• Journal of Aquaculture
• /
• v.9 no.3
• /
• pp.233-237
• /
• 1996

A growth study was conducted to investigate the effect of stocking density on performance of juvenile fat cod (Hexagrammos otakii Jordan et Starks.). Fish averaging 13 g were stocked into duplicate tanks ($250\;{\ell}$ each) at four different densities of 330 g/$100\;{\ell},\;660\;g/100\;{\ell},\;990\;g/\;100\;{\ell}$, and $1330\;g/100\;{\ell}$, and fed MP diet containing $50\%$ frozen horse mackerel and $50\%$ commercial binder meal for 2 months. Weight gain, feed efficiency, survival rate, and protein retention were decreased as density increased. Whereas these parameters were not significantly different (P>0.01) fish stocked at initial stocking densities of $330\;g/100\;{\ell},\;660\;/g/100\;{\ell}\;and\;990\;g/100\;{\ell}$. Moisture and lipid content of whole body were not affected by stocking densities (P>0.01). These results indicate that stocking density should be considered, and $1{\~}2$ kg fish/$100\;{\ell}$ final stocking density for juvenile fat cod could be used to decrease production cost for the indoor tank (culture) system.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.12
• /
• pp.1143-1150
• /
• 2009

This study was carried out to investigate of aerobic granulation by using sequencing batch reactor(SBR). To make aerobic granular sludge in short period of time, we used polymer. In case of SBR, we have studied on physicochemical characteristics of particle size, settling velocity, surface charge, and specific oxygen utilization rate(SOUR) depending on aerobic particle's formation. The results of running SBR with $5.4kg{\cdot}COD/m^3{\cdot}d$ of COD loading rate and 20 days reaction time showed that aerobic particle size, settling velocity, SOUR, surface charge, polysaccharide/protein(PS/PN) ratio were 2.6 mm, 1.7 cm/s, $346mg{\cdot}O_2/g{\cdot}MLVSS{\cdot}hr,\;(-)0.26{\cdot}meq/g{\cdot}MLVSS$, and 2.06 mg/mg respectively.

• Korean Journal of Ecology and Environment
• /
• v.45 no.1
• /
• pp.42-51
• /
• 2012

This study investigated the characteristics of natural organic matter (NOM) with general water characteristics (pH, DO, electrical conductivity, BOD, COD, TN, TP, Chl-$a$, DOC, $UV_{254}$, SUVA) and the 3D fluorescence excitation-emission matrix (FEEM) in the Yeongsan River basin. FEEM was used to classify protein-like and fulvic & humiclike substances with fluorescence intensity in the matrix of excitation and emission wavelength. The concentration of BOD, COD, TN, electrical conductivity and DOC in the region of Gwangju city (Gwangju sewage treatment plant: GJS, Gwangjucheon: GJC, Gwangju 2: GJ2) was relatively higher than the upper reaches and lower reaches of the Yeongsan River basin. SUVA in most sites was lower than 3 L $mg^{-1}\;m^{-1}$ as the hydrophilic substances, except Damyang (DY) in the upper reaches of Yeongsan river was higher than 3 L $mg^{-1}\;m^{-1}$ as the hydrophobic substances during winter and autumn. In the FEEM investigation the fulvic and humic substances were found in most sites, and in sites regarding Gwangju city (GJS, GJC, GJ2) during winter and GJC in summer, protein-like substances were found. The trend of fluorescence intensities from the upper reaches to the lower reaches in most sites corresponded to that regarding the concentration of water characteristics (BOD, COD, TN, DOC). That is why the region of Gwangju city (GJS, GJC, GJ2) was relatively higher. This results were an equivalent trend to those of fluorescence index (FI) in most sites, and the higher FIs in the sites of Gwangju city indicate more microbial-derived substances due to enormous effluent organic matters (EfOM) from huge Gwangju sewage treatment plants.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.25 no.3
• /
• pp.5-13
• /
• 2023

This study aims to assess the water quality of the Eoran and the Imha aquafarm with different aquafarm environments in Haenamn-gun, and analyzed the composition of total amino acids (TAAs) and free amino acids (FAAs) in three Neopyropia dentata cultivars (Yuldo, Supum1 and 2) in two aquafarms. Mean water temperature ranged from 22.9 to 10.9℃ during September to November 2018. In Eoran aquafarm, the water quality analysis showed that NO₂-N was high in September, NH₄-N and COD in October, and NO₃-N, DIN, and DIP in November. In Imha aquafarm, the water quality analysis showed that NH₄-N and COD was high in September, NO₃-N and DIN in October, and NO₂-N and DIP in November. We confirmed the proximate composition, amino acid composition (TAA/FAA) in two auqufarms. In the Eoran aquafarm, the 'Yuldo' cultivar had significantly higher crude lipid content than two other cultivars (Supum 1 and 2). The 'Supum1' cultivar had significantly higher moisture content, whereas the highest content of crude protein, crude lipid, crude ash, and carbohydrates was found in the 'Supum2' cultivar. In the Imha aquafarm, the content of crude lipid and crude ash was highest in the 'Yuldo' cultivar. The highest content of crude protein and carbohydrates was found in the 'Supum1' cultivar, while the 'Supum2' cultivar had the highest content of moisture. The highest concentration of glutamic acid belong to TAAs is observed in all cultivars from Eoran and Imha aquafarm, while all cultivars in two aquafarm also contained higher content of alanine among the detected FAAs.

• Journal of Aquaculture
• /
• v.11 no.4
• /
• pp.421-428
• /
• 1998

This study was performed to determine the level of soybean meal (SM) or feather meal (FM) that could substitute for fish meal in fat cod(Hexagrammos otakii Jordan et Starks) diet. A control diet with fish meal as protein source was included. The amount of 5, 10, 15 and 20% of SM or FM substituted for fish meal in the control diet, respectively. Amino acids supplementation in the 20% SM diet was compared. In addition, combination of 5% SM, 5% corn gluten meal, 5% meat meal, 5% blood meal and 5% FM was substituted for fish meal in the control diet. Duplicate groups of the 40 fish averaging 21g were fed one of 11 isoproteic (45%) and isolipidic (15%) experimental diets to satiation twice a day for 2 months. No significant differences were found among fish fed the control, substituting up to 20% SM or 10% FM in weight gain, feed efficiency, daily feed intake, and protein efficiency ratio (P>0.05). It is concluded that SM or FM can be used as a partial substitute for fish meal up to 20% or 10% in the control diet, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.37 no.6
• /
• pp.492-497
• /
• 2004

Waste concentration and waste generation rate in seawater aquaria by common conger (Astrocongey myriaster) and olive flounder (Paralichyhus olivaceus) were investigated. The initial fish density of common conger and olive flounder were $3{\%}\;and \;2.8{\%}$ of total weight of aquarium water, respectively Wastes in the seawater aquaria, such as protein, total suspended solid (TSS), ammonia, turbidity and chemical oxygen demand (COD) increased with days after stocking. Protein generation rate of common conger increased until 1 day after stocking while that of olive flounder increased until 3 days. The average protein generation rates of common conger and olive flounder were $0.28g/kg{\cdot}day\;and\;0.21g/kg{\cdot}day$, respectively. The trends of other waste generation rate were similar to protein generation rate.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.37 no.6
• /
• pp.498-504
• /
• 2004

Removal of waste generated by Paralichthys olivaceus in the seawater aquarium using a foam separator was investigated. Protein concentration without a foam separator continuously increased until 3 days after stocking and reached at 25 mg/L after 5 days stocking, but protein concentration became lower than the initial protein concentration (2.5 mg/L) with a foam separator. The trends of other fish wastes such as ammonia, total suspended solids (TSS) and chemical oxygen demand (COD) were similar to protein. Dissolved oxygen (DO) in the aquarium decreased below 6.0 mg/L without a foam separator, but with a foam separator the average DO in the aquarium was 7.3 mg/L. Foam separation with the increase of superficial air velocity (SAV) was more effective than that with the fixed SAV. This study showed that wastewater. treatment of seawater aquarium using a foam separator is effective method for a fish waste removal and oxygen supply.

• Journal of the Korean Society of Food Culture
• /
• v.37 no.3
• /
• pp.213-238
• /
• 2022

This study aims to investigate protein consumption market trends in Korea. Protein consumption was divided according to the protein source into meat, fishery, and plant-based protein. To accomplish the goal of this study, food purchase data from 525 households panels collected by the Rural Development Administration over the last 10 years were used. The results of the study showed an increase or decrease in protein consumption by protein type over the last 10 years, and a reason to explain this change has been suggested. Specifically, this study found a dramatic increase in the consumption of several proteins, including beef sirloin, beef tenderloin, seasoned beef & steak, pork belly, pork shoulder, pork neck, seasoned pork, pork cutlet, sweet and sour pork, canned ham, chicken drumstick, chicken breast, dak gangjeong, Chinese fried chili chicken, salmon, eel, abalone, squid, octopus, webfoot octopus, octopus minor, canned whelk, tofu, cold bean soup,and plant-based milk. Some items showed no increase in consumption (such as beef jerky, pork rib, sausage, bacon, whole raw chicken, cutlass fish, oyster, fish cake, crab stick, surimi sausage,and canned fishery), whereas a few items showed decreased consumption (e.g., mackerel, pollack, cod,and canned tuna)

• Korean Journal of Agricultural Science
• /
• v.3 no.2
• /
• pp.244-250
• /
• 1976

Candida brumptii was one of the best isolates which could grow on alcohol distillation slops (reported in the previous paper). Attempts were made to investigate the cultural conditions for cell mass production by this strain, and the results obtained were as follow. The supernatant of the alcohol distillation slops without dilution support ed better growth of the strain than diluted ones. The addition of ammonium sulfate (0.2%), ammonium phosphate (0.1-0.2%), potassium phosphate (0.2%) to the supernatant resulted in positive effects for the growth, among the various inorganic nitrogen and other salts supplements. BOD and COD of the supernatant were reduced approximately 30% and 20%, respectively in 3 days culture. Cell production was maximized when grown at $35^{\circ}C$ and pH 5.0. The yield of cell mass was 1.03% by dry weight and its crude protein content was about 52.65%

• Journal of Korean Society on Water Environment
• /
• v.23 no.6
• /
• pp.863-871
• /
• 2007

Spectroscopic characteristics of river water from four major watersheds in the Ulsan area were measured to examine their potential for estimating water quality parameters. The total 176 river samples were collected from 44 sites of small streams within the watersheds during the year 2006. Spectroscopic characteristics investigated included protein-like fluorescence (FLF) intensity, fulvic-like fluorescence (FLF) intensity, terrestrial humic-like fluorescence (TLF) intensity, UV absorbance at 254 nm, and UV absorbance difference at 220 nm and 254 nm. Protein-like fluorescence intensity showed linear relationships with biochemical oxygen demand (BOD), chemical oxygen demand (COD), total phosphorous (TP) concentrations of the samples with the correlation of 0.784, 0.779, and 0.733, respectively. Due to the UV absorption characteristics of nitrate at 220 nm, UV absorbance difference at 220 nm and 254 nm was selected to represent total nitrogen (TN) concentration. Exclusion of some samples with PLF intensity higher than 5.0 improved the correlation between the UV absorbance difference and TN as demonstrated by the increase of the correlation coefficient from 0.392 to 0.784. Instead, for the samples with PLF intensity lower than 5.0, the highest correlation of TN was achieved with UV absorbance at 254 nm. The results suggest that PLF intensity could be used as the estimation index for BOD, COD, and TP concentration of river water, and as the primary screening index for the prediction of TN using UV absorbance difference. Some BOD-based water quality levels among the river water were statistically discriminated by the PLF intensity. Low p-values were obtained from the t-tests on the samples with the first level and the second level (p=0.0003) and the samples with the second and the third levels (p=0.0413). Our combined results demonstrated that the selected spectroscopic characteristics of river water could be utilized as a tool for on-site real-time monitoring and/or the primary estimation of water quality.