• 수산해양기술연구
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• 제58권1호
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• pp.75-84
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• 2022

Since South Korea did not adopt the recreation fishing using right (coupon) system, there were no recreation fishing statistics. This study selected 480 fishing vessels (10.4%) of a total of 4,611 fishing vessels (as of December 2019) as a survey sample using stratified sampling. Unlike other research institutes that conducted surveys related to the amount of tide on a one-time, this survey was conducted for five months (from May to October 2020, except the month of August). The captain investigated about types of fish, size, weight, etc. to anglers. A difference from previous studies was that about 7.0 million angler population (fishing more than three times a week) had 19.4 kg of catch per person for a year while other studies showed about 25.5-52.0 kg, respectively. The total fisheries resource catch amount was analyzed to be about 95,000 tons in this study and 116,000-166,000 tons in other studies. So there was a difference of about 1.2 to 1.8 times. This study aims to lay the foundation for the development of the fishing industry by preparing accurate statistical data and securing reliable basic statistics related to the fishing industry. Also, it could be usefully used as basic policy data such as introduction of a fishing using right (coupon) system.

• 기술혁신연구
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• 제15권1호
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• pp.27-63
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• 2007

Recently, Kim and Mauborgne (2005a) has introduced the concept of blue ocean strategy that provides quantum leap in value innovation, thus creating new market space. This study, based on the blue ocean strategy concept, suggests blue ocean new product development strategy, and attempts to examine how much impact this blue ocean new product development strategy has on new product performance, compared to existing new product development strategy perspectives based on competitive strategy-based new product development strategy and resource-based new product development strategy, in an empirical way. The research results show that the blue ocean new product development strategy has a statistically significant impact on new product performance. In addition, it was revealed that such contingency variables as firm size and environmental dynamism have moderating effect on the relationship between the blue ocean new product development strategy and new product performance. The blue ocean new product development strategy is more effective in the small-sized firms than the large-sized ones, and its effect on new product performance is different according to environmental dynamism.

• 수산해양기술연구
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• 제15권2호
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• pp.77-82
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• 1979

멸치는 남해안에서는 여러 단계의 크기의 것이 혼획되는데, 가다랭이 미끼용으로는 채장 6-7m의 것이 알맞으므로, 이 크기의 것을 가급적 언중 확보하기 위해서는, 그 분포상을 조사하여 적정 자원이 가장 많이 출현하는 해역을 알 필요가 있다. 또, 멸치의 크기에 따라 상품가치도 크게 다르므로 멸치 어업을 합리적으로 운영하기 위해서나, 자원의 관리를 위해서도 채장 조사는 중요하다. 여기서는 멸치어업이 주로 이루어지는 7월부터 12월의 한국 동남 해역에 있어서의 멸치의 분포상에 관하여 조사한 것을 보고한다

• 수산해양기술연구
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• 제47권1호
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• pp.18-26
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• 2011

This study is to contribute to income growth of fishermen by the common octopus fishery characterized in the Tando Bay on the southwest coast of Korea. This area is engaged in Longline fishing (301 persons), Shovel fishing (196 persons), Trap fishing (14 persons) and Torch light fishing (40 persons) in 2008. Population who is joined in the spring becomes main fishery target population of longline fishery in the fall because entering fishing ground in August, and is joined in the fall becomes main fishery target population of longline fishery in the spring because entering fishing ground in December. Average size of common octopus examined by longline 6.26cm, 5.82cm for Shovel fishing, 8.09cm for trap, and expressed big difference by fishery. It needs necessary various kinds of Octopus resource management actions and methods in continuous use. Specially, Fishing force increased by fishing automation system, so the reduction of fishing force is needed to increased by fishing force. Government support and fishermen's self-conscious of resource management is needed.

• 수산해양기술연구
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• 제41권3호
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• pp.179-187
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• 2005

This study was conducted in order to the experiment of bottom trawl fisheries in the sea mount of central northern pacific($30^{\circ}-40^{\circ}N$, $170^{\circ}-175^{\circ}E$), during the period of July 1 to August 25, 2004 by commercial trawl ship. Fishing experiment was carried out by bottom trawl, with the codend of 110mm mesh size. The number of 101 test fishing was done in the sea mount of central northern pacific during 56 days and the total catches were 198,593kg as 18 fish species, and CPUE/day and catches/day were 8.3 hours towing time and 3,546kg. Catch ratio according to each fishing ground was higher with the order of B, C, and E, and catches for B was 7,171.0kg during the towing time of 13.2 hours. Main target species were Pseudopentaceros richardsoni and Beryx splendens, there was 14.9% of damage ratio for fishing gears on catching the target fishes inhabiting on the rough sea bottom. Catches by water depth was the order of 300m below, 301-350m, 451-500m and 351-400m. It is thought that there was no problem on the mesh size because most of fishes caught from the experimental fishing was 30cm over.

• 수산해양기술연구
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• 제43권4호
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• pp.241-250
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• 2007

Fishes were caught by a bottom trawl in the Yeo-ja bay of Korea by every three month(March, June, September and December) and seasonal variation of abundance and species composition were studied in 2005. The catches were 1,187kg and were composed of 115 species with 20 hauls by 5 stations. The dominant species caught were Charybdis bimcaulata, Crangon hakodatei, Parapenaeus fissurus, Oratosguilla oratoria, and Thryssa purava. One hundred fifty species were identified as fish(38%), crustacea(20%), mollusca(4%) and others(38%) which including of Asterias amurensis. The amount of species was high in June and September and low in March and December. The diversity index(H') was about 1.2－2.5 and station similarity of fishes caught among the community was 0.009－0.230.

• International Journal of Ocean System Engineering
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• 제3권4호
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• pp.164-168
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• 2013

Tidal-current power is now recognized as a clean power resource. The turbine blade is the fundamental component of a tidal current power turbine. The kinetic energy available within a tidal current can be converted into rotational power by turbine blades. While in service, turbine blades are generally subjected to cyclic fatigue loading due to their rotation and the rotor-tower interaction. Predicting the fatigue life under a hydrodynamic fatigue load is very important to prevent blade failure while in service. To predict the fatigue life, hydrodynamic load data should be acquired. In this study, the vibration characteristics were analyzed based on three-dimensional unsteady simulations to obtain the cyclic fatigue load. Our results can be applied to the fatigue design of horizontal-axis tidal turbines.

• Ocean and Polar Research
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• 제43권3호
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• pp.165-178
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• 2021

Gadolinium (Gd), one of a rare earth element (REE), has been widely used worldwide since the 1980s, as a resource material for contrast agents injected into examiners of magnetic resonance imaging (MRI) test. The organic complexed form of Gd shows an extremely stable behavior in natural environment (water), so is known that the artificial Gd from medical uses is not removed from the waste water treatment plant (WWTP) and eventually introduced into the ocean through the estuary. Since the 1990s, some previous studies have often been conducted on Gd anomalies in natural water and their effects an artificial origin from land or metropolitan areas, but little research has been potential impacts on the ocean water. In this paper, we review and introduce recent studies related to Gd anomaly in natural water and related marine effects, and also propose the future research directions.

• Ocean and Polar Research
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• 제44권2호
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• pp.113-126
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• 2022

This study was carried out to investigate the benthic polychaetous community and benthic ecosystem quality status on the adjacent continental shelf of Jeju Island, and field surveys were conducted at 31 stations in July and August, 2020. The surface sediment was generally composed of muddy sand facies and sandy mud facies, and the average particle size was medium silt (6.1±1.6∅). The benthic polychaetous community revealed a total of 73 species with a mean density of 242 ind./m². The major dominant species were Notomastus latericeus, Ampharete arctica and Onuphis shirikishinaiensis. By the cluster analysis and nMDS results based on species composition of the benthic polychaetous community, the study area was divided into three station groups arranged from east to west by the water depth and sedimentary facies. The station group located in the west was subdivided into two station groups from south to north. From results of correlation analysis and PCA, it was found that the benthic polychaetous community in the study area had a strong correlation with the sedimentary environment and water depth. The benthic faunal community (or ecosystem) on the adjacent continental shelf of Jeju Island was assessed to be in a healthy state by biotic indices such as AMBI and BPI.

• Ocean and Polar Research
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• 제45권3호
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• pp.173-183
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• 2023

The barren ground phenomenon in Korea began to occur and spread in the southern coast region and in Jeju Island in the 1980s, and since the 1990s, the damage has become serious in the east coast region as well. Korea has enacted the fisheries resource management act to manage such barren ground through the installation of sea forests among projects for the creation of fishery resources. Until now, projects related to the identification of the cause of barren ground have focused on the density of crustose coralline algae, sea urchins and seaweed, so the original cause of barren ground has not yet been identified. In order to manage barren ground, it is necessary to identify the cause of barren ground. To identify these causes, it is necessary to comprehensively consider i) studies on spatial characteristics such as rock mass distribution, slope and water depth, ii) studies on ecological and oceanographic characteristics such as water temperature, salinity, El Niño, and typhoons etc, iii) studies on organisms such as crustose coralline algae, macroalgae, and sea urchins, and iv) studies on coastal use such as living and industrial sewage inflow. Next, as with regard to legislative policy proposals , it is necessary to prepare self-management measures by the government, local governments, and fishermen as well as address management problems related to the use of sea forests by fishermen after their creation . In addition, when creating a sea forest, a management model for each resource management plan is required, and evaluation indicators and indexes that can diagnose the cause of barren ground and guidelines for barren ground measures should be developed.