• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.38 no.2
• /
• pp.91-100
• /
• 2002

The field experiments were carried out to examine for the mesh selectivity in trammel net and optimum mesh size, during Aug. 10~13, Non 9~13 2000 in Jumunjin, Kangwon-Do and during Jun. 1~27 2001 in Suyong-Bay, Busan. The experiments in Jumunjin area were conducted by using trammel nets with seven different mesh sizes (60, 75, 90, 105, 135, 150, 180mm) and those in Suyong-Bay were done by using trammel nets and gill nets with three different mesh sizes (60, 75, 90mm) in order to compare two types of nets of same structure. The mesh selectivity analysis was done mainly with flat fish(Eopsetta grigorjewi) that was occupied 60% out of total catches. And the mesh selectivity was written by extension of Kitahara's method included master curve with function type. The results obtained are summarized as follows 1. Total number of catch by, trammel net was 2,331 and that of gill net was 1,433, and flat fishes occupied 59.8 ~60% in total catches. 2. The value of optimum l/m by, trammel net was higher about 0.1 than that of gill net according as trammel net was 2.56, and gill net was 2.47. 3. The 50% selection range by, trammel net was wider about 1.5 time than that of gill net according as trammel net was 1.88~3.36(1.48) and gill net was 2.00~3.02(1.02). 4. The optimum mesh size(OMS) was estimated that trammel net was about 141mm and gill net was about 132mm on first maturity length(FML) 265mm of flat fish. 5. On the optimum mesh size based on the first maturity length of flat fish, The 50% range by, trammel net was wider about 76mm than that of gill net according as trammel net was 265 mm~474mm and gill net was 265mm~398mm.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2003.10a
• /
• pp.27-30
• /
• 2003

자망이나 삼중자망은 그물에 고기가 꽂히거나 얽히게 하여 어획하는 어법이다. 흐름이 있는 곳에서 어구는 저항을 받게 되고, 이에 따라 형성되는 어구 형상은 유속 세기와 부력 및 사용된 그물의 망지 길이(뻗친 높이)와 관련된다(장ㆍ서, 1982; 천상, 1981; 송전, 2001). 이때 자망의 높이는 어획 효율에 영향을 미치는 매우 중요한 요소이다. 저자망의 경우 뜸줄의 높이는 바다에서 다이버나 자기기록식 기록계에 의해 기록되거나 flume tank에서 여러 가지 망목크기와 길이 및 망사직경에 대해 조사된 바가 있다 (Matuda, 1988; Stewart, 1988). (중략)

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.8 no.1
• /
• pp.7-10
• /
• 1975

The catches of mackerel by monofilament and multifilament net were compared by means of $x^2$ and t-test method. In order to improve the netting twine of drift nets, 6 shoots 5 different mesh and nylon-monofilament netting twines $(B\times2,\;C\;D,\;F,)$ and 2 shoe nylon-multifilament $(A\times2)$ which are using near the Jeju Island in contemporary days were used for the experiment. These gill no were connected in order of A, ,B, C, A, B, E, F and operated fly fishing boat Taeann Ho (7T) near sea of Jeju Ialand from May 1974 to August 1974. The results obtained are as follows: 1. B type nylon-monofilament gill nets were superior to nylon-multifilament gill nets in catch according to the result of $X^2$ test and t-test, and the catch ratio was $M_A:\;M_B=1:1.8$. 2. 75mm mesh size C, D nylon-monofilament gill nets were superior to 85mm mesh size nylonmonofilament gill nets, and their catch ratio were E, F: C, D=1:2.8. 3. The catch ratio C, D and E, F type nets were compared by means of t-teat, however could not recognized their relationship.

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

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2003.10a
• /
• pp.51-54
• /
• 2003

인공어초 시설사업은 수산자원을 조성하고, 조성된 자원을 효율적으로 이용하는데 있다. 지금까지 어업인들은 어초의 구조적 특성과 어구 운용의 편리성 때문에 삼중자망으로 인공어초 어장에서 조업이 이루어지고 있다. 삼중자망어구는 미성숙어를 비롯한 다양한 어류가 어획되기 때문에 수산자원보호 측면에서 한국의 일부해역을 제외하고는 수산업법상 불법어구로 규정하고 있다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2002.10a
• /
• pp.39-40
• /
• 2002

전어는 한국 연안에 널리 분포하고 있으며, 주로 남해안과 동해안에서 어획이 이루어지고 있다. 전어의 어획 방법은 1978년까지는 주로 자망에 의하여 어획되었으나, 최근에는 소형 선망에 의한 어획량이 증가하고 있으며, 이것은 소수의 소형 선망에 전어가 대량으로 어획되는 영향에 기인한다. 그러나, 자망은 다른 어구에 비하여 어구의 비용이 적게 들고 소형 어선으로도 조업이 가능하므로 여전히 많은 수의 자망 어선이 전어가 연안으로 회유하여 오는 봄과 가을에는 선자망을 사용하여 조업을 행하고 있다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2001.10a
• /
• pp.51-52
• /
• 2001

남해안의 사니질에 주로 서식하는 보리새우(변, 1970, 1974)는 주로 삼중자망으로 어획되고 있으며, 활어 또는 선어 상태로 고가로 소비되고 있는 중요한 어업생물이다. 보리새우의 생태, 습성 등으로 미루어보아 현재 허가된 대하 삼중자망외의 어구, 어법으로는 어획이 거의 없거나 조업이 불가하여 합법적으로 어획하지 못하고, 보리새우 자원을 방치해야할 실정이다. 따라서 본 연구에서는 수조에서 보리새우의 습성과 그물에 대한 반응행동 및 어획시 이동 현상 등을 관찰하고, 새로운 홑자망을 구성하여 삼중자망 등과 같이 시험조업을 실시하고 현재까지의 결과를 보고한다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2004.10a
• /
• pp.40-43
• /
• 2004

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2004.05a
• /
• pp.69-71
• /
• 2004

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.36 no.2
• /
• pp.89-95
• /
• 2000

Test fishing was carried out to examine the selectivity of the mesh size in trammel net for tonguefish (Cynoglossidae spp.) from May to August, 1999 and a total of 30 times of test fishing have been done in the coastal waters around Dolsando, Yosu, South Chunra province, Korea. A gill net and a trammel net which were composed of three different mesh sizes (70.5mm, 86.6mm and 101mm) were used for the experiment. The selectivity curve of mesh size was estimated by Kitahara's method for Robust tonguefish (Cynoglossus robustus). The results obtained are summarized as follows ; 1. Catching efficiency of the trammel net (70.5mm-sized-lint main net) was 39.0% and it was 2.5 times higher than 15.8% for the gill net. 2. The optimum l/m value of the trammel net was 3.51 and it was 0.13 higher than 3.38 for the gill net. 3. The selectivity of trammel net was similar to that of the gill net for low length-class. However, the selectivity of trammel net was not good compared with that of the gill net for high length-class. The 50% selectivity was 1.33 for the trammel net and 0.83 for the gill net. According to the experimental results, fishing efficiency of the trammel net was better than that of the gill net for tonguefish (Cynoglossidae spp.) and it was known that catch length for targeted species could be selected by controlling the mesh size.