To develop the artificial spawning seaweeds of the sandfish, Arctoscopus japonicus, the effects by the material type of artificial spawning seaweeds were investigated at Dongsan port in Gangwon-do from December 2006 to March 2007. Sargassum fulvellum, S. horneri, rope and net were used as materials for artificial spawning seaweeds, and the most effective thing among them was S. fulvellum. A. japonicus began to attach the egg mass to artificial spawning seaweeds when sea temperature dropped below 10℃ in December, spawned heavily when it was around 8℃ in January, and completed the behavior when it started to increase over 10℃ in February. The hatching period of eggs was estimated to be about 60 days. The middle position in artificial spawning seaweed had the highest number of egg masses and the diameter of the egg mass ranged from 25mm to 62mm. Based on the result for the effects, the artificial spawning seaweeds of A. japonicus were developed and it is possible to use them to form seaweed forests or spawning grounds of other species.

Cast fishing gear needs some time for fishing progress, and catches and their composition by submerged time can change by several cause. Therefore, it is very importance to study fishing capacity of fishing gear by submerged time. This study is to investigate catches and their composition of shrimp trap, that is used in the coastal of the East Sea, and to find the fittest lifting time of trap. Experimental term are September 2006 and August 2007, the location is the coastal of Oho, Goseong, Gangwondo, Korea and one hundred trap is used at each casting and lifting of gear. For convenience of description, survey of 2006 and 2007 are dented as experimental code 1 and 2, and submerged time 21hr, 43hr and 66hr are dented as code A, B and C. The result of obtained from the above approach are summarized as follows: Many Northern shrimps(Pandalus eous), dominated 96.36%, are only catched in experimental code A, and in code B and C, some of coonstripe shrimp(Pandalus hypsinotus) and few morotoge shrimp(Pandalopsis japonica) are catched. CPUE of code 1A, 1B and 1C per trap were 21.67g, 29.51g and 28.48g, and those of code 2A, 2B and 2C per trap were 25.44g, 32.93g and 33.36g. Therefore, 24.66% of catch increased according as submerged time passes from 1 day to 2 days, and almost no change of catch was to be -1.1%. Carapace length of code 1A, 1B and 1C were 23.77mm, 25.00mm and 25.57mm, and those of code 2A, 2B and 2C per trap were 23.83mm, 24.95mm and 25.45mm. Thus, the more submerged time is, the less catch of small fish is and the more catch of large fish is. Consequently, fit lifting time of shrimp trap is after 2 days, and if considered trouble of fishing gear and condition of catch, the fittest lifting time is the third successive day of casting date.

This study shows that the distribution density of snow crab, Chionoecetes opilio, was estimated using an underwater video monitoring system attached on the towing sledge. The field experiments were carried out at the coastal waters around Chuksan, East Sea, where ranged from 110 to 130m depth during September and October 2007. The sledge was towed for 40 minutes and the towing speed was controlled between 1.5 to 1.7 knot and each research areas were calculated to multiply towed distance by the detection width of the video monitoring system(1.2m), and then, distribution density of snow crab in each observations were estimated as a counted number of crab per 1,000m2. The result shows that their survey, taken between two months, reflected similar results during survey period, and the maximum and mean distribution densities in September estimated to be 77.0(number/1,000m2) and 19.9, respectively, and those of October were 36.0 and 21.8, respectively.

A series of fishing experiments was carried out in the eastern coastal waters of Korea from January, 2002 to March, 2003, using gill nets of different mesh sizes (m 180, 210, 240, 270 and 300 mm) to determine the size selectivity of gill net for female snow crab, Chionoecetes opilio. The catch of experimental gears was mostly snow crab (97%), Chionoecetes opilio. The maximum carapace length (RL) of each female snow crab caught in the fishing experiments was measured. The master selection curve was estimated by applying the extended Kitahara s method. The selection curve showed that the gill nets of larger mesh size allowed more female crabs of small carapace size to escape. The optimum values of RL/m for 1.0 of retention probability was 0.563 and RL/m was estimated to be 0.249, 0.290, 0.319, 0.344 and 0.367 when the retention probability were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively.

For an effective management of fisheries resources, we need fisheries informations necessary for the establishment of reasonable fishing effort and TAC distribution. We carried out fishing research using trammel nets in the coastal sea of Susan-port(Yangyang, Gangwondo, Korea) and Hupo-port(Uljin, Gyeongbukdo, Korea) and analyzed fishing power variation of the fishing gear in terms of species composition, condition and so on for both sites. A total of 29 species were caught with most dominant species of Hippoglossoides dubius followed by Pseudopleuronectes herzensteini, Lophius litulon and Alcichthys elongatus in Susan. The total number of species caught in Hupo was 37 species with most dominant species of Todarodes pacifius followed by Lophius litulon, Hexagrammos agrammus and Pseudopleuronectes herzensteini. CPUE of Susan fishing area per trammel net was 12.74 fish and 2.00kg on average, while it was 6.80 fish and 2.27kg on average for Hupo. The fishing power index for both sites was 1, placing the two fishing grounds in a same level.

The fishing lamp is a fishing gear that gathers fish at night. But the cost of oil, which is used to light fishing lamp, has been risen significantly up to 30-40% of total fishing costs. Therefore it is very urgent to develop an energy economical fishing lamp in order to solve the business difficulties of fisheries. Under this background, this research aims at developing a fishing lamp for squid jigging and hairtail angling fishery using the LED, which has excellent energy efficiency and durability. The LED fishing lamp developed can be controlled to fix a fit direction of fish shoal deep because a fishing lamp can be adjustable up and down directions. One unit of fishing lamp has about an 80Watt capacity and the frame of fishing lamp is made of aluminium to emit generated heat of LED to outside. The LED lamp developed was highly durable, only 5.7% of emitting efficiency decreased for 18 months. The illuminance of a unit LED lamp was 2,070lux at 1m and 21lux at 10 m distance, and the intensity of LED lamp system emitted 2,580lux and 400lux at the respective distances. After development of this fishing lamp, 100 units are installed on operating fishing vessels. Experimental results show that energy consumption of squid jigging and hairtail angling was reduced by 40% and 87%, respectively. In conclusion, our methods showed elevated fishing power, compared with traditional fishing method: 37.7% for squid jigging and 24.5% for hairtail angling.

Squid jigging fishery is very important in that there are about 1,000 jigging vessels more than 10 tonnage and about 5,000 ones less than 10 tonnage in Korea. But the cost of oil which is used to light fishing lamps, goes significantly up to almost one hundred million won for 50 tonnage vessels and forty million won in case of vessels less than 10 tonnage. This cost has almost taken 40% of total fishing costs. That is, the fishing business condition of squid jigging fishery is recently in the very difficult situation. As oil price increases, the business condition of the fishery gets worse and worse. Therefore it is very urgent to develop an economical fishing lamp, to solve this problem of fishery's business difficulty. This research aims at developing a fishing lamp for squid jigging fishery using the light emitting diode which has very excellent efficiency and durability. We made a water tank with 20 meters width which is a shape of raceway to research behavioral characteristics of Japanese flying squid to LED light, and made an experiment to investigate optimum wave of LED light to lure squid. The method is to establish LED lamps on both ends of water tank and to observe squid's behavior. Colors and wave lengths of LED lamps, used in experiment, are red(634nm), yellow(596nm), green(523nm), blue(454nm) and white(454nm+560nm). In experiment for attractive capability of LED lamp to squids, Japanese flying squid are highly attracted to blue lamp and white lamp. However, they are dispersed to red and yellow lamps. In addition, Japanese flying squid have moved and stayed in both dark ends of water tank. When compared intermittent lamp with continuous lamp, Japanese flying squid are highly attracted to intermittent lamp when intermittent interval is 0.25 second.

The mesh selectivity of gill net for Japanese sandfish (Arctoscopus japonicus) caught in the East Sea, Korea was described. The experiment was conducted with five different kinds of mesh size (39.4, 45.5, 51.5, 53.0, 57.6mm) between November and December 2006 in spawning season. The catch was mostly Japanese sandfish (93.3%) and some others (6.7%), and almost all of the female Japanese sandfish were larger than the fork length at 50% maturity (16.7cm). The selection curve for the female Japanese sandfish caught from the experiments was fitted by the Kitahara's method to a polynomial equation which was s(R)=exp{(0.2584R3-5.3445R2+32.269R-59.868)-0.6585} where R＝l/m, and l and m are fork length and mesh size, respectively.

The investigation for the species composition and catch in the deep East Sea was carried out with commercial trawlers from 2004 to 2006. The catches were 6,043kg and were composed of 43 species with 34 hauls between 250m and 1,030m in depth. The principal species caught were Allolepis hollandi, red crab (Chionoecetes japonicus), Careproctus rastrinus, Argis lar, Chionoecetes opilio, Malacocottus gibber, Petroschmidtia toyamensis, Pandalus eous Makarov, and Dasycottus setiger. The rate of discarded catches in situ was about 50%. The diversity indexes of 2005 and 2006 were 1.152 and 0.878, respectively, and the evenness indexes at those years were 0.752 and 0.583, respectively, which implied one dominant species caught in 2006.

This paper introduces an auto-feeding system to exactly control the feeding time and the amount to cultured fishes in aquaculture industrial field. To reduce expensive costs or labors in this field, it was designed by the concept of controlling feed quantity exactly on the basis of fish's feeding behavior pattern in water tank. A feed control method of this system was developed for controlling feed amount by rotor capacity and motor rotated number. Moreover, a scattering section was selected by rotate way of propeller wing to scatter dried feed to designated site, and then, the diameter of its wing was 250mm and maximum scattering distance was 7.6m for 600rpm. Furthermore, the scattering ways were embodied 2 types such as a simplified way and a multistage shift way looks like a manual scattering. As a results, the multistage shift way is more effective to discharge the dried feed widely than the simple way in the water tank.

This research aims at establishing the application of canvas kite to the fishing gear through the analysis of the lift/drag tests of the kites have been performed in our previous finding. Now that several methodologies were designed to find the most effective triangular model as a buoyancy device applied to the fishing gear. Comparisons of drag/lift were made by installing the model in an installation frame instead of the prototype. Also, we have considered the application of canvas kite to the prototypic fishing gear by calculation using the result of this test. The results obtained from the above approaches are summarized as follows, where attack angle, lift coefficient, maximum lift coefficient and drag coefficient are denoted as B, CL, CLmax and CD respectively. The camber showed a gradual increase with an increase of fluid velocity. There was a big discrepancy in B=20 unlike B=30. Even if the kite retreats along the fluid flow, there is little relationship with the velocity variation. Lifts calculated with the kites were bigger and drags were smaller than those of the calculations with the float only. The kite as the buoyancy device will be very useful when the appropriate applications and the stability are met.

This research aims at establishing the fundamental characteristics of the kite through the analysis of the flow field around various types of kites. The approach of this study were adopted for the analysis; visualization by CFD(computational fluid dynamics). Also, the lift/drag and PIV(particle image velocimetry) tests of kites had been performed in our previous finding. For this situation, models of canvas kite were designed by solidworks(design program) for the CFD test using the same conditions as in the lift/drag tests. And we utilized FloWorks as a CFD analysis program. The results obtained from the above approach are summarized as follows: According to comparison of the measured and analyzed results from mechanical tests, PIV and CFD test, the results of all test were similar. The numerical results of lift-coefficient and drag-coefficient were 5-20% less than those of the tests when attack angle is 10˚, 20˚ and 30˚. In particular, it showed the 20% discrepancy at 40˚. The numerical results of the ratio of drag and lift were 8-13% less than those of the tests at 10˚ and 10% less than those of the tests at 20˚, 30˚ and 40˚. Pressure distribution gradually became stable at 10˚. In particular, the rectangular and triangular types had the centre of the high pressure field towards the leading edge and the inverted triangular type had it towards the trailing edge. The increase of the attack angle resulted in the eddy in order of the rectangular, triangular and inverted triangular type. The magnitude of the eddy followed the same order. The effect of edge-eddy was biggest in the triangular type followed by the rectangular and then the inverted triangular type. The action point of dynamic pressure as a function of the attack angle was close to the rear area of the model with the small attack angle, and with large attack angle, the action point was close to the front part of the model.

This research aims at establishing the fundamental characteristics of the kite through the analysis of the flow field around various types of kites. The approach of this study were adopted for the analysis; visualization by PIV(particle image velocimetry). Also, the lift and drag tests of kites had been performed in our previous finding(Bae et al., 2004a; Bae et al., 2004b). For this situation, models of canvas kite were deployed in the circulating water channel for the PIV test using the same conditions as in the lift and drag tests. The results obtained from the above approach are summarized as follows: Given the rectangular and triangular kites when attack angle is 20˚, vortex by the boundary layer separation was seen in the leading edge and the flow towards the trailing edge was more turbulent. But, the inverted triangular type kite was seen to be stable without any boundary layer separation or turbulence. The increase of the attack angle resulted in the eddy in order of the rectangular, triangular and inverted triangular type. The magnitude of the eddy followed the same order. The effect of edge-eddy was biggest in the triangular type followed by the rectangular and then the inverted triangular type. The kite as the buoyancy device or the opening device will be very useful when the appropriate applications and the stability are met.

종횡비, 다각형 모양에 따른 평판과 범포의 유체역학적 특성을 규명하고자 직사각형, 사다리꼴 모양으로 모형 평판과 범포를 제작하고 회류수조에서 양 · 항력 실험을 수행하였다. 그 결과를 요약하면 다음과 같다. 1. 삼각형 평판의 경우, 종횡비가 1 이하인 모형에서는 38~42˚에서 최대 CL이 1.23~1.32, 1.5 이상인 모형에서는 20~50˚에서 CL이 약 0.85 전후였다. 역삼각형 평판의 경우, 종횡비가 1 이하인 모형에서는 영가가 36~38˚에서 최대 CL이 1.46~1.56, 1.5 이상인 모형에서는 22~26˚에서 1.05~1.21 정도였다. 같은 삼각형 평판 모형에서는 전자의 모형이 후자보다 CL이 작게, 양항비도 작게 나타났다. 2. 삼각형 범포의 경우, 종횡비가 1 이하인 모형에서는 영각 46~48˚에서 최대 CL이 1.67~1.77, 1.5 이상인 모형에서는 20~50˚에서 CL이 약 1.1 전후였다. 역삼각형 범포의 경우, 종횡비가 1 이하인 모형에서는 영각 28~32˚에서 최대 CL이 1.44~1.68, 1.5 이상인 모형에서는 18~24˚에서 10.3~1.18 정도였다. 같은 삼각형 범포 모형에서는 전자의 모형이 후자보다 CL은 크게, 양항비는 작게 나타났다. 3. 모형에서 물의 유체력을 많이 받을 수 있는 곳에서 만곡꼭지점이 만들어지며, 삼각형 모형에서는 종횡비가 클수록, 역삼각형 모형에서는 작을수록 만곡꼭지점의 위치도 컸다. 4. 만곡도는 전 모형에서 종횡비가 클수록 컸으며, 삼각형 모형에서는 영각이 클수록 컸고 역삼각형 모형에서는 작을수록 컸다.

종횡비, 다각형 모양에 따른 평판과 범포의 유체역학적 특성을 규명하고자 직사각형, 사다리꼴 모양으로 모형 평판과 범포를 제작하고 회류수조에서 양 · 항력 실험을 수행하였다. 그 결과를 요약하면 다음과 같다. 1. 직사각형 평판의 경우, 종횡비가 1 이하인 모형에서는 영각 40~42˚에서 최대 CL이 1.46~1.54, 1.5 이상인 모형에서는 20~22˚에서 10.7~1.11 정도였다. 직사각형 범포의 경우, 종횡비가 1 이하인 모형에서는 영각 32~40˚에서 최대 CL이 1.75~1.91, 1.5 이상인 모형에서는 18~22˚에서 1.248~1.40 정도였다. 같은 직사각형 모형에서는 범포가 평판보다 CL은 크게, 양항비는 작게 나타났다. 2. 사다리꼴 범포의 경우, 종횡비가 1.5 이하인 모형에서는 영각 34~44˚에서 최대 CL이 1.65~1.89, 2인 모형에서는 14~48˚에서 CL이 약 1.00 전후였다. 역사다리꼴 범포의 경우, 종횡비가 1.5 이하인 모형에서는 영각 24~36˚에서 최대 CL이 1.57~1.74, 2인 모형에서는 18˚에서 1.21이었다. 같은 사다리꼴 범포 모형에서는 전자의 모형이 후자보다 CL은 조금 크게, 양항비는 작게 나타났다. 3. 모형에서 물의 유체력을 많이 받을 수 있는 곳에서 만곡꼭지점이 만들어지며, 직사각형, 사다리꼴 모형에서는 종횡비가 클수록, 역사다리꼴 모형에서는 종횡비가 클수록, 역사다리꼴 모형에서는 작을수록 만곡꼭지점의 위치도 컸다. 4. 만곡도는 전 모형에서 종횡비가 클수록 컸으며, 직사각형, 사다리꼴 모형에서 영각의 클수록 컸고 직사각형 모형이 사다리꼴 모형보다 컸다.

초망어업에 있어서 멸치군을 집어하기 위한 집어등의 광량을 구명하기 위한 기초연구로서 1 ㎾ 와 2 ㎾ 백열등의 방사조도 특성을 계측하였으며, 그 결과를 요약하면 다음과 같다. 1. 백열등의 수중방사조도는 파장 690 nm에서 최대치를 보였고, 2가지 백열등의 수중 방사조도 L(W/ cm2/nm)와 섬도 Z(m)와의 관계식은, 1 ㎾ : L = 3851.9 e-1.4587Z R2=0.9952 2 ㎾ : L= 8211.9 e-1.2852Z R2=0.9977이었다. 2. 2 ㎾ 백열등의 수중 방사조도는 섬도 4m 층보다 얕은 수층에서는 1 ㎾ 백열등보다 3~4배 높게 나타났지만 심도 6m보다 깊은 수층부터는 동일한 밝기를 나타내었다. 3. 1 ㎾ 백열등의 빛은 정횡방향보다 연직방향쪽으로 많이 투과되었으며, 집어등의 연직방향에 있어서 심도 20m층의 수중방사조도는 0.1 lχ이었다.

멸치초망어업에서는 반사갓에 AC 100V, 1kW 백열등 1개를 끼워서 집어등으로 사용하고 있다. 집어등은 저층에 있는 어군을 표층까지 부상시키고, 또한 표층에 유집된 어군을 자루그물로 유도하는 역할을 수행하고 있다. 본 연구에서는 멸치군을 유효하게 집어, 유도할 수 있는 집어 등을 구명하기 위한 기초연구로서 현재 초망어업에서 사용되고 있는 반사갓의 방사효율과 1kW 백열등의 파장별 방사특성을 계측하였으며, 그 결과를 요약하면 다음과 같다. 1. 반사갓은 백열등의 방사효율을 1.8배 정도 증가시켰으며, 전구를 중심으로 원형에 가깝게 빛을 수중으로 방사시켰고, 이는 수중광도계로 측정한 방사조도와도 잘 일치하였다. 2. 공기중에서 백열등의 방사조도는 994nm의 파장에서 최대치를 보인 반면 심도 0.5m, 1.0m 층에서 최대치를 보인 반면 심도 0.5m, 1.0m층에서는 모두 690nm의 파장에서 최대치를 보였다. 3. 집어등의 연직 하방에 있어서 심도(x)과 수중조도(y)와의 관계식은 다음과 같다. y=146.03e 상(-0.37x) 4. 1kW 백열등의 빛은 정횡방향보다 연직방향쪽으로 많이 투과되었으며, 집어등 직하에서의 빛은 심도 20m이심에는 도달하지 않는다고 추정된다.

멸치초망용 챗대의 유압 권양장치를 개발하기 위하여 모형 챗대와 그물을 실물의 1/5크기로 제작하여 챗대를 권양할 때의 장력을 측정하고, 이를 토대로 권양기 3종을 설계 제작하여 그 성능을 시험한 결과를 요약하면 다음과 같다. 1. 챗대를 건양하는데 가장 큰 장력이 작용할 때는 챗대 끝이 수면 하 4m에 있을 때이었고, 이 때 챗대줄에 작용하는 장력은 187.5kgf이었다. 2. 멸치초망 어업에 적합한 권양기의 조건은 어탐중 챗대가 움직이지 않아야 하며, 그 방법으로 감속기나 전자브레이크를 장치하는 것보다 시간 경과에 따른 누수량이 적은 것을 사용하는 것이 바람직하였다. 3. 시험에 사용된 권양기 중 최적의 권양기에 있어서 압력차 δP를 130kgf/ cm2으로 고정하였을 때, 권양기에 감겨지는 챗대줄의 권양속도는 2m/sec로서 재래식 방법보다 0.48m/sec 빠르게 나타났으며, 양망당 약 1.6톤의 멸치를 어획할 수 있다. 4. 권양기 2대를 설치함으로써 조업인원 2명을 절감할 수 있었다.

본 연구는 원양 다랭이 연승 어획량을 데이터 베이스 처리하여 여러 가지 정보를 제공함으로써 조업시 경제성 있는 어장 선정에 도움을 주기 위하여 처리 프로그램을 작성하여 그 실용성을 검토해 보고자 하였다. 자료는 국립수산진흥원에서 발행한 보고서의 어획량 데이터를 이용하였고, 데이터 베이스 처리를 위한 프로그램을 설계한 후 실행해 보았다. 1)프로그램은 Quick Basic을 이용하여 작성하였고, 데이터 파일은 random 파일로 변환하여 사용하였다. 데이터 베이스 프로그램은 구획별로 조획율을 나타내는 어장도를 그리는 프로그램과 조획율을 나타내는 그래프 및 도표를 구성하는 프로그램, 데이터 통계를 나타내는 프로그램, 그리고 어장 평가 지수를 나타내는 프로그램으로 구성하였다. 2)조획율을 나타내는 어장도에서는 5˚간격의 해구에 조획율의 크기를 나타내는 원을 나타냄으로써 사용자가 쉽게 어획이 잘되는 해역을 판단 할 수 있었다. 3)조획율을 수치로 나타내는 도표를 통하여 원의 크기로 나타내었던 조획율 값을 좀 더 상세히 알 수 있었다. 4)시기, 저장, 어종에 따른 조획율 및 어획마리수의 그래프는 그것의 변화패턴의 규명에 도움이 되었다. 5)어장의 경제성을 비교해 볼 수 있는 시뮬레이션 기능을 이용하여 조업자가 경제성 있는 어장을 권고 받을 수 있었다.