• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.3
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• pp.182-188
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• 2004

It has been, in general, known that the catching efficiency of a trammel net is better than that of a gill net because of the variability of catch species and size. In this stidy, A fishing gear test was carried out to analyze the catching efficiency of the gill net and the trammel net on the coast of Geomun-do of southern Korean waters and fish school aggregation was also investigated using a underwater video camera. CPUE of the gill net was 49.2% higher than the trammel net but fish species was 34.5% lower where there was no difference on the significance level of 5% by ANOVA test. Main catch species caught by the gill net were red seabream(Pagrus major) and triggerfish(Aluterus monoceros), skate ray(Raja Kenojei) and red seabream for the trammel net, and the average body length of red seabream was shorter than the trammel net. It was thought that the reason of higher catch in the gill net than the trammel net was a fish school which can be caught easily by gill net and the size of population was suitable for the gill net.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.4
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• pp.310-314
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• 1990

In order to find out the most favorable shape and structure of pot for crab, Charybdis japonica Edwards, the common box type and cylinder type of net pots with two entrances, and the modified cone type and box type of net ones with four were prepared respectively. Then, the ability of the above pots attracting the crab into them and their catches were investigated through tank and field experiments. The attracting ability was higher in pots with four entrances than those with two. In case of two entrance pots, the ability was a little higher in the cylinder type than in the box type. But in four entrance pots, the box type yielded a little higher ability than the cone type. The catches were also arranged by the pots in almost same order with the attracting ability. But, it was only added to the arrangement that the cone type with four entrances had no significant difference of catch with the cylinder type with two entrances. Thus, the most favorable pot for the crab was concluded to be the box type with four entrances.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.10a
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• pp.63-66
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• 2003

남획에 의한 어자원 감소와 오염으로 인한 해양 환경의 변화, 그리고 주변국과의 어업협정 체결 및 수입 개방 조치 등에 의한 어업정책의 변경으로 어업인의 소득이 심각한 타격을 입게 되면서, 어획 성능이 우수하고 조업 방식이 간편하며 소요 경비가 절감되는 어구어법으로의 전환이 빠르게 진행되고 있는 실정이다. 삼중자망은 홑자망, 통발에 비해 조업방법이 간단하고 특별한 어로설비를 필요로 하지 않으며 우수한 어획성능을 가지고 있어 어업인들이 선호하고 있으나 심각한 자원 남획을 유발하는 어구이기 때문에, 삼중자망의 불법사용에 대한 규제와 단속을 지속적으로 실시하고 있다. (중략)

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.197-201
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• 1975

다랭이 주낚의 양승방식에는 방향의 양승(On-tracing retrieve)방식과 역방향의 양승(Back-tracing retrieve) 방식의 두가지 방식이 있다. 순방향의 양승은 최초에 투승된 주낙끝에서부터 양승하기 시작하여 투승한 순과 같은 순으로 양승하는 것이고 역방향의 양승은 최후에 투승된 주낚끝에서부터 양승하기 시작하며 투승한 순과 반대순으로 양승하는 것이다. 주낚의 조업소요시간을 변갱하지 않고 양승방식만 변갱한다면 주낚의 평균침지시간은 변하지 않고 다만 침지시간의 분포구간만 변한다. 투승작업시간을 $\tau_1$, 투승작업이 끝나고 양승작업을 시작하기까지의 대기시간을 $\tau_2$, 양승작업시간을 $\tau_3$하면 주낚의 침지시간분포범위는 양승방식에 따라 다음과 같이 서로 다르다. $\tau_2$부터 $\tau_1+\tau_2+\tau_3$까지의 범위 역방향으로 양승할 때 $\tau_1+\tau_2$부터 $\tau_2+\tau_3$까지의 범위 임의시의 낚시 어획성능은 $F_0\varrho-^{-zt}$ ($F_0$는 초기어획성능, z는 감소계수, t는 투승후 경과시간)으로 나타낼 수 있고 침지시간 t인 낚시 Hro의 어획미수는 $H_{F_0}\frac{1-\varrho^{-zt}}{z}$로 나타낼 수 있으므로 주낙조업에서 낚시수 $H_G$개 이고 침지시간이 $\tau_\alpha$와 $\tau_\beta$ 범위내에서 분포하면 어획미수는 $C_G$는 다음과 같이 나타낼 수 있다. $$C_G=\frac{H_G}{\tau_\beta-\tau_\alpha}{\cdot}\frac{F_0}{Z}\int^{\tau_\beta}_{\tau_\alpha}(1-\varrho^{-zt})dt$$ $\tau_\alpha,\;\tau_\beta$의 값은 순방향의 양승에 있어서는 $\tau_\alpha=\tau_1+\tau_2,\;\tau_\beta=\tau_2+\tau_3$, 역방향은 양승에 있어서는 $\tau_\alpha=\tau_2,\;\tau_\beta=\tau_1+\tau_2+\tau_3$. 따라서 다랭이 주낚의 어획미수는 그 양승방식에 따라 차가 있고 순방향의 양승으로 더 많은 어획미수를 얻을 수 있다.

• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.69-70
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• 2006

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2005.05a
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• pp.109-111
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• 2005

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2010.05a
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• pp.199-202
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• 2010

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2005.11a
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• pp.45-48
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• 2005

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.2
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• pp.95-105
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• 1987

Traditional sea Eel pots can be divided into two groups such as bamboo and plastic pots, however they are nearly same in a shape with one entrance and fishing efficiency, except their materials. Very few yet have been studied on their catching methods or catching mechanisms at the view point of behavior. Accordingly, we have designed tubular pots in order to fill up faults of traditional fishing gear construction and behaviors of sea eel. The suitable tubular pots was decided by comparative experiments in the water tank and the fishing efficiency was compared through the field experiments. The results obtained are as follows : 1. The differences between traditional plastic pots and improved tubular pots are firstly two entrances in both ends of tube without holes, secondly flapper nets are fixed at the end of each cone, and thirdly a bait bag is fixed at the center of pot. 2. The standard size of the suitable tubular pot is: $$Tube\;:\;\phi\;12\~13{\times}L80\;cm$$, $$Cone\;:\;Inside\;ring\;\phi6{\times}D5\;cm$$, Flapper : L10 cm. 3. The fishing efficiency of tubular rots is 2.3 times better than that of plastic pots.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.25 no.2
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• pp.61-69
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• 1989

Mackerel purse seine fishery operating in the sea area of Cheju and Tsushima is one of the most important fishery in Korean off shore fishery, which a fishing fleet are generally composed with one purse seiner, two light ships and three or four fish carriers. In this study, purse seiners are classified in to four classes in term of their gross tonnage : A class(80-100tons), B class(100-120tons), C class(130-140tons), and D class(140-150tons). Operating sea area are divided into five sectors including east and west sea area of Tsushima Island, coastal sea area of Cheju Island and south and west sea area of Cheju Island. The performance of the purse seiner, the fishing efficiency, the dimension of fishing gear and variation of CPUE in each operating sea area are summarized as follows: 1. The relationship between a gross tonnage x and net area of purse seine y of a purse seiner can be expressed as : y=538.8x+99657.3 2. The index of seasonal variation of CPUE from May to October is lower than the standard value, whereas index from November to April is higher. 3. The power factor of fishing efficiency by classes of boat-size shows significant differences with 1% level in each operating sea area. 4. The net efficiency of purse seiner by classes of boat-sea shows that B and C classes are higher than A and D classes.