• The Journal of Fisheries Business Administration
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• v.43 no.2
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• pp.79-94
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• 2012

The purpose of this study is to investigate the production efficiencies of the Korean aquaculture fishery with respect to species and methods using a Data Envelopment Analysis. The study extracted the 8 fishes in each of the sea cage culture, aquarium basin, and enclosed aquaculture for the analytical purposes. First, the study estimated the technical, pure technical, and scale efficiencies of the total of 24 aquaculture fishes based on the traditional DEA under the assumptions of both CRS and VRS. 2 fishes were identified as the efficient DMUs under the CCR-model, and 6 fishes under the BCC-model. Second, we tested to see if there was any difference in production efficiencies regarding those three different methods of aquaculture. we could not find any evidence of the differences in efficiency using a rank sum test based on the traditional DEA. However, we could do find that the pure technical efficiency in the sea cage culture was lower than others at 1% level of significance and the pure technical efficiency in enclosed aquaculture was also lower than others at 5% level of significance using Bilateral-DEA, which could explicitly consider the heterogeneity in the 3 production methods of aquaculture. Finally, the study obtained the 95% confidence intervals of the efficiency scores for the 24 fishes under our study using the smoothed bootstraping method in the process of the re-sampling in cooperation with both a kernel density estimation and a reflection method. At the same time, we could estimate the bias-corrected efficiency scores while the traditionally estimated efficiency scores suffered from the biases in the process of solving a linear programming with the deterministic nature of a production frontier. And hence, we could distinguish the differences in production efficiencies of the 8 fishes with respect to those 3 methods of aquaculture.

• Journal of fish pathology
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• v.3 no.1
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• pp.11-19
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• 1990

Yellow tail (Seriola quinqueradiata) infected by Pasteurella piscicida have been occurred to mass mortality without showing apparent surface lesions in cage culture farms. In this case, it is necessary to consider countermeasure by rapid diagnosis of infected fish. The purpose of the present study was to investigate usefulness of the direct fluorescent antibody technique(FAT) for rapid diagnosis of pseudotuberclosis of cultured yellowtail caused by P. piscicida. Antibody produced by inoculating rabbit with formalin killed pseudotuberclosis bacteria antigen(strain KNP-2). Immunoglobulin-G(IgG) was purified from antisera by DEAE-cellulose column chromatography and conjugate with fluorescein isothiocyanate. Fluorescein-labeled antisera was purified by sephadex G-25 gel column chromatography. The fluorescein/protein molar ratio of labeled antisera was determined as 8.8-9.5. Diagnosis of cultured yellowtail was examined in cage culture farms which located in Tongyung, kyungnam from July to October 1990. The causative bacteria of pseudotuberclosis could be detected within two hours after the specimens were transferred to the laboratory for FAT, and it showed that FAT could be adapted as a rapid and accurate diagnostic method of pseudotuberclosis in yellowtail.

• Journal of Aquaculture
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• v.14 no.3
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• pp.181-195
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• 2001

To stabilize the lantern cage culture system of Patinopecten yessoensis(Jay) in the eastern coast of Korean peninsula, optimum conditions such as time of transplantation, rearing density and depth, and time of harvest were identified. During the period from January 1991 to December 1998, the water temperature ranged from 4.7 to 21.4$^{\circ}C$ at 15-30 m depth and 4.9 to 25.7$^{\circ}C$ at the surface; these thermal ranges were within the optimal ranges (5-23$^{\circ}C$) prevailing at 15-30 m depth at surface water. Annual thermal changes indicated that the prevailing temperature during the years 1993 and 1996 was near optimum, but higher during the years 1994, 1997 and 1998, when mass mortality and growth retardation occurred. Salinity (32.0- 34.4$\textperthousand$) and dissolved oxygen (4.14 -8.11 $\mu\textrm{g}$/l) at 15 m depth were well within the optimum ranges. The chlorophyll concentrations (0.06 - 2.73$\mu\textrm{g}$/l) indicated that the study area was oligotrophic, although mass mortality did occur, when chlorophyll concentrations were high, especially in summer. Hence water temperatures and chlorophyll concentration are major factors related to survival and growth of the scallop. In terms of the shell height maximum growth occurred during spring (March-May; 8 - l3$^{\circ}C$) and fall (October-December; 11-l7$^{\circ}C$) in the lantern cage culture. Slow growth was recorded during late winter January-february; less than 7$^{\circ}C$) and mid-summer (August- September; more than 18$^{\circ}C$). Daily growth of shell height and total weight were 0.02∼0.24 mm and -0.07∼0.90 g at the rearing density of 12 individuals per net. Optimal .earing density in the lantern cage (ø50${\times}$20 cm) was 10∼15 individuals with the shell height of 5∼6 cm. The fastest growth rates were observed at 15∼20 m depth; however, it is recommended that 20∼30 m would be optimal. The scallops require 22 months to attain the commercial size of 10 cm shell height and 140 g total weigh, and are best harvested and sold during March-April.

• The Korean Journal of Malacology
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• v.31 no.2
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• pp.73-81
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• 2015

This study was conduct to investigate the effect of intermediate culture types on the growth and survival rate of the juvenile abalone, Haliotis discus hannai fed seaweed and artificial diet. Intermediate cultures were to determine there that was to fed seaweed (SW) of artificial diet (A) of floor culture (FC), net floor culture (NFC), double shelter culture (DSC) and indoor net cage culture (INCC) in land-based tank, in two replicate. In the growth performance of juvenile abalone reared through intermediate culture to fed SW of A, that the absolute growth rate ($AGR_{SL}$, $AGR_{SB}$), daily growth rate ($DGR_{SL}$, $DGR_{SB}$), and specific growth rate ($SGR_{SL}$, $SGR_{SB}$) to the shell length (SL) and shell breadth (SB) of experimental groups were not significant. As weight gain (WG), daily weight gain (DWG) and specific weight gain (SWG) to body weight through intermediate culture types in land-based tank was not significant. However, as to survival rate to experimental groups, A-FC was higher than those of different groups (P < 0.05). Therefore, these results is showed that was not difference to growth of juvenile abalone over 2 cm fed seaweed diet and artificial diet according to intermediate culture types. But floor culture with artificial diet indicate that was highest to survival rate, therefore, it is beneficial for higher productivity in floor culture with artificial diet among intermediate culture types.

• The Journal of Fisheries Business Administration
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• v.47 no.3
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• pp.35-52
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• 2016

This paper analyzed economic feasibility of aquacultural construction which of large-scale. The results of the economic analysis, cage cultural and water recycling cultural by post-water treatment were analyzed that NPV is 2,083,685 thousand won and -14,105,896 thousand won and B/C ratio is 0.590 and 0.855, respectively. These were shown economic infeasibility. But, running water culture by pre-water treatment(small scale) and running water culture by pre-water treatment(large scale) were analyzed that the one is 5,555,747 thousand won and 15,048,589 thousand won and the other is 1,154 and 1,1221, respectively. these were shown economic feasibility. In addition, measurement of B/C ratio through a sensitivity analysis on running water cultural by pre-water treatment(small scale) and running water cultural by pre-water treatment(large scale) is economic feasibility in all cases. However, these were analyzed when the selling price was falling to 20 percent, it has shown economic infeasibility and when the selling price rises to 20 percent, water recycling culture by post-water treatment has economic feasibility. The significance of the study analyzed a sensibility as well as economic feasibility by methods and scales. It is expected that used as basic materials when constructing and operating of land aquaculture in order to minimize the damage from natural disasters.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.3
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• pp.417-421
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• 1999

This experiment examined the effects of feeding Aspergillus oryzae (AO) culture to laying hens, on fecal microbial populations, fecal pH and moisture content, egg quality, and metabolizabilities of several nutrients. Sixteen commercial 38-wk-old laying hens were randomly allotted to four diets: control; with 0.15% locally produced AO culture; with 0.3% locally produced AO culture, and; or with 0.3% imported AO. Each treatment consisted of four replicates (cages) containing one bird per cage according to a completely randomized design. After 4 wk, AO were recovered in the feces of birds fed the AO diets, indicating that AO might pass through the fore-gut alive and become active in the hind gut. The number of Lactobacillus spp. in feces was higher in all treated groups than that of the control, indicating that AO would provide a beneficial environment for the Lactobacillus spp. to proliferate in the intestine. The number of fecal E. coli was significantly reduced by the addition of AO. A similar trend was also found for aerobic bacteria. Although not significant, fecal moisture contents tended to be reduced by the addition of AO. Fecal pH was not significantly different among the treatments. The addition of AO did not affect the various economic traits of eggs. Metabolizabilities of gross energy and dry matter measured during the 5th wk were increased by the AO supplementation. It appears that AO culture alone could be used as a probiotic supplement for layers.

• Journal of Aquaculture
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• v.11 no.4
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• pp.465-474
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• 1998

Shell necrosis, which is found in the juvenile stage of Haliotis discus hannai in th culture process, was examine in this study. In the necrosis shell, bacteria of rod type and a blue green algal species with heterocyst were observed. However, it appears to be caused by a boring blue green alga, Mastigocoleus sp., as based on SEM data. At the time of its infection, the shell was discolored from green into bright-grey, and then began to be brittle at the 4th to 6th breathing hole. After 60 days of culture, necrosis occurred in the breathing holes with many brown tiny colony, and continued to 3 years after culture. This shell necrosis was found in the tank culture system in land rather than in the cage culture system in sea, and greatly affected to the growth of Haliotis discus hannai, resulting in very small size of 16mm in 3 year old shell.

• The Korean Journal of Malacology
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• v.31 no.2
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• pp.83-92
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• 2015

The effect of different intermediated rearing method by expanding the attached floor space in order to highly density culture on the growth characteristics and survival rate of the juvenile abalone, Haliotis discus hannai, were investigated in land-based tanks. The intermediated culture methods was determined thru the shelter counts and layer for 10 month with two replicates : the single layer shelter (SLS), the double layer shelter (DLS), the triple layer shelter (TLS) and the single layer shelter under net cage (SLSNC). In addition, the culture on shallow race way tank had to set up as culture of the ditch raceway tank (CDRT) and the floor race way tank (CFRT). In the growth performance of reared abalone (initial mean shell length $54.18{\pm}7.39mm$ and weight $1.93{\pm}0.14g$) at experimental tanks, that the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rate (SGR) to the shell length and shell breadth was not significant at each experimental tanks except SLSNC. As well as too, weight gain (WG), daily weight gain (DWG) and specific weight gain (SWG) to weight was not significant at each experimental tanks except SLSNC, too. Survival rates of CDRT and CFRT was lower than those of different experimental tanks (P < 0.05). Therefore, these results is showed that high density different intermediated rearing method by expanding the attached floor space for juvenile H. discus hannai was not have difference as growth performance and survival rate both one layer shelter and multi layer shelter. Also, it is considered that shallow race way tank was not useful rearing for the juvenile intermediate culture of H. discus hannai in land based.

• The Korean Journal of Malacology
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• v.30 no.3
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• pp.219-226
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• 2014

The effects of different stocking densities on the growth and survival rate of the abalone, Haliotis discus hannai, were investigated in marine net cage for two years. Stocking density was set 15, 30, 45 and 60 percentage $(=per.)/m^2$ with share to cross-sectional area per shelter. The primary rearing period (PRP) and the secondary rearing period (SRP) were conducted by a year. One year mean water temperature of PRP and SRS showed the difference about $2^{\circ}C$. In the growth (initial mean shell length of abalone : $36.14{\pm}2.28mm$) of PRP, the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rate (SGR) of the $15per./m^2$ were higher than those of density groups (P < 0.05). Survival rates of all density groups were showed no significant difference. In the growth (mean shell length of abalone : $55.26{\pm}6.93mm$) of SRP, ARG, DGR and SGR of stocking density groups showed no significant difference except for $45per./m^2$ density group. Survival rate in the low-density (15, $30per./m^2$) was more than 70%, and those of the high-density (45, $60per./m^2$) were less than 31% and 9%, respectively. These results showed that the appropriate stocking density for $15per./m^2$ was seven hundred fifty number per one net cage ($2.4{\times}2.4m$), during PRP using 3-4 cm abalone in length. Also for the secondary rearing period, the optimal stocking density (shell length 5-6 cm of abalone) consider with the economical efficiency was determined to be $30per./m^2$, resulting the productivity improved.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1752-1760
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• 2005

In this experiment, the effects of cage density (CD) and probiotic supplementation (PS) on laying performance, metabolic profile, and egg quality in peak-producing hens were evaluated. After blocking according to the cage location, Lohman layers (n = 180, 46 wks of age) were allocated randomly to two levels of CD (540 vs. 360 $cm^2$/hen) and three levels of PS (0, 0.15, and 0.30%). Probiotic contained Enterococcus faecium culture (10${\times}$10$^9$ cfu/g). Egg production (EP) and feed consumption (FC) were measured daily; egg weight (EW) was measured bi-weekly; BW was measured before and after the experiment; and blood samples were obtained at the end of the experiment. The data were analyzed using two-way ANOVA. Increasing CD decreased FC (125.0 vs. 120.8 g/d, p<0.0001) and FCR (1.93 vs. 1.87, p<0.0001) and did not alter EP, EW, and BW. Increasing level of PS linearly decreased FC (p<0.02) and FCR (p<0.006). Averages were 123.9, 123.2, and 121.6 g/d for FC and 1.91, 1.92, and 1.86 for FCR in hens supplemented with 0, 0.15, and 0.30% probiotic, respectively. Hens placed in high-density cages had greater serum corticosterone concentration than hens placed in normal-density cages (12.8 vs. 11.3 $\mu$g/dL, p<0.04); CD did not affect concentrations of other metabolites. Increasing level of PS linearly increased serum glucose, albumin, and creatine concentrations and quadratically increased total protein, globulin, Ca, and P concentrations. Average concentrations (mg/dL) were 260, 297, and 305 for glucose; 6.28, 8.09, and 7.58 for total protein; 1.98, 2.48, and 2.38 for albumin; 4.30, 5.62, and 5.19 for globulin; 0.40, 0.52, and 0.54 for creatine; 16.0, 16.5, and 16.3 for Ca; and 6.27, 8.14, and 7.17 for P in hens supplemented with 0, 0.15, and 0.30% probiotic, respectively. There was no effect of CD on egg quality. Increasing level of PS linearly improved yolk color (YC) and quadratically increased albumen index (AI) and Haugh unit (HU). The mean values were 9.67, 9.75, and 10.58 for YC; 8.94, 6.93, and 8.72% for AI; and 85.6, 74.9, and 82.9 for HU for hens supplemented with 0, 0.15, and 0.30% probiotic, respectively. There was also CD by PS effect on FC, EP, and serum glucose, total protein, albumin, globulin, creatine, Ca and P concentrations. In conclusion, increased CD partially depressed laying performance and caused stress. Probiotic supplementation improved laying performance and metabolic profile. It also partially alleviated the adverse effects of stress resulting from increased caging density.