• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.449-455
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• 2009

In Hansan Geojeman area, 2,050 ha of shellfish growing area has been designated as shellfish production area for export. The main shellfish species from the designated area is oysters. For the sanitary management of the designated area established in Hansan Geojeman area, bacteriological examination of sea water and shellfish at the sampling stations inside and outside of the designated area were performed from January 2006 to December 2008. The range of fecal coliform of 756 sea water samples at 21 stations located in the designated area were <1.8~>1,600 MPN/100mL. And the range of geometric mean and the estimated 90th percentile of fecal coliform were 1.8~2.9 and 2.7~15.8 MPN/100mL, respectively. Sanitary conditions of the current designated area in Hansan Geojeman meets the required standards of the Fisheries Product Quality Control and National Shellfish Sanitation Program (NSSP, USA) criteria for the approved area. Also, the sanitary status of the shellfish harvested from the designated area met the Korean Shellfish Sanitation Program (KSSP) fecal coliform criterion (<230 MPN/100g). And the human pathogen such as Salmonella spp. and Shigella spp. were not detected from the examined shellfish samples.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.442-448
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• 2009

Bacteriological examination of a 12,700 ha area within Jaranman Saryangdo area, located in Jaran bay and Saryangdo island, was conducted with 35 fixed (designated areas and adjacent areas) seawater sampling stations between January 2006 and December 2008. According to results, the geometric mean range and the estimated 90th percentile range of fecal coliform counts in sea water samples collected in the designated area were <1.8-2.4 and <1.8-8.6 MPN/100mL, respectively. The estimated 90th percentile range of fecal coliform counts in sea water samples collected from 6 sampling stations in the adjacent areas were 6.1-34.6 MPN/100mL. Based on these results, bacteriological water quality of the designated areas in the Jaranman. Saryangdo area meet the NSSP (National Shellfish Sanitation Program) guidelines for approved area. The bacteriological sea water quality in Jaranman.Saryangdo area has been shown to be favorable at all investigated sampling stations except for July and August which coincided with heavy rainfall. In fact, the bacteriological water quality was not affected if rainfall was less than 30 mm rainfall. However, the degree of bacteriological contamination increased rapidly and the water quality exceeded approved NSSP guidelines set for rainfall above 60 mm.

• The Journal of Fisheries Business Administration
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• v.41 no.1
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• pp.53-72
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• 2010

The objects of this study are to consider the current features and the development process of the utilizing system of aquaculture farms in Japan, and to suggest the theoretical basis for improvement of aquaculture system of Korea in the future through the analysis of background of the liberalization theory proposed recently. The aquaculture-fishery system of Japan was begun from the Meiji Era Fishery Act and New Fishery Act of the World war II. A small sum of fishery fee is paid to the fishery cooperative having fishing rights for securing fishing area newly, because the aquaculture of Japan belong to fishery cooperative not individual ownership of union membr of cooperative society, the other words, cultivation fisheries household. In case of Korea, there are several differences with Japan as follows; almost cultivation fisheries household has a individual license, the lisence of fishing rights are recognized as an article, the license of fishing lights are able to do sale. Therefore, it is needed to paid a lots of money for securing fishing area newly. On the other hand, advanced countries in the marine aquaculture such as Norway have reached the stage where the managing abilities of marine aquaculture are similar to those in the manufacturing industry. And the number of large scale aquaculture farms with developed technologies and advanced marketing strategies in those countries is increasing. Considering that the marine aquaculture in Japan under the similar fishery systems of Korea has developed the state-of-the-art management skills or lead to large scale management, it is difficult to expect the decrease in the production costs under the small scale family business in Korea and this will lead to the decreasing competitive advantage over the imported seafood. Therefore marine aquaculture in Korea needs to increase the economy of scale to acquire the competitive advantage.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.493-498
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• 2004

The objective of the present study is to compare various conventional and recently evolved satellite image-processing techniques and to ascertain the best possible technique that can identify and position of aquaculture farms accurately in and around the Younggwang coastal area. Several conventional techniques performed to extract such information fiom the Landsat-TM imagery do not seem to yield better information about the aquaculture farms, and lead to misclassification. The large errors between the actual and extracted aquaculture farm information are due to existence of spectral confusion and inadequate spatial resolution of the sensor. This leads to possible occurrence of mixture pixels or 'mixels' of the source of errors in the classification techniques. Understanding the confusing and mixture pixel problems requires the development of efficient methods that can enable more reliable extraction of aquaculture farm information. Thus, the more recently evolved methods such as the step-by-step partial spectral end-member extraction and linear spectral unmixing methods are introduced. The farmer one assumes that an end-member, which is often referred to as 'spectrally pure signature' of a target feature, does not appear to be a spectrally pure form, but always mix with the other features at certain proportions. The assumption of the linear spectral unmxing is that the measured reflectance of a pixel is the linear sum of the reflectance of the mixture components that make up that pixel. The classification accuracy of the step-by-step partial end-member extraction improved significantly compared to that obtained from the traditional supervised classifiers. However, this method did not distinguish the aquaculture ponds and non-aquaculture ponds within the region of the aquaculture farming areas. In contrast, the linear spectral unmixing model produced a set of fraction images for the aquaculture, water and soil. Of these, the aquaculture fraction yields good estimates about the proportion of the aquaculture farm in each pixel. The acquired proportion was compared with the values of NDVI and both are positively correlated (R$^2$ =0.91), indicating the reliability of the sub-pixel classification.ixel classification.

• Journal of Environmental Impact Assessment
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• v.14 no.3
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• pp.127-134
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• 2005

Recently, aquaculture farm sites have been increased with demand of the expensive fish species and sea food like as seaweed, laver and oyster. Therefore coastal water quality have been deteriorated by organic contamination from marine aquaculture farm sites. For protecting of coastal environment, we need to control the location of aquaculture sites. The purpose of this study is to detect the laver aquaculture sites using multispectral remotely sensed data with autodetection algorithm. In order to detect the aquaculture sites, density slice and contour and vegetation index methods were applied with SPOT and IKONOS data of Shinan area. The marine aquaculture farm sites were extracted by density slice and contour methods with one band digital number(DN) carrying 65% accuracy. However, vegetation index algorithm carried out 75% accuracy using near-infra red and red bands. Extraction of the laver aquaculture site using remotely sensed data will provide the efficient digital map for coastal water management strategies and red tide GIS management system.

• The Journal of Fisheries Business Administration
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• v.34 no.2
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• pp.75-90
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• 2003

When we think of fundamental problems of the aquaculture industry, there are several strict conditions, and consequently the aquaculture industry is forced to change. Fish aquaculture has a structural supply surplus in production, aggravation of fishing grounds, stagnant low price due to recent recession, and drastic change of distribution circumstances. It is requested for us to initiate discussion on such issue as “how fish aquaculture establishes its status in the coastal fishery\ulcorner, will fish aquaculture grow in the future\ulcorner, and if so “how it will be restructured\ulcorner” The above issues can be observed in the mariculture of yellow tail, sea scallop and eel. But there have not been studied concerning seabream even though the production is over 30% of the total production of fish aquaculture in resent and it occupied an important status in the fish aquaculture. The objectives of this study is to forecast the future movement of sea bream aquaculture. The first goal of the study is to contribute to managerial and economic studies on the aquaculture industry. The second goal is to identify the factors influencing the competition between production areas and to identify the mechanisms involved. This study will examine the competitive power in individual producing area, its behavior, and its compulsory factors based on case study. Producing areas will be categorized according to following parameters : distance to market and availability of transportation, natural environment, the time of formation of producing areas (leaderㆍfollower), major production items, scale of business and producing areas, degree of organization in production and sales. As a factor in shaping the production area of sea bream aquaculture, natural conditions especially the water temperature is very important. Sea bream shows more active feeding and faster growth in areas located where the water temperature does not go below 13∼14$^{\circ}C$ during the winter. Also fish aquaculture is constrained by the transporting distance. Aquacultured yellowtail is a mass-produced and a mass-distributed item. It is sold a unit of cage and transported by ship. On the other hand, sea bream is sold in small amount in markets and transported by truck; so, the transportation cost is higher than yellow tail. Aquacultured sea bream has different product characteristics due to transport distance. We need to study live fish and fresh fish markets separately. Live fish was the original product form of aquacultured sea bream. Transportation of live fish has more constraints than the transportation of fresh fish. Death rate and distance are highly correlated. In addition, loading capacity of live fish is less than fresh fish. In the case of a 10 ton truck, live fish can only be loaded up to 1.5 tons. But, fresh fish which can be placed in a box can be loaded up to 5 to 6 tons. Because of this characteristics, live fish requires closer location to consumption area than fresh fish. In the consumption markets, the size of fresh fish is mainly 0.8 to 2kg.Live fish usually goes through auction, and quality is graded. Main purchaser comes from many small-sized restaurants, so a relatively small farmer and distributer can sell it. Aquacultured sea bream has been transacted as a fresh fish in GMS ,since 1993 when the price plummeted. Economies of scale works in case of fresh fish. The characteristics of fresh fish is as follows : As a large scale demander, General Merchandise Stores are the main purchasers of sea bream and the size of the fish is around 1.3kg. It mainly goes through negotiation. Aquacultured sea bream has been established as a representative food in General Merchandise Stores. GMS require stable and mass supply, consistent size, and low price. And Distribution of fresh fish is undertook by the large scale distributers, which can satisfy requirements of GMS. The market share in Tokyo Central Wholesale Market shows Mie Pref. is dominating in live fish. And Ehime Pref. is dominating in fresh fish. Ehime Pref. showed remarkable growth in 1990s. At present, the dealings of live fish is decreasing. However, the dealings of fresh fish is increasing in Tokyo Central Wholesale Market. The price of live fish is decreasing more than one of fresh fish. Even though Ehime Pref. has an ideal natural environment for sea bream aquaculture, its entry into sea bream aquaculture was late, because it was located at a further distance to consumers than the competing producing areas. However, Ehime Pref. became the number one producing areas through the sales of fresh fish in the 1990s. The production volume is almost 3 times the production volume of Mie Pref. which is the number two production area. More conversion from yellow tail aquaculture to sea bream aquaculture is taking place in Ehime Pref., because Kagosima Pref. has a better natural environment for yellow tail aquaculture. Transportation is worse than Mie Pref., but this region as a far-flung producing area makes up by increasing the business scale. Ehime Pref. increases the market share for fresh fish by creating demand from GMS. Ehime Pref. has developed market strategies such as a quick return at a small profit, a stable and mass supply and standardization in size. Ehime Pref. increases the market power by the capital of a large scale commission agent. Secondly Mie Pref. is close to markets and composed of small scale farmers. Mie Pref. switched to sea bream aquaculture early, because of the price decrease in aquacultured yellou tail and natural environmental problems. Mie Pref. had not changed until 1993 when the price of the sea bream plummeted. Because it had better natural environment and transportation. Mie Pref. has a suitable water temperature range required for sea bream aquaculture. However, the price of live sea bream continued to decline due to excessive production and economic recession. As a consequence, small scale farmers are faced with a market price below the average production cost in 1993. In such kind of situation, the small-sized and inefficient manager in Mie Pref. was obliged to withdraw from sea bream aquaculture. Kumamoto Pref. is located further from market sites and has an unsuitable nature environmental condition required for sea bream aquaculture. Although Kumamoto Pref. is trying to convert to the puffer fish aquaculture which requires different rearing techniques, aquaculture technique for puffer fish is not established yet.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.1 s.28
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• pp.61-67
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• 2007

This paper describes the implementation procedures and results of Fishery Safety and Security System to secure an aquaculture area from a thief. The system designed with various functional modules to implement selectively available system providing low cost to high cost and simple function to high function according to user's requirement in a practical fishing fields. In the abalone farm field located in Jin island, Jeonranam province and having condensed aquaculture facilities with 50 cages (10 row by 5 column) within 0.5 miles from coast, practical field tests are carried out. As results from that tests, it is found that the system can guard not only the whole area of cultivating farm field but also each cages with detail.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.3
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• pp.341-346
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• 2023

This study aimed to suggest an alternative income generation (AIG) for local artisanal fisheries communities in the southern coastal area of Bangladesh, which is vulnerable to climate change. To analyze the problems of local artisanal fisheries caused by climate change, field surveys and in-depth interviews with fishermen and government officials were conducted. Livelihood risk factor (LRF) in the marine fishing sector included reduction of fishing days and fish production and damage to fishing vessels and fishing gear due to cyclone and sea-level rise. LRF in the aquaculture sector included cultured fish escape, reduction of aquaculture production, and water pollution due to Monsoon flood. A common challenge for two sectors was high interest rate on commercial loans. Small-scale tank aquaculture is recommended as AIG for securing income of artisanal fisheries communities. In the early stages of dissemination of small-scale tank aquaculture technology, it is necessary to prevent fishermen from struggling to repay high-interest rate loans through technology transfer and facility support by official development assistance. The aquaculture training center, along with the technical education, will also contribute toward expansion of local distribution network and marketing support to establish a value chain for local artisanal fisheries communities.

• The Journal of Fisheries Business Administration
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• v.44 no.3
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• pp.77-84
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• 2013

While some steps in laver aquaculture production can be controlled artificially to a certain extent, the culturing process is largely affected by natural factors, such as the characteristics of seawater, climatic and oceanographic conditions, etc. This study aims to find a direct relationship between climatic and oceanographic factors (water temperature, air temperature, salinity, rainfall, sunshine duration and wind speed) and laver aquaculture production in Wando region, the biggest aquaculture production area of laver, located in the southwest coast of Korea using a multiple regression analysis. Despite the small sample size of a dependent variable, the goodness of model fit appeared acceptable. In addition, the R-squared value was 0.951, which means that the variables were very explanatory. Model results indicated that duration of sunshine, temperature, and rainfall during the farming period from the end of September to the end of April would be important factors affecting significantly to the laver aquaculture production.

• Journal of Environmental Impact Assessment
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• v.13 no.5
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• pp.231-241
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• 2004

This study aims to detect the change of marine aquaculture farm within the boundary of Hallyeo Marine National Park. Comparison has been made on the Landsat images taken in 1984 and 2002 respectively by using feature extraction methods and other image analysis techniques. During the 18 year period between 1984 and 2002, total area of the aquaculture farms has been decreased in 63 percent. The reason for the change seems to be that aquaculture farms became concentrated only around the Geoje Islands due to the growth of the labor- and capital-intensive cage aquaculture for the expensive fish species instead of traditional oyster farming. Authors suggest the monitoring using remotely-sensed data as the best tool for the management of marine aquaculture farms on the basis of accuracy of analysis and relatively cheap cost. Management strategies of salmon farms in Tasmania, Australia has been analyzed to find the field techniques necessary for the management of aquaculture.