bluuebunny/crossref_metadata_2025 huggingface dataset:
Cathepsin characterization from crude extract of yellow pike (Congresox talabon)
Authors: Pertiwi R M , Pamungkas I D , Prastyo D T , Trisdiani D U , Pasaribu E , Nurhayati T
Published: December 2019

Fish is a highly perishable food due to internal and external factors. Cathepsin, a proteolytic enzyme available in animal tissues, affects quality deterioration of fish by hydrolizing muscle proteins. Yellow pike fish have an edible portion that is relatively high but has not been used optimally. The aim of the study was to extract the cathepsin enzyme from yellow pike meat. The method used extraction, characterization, and precipitation of ammonium sulfate (NH4)2SO4 fraction at concentrations of 40-50% to 70-80%. The extraction results showed the crude extract activity of cathepsin from yellow pike fish which was 0.19 U/mL. The optimum activity of the cathepsin enzyme at a pH 5 (0.24 U/mL), temperature of 50°C (0.10 U/mL) and metal ions increased cathepsin activity, one of which was CuCl2 increased cathepsin activity to 0.92 U/mL and FeCl3 increased activity to 1.41 U/mL. The best precipitate at 40-50% ammonium sulfate concentration with specific activity 1.15 U/mg.
The effect of degradation time in the simulated gastric fluid for bioactive compounds from bekasam
Authors: Rinto  , Lestari S D , Baehaki A , Sari Y
Published: December 2019

Bekasam contains bioactive compounds (lovastatin and peptide) that has function as anticholesterol. This research was aimed to determine the effect of pH and degradation time to lovastatin, peptides, and dissolved protein in bekasam seluang extract (Rasbora sp.). This study used a laboratory experimental method with 4 levels of treatment (degradation in simulation gastric fluid pH 2, pH 3 pH 4 and control without simulated gastric fluid). The degradation results were observed every the 2nd hours, the 4th hours, and the 6th hours. Each treatment level repeated 3 times. The stages of the study consisted of making bekasam, extracting of bekasam, calculating the yield of bekasam extract and testing pure bekasam extract in simulated gastric fluid. The analysis was carried out using a descriptive method, which is to describe each parameter obtained. The parameters observed are analysis of lovastatin level, dissolved protein levels, and peptide levels. The results showed that the levels of lovastatin, dissolved proteins and peptides were still detectable after have degraded in simulation gastric fluid an acidity level of pH 2, pH 3 and pH 4 for 2nd to 6th hours.
Biological aspects of Leptobrama pectoralis Ramsay and Ogilby 1887 (Leptobramidae) in Merauke, Papua, Indonesia
Authors: Kembaren D D , Taufik M
Published: December 2019

Long-fin beach salmon (Leptobrama pectoralis) is an endemic species to Arafura and distributed from northern Australia to Merauke, Southern Papua, Indonesia. The biological information of this species is still limited. This study aimed to provide biological information on long-fin beach salmon to fill the research gap of this fish. Parameters collected including length, weight and gut content. A total of 2,640 specimens were collected gill net landing based in Merauke from February to November 2016. The analysis results showed that maximum length and weight of long-fin beach salmon from Merauke waters were 40.4 cmFL and 859 g. The length-weight relationship formula was found as W=0.016L2.897. The average maximum length (L∞) and instantaneous growth rate (k) were 42 cm and 0.8 year−1 while the total mortality (Z) was estimated as 4.2 year−1 and maximum recruitment occurred in November. Length at capture lower than length at maturity (Lc<Lm). The stomach content of this species was dominated by fish (38.19%). The result of this study can be served as a piece of early information on the species’ status.
Combination of cell disruption method and pH variation as pre-treatment for lipid extraction of Nannochloropsis sp.
Authors: Melanie S , Fithriani D
Published: December 2019

The quantity of fossil-based fuel also has depleted due to over-exploitation. Therefore, environmentally friendly and more sustainable energy resources are being searched to fill in the energy supplies in the future. Microalgae have been considered by the researcher as alternative biofuel feedstock due to their high lipid content. Lipid extraction is one of the crucial steps in biofuel production from microalgae. The aim of this study was to analyze the best combination of pre-treatments to obtain microalgae lipid for biodiesel. The utilization of different cell disruption methods, including sonication and microwave, combined with pH variation (3, 5, 7) was implemented on microalgae Nannochloropsis sp. The experiment shows cell disruption with sonication and combined with low pH 3 of oil extraction from Nannochlorpsis sp. resulted in the highest yield of oil content (1.15% gr/gr dry weight). The lipid extracted from each pH pre-treatment were analyzed using GCMS for its fatty acid profile. The best pretreatments combination was obtained from lipid extraction from pH 5 and sonication-assisted method.
Comparison of microplastic abundance in aquaculture ponds of milkfish Chanos chanos (Forsskål, 1775) at Muara Kamal and Marunda, Jakarta Bay
Authors: Priscilla V , Patria M P
Published: December 2019

Jakarta contributes to 12% of the plastic pollution in Indonesian waters. Most of the plastic trash is mismanaged and end up accumulating in river mouths located along Jakarta Bay. This research analyzed the abundance and types of microplastic in milkfish Chanos chanos, surface water, and sediment of milkfish aquaculture ponds in Muara Kamal and Marunda, Jakarta Bay. Samples of each subject were obtained from each location. Digestive tracts extracted from milkfish were destructed with strong nitric acid. Water samples were filtered while sediment samples were dried. Concentrated NaCl solution was used to achieve microplastic flotation. Counting of particles was done under a light microscope. Overall results from Muara Kamal showed the microplastic abundance was 9.58±3.3 particles g−1 in milkfish digestive tracts, 103.8±20.7 particles L−1 in water, and 111,680±13,204 particles kg−1 in sediments. Microplastic abundance was found lower in samples from Marunda with 8.80±2.7 particles g−1 in milkfish digestive tracts, 90.7±17.4 particles L−1 in water, and 82,480±11,226 particles kg−1 in sediments. These results were consistent with the water pollution levels obtained by the Living Environment Agency DKI Jakarta that states heavier pollution by Pollution Index in Muara Kamal drain than in Marunda drain.
Characterization of aquatic plant (Egeria densa) pre-treated by alkaline hydrogen peroxide
Authors: Hardiningtyas S D , Aziz F , Santoso J , Uju
Published: December 2019

Egeria densa is an aquatic plant growing very rapidly in freshwater. It is very potential as a lignocellulose source to produce bioethanol. However, the challenge of bioethanol production from lignocellulose biomass is the difficulty of hydrolyzing lignocellulose because cellulose in biomass is blocked by lignin and hemicellulose, and it has high crystallinity. To overcome the problems, pre-treatment process is absolutely required. The objectives of this study were to characterize the chemical compound of Egeria densa and to evaluate the effect of concentration, temperature and time pretreatments of alkaline hydrogen peroxide (AHP) on yield, physical and chemical structures of Egeria densa. Dried biomass of Egeria densa contained 35.47±0.77% of hemicellulose, 13.56±0.61% of cellulose, and 13.58±0.22%; of lignin. The yield and lignin content of pretreated E. densa decreased with increasing H2O2 concentration, temperature and time of pretreatment. In addition, the structure of pretreated E. densa became smoother compared with its untreated. The structure of cellulose was changed after pre-treatment, from the crystaline to more amorphouse form. Alkaline hydrogen peroxide pre-treatment also could produce simple sugar, such as glucose, maltose and arabinose, which important for bioethanol conversion.
Performance analysis of small pelagic fishing unit in Tawang fishing port, Kendal Regency
Authors: Prasetiyo S L , Baskoro M S , Yusfiandayani R , Pahlevi R
Published: December 2019

Kendal Regency holds relatively large potential, especially small pelagic fisheries. One of the main bases of the capture small pelagic fisheries industry is Tawang fishing port (PPP). However, many fishermen still use mini trawl that can cause problems related to fish resources, social and environmental. The purpose of this research was to determine the best type of small pelagic fishing unit from technical, environmental, socio-economic and financial aspects in PPP Tawang, Kendal Regency. The research method used was a survey method using descriptive and scoring analysis. The sampling method used was purposive and snowball sampling. Based on the analysis, it was found that the purse seine gets priority I with a value of 12.27, priority II pelagic danish seine with a value of 11.87 and priority III of gillnet with value of 9.67. In conclusion, purse seine is the best small pelagic fishing unit in PPP Kendal.
Preliminary study: paired clownfish (Amphiprion sp.) spawning pattern in indoor rearing system
Authors: Sahusilawane H A , Junior M Z , Suprayudi M A , Soelistyowati D T , Tumbelaka L I T A , Effendi I
Published: December 2019

Amphiprion sp. is known as the most popular tropical marine ornamental fish with unique colours and sequential hermaphroditic, social hierarchy and monogamous characteristics. Information on the spawning pattern of clownfish is very important. The purpose of this study was to evaluate the spawning patterns of Amphiprion sp. in indoor rearing system. Observations of spawning patterns were conducted for 14 days in paired of clownfish reared in aquarium sized 40×40×30 cm3 with running water system. The results showed that maturation process in female started with the appearance of swollen abdomen and extended oviduct from the genital hole of female, then parent pair fish together cleaned the egg laying area, and spawned at 13.00-16.00. Spawning occurred on the fourth day to the seventh. The eggs were incubated for one week. During the incubation period, egg colour changed from orange on the first day to silver eye on seventh day, and the eggs hatched at 18.00-20.00 on eighth day. The spawning pattern of clownfish in indoor system is highly determined by time and environmental conditions.
Characterization of ammonium sulphate fraction of pepsin from fish stomach
Authors: Sholeh M M , Ambarsari L , Nurcholis W , Nurhayati T
Published: December 2019

Pepsin is one of the digestive enzymes often used in various fields, especially for industry. Pepsin can be isolated from fish viscera. This study was aimed to obtain the source of pepsin having high activity and the characteristics of the pepsin. Fish used in this study including tuna, Hemigaleus balfouri, skipjack, and cob. Pepsin was purified using ammonium sulfate. The results showed that pepsin from tuna and H. balfouri had the highest activity. The activity of the purified pepsin as 101,061 AU/mg. The pepsin worked in a temperature range of 40-60 °C and pH 2 having activity up to 9,000 AU mL, and 9,800 AU/mL, respectively.
Accumulation of lead (Pb) on fish caught by millennium gillnets (ply) in Musi estuary, Banyuasin waters, South Sumatera, Indonesia
Authors: Agustriani F , Purwiyanto A I S , Putri W A E , Fauziyah  , Suteja Y
Published: December 2019

Millenium gillnet (ply) fishing gear began operating in the coastal waters of Banyuasin in 2016. This tool is a government alternative to replace trawl fishing gear. The catches obtained include economic fish. The study was aimed to analyze the accumulation of lead on fish caught by millenium gillnet (ply) in Musi estuary. Fish were obtained from fishing ground fishermen. The samples taken were fish organs (gills, gastric contents and fish meat) then the samples were reconstructed using HNO3 and analyzed by atomic absorption spectrophotometer (AAS). The results showed that Pb accumulated in all types of fish caught using ply in Musi estuary coast and the amount exceeded the safe consumption limits applied by FAO, BPOM, and several countries. Overall, there is a tendency for the highest Pb metal accumulation in gills organs.
Distribution and abundance of the arfak rainbowfish, Melanotaenia arfakensis Allen, 1990 in Prafi River system, Manokwari, West Papua: due to habitat degradation?
Authors: Manangkalangi E , Rahardjo M F , Hadiaty R K , Hariyadi S , Simanjuntak C P H
Published: December 2019

Arfak rainbowfish, Melanotaenia arfakensis, is one of the freshwater endemic fish in Manokwari, West Papua. The presence of the Arfak rainbowfish is currently experiencing many disturbances related to anthropogenic activities. This research, therefore, was conducted to describe habitat condition, distribution and abundance of the Arfak rainbowfish in the Prafi River system spatially. This study was conducted for 12 months on 12 sites in Nimbai and Aimasi Streams, the Prafi River system. The results showed that this species was mainly distributed in the upper reaches of the Nimbai and the Aimasi streams based on the frequency of occurrence (>90.9%) and relative abundance (≥25.5%). The lower fish occurrence and abundance was found at site of the sewerage and downstream. The highest value of the habitat utilization overlap index between Arfak rainbowfish and alien fish species was found in lower reaches. Decreasing habitat quality in lower reaches of the river causes limited distribution and decline in abundance of this species. To conserve this endemic fish population, it is necessary to maintain habitat condition in the upstream area and restore the damaged habitat in lower reaches of the Prafi River system.
Coral recruitment on concrete blocks at Gosong Pramuka, Kepulauan Seribu, Jakarta
Authors: Subhan B , Hudhayani N N , Ervinia A , Santoso P , Arafat D , Khairudi D , Soedharma D , Dhere R M , Madduppa H
Published: December 2019

The current research was conducted to study the coral recruitment on concrete blocks at Gosong Pramuka, in Kepulauan Seribu. The concrete blocks were observed based on the wave exposure, i.e. the exposed area and sheltered area. A total of 247 coral recruits colonies was recorded on concrete substrates in Gosong Pramuka. The number of coral colonies in the exposed area (210 colonies) was higher than in the sheltered area (37 colonies). Coral recruit density in the exposed area was 1.37 colony/m2 and in the sheltered area was 0.23 colony/m2. A total of four genera was observed in these areas (Acropora, Porites, Montipora, and Pavona). The branching Acropora colonies were predominant for both areas, while encrusting non-Acropora was primarily found in the exposed area and massive non-Acropora was the major colonies in the sheltered area. The coral size of branching and encrusting Acropora in the sheltered area was significantly bigger than in the exposed area (P <0.05). In the exposed area, corals are found in the center of the concrete, but in the sheltered area, they are located in the corner and the edge of the concrete.
Antibacterial activity of sea cucumber (Holothuria atra) against Pseudomonas aeruginosa
Authors: Sukmiwati M , Ilza M , Putri A E , Sidauruk S W
Published: December 2019

Sea cucumber (Holothuria atra) is one of the bioresources that has not been utilized optimally. This marine animal contains potentially bioactive compounds, therefore it can be used as an alternative by fishery products processing industries. This study was aimed to determine the potential of the bioactive compound in sea cucumber and to determine the antibacterial activity of sea cucumber against Pseudomonas aeruginosa. Experiments were carried out using diffusion method with concentration 0.50, 0.75, 1 mg/disc. The results showed that methanol extract of sea cucumber contained terpenoids, saponins, and phenolic. The diameter of methanol extract inhibition zone at 1 mg concentration of 12.25±0.05 mm and of three types of fractions used hexane fraction had a more dominant antibacterial potency with diameter inhibition zone at 1 mg concentration of 14.61±0.02 mm. Based on the results of research that the methanol extract and hexane fraction of sea cucumber has potential as an antibacterial.
Characteristic of carrageenan Eucheuma cottonii collected from the coast of Tanjung Medang Village and Jaga Island, Riau
Authors: Diharmi A , Rusnawati  , Irasari N
Published: December 2019

Carrageenan is a group of polysaccharides extracted from red seaweed. Carrageenan extraction can be done by several methods, one of which is alkaline solution (KOH) because KOH produces a stronger gel than other alkalis. Carrageenan was extracted using hot alkali followed by precipitation, drying, and milling. The purpose of this study was to determine the chemical composition of dried E. cottonii from North Tanjung Medang Village and Jaga island coastal sea regions and physico-chemical characteristics of carrageenan extracted with KOH solutions 4, 8 and 12%. The results of analysis showed that the chemical composition of dried E.cottonii of both costal sea regions not significant. The chemical characteristics of carrageenan from Tanjung Medang Village and Jaga Island using KOH 4, 8, and 12%, were moisture (11-8%), ash (27-36%), acid-insoluble ash (1.66-2.0%), and sulphate content (24-29%), those not significant all carrageenan except ash content. Whereas the physical characteristics of both carrageenan were significantly different. The results of this study indicated that the carrageenan extracted with KOH (4.8, and 12%) has similar physico-chemical characteristics except for gel strength, viscosity, and ash content.
Characterization and formulation of sunscreen from seaweed Padina australis and Euchema cottonii slurry
Authors: Nurjanah  , Suwandi R , Anwar E , Maharany F , Hidayat T
Published: December 2019

Exposure of UV light can cause skin rashes and sunburn, stimulating the formation of melanin. Long term UV exposure also can cause skin cancer. One way that can reduce negative impact of UV exposure is by using sunscreen. The aims of this study were to obtained the best ratio of seaweed P. australis and E. cottonii slurry to produce sunscreen cream and as well as obtaining sunscreen formulation with good stability. Creams were formulated consist of cream with different ratio of seaweed P. autralis and E. cottonii slurry, i.e. A (control), B (1:1), C (2:1) and D (1:2). The commercial creams product also used as a comparator (KI and KII). The best ratio of P. australis and E. cottonii slurry was showed on cream B (1:1). Sunscreen creams have a good level stability, with no phase separation of dispersant and dispersed phase, and also no discoloration. Sunscreen creams have at least 1 year shelf life as there was no phase separation after centrifugal force at 3,800 rpm for 5 hours.
Collagen peptides from Pangasius fish skin as antioxidants
Authors: Azizah N , Ochiai Y , Nurilmala M
Published: December 2019

Fish skin can be extracted and hydrolyzed into collagen peptide to enhance the antioxidant activity. The research objectives were to determine the characteristics of collagen peptides from pangasius fish skin as antioxidants. The fish skin was extracted and hydrolyzed using 2% Alcalase and fractionated using a molecular sieve membrane. The gelatin yield was 15.07±1.45% against the starting material. The pH value of gelatin was 4.76±0.02. SDS-PAGE showed β band 221.3 kDa, α1 band 137.1 kDa and α2 band 117.7 kDa. The hydrolysis of gelatin resulted in the degree of hydrolysis of 48.06±1.97% with Alcalase at 55°C for 180 min. The total antioxidant activity (TEAC) was calculated with ABTS assays. The TEAC values were 24.53±0.78 μmol TE/g for the gelatin, 44.40±0.13 μmol TE/g for the peptides, 45.07±0.12 μmol TE/g for the >30 kDa fraction, 45.85±0.04 μmol TE/g for the 10-30 kDa fraction, 45.93±0.04 μmol TE/g for the 3-10 kDa fraction, and 45.98±0.04 μmol TE/g for the <3 kDa fraction.
Identification and characterization of solid waste from Gracilaria sp. extraction
Authors: Basmal J , Munifah I , Rimmer M , Paul N
Published: December 2019

The identification and characterization of chemical composition of solid agar extracted solid waste were carried out. The method used was to take samples randomly in several seaweed processing industries to analyze their chemical composition. The parameters tested included the micro-nutrient and macro-nutrient content, growth-stimulating hormone level, and ash contents. The results showed that solid waste from agar extraction consist of micronutrients such as: Cu (4.80 ppm), Fe (0.24 ppm), Zn (8.42 ppm), Mn (57.58 ppm), B (32.32 ppm) as well as the macronutrients such as: N (0.20%), P (0.12%), K (0.17%), C-organic (10.96%), Na (0.66%), Ca (0.61%), Mg (0.09%), CEC (13.5 me/100g), and N/C ratio of 54:7. Growth hormones auxins (191 ppm), gibberellin / GA3 (509.5 ppm), cytokinin-kinetin (244.5 ppm) and cytokinin-zeatin (70.5 ppm). The ash content was 60.19%, a slightly acidic pH of 6.3, diluted in cold water (11.67%) and hot water (23.17%) as well as in 1% sodium hydroxide solution (35.32%). Based on the results of identification and characterization, the solid waste of agar extraction was useful as a raw material for plant fertilizer.
The ratio of native and alien fish species in Buyan and Tamblingan lakes, Bali
Authors: Pertami N D , Tampubolon P A R P , Parawangsa I N Y , Persada P R G , Manangkalangi E , Syafei L S
Published: December 2019

Buyan and Tamblingan lakes were often mentioned as twin lake because of its adjacent location. These two lakes were separated by approximately one-kilometer forest. Studies which recorded the fish species in those lakes were very limited so that a study was needed regarding that conditions as the initial step of management. This study aims to reveal and analyze the ratio of native and alien fish species which were found in Buyan and Tamblingan lakes, Bali. The fish sampling was held three times in different months at Buyan and Tamblingan lakes during 2017-2018, using a purposive sampling method. There were six locations sampling fish on each lake. It used experimental gill net with mesh size 0.5; 1.0; 1.5; 2.0; 2.5; 3.0; 3.5; 4.0 inches and trap. Three of the nine species that found in Buyan and Tamblingan lakes were native fish species. The ratio of native and non-indigenous fish caught in Buyan lake was bigger than from Tamblingan lake. Based on the length size of the most captured fish, the native fish of Osteochilus vittatus in Buyan lake was longer than Tamblingan, while the non-indigenous one, Poecillia reticulata had the same length size on the two lakes.
Characterization of refined carrageenan from Kappaphycus alvarezii extracted using marine fungi
Authors: Sulistiawati S , Ain N H , Uju  , Tarman K
Published: December 2019

Carrageenan is a polysaccharide that widely used in food, pharmaceutical, cosmetic, textile and printing industries as a coagulate agent, stabilizer, and gelling agent. The extraction of carrageenan usually is carried out by alkali treatment, but it may have toxic effect for the environment. Therefore, another extraction method is required to reduce the toxic effect from carrageenan. Carrageenan can also be extracted by using a cellulolytic enzyme. A natural cellulolytic enzyme can be produced from endophytic fungi. The objective of this research was to extract carrageenan using endophytic fungal cellulase and to evaluate the effect of fungal cellulase concentration and extraction time on the quality of carrageenan. The materials used in this research were marine endophytic fungus (EN) and dried seaweed Kappaphycus alvarezii. This research was conducted in three steps. The first step was cultivating of endophytic fungus (EN) in cellulose basal medium. The second step was cellulase extraction from endophytic fungus EN. The last step was extraction of carrageenan by cellulase endophytic fungus. The highest yield was obtained by added 1% of EN cellulase enzyme and extraction period for 3 hours. Characteristics of carrageenan in generally met the standard, but the gel strength and whiteness was still below the standard.
Application of end-point PCR technique to detect bacteria encoding tyrosine decarboxylase (TDC) gene in scombridae fish
Authors: Abdullah A , Nurilmala M , Budiarti A S
Published: December 2019

Tuna, little tuna, and skipjack can form tyramine from decarboxylation of tyrosine by tyrosine decarboxylase (TDC) enzyme. High tyramine level in fish could cause toxicological effects. Early detection of the tyramine-forming bacteria by using DNA-based methods is needed for seafood safety assurance because it is more sensitive, specific, and faster. This study was aimed to obtain bacterial isolates, detection of TDC and 16S rRNA genes and identifying species of bacteria that encode TDC and 16S rRNA genes. The methods of this study included several steps including bacterial cultivation, DNA isolation and amplification of TDC and 16S rRNA gene markers as well as sequencing of amplicons. Bacterial DNA isolates were successfully obtained from samples by cultivation method. The TDC gene was successfully amplified and identified as belong to Carnobacterium genus, whereas the 16S rRNA gene belong to Enterobacter tabaci, E. hormaechei, Escherichia marmotae, and Peptoniphilus genus. The DNA-based method targeted tyrosine decarboxylase gene can be applied for early detection of biogenic amine accumulation in fishery products.
The effect of bait types on the catch of foldable dome fishing pots operated in Tuban regency
Authors: Ningtiyas SR , Rachman F , Setyobudi E , Djumanto  , Djasmani SS
Published: December 2019

Foldable dome fishing pots are commonly used by fishermen in Tuban regency. A concern regarding that gear is the availability of trash fish as the common bait. Alternatively, chicken innard produced from local poultry industry could be used to substitute the bait due to its abundance. The purpose of this study was to compare the effect trash fish and chicken innard on the catch of the foldable dome fishing pots. The study was conducted in 10 days experimental fishing in October-December 2018 in Socorejo Village, Jenu District, Tuban regency, East Java, using 60 units of pots. The bait was placed in the middle of the pot. The catch were grouped based on types of bait. The length (cm), width (cm) and weight (gr) were measured for each type of fish or crab caught in the pots. Data were analyzed using t-test. The total catch of pots during the study consisted of octopus, fish, swimming crabs, other crabs, shellfish, snails and shrimp. The t-test shows that there is no significant effect between different baits on the catch of foldable dome fishing pots.
Quality of brine boiled Indian mackerel (Rastrelliger sp.) with different cooking methods and additions of liquid smoke
Authors: Pertiwi M D , Swastawati F , Amalia U
Published: December 2019

Indian mackerel (Rastrelliger sp.) is an important commodity and widely processed into brine boiled fish involving salt in the process. Improper cooking process could reduce nutritional value including amino acids lysine. This study was aimed to process brine boiled fish with two different methods. Effects of concentration of liquid smoke and processing methods were evaluated. Brine boiled fish with the addition of 5% liquid smoke with steaming and boiling methods had higher levels of lysine (0.12% and 0,05% compared to brine boiled fish 0%). Brine boiled fish with the addition of 5% with steaming and boiling methods had higher levels of dissolved protein which were 0.08% and 0.06% compared to brine boiled fish 0%. Brine boiled fish 5% with the steaming method produced lower moisture content i.e 1.82%, and 1.18% compared to brine boiled fish 0%. The best quality brine boiled fish was obtained with the steaming method and the addition of 5% liquid smoke, produced 0.56% of lysine content, 0.65% of dissolved protein content and 72.43% of moisture content, and organoleptic value was 7.51 < µ < 7.99.
Potential risks of tuna fishing conducted in Indonesia’s waters and its impact on tuna and shark
Authors: Sadiyah L , Satria F , Hargiyatno I T , Widodo A A
Published: December 2019

Bigeye tuna (BET), yellowfin tuna (YFT) and skipjack tuna stocks in the Pacific Ocean, in general, are underfished. However, according to Western and Central Pacific Fisheries Commission (WCPFC) who is mandated to assess the fishing impact on tuna and bycatch, the fishing impact on BET juveniles (including from Indonesia) were identified as high level impact. Productivity-susceptibility analysis (PSA) was used to assess the risk of tuna and sharks. The objectives of this study were to identify the types of tuna fisheries operated in Indonesias water (FMAs 713-715) which harm tuna and sharks species. Result shows that tuna was mainly caught by purse seine, pole and line, and longline. Purse seine fishing has a higher impact than the pole and line and longline fishing. Blue shark, hammerhead shark and silky shark in particular whale shark were at risk due to purse seine fishing, without proper management. Information regarding their niches and seasonal migrating patterns are required for further studies.
Preliminary uncertainty analysis in fisheries – the case of two fisheries in Indonesia
Authors: Adrianto L , Aprilyanti D , Sitohang R M , Nurokhmah I
Published: December 2019

Fisheries is a complex system which comprises two coupled and irreversible systems namely ecological system and social system. Moreover, these two systems have structural and functional integrity in which social or human system is part of ecological systems. Consequently, dynamics of these systems in the context of structural and functional interactions are high. In fisheries, this dynamics of interactions between intra and extra systems create uncertainty. This paper was aimed to explore the use of preliminary uncertainty analysis (PUA) in fisheries management in Indonesia using the comparison between two fisheries i.e. blue swimming crab fisheries and hairtail fisheries. From this paper we can reveal that magnitude of uncertainty in ecological system are lower than social/human system. In this regards a systematic ecosystem approach to fisheries management should be functionally adopted.
Increasing economic value of mondol and thorn stingray skin through the processing of commercial leather creative products
Authors: Sahubawa L , Pertiwiningrum A
Published: December 2019

The aim of the study was to compare the total economic value, added-value, consumer preferences and the superiority of commercial products developed from mondol and thorn stingray skins. The stingray skins were processed into wallet and women products and this processing increased the value of mondol and thorn sink up to 1,650,000 and IDR 2,300,000, respectively. Survey on customer preferences found that the model, colour, quality, price and purchasing power of commercial products from thorn stingray more preferred than those from mondol stingray. In conclusion, the commercial products from thorn stingray skin is better than those from mondol stingray.
Physiological response and quality of red tilapia Oreochromis sp. in the culture system using lemna (Lemna perpussila) as phytoremediator
Authors: Nirmala K , Widia L , Hastuti Y P , Nurussalam W , Fauzi I A
Published: December 2019

This study used Lemna as phytoremediator plant in red tilapia culture system and given as feed additive among treatments. The purpose of this study was to measure the production performance (quantity and quality) and physiological response of red tilapia. Study was conducted with two treatments: TL (without lemna) and L (with lemna) treatment. The results showed that L treatment gave the best result based on better feed convertion ratio. However there are no significant difference found in organoleptic test, growth performance, and blood cholersterol parameters. In addition, optimum water quality media that stimulated by lemna, can create a comfortable environmental conditions for red tilapia.
Evaluation of physiological responses and production performance of spiny lobster with different density treatments in floating net cage
Authors: Supriyono E , Lesmana D , Nirmala K , Adiyana K , Setyawidati N A R
Published: December 2019

The weak in survival rates and low productivity of spiny lobster are influenced by stock density. Thus it is necessary to find the optimum stock density to minimize stress levels and increase productivity. This study was consisted of 2 treatments, consisting of a 25 individuals/m2 and 50 individuals/m2 with a sheltered environment. The research analysis used descriptive analysis. The lowest stress levels was found in treatment of 25 lobsters/m2 (cortisol 1.17±0.14 nmol/L and glucose level 8.34±0.5 mg/dL) and the highest weight gain (26.29±1.69%) as well as the specific growth rate (0.77±0.014%). However, the highest value of survival rate of spiny lobsters (95±0.03%) with lowest specific growth and weight gain was found in 50 lobsters/m2 treatments.
Experimental investigation of the passive control of unsteady cloud cavitation using miniature vortex generators (MVGs)
Authors: Kadivar Ebrahim , Timoshevskiy Mikhail , Pervunin Konstantin , Moctar Ould el
Published: December 2019

The research is aimed at the study of a passive control method to control unsteady cloud cavitation that is characterized by regular shedding of large vapour structures from the solid surface of a cavitating immersible body. The unsteady cloud cavitation is an important subject of research because of its destructive impacts in various industrial applications, including ship propellers and rudders, pumping and hydraulic machinery systems. For this, we placed miniature vortex generators (MVGs) of a cylindrical type on the surface of a benchmark CAV2003 hydrofoil and investigated effects of these MVGs on the spatial structure of unsteady cavitation clouds. We analyzed the temporal and spatial cavity characteristics in comparison with those for the original hydrofoil (without MVGs) by means of high-speed imaging. In addition, we used a hydrophone to register the signal of pressure pulsations in time and thereby derive power spectra of the pressure pulsations. The results showed that the implemented cavitation control method is an effective tool to manage the unsteady behaviour of cloud cavitation and to mitigate the amplitude of pressure pulsations. It was revealed that, with this control approach, the large-scale cavitation clouds appear to be broken and only small-scale cavity structures are shed away from the hydrofoil surface. Moreover, a notable reduction in the cavitation-induced vibrations of the solid surface may be expected.
Vibration and acoustic emission monitoring of a centrifugal pump under cavitating operating conditions
Authors: Mousmoulis G , Yiakopoulos C , Kassanos I , Antoniadis I , Anagnostopoulos J
Published: December 2019

Centrifugal pumps are widely used in industry and cover a significant percentage of the total energy consumption of a power plant. This fact makes the application of efficient maintenance tools to be of crucial importance and obliges researchers and engineers to develop reliable detection methods for special types of malfunction, such as cavitation. Cavitation is a hydrodynamic mechanism that affects the steady and dynamic operation of a pump and is usually responsible for its head and efficiency reduction, as also for premature wear and destruction of the impeller. The stochastic nature of the phenomenon and the complex flow characteristics, as well as the noise from the mechanical components of the pump complicates the detection of cavitation. For this reason the use of several sensors in combination with advanced signal processing techniques is often proposed for the successful identification of two phase flow in the signal obtained. In this study, a radial centrifugal pump is tested under various flowrates in order to derive its cavitation characteristic curves. At the same time, the signal obtained from various vibration and acoustic emission sensors is recorded. The sensors are located at the rolling bearings that support the overhung impeller, and close to the suction of the pump, where the static pressure takes its minimum value. Subsequently, by processing the digitized signals of all noise and vibration measurements both in time and frequency domains, it is possible to identify the appearance of cavitation. Finally, the results show that the position of the sensor and the acquisition characteristics undoubtedly affect the detection of cavitation.
Troubleshooting of Von Karman Induced Penstock Protection Valve Resonance at FMHL+
Authors: Nicolet C , Alligné S , Furrer M , Fischer D , Grognuz J , Chène O , Valluy B
Published: December 2019

The FMHL power plant was originally a 240 MW pumped-storage power plant in Switzerland, put in operation in 1971 which installed capacity was extended to 480 MW in 2016 with maximal output power set to 420 MW including 60 MW as reserve. The significant increase of the total discharge of the power plant in generating mode from 32 m3/s at 240 MW to 57 m3/s at 420 MW might be critical due to the higher flow velocity throughout the different safety valves of the power plant. During commissioning, the discharge was increased stepwise from 32 to 57 m3/s while monitoring the vibration of the safety valves. Significant vibration amplitudes have been recorded at a frequency of 62.5 Hz on the penstock protection valve for a discharge of 43 m3/s. Von Karman vortex shedding induced resonance on the stiffener of the bi-plan valve obturator was then suspected. The paper presents troubleshooting of this resonance problem, where CFD and FEM investigations have been performed to define appropriate trailing edge modifications of the obturator stiffener plates able to significantly reduce the Von Karman dynamic lift coefficient and thus reduce drastically vibration amplitudes.
Axial check valve behaviour during flow reversal
Authors: Himr Daniel , Habán Vladimír , Závorka Dalibor
Published: December 2019

An ideal check valve is supposed to have a zero pressure loss when the flow rate direction is positive and a negative flow rate is not possible. A real check valve has a low pressure loss and it is possible to suppress negative flow (especially when the check valve is new) under steady conditions. The transition between the steady positive flow and zero flow is often connected with a water hammer, here called check valve slam. An experimental investigation of behaviour of the axial check valve disc during the flow reversal is described in this paper. A high-speed camera was used for the disc position observation and pictures are compared with pressure pulsations and the flow rate.
Dynamic response analysis of powerhouse under turbine pressure pulsation with different distributions and application methods
Authors: Ma Z Y , Ran Y C , Zhang H Z
Published: December 2019

Hydraulic excitation oriented from the turbine is one of the main sources of vibration for hydropower plants. Under different operation conditions, the amplitude, frequency and phase of pressure pulsation are different. The pressure pulsation of spiral case belongs to non-stationary waves, including traveling waves and standing waves. In this paper the pressure pulsation distribution characteristics of the spiral case were discussed and two kinds of distributions were assumed. The dynamic response of the powerhouse structure was simulated with FEM model through harmonic response analysis and transient dynamic analysis and the sensitivity of the pressure behaviour on the structure’s response were presented. The time history responses were also calculated under different turbine loads with different amplitude and frequency. The conclusion is that the structure dynamic responses under the traveling or standing waves are all greater than that with uniform assumption. So the distribution characteristics of pressure pulsation should be reasonably simulated to the dynamic analysis of the concrete structure.
Numerical study of the Winter-Kennedy method for relative transient flow rate measurement
Authors: Baidar B , Nicolle J , Gandhi B K , Cervantes M J
Published: December 2019

The Winter-Kennedy (WK) method is used to estimate relative flow rate using the differential pressure between two taps located at a radial section of a spiral casing (SC). It is widely used in index testing, for double regulated turbines optimization and sometimes for continuous discharge measurement in low head plants. This paper explores the possibility of using the WK method for relative transient flow rate measurements.

A numerical model of a Kaplan model turbine from the penstock to the distributor has been developed. Unsteady RANS simulations with k-ω SST turbulence model are performed. Previously conducted experiments on the model turbine are used to validate the numerical results. In the simulations, the guide vanes (GVs) are closed from 26.5°, the best efficient point (BEP), to about 5° opening angle. Two azimuthal locations of the SC and four different WK configurations at each location are considered. The variation of the WK coefficients with time are investigated and compared to the ones at several stationary GV angles. The results showed a difference between the WK coefficients obtained at transient and stationary operations. However, there may be a possibility of using the WK method during transients by locating the pressure taps in appropriate locations for an acceptable variation of the WK coefficient from its BEP value.
Simulation of stochastic pressure loads on a medium head Francis runner
Authors: Morissette J F , Nicolle J
Published: December 2019

In recent years, major advances have been made in simulating dynamic and transient flows in hydraulic turbines. Overall, computational fluid dynamics (CFD) and finite element analysis (FEA) simulations have been quite successful and have helped to advance knowledge beyond the best efficiency point. The simulation of transient operations like startup and runaway has nearly become part of the standard toolbox. However, numerically predicting stochastic flows, such as those occurring during speed-no-load (SNL) regime, remains a challenge. Since these flows can have a significant impact on turbines’ life expectancy, CFD methods need to be improved. In this paper, we examine the SNL regime in a Francis turbine in which extensive dynamic fluctuations were measured. The approach used was to first focus on the CFD methodology required to better predict stochastic pressure loads with hybrid turbulence models such as the Scale-Adaptive Simulation–Shear-Stress Transport (SAS-SST) model and the relatively new Stress-Blended Eddy Simulation (SBES) model. This will then allow us to determine the amount of LES content required to accurately predict large-scale turbulent structures and the corresponding pressure fluctuations that they generate on blades.
Analysis of a propeller turbine operated in a full load operating point
Authors: Junginger Bernd , Riedelbauch Stefan
Published: December 2019

A full load operating point of a propeller turbine is investigated both numerically and experimentally. Steady state and unsteady flow simulations, using four different turbulence models with grid sizes up to 100 million elements, are validated with experimental results which are performed according to IEC 60193 standard. Due to the high swirl number of S = -0.175 at the runner outlet, steady state and unsteady RANS simulations are no longer capable to predict the correct flow field in the draft tube of the turbine. Hence, unsteady simulations with scale-resolving turbulence models, are performed. As a result of the high swirl a full load vortex rope is generated starting at the runner hub developing in the center of the draft tube. The integral quantities head and torque as well as the axial and tangential velocity components at five evaluation lines in the draft tube are validated with experimental results. Velocity components are both time- and phase-averaged, using the runner as trigger signal. Additionally, a comparison of local quantities, head loss in the draft tube and the pressure recovery factor is carried out. The turbulence quantities of the different approaches are evaluated at the evaluation lines applying the viscosity ratio or energy spectra at discrete points in the draft tube of the turbine.
Numerical investigation of solutions to suppress the inlet vortex of an existing booster pump
Authors: Decaix J. , Gaspoz A. , Fischer D. , Münch-Alligné C.
Published: December 2019

The study focuses on a booster pump used to feed the main pump of one unit of the FMHL hydropower plant (Veytaux I). From the beginning of the operation of the power plant, vibrations have been observed on this booster pump with sometimes the presence of cavitation erosion. The visualisations carried out show that a cavitating vortex develops at the suction side of the booster pump runner and causes the measured vibrations. The booster pump is running without any modification since the beginning of the operation of the power plant, however future mechanical failures cannot be excluded, since in these harsh conditions, the permissible mechanical strain shall be exceeded.

Flow numerical investigations have been carried out using OpenFOAM and shown the presence of vortices below the bell of the booster pump. The main vortex observed is assumed to be responsible for the vibrations due to its interaction with the runner blades and to promote the inception of cavitation, which could explain the cavitation erosion observed.

Several modifications of the chamber have been considered by simulation. Two of them provide a solution to suppress or at least to damp the vibrations due to the presence of vortices in the bell inlet.
Cost-effective CFD simulation to predict the performance of a hydrokinetic turbine farm
Authors: Pacot O , Pettinaroli D , Decaix J , Münch-Alligné C
Published: December 2019

After the performance assessment of a new hydrokinetic turbine prototype in the tailrace channel of a run-of-river power plant (Lavey, CH), the possibility to install a farm of such hydrokinetic turbines on this pilot site is investigated. In order to identify the optimal number and size of the machines as well as their location on this site, numerical simulations are carried out. Such a process requires to simulate a set of several free surface flow computations including different configurations of the farm in order to maximize the energy tapped by the machines. However, free surface flow computations are time and resources consuming. To allow such flow investigations, a different approach has been selected. In the present study, the turbines were replaced by a model mimicking the resistance effect of the machines. This model consists in a pressure drop applied at the turbine location to emulate the disturbance effect on the flow, especially the wake effect that will modify the available kinetic energy for the neighboring machines. Finally, it results that such a low CPU approach allows us to estimate the best location of the hydrokinetic turbines maximizing the energy harvested.