D). Kultur Oithona sp. dilakukan di dalam 14 toples plastik bervolume 9 L yang diisi air media sebanyak 2,5 L. Pemeliharaan dilakukan selama 20 hari. Pada setiap kultur Oithona sp. dalam toples plastik diberikan pakan sebanyak 50% dari sel mikroalga Chaetoceros calcitrans dan 50% pakan organik yang telah difermentasi. Hasil penelitian menunjukkan kandungan protein pakan organik berpengaruh sangat nyata terhadap pertumbuhan Oithona sp. (P0,05). Pemberian 30% protein pada pakan organik merupakan dosis terbaik dalam penelitian ini. Kepadatan total Oithona sp. dengan pemberian kandungan protein pakan organik 30 % mencapai 76,5±3,1 ind/ml (terdiri dari stadia nauplii sebanyak 35,0±2,6 ind/ml, stadia copepodit sebanyak 12,8±1,3 ind/ml, dan stadia dewasa 21,0±1,6 ind/ml) dan rata-rata produksi telur sebanyak 3,2±0,3 butir/ind

Ikan nila (Oreochromis niloticusmerupakan salah satu hasil perikanan air tawar unggul yang terjangkau sebagai komoditas program nasional untuk dijual di pasar domestik dan luar negeri, sehingga perlu adanya pemenuhan permintaan pasar. Budidaya padat tebar tinggi dapat meningkatkan produksi, namun dapat meningkatkan limbah nitrogen yang dapat menyebabkan lambatnya pertumbuhan bahkan kematian pada ikan. Sistem resirkulasi akuakultur dapat memperbaiki dan menggunakan kembali air dengan filter mekanik dan biologi. Spons dapat menyaring dan menahan kotoran, arang memiliki pori halus yang dapat menyerap molekul polutan air, serta zeolit memiliki struktur pori yang mampu bertukar ion. Kombinasi filter tersebut baik untuk memperbaiki kualitas air, sehingga perlu adanya kajian aplikasi komposisi filter agar dapat memperbaiki kualitas air, pertumbuhan dan kelulushidupan ikan nila. Tujuan penelitian ini yaitu untuk mengetahui pengaruh serta komposisi filter terbaik terhadap kualitas air, pertumbuhan dan kelulushidupan ikan nila. Penelitian ini menggunakan 20 ekor ikan setiap wadahnya dengan ukuran 8 cm dan bobot 10,23±1,6 g. Penelitian ini menggunakan metode eksperimen rancangan acak lengkap (RAL), 4 perlakuan 3 ulangan. Komposisi filter yang digunakan yaitu kontrol (A), 25% arang + 75% zeolit (B), 50% arang + 50% zeolit (C), dan 75% arang + 25% zeolit (D). Data yang dikumpulkan yaitu kualitas air, nilai pengurangan total amonia nitrogen (TAN removal), volumetric TAN removal (VTR), total kelimpahan bakteri, laju pertumbuhan relatif (RGR), total konsumsi pakan (TKP), rasio konversi pakan (FCR) dan kelulushidupan (SR). Hasil penelitian menunjukkan bahwa aplikasi komposisi filter berpengaruh nyata terhadap TAN removal, VTR, total kelimpahan bakteri, RGR, TKP, FCR dan SR, perlakuan terbaik terdapat pada komposisi filter 25% arang + 75% zeolit (B) yaitu 97,53%, 50,69 g m^-3 day^-1, 2,35 x 10⁴ CFU mL^-1, 238,33 g, 2,67% day^-1, 1,47 dan 95%. Kata Kunci : Ikan nila, sistem resirkulasi, komposisi filter, spons, arang kayu, batu zeolit.

Phronima sp. is a natural feed with high nutrient content, and it can be an alternative substitute for Artemia. The existence of probiotic bacteria in culture media aims to improve water quality through biodegradation, maintain microbial balance and control pathogenic bacteria, so that nutrients in culture media can be utilized by Phronima sp. This study aimed to determine the effect of fermented organic fertilizer by probiotic bacteria in mass culture media on the population density, biomass production and nutrient content of Phronima sp. and to find the best culture media composition for mass culture of Phronima sp. The study was conducted with a completely randomized design with five treatments and three replications. The treatments were as follows: A: 0% chicken manure, 50% rice bran, 50% tofu waste; B: 25% chicken manure, 37.5% rice bran, 37.5% tofu waste; C: 50% chicken manure, 25% rice bran, 25% tofu waste; D: 75% chicken manure, 12.5% rice bran, 12.5% tofu waste and E: 100% chicken manure. The test animals were Phronima sp., and during cultivation, fertilization was carried out every 3 days. Population density and biomass were observed, and proximate analysis, amino acid profile analysis and fatty acid profile analysis were performed. The highest population density was at treatment B, with a peak population of 98 individuals/L that occurred on the 16th day of maintenance culture, and the highest biomass of 0.51 g was at the same treatment. The highest nutrient content was obtained at treatment B, for which the highest protein proximate analysis value was 58.90%, the proportion of the fatty acids comprised of eicosapentaenoic acid was 7.53%, and lysine amino acids were found at 44.16 ppm.

High price of fish meal for artificial feed provides an alternative solution to use maggot meal as fish meal substitute for decreasing production cost, because it is cheaper and easier to be obtained. The study aimed to determine and analyze the substitution of fish meal with maggot meal derived from various wastes as artificial feed, for improving carp (Cyprinus carpio) production and quality. The study used experimental method with completely randomized design (CRD). This study used four treatments and three replications. About 120 of carps with 0.62±0.14 g/fish of average individual weight maintained at 1 fish/L of stock density for 45 days. Pellet-shaped feed with 30% of protein content was used. The feed was given to tested fish with fixed feeding rate three times a day. The treatments conducted in this study were: 150g/L tofu waste (A); 50g/L fruit waste + 100g/L tofu waste (B); 50g/L vegetable waste + 100g/L tofu waste (C); 50g/L chicken manure + 100g/L tofu waste (D). Primary data were Total Feed Consumption (TFC), Feed Utilization Efficiency, Protein Efficiency Ratio (PER), Specific Growth Rate (SGR), and Survival Rate. The result of fish meal substitution with maggot meal for artificial feed which cultured with 50g/L chicken manure + 100g/L tofu waste gave a significant effect (P0.05) on TFC. The results were 74.93±0.91 of feed utilization efficiency, 2.24% of protein efficiency ratio, 2.81% of specific growth rate, and 91.11% of survival rate. The best lysine amino acid profile was 32.83%, and the highest linoleic fatty acid was 7.26%.

Arafura Sea is one of the waters in the eastern region of Indonesia that is rich in marine and fisheries potentials because of its fertile conditions which is suitable for fishing ground. One of the fish resources which have important economic value at the Arafura Sea is big pelagic fish such as Mackerel. Thus this study aims to determine the spatial and temporal distribution of Mackerel in the Arafura Sea based on fishing boat coordinate data, to know the distribution of chlorophyll-a concentration and SST from MODIS satellite data in the Arafura Sea and to determine the correlation of chlorophyll-a and SST to the Mackerel catch distribution. This study was conducted in December 2016 until February 2017 in the Arafura Sea, image data analysis of MODIS level-3 conducted at the Laboratory of Oceanography FPIK UNDIP. The data used are Mackerel catch data, the Chlorophyll-a data and SST from MODIS satellite from June to August 2015. The results of this study showed that the distribution of Mackerel catch from June to August more were caught in August a total of 62.2 tons for 19 trips. While the chlorophyll-a between June and August ranged from 0.30 to 8.04 mg/m3 and SST in June-August ranged from 24.6 °C - 28.4 °C. The correlation between chlorophyll-a and Mackerel catch results showed very strong correlation (correlation coefficient (r) 0.934). While the correlation between SST with the Mackerel catch showed a strong correlation (correlation coefficient (r) 0.664).

The Asian swamp eel (Monopterus albus) is a high protein content fish with delicious taste that can survive for 6–8 months. The growth performance and nutrient quality of Asian swamp eels in a freshwater aquaculture system in Central Java, Indonesia was studied using a completely randomized design. Golden snails, snails, silkworms, and earthworms were the feeding treatments at 5% of total body weight. The test animals weighed 5.68 ± 0.35 g after a 60-day culture, and the density was 36 eels/m². Providing different types of feed had significant effects (P < 0.05) on relative growth rate (RGR), feed intake, and survival rate (SR) but did not significantly affect the protein efficiency ratio (P > 0.05). The best final weight, RGR, and SR results were 11.80 g, 2.64%, and 80.95% during a 60-day culture with silkworms used as feed. The nutrient quality in a similar treatment found with the best proximate composition was 76.90% protein, 3.24% fat, 25.19% palmitic acid, 15.41% oleic acid, 15.9% glutamic acid, 8.2% isoleucine, and 8.9% lysine.

Irawan A, Supriharyono, Hutabarat J, Ambariyanto. 2018. Seagrass beds as the buffer zone for fish biodiversity in coastal water of Bontang City, East Kalimantan, Indonesia. Biodiversitas 19: 1044-1053. The purpose of this study was to demonstrate the importance of seagrass beds as a buffer zone for fish biodiversity in a coastal ecosystem. The sampling of seagrass and fish were done in seagrass beds associated with mangrove (ST1) and coral reef (ST2). Sampling period was executed from May 2011 to May 2017. Sampling was done on the lowest tide with a six-month interval. Seagrass sampling was carried out using line transect, and fish sampling was performed using set net (belat local name) operated by local fisherman. The results showed that seagrass beds at ST1 composed of C. rotundata and E. acoroides and that at ST2 composed of C. rotundata, E. acoroides, H. pinifolia, H. minor and T. hemprichii. The total number of individual was 42574 divided into 112 fish species. There were 17 species (population: 15.18%) associated explicitly with ST1 and 39 species (population: 34.82%) specifically associated with ST2 while 56 fish species (population: 50.0%) were prevalently spread in both stations. This research proved the existence of seagrass beds as a buffer zone for fish biodiversity.