• The Journal of Fisheries Business Administration
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• v.32 no.2
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• pp.73-89
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• 2001

The market conditions of sea mustard is changing by overproduction, decreasing price, Import of blanched and salted sea mustard from China into Korea domestic market and increasing market share of sea mustard of China in Japan. In addition, the price support program in sea mustard aquaculture must be modified due to the restriction of domestic support by international organization such as WTO. There are two ways to solve those problems. First is that finding a way to solve the overproduction of sea mustard. One of possible ways is the production adjustment by Marketing Order. Second is that finding an alternative way to replace price support program. The possible way is Direct Payment instead of purchase stockpile system. To introduce marketing Order, outlook center, organization of self-management, production adjustment through output control measure, improvement of market structure, and education/publicity arc necessary. Also, to implement marketing order, setting a model business by government is required. There are two steps for implementation of marketing order. First step is to construct Order Committee including organization of producer, people related marketing. However, this committee must run by government for certain short-term. Second step is to improve quality of product and acceleration of demand. At visual point that enforcement of the first step is completed, government has process that government transfers Order Committees self-correcting. It is desirable that government only conduct the support acts such as quality improvement and acceleration of demand. Also, at early stage it is necessary to have aid system for marketing order For example, we can expect that income increase by production adjustment in long run. However, in short run the income of producer may decrease so, it is required to compensate his economic lose. For compensation, The useful means that can be utilized is direct payment. Direct payment is not continued policy. Also, when production adjustment policy such as Marketing Order has effective results, Direct Payment as an assistant measure must be reduced or abolished. Therefore, when production adjustment acts as an effective tool to control overproduction, Direct Payment system.

• The Journal of Fisheries Business Administration
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• v.54 no.2
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• pp.045-058
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• 2023

This study aims to analyze the cost of climate change damages to laver and sea mustard aquaculture, which are considered to be highly vulnerable to climate change in Korea. For this purpose, the correlation between aquaculture production and climate factors such as water temperature, salinity, air temperature, and precipitation was estimated using a panel regression model. The SSP scenario was applied to predict the changes in production and damage costs due to changes in future climate factors. As a result of the analysis, laver production is predicted to decrease by 18.0-27.2% in 2050 and 20.6-61.6% in 2100, and damage costs are predicted to increase from 29.7-50.8 billion KRW in 2050 to 35.7-116.1 billion KRW in 2100. Sea mustard production is projected to decrease by 24.5-37.2% in 2050 and 24.0-34.5% in 2100, with similar damage costs of 41.1-61.8 billion KRW and 41.1-58.6 billion KRW, respectively. These damage costs are expected to occur in the short term as damage caused by fishery disasters such as high temperatures, and in the long term as a decrease in production due to changes in aquaculture sites. Therefore, measures such as strengthening the forecasting system to prevent high-temperature damage, developing high-temperature-resistant varieties, and relocating fishing grounds in response to changes in aquaculture sites will be necessary.

• The Journal of Fisheries Business Administration
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• v.50 no.4
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• pp.1-9
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• 2019

Seaweed by-products have been dumped into the sea and induced marine pollution. However, they can be recycled as a valuable natural resources. Approximately 240,000 tons of sea mustard and kelp by-products were estimated to be producted during the last three years. The estimate corresponds 6.7% of the total production of marine aquaculture and 14.9% of the total production of seaweeds. When adding up the by-products from fish and mollusks, approximately 1,000,000 tons of fisheries by-products were thrown out into the sea every year. A three-step strategy is required for the industralization of fisheries by-products. The first step is the construction of the processing foundation of by-products, the second is its food industralization, and the third is its recycling as raw biomaterials. The stable supply of raw materials is the prerequisite for the industralization. Thus, it is necessary to construct the refuse logistics around chief production districts and to build the processing facility and frozen storage of by-products. Cooperation among private enterprises and government investment for research and development is required the second and third steps.

• Journal of Aquaculture
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• v.7 no.2
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• pp.77-87
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• 1994

The study was conducted to develop the suitable abalone's diets for the indoor tank culture. The young abalone Haliotis discus hannai Ino sized ca. 20, 30 and 40 nun in shell length were fed three different diets, dried sea mustard Undaria pinnatifida HARVEY (control), artificial diet and terrestrial plants e. g. Chinese cabbage and Perilla leaf for 2 years. The growth rate of abalones fed an artificial diet was slightly higher than that of abalones from the control. However, the growth rate of abalones from terrestrial plants was significantly lower than that of abalones fed a control or an artificial diet (P< 0.05). The daily feeding rate of young abalones from terrestrial plants was slightly higher than that of abalones from the control. While, that of abalones from an artificial diet was approximately $30\%$ of that of abalones from a control or a terrestrial plants diet. The feed efficiency of abalone from artificail diet was higher than that of abalones from a control or a terrestrial plants diet, and the smaller size of young abalone showed the higher the feed efficiency. The EFA index values ${{\sum}n9/(20:4n6+20:5n3+22:6n3}$ of the dried sea mustard and the artificial diet were 1.26 and 3.64, respectively. These values were favorable, but the value of terrestrial plant, Perilla leaf was 127.00 indicating poor EFA index for normal growth of abalone.

• Journal of Aquaculture
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• v.7 no.1
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• pp.9-20
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• 1994

To find out suitable indoor rearing tank shape and stocking density of the abalone Haliotis discus hannai, young abalones were reared in the square or ellipse shape tanks with various stocking densities and were fed dried sea mustard, Undaria Pinnatifida HARVEY for three years. There were no significant differences between the square rearing tank and the ellipse one in growth rate and survival rate. With regard to vertical design of rearing tanks with three floors, the significant differences were not found among culture floors. However, the growth and survival rates of young abalones from the running water system were significantly higher than those of the abalones from the circulating system (P< 0.05). For the stocking density experiment with 1,000, 1,500 and 2,000 individuals of 20 mm young abalone, there was no significant differences in growth and survival rates among these groups. However, in that of 200-400 individuals of 40 mm abalone and 100-300 individuals of 50 mm abalone, the lower stocking density of young abalone showed the higher growth and survival rates. The lower stocking density and the smaller size of young abalones showed the higher daily feeding rate and feed efficiency.

• Journal of Aquaculture
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• v.6 no.2
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• pp.71-87
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• 1993

Two forms of sea mustard, Undaria Pinnatifida were cultured in order to compare the morphological characteristics and the efficiency of production. U. Pinnatifida f. distans was collected from Wando, Korea and U. Pinnatifida f. typica was transplanted from Sanriku, Japan. The latter form grew faster in length and weight than the former. Maximum growth was shown in early April for both forms, and the growth rates decreased after this. Absolute growth rates between the two forms were quite different. Average total lengths at the harvest season was 161.1cm in U. Pinnatifida f. distans and 183.5 em in U. Pinnatifida f. typica and average weights of those two forms were 1,003.4g and 1,314.6g, respectively. The weight of available parts for the salting process of the two forms were 734.8g and 968.5g, respectively. The rates of total length versus the length of the available part of the two forms were $76\%$ and $83\%$, respectively and those of the total length versus weight of the available part of them were $43.8\%$ and $52.7\%$, respectively. The results of this study suggest that the U. pinnatifida f. typica had more available part per unit weight than that of the U. pinnatifida f. distans for the efficiency of salt processing.

• Journal of Fisheries and Marine Sciences Education
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• v.22 no.3
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• pp.362-373
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• 2010

We reviewed previous studies on well-performing aquaculture facilities, rearing environment, breeding management and feed supply to find the optimal conditions of the abalone aquaculture in marine cage. The size of marine cage varied depending on local area where the abalone farms are located. The small size cage ($2.4{\times}2.4{\times}2.5$ m) was used in Wando, Jindo and Hanam area where much of the provincial's abalone production is conducted and the middle size cage ($2.4{\times}4.8{\times}2.5$ m) was used in Huksando area. Big size group, above 2 cm in shell length, was produced from the end of October to the middle of November and small size group, below 2 cm in shell length, was produced from the end of March to the beginning of April next year in case of juvenile abalone of land production. The initial stocking density was 517-1,653 individuals/culture square meter($m^2$) in case of the big size group. The optimal rearing density was 326 and 263 individuals/culture square meter ($m^2$) after 1 year and 2 year's rearing, respectively. It is shown that relationship between individual shell length (x) and rearing density (y) is estimated to be $y=2,803.1x^{-1.4641}$ ($r^2=0.9687$). In addition, The obvious relationship was indicated between number of cage (x) and sea weed production facilities (y) as y=1.1542x+10.832 ($r^2=0.918$) in Wando, because sea mustard (Undaria pinnatifida) or japanese tangle (Laminaria japonica) was supplied as a feed for abalone culture. The general pattern of relationship between shell length (x) and shell weight (y) of cultured abalone is estimated to be $y=0.1443x^{2.9461}$ ($r^2=0.9997$).

• Journal of Aquaculture
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• v.3 no.1
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• pp.89-125
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• 1990

In order to improve top shell seed production techniques spawning and larvae rearing were done in rearing tanks. Growth of young top shell in the nursing ground were also investigated. For induced spawning, top shells were maintained in still water during night time. Then they were treated with ultra violet iradiated sea water after dried up in air for 60 minutes. Spawning rate were 10 to $39.77\%$. It was found that young top shells moved in the growing grounds from nursing grounds when they reached approximately 30-40mm in shell heignt. Among main food algae for top shell in the natural growing grounds, sea mustard were melted away during June. Therefore, presence of another food algae such as Ecklonia cava or Sargassum spp. seems to be the main limiting factor for survival of top shell during summer. The tolerance of top shells ranging from 30mm to 60mm to low density of seawater for were tested at the temperature between 29.5 and $31.4^{\circ}C$. Hundred percent mortality occoured in 20, 55 and 90 hours after first stocking at the specific gravity of 1.010, 1.015, and 1.020, respectively.

• Journal of Aquaculture
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• v.11 no.2
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• pp.133-140
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• 1998

A 20-week growth trial was conducted in flow-through aquarum system to investigate the practical dietary carbohydrate sources for juvenile abalone (Haliotis discus hannai). Four replicate grops of the abalone averaging 0.125g were fed one of eight diets containing 24.2% wheat flour (WF), 20% dextrin (DEX), 20% sucorse (SUC), 10% $^{\alpha}$-potato starch+10% $^{\beta}$-potato starch (ab-S), 15% $^{\alpha}$-potato starch (a-S15), 20% $^{\alpha}$-potato starch (a-S20), 25% $^{\alpha}$-potato starch (a-S25), or mixture (MIX) with practical ingredients such as soybean meal, corn gluten meal, cotton seed meal and heat flour. In addition, these formulated diets were compare with macroalgae such as dried sea mustard Undaria (D-SM) or dried sea tangle Laminaria(D-ST). Survival rate, weight gain, shell growth and soft body weight of abalone were not significantly affected by the different dietary carbohydrate sources (P>0.05), whereas those fed a-S15 diet were slightly low. These values of abalone fed D-ST were lowest (P<0.05), followed by those fed D-SM. Lipid contents of soft body from abalones fed a-S25, D-ST or D-SM were significantly lower than those of abalone fed other diets (P<0.05). These data indicate that abalone can equally utilize any carbohydrate sources used in this study.

• The Journal of Fisheries Business Administration
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• v.16 no.1
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• pp.91-124
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• 1985

Mariculture is contrasted with inland aqua-culturing fisheries. It is defind as the Industry of rearing Aquaorganism in limited coastal area relatively shallow in depth. Then, It's coming into being realization of Mariculture in it is long in history that Mariculture was realized in Korea. But it is from the early part of 1960s, that this industry has normally developed. Owing to 200 miles economy-zone problems of coastal countries, the development of deep sea fishing was limited, so the Korean Government has now appreciated the importance of cultured industries in the field of coastal fisheries. And the Korean Mariculture the output of which was only 18, 000 M/T in '60s attained 540, 000M/T in 1980s, has now occupied its relative importance in Korean Fisheries Industry. So the purpose of this report is to suggest the prospect of technical development of mariculture in the future of Korea, through the analysis of the various problems that affect upon the individual management '||'&'||' fishing ground utilization, along with the appreciation of "how to extend of those technical innovation" and "how the fishermen's technique level is extended at this stage. According to this study, the result is summarized as follows. First, Maricultural technique is classified into 8 sub-techniques as follows, as shown in fig. 1.Fig. 1. The Formation structure of mariculture technique Second, the change of technical method of mariculture in coastal area of Korea has made as 5 stages; 1) Scattering of culturing organism 2) Culturing by putting stone and installing bamboo 3) Culturing by installing rope and seeding 4) Culturing of putting objectives in cages 5) Culturing fish by feed Third, the maricultural fisheries of Korea has about 70 years long in history. It began from 1910s. But at that time there was no special technique in aquaculture and its technique was confined in searching out the object of species. The species was laver, oyster ect.Forth, although realization of mariculture in Korea has been long time, it is of late from 1960s that this has been industrial with normal development, and its technique of mariculture has mainly has developed from 1970s. Its result not only contributed to the high growth in Korean ecconomy along with the well balanced development between industires, but also it played a great role for the resolution of nation's food problem. Especially maricultural production has shown its sustained annual increase of 13.8% during the last 20 years. So the portion of mariculture among total fisheries stucture was extended from 4.1% in the early 1960s to 22.4% in 1980s.Fifth, it could be safely said that such development in maricultural field is resulted from the activity of aquacultural institutes such as Fisheries Reseach '||'&'||' Development production of major kinds such as Oyster, Sea-mustard, and Laver etc. As well as in the innovation of aquaculturing method with synthetic fiber utilization. FRDA has played important role in the efficient propargation of new aquacultural technique.Sixth, as for the change in aquaculture structure and its during period between 1970s and 1980s, the private management participation shown 25% increase from household number of 45, 173 to 56, 268 in total number. And in the respect of the management scale, of their management decreased, while it showed an increase in relative large scale management, the increase over 3 employees compared with other fisheries field between '70s and 80s. This must be an major trait to be recorded, Now the data above mentioned are shown as in table 1 and 2.Table 1. The maricultural fishing ground development situation in 982.Table 2. The mariculture management as seen in the employmnet size in high seasion.Owing to the technical innovation, of the mariculture in coastal area new income of fishermen increased and it also is true that the number of fishermen participating in its industrialization increased. But the problem being from now on is the self-discharge of the destruction fishing ground considered resulted from rapid expansion in aquaculture industry and the preventive system of sentility of fishing ground. sentility of fishing ground.