Anchovy Boat Seine Research Articles

A study on the improvement of fishing system using miniaturized nets for anchovy boat seine to reduce the fleet size

A study on the improvement of fishing system using miniaturized nets for anchovy boat seine to reduce the fleet size

Analysis of profitability deterioration factors of anchovy boat seine fishery in South Korea

Analysis of profitability deterioration factors of anchovy boat seine fishery in South Korea

The opening efficiency of the miniaturized small-scale net for anchovy boat seine to reduce the fleet size

The opening efficiency of the miniaturized small-scale net for anchovy boat seine to reduce the fleet size

The Performance of the New Fishing Gears of the Anchovy Boat Seine Fishery Using a Hydroacoustic Method

The anchovy boat seine fishery is conducted only in South Korea and Japan. This fishery has the largest fishing gear among towing net fisheries in the world. Hence, the expenses of manufacturing and repairing the fishing gear become formidable, and handling the huge fishing gear involves significant labor force and risk. Our research team has developed a small and a large improved fishing gears of the anchovy boat seine fishery. The performance of two improved fishing gears compared to the existent fishing gear was investigated using a hydroacoustic method. In particular, net shapes of the two improved gears and existent one were examined. As a result, it had a tendency that the height of the net mouth increased as the distance between two net vessels broadened. Between the small and large improved fishing gears, the height of the net mouth was not much different. The morphological characteristics of fish schools among two improved fishing gears and the existent one were precisely described. In consideration with the net shape, noise, and the number of escaped anchovy schools, the large improved fishing gear had the best performance. In addition, the water temperature and salinity at 10 ~ 20 m where anchovy schools were mainly distributed was approximately 16 °C and 33.3 psu, respectively. These results can contribute the efficiency and safety of the anchovy boat seine fishing operation.

The opening efficiency of the miniaturized large-scale net for anchovy boat seine to reduce the fleet size

The opening efficiency of the miniaturized large-scale net for anchovy boat seine to reduce the fleet size

The opening efficiency of the existent net of the anchovy boat seine

The opening efficiency of the existent net of the anchovy boat seine

탄소저감형 권현망어구 개발의 경제성 분석

The main purpose of this study is to analyse economic feasibility of low-carbon-oriented gear for anchovy boat seine. The results of benefit/cost analysis showed that use of the low-carbon fishing gear is economically feasible. Considering the fuel saving and relatively low emission by reducing the resistance of gear, net present value by such type 1 gear improvement was estimated about -2,490 ~ -1,580 million won with the benefit-cost ratio 0.81~ 0.88. And net present value by such type 2 gear improvement was estimated about 6,540 ~ 7,780 million won with the benefit-cost ratio 1.79 ~ 1.94. Development of lowcarbon trawl gear would render significant contributions to reducing emission in fishing operations and lead to reduce fishing costs due to fuel savings.

Fishery Despoliation of Japan and History of Anchovy Boat Seine Fisheries

Fishery Despoliation of Japan and History of Anchovy Boat Seine Fisheries

기선권현망어업의 3척식 자동화 양망시스템 개발

This study was conducted in order to improve the automatic fishing operation system for anchovy boat seine by comparison with the fishing gear geometry and efficiency using the labor saving nets and the combined type net with midwater trawl. Field experiments were carried out to observe the geometry of nets and improve the fishing operation system by catcher boats. The vertical net opening of fore wing net, square, fore bag net and after bag net of the combined type net were varied in the range of 9.9~12.9. 16.2~28.2, 6.8~12.1 and 9.5~15.2m respectively, when the towing speed was 1.0m/sec and the distance between boats were 100m, 200m, 300m. The vertical net opening of the combined type nets was gradually decreased as function of with increasing the distance between catcher boats. Labor saving net which was maintained the net opening and towing depth stable was more suitable for the automatic hauling operation system by improvement of bag net rather than the combined type nets which was impossible in swallow depth and near to anchovy school. 3 boats hauling operation system of the labor saving net was carried out by crane with power block in 2 catcher boats for improvement of hauling operation and pushing equipment of anchovy cooking system in the processing boat for maintain more anchovy in dry frame. From the results of field experiments, 3 boats hauling operation system with power block and improved cooking system was very 3 boats hauling operation system with power block and improved cooking system was very useful and more practical as hauling time 20~35min and No. of fishermen 12~13 in comparison with the traditional system such as hauling time 30~50 min and No. of fishmen 28~38.

기선권현망어구의 조업과정중 수중형상

This study was carried out to observe the underwater geometry of the anchovy boat seine by two fishing operation systems. One was a traditional operation system that used a fish detecting boat, another was a new operation system that used the same fishing gear with floats and sinkers in comparison with a fish detecting boat. Vertical opening of the fishing gear that used a casting net, working depth of each part of the fishing gear that used a new operation system was almost canstant, but was gradually shallow in a traditional operation system. Just before hauling net, working depth of each part of the fishing gear that used a new operation system was maintained stable, but was vertically unstable in a traditional operation system because as rear part of the fishing gear was risen up the upper layer. Just after hauling net, working depth of the fishing gear that used a new operation system was also maintained stable, and then anchovy school could be lead to bag net.

생력형 기선권현망 어구의 전개성능

기선권현망어업의 어구 개량과 조업시스템 개선을 목적으로 생력형어구를 제작하여 현장조업선에 의한 해상실험을 실시하여 어구의 형상과 조업시스템을 관찰한 결과를 요약하면 다음과 같다. 1. 생력형 어구의 양선간격에 따른 오비기 앞끝, 오비기, 수비, 앞창, 자루그물 입구, 깔때기, 자루그물 뒤끝의 망고 변화폭은 각각 5.0<TEX>${\sim}$</TEX>7.8, 14.4<TEX>${\sim}$</TEX>21.1, 16.2<TEX>${\sim}$</TEX>21.2, 14.0<TEX>${\sim}$</TEX>17.3, 11.7<TEX>${\sim}$</TEX>13.9, 5.4<TEX>${\sim}$</TEX>6.9, 8.2<TEX>${\sim}$</TEX>9.8m이었고, 각 부분의 실제 전개율은 50<TEX>${\sim}$</TEX>78, 25<TEX>${\sim}$</TEX>36, 24<TEX>${\sim}$</TEX>31, 31<TEX>${\sim}$</TEX>38, 61<TEX>${\sim}$</TEX>73, 71<TEX>${\sim}$</TEX>91, 87<TEX>${\sim}$</TEX>104%로 나타났다. 2. 생력형 어구는 그물목줄 부착으로 오비기 앞끝의 전개가 신속하게 이루어지고 있으며, 개량된 나발그물 부착으로 축소형 개량어구보다 포켓형상을 대폭 개선시켜 어군의 유도가 매우 원활하였다. 또한, 양선간격 및 예망속도 변화에 따른 어구 형상이 매우 안정되었으며, 망고의 변화 폭이 크지 않아 어구의 전개성능이 향상되었다. 3. 자루그물의 개량으로 어구저항 감소, 예망속도 증대 및 입망된 어군의 도피가 현저히 감소하여 어획량이 현용어구보다 증가하였으며, 조업시스템의 개선이 가능하였다. This study was conducted in order to improvement of fishing gear and fishing operating system for anchovy boat seine by labor saving improved nets. Field experiments were carried out observe geometry of nets and fishing operating system by catcher boats. The obtained results are summarized as follows : The Vertical net opening of fore wing net, wing net, inside wing net, square, fore bag net, flapper, after bag net of the labor saving improved net according to the distance between catcher boats were varied in the range of 5.0<TEX>${\sim}$</TEX>7.8, 14.4<TEX>${\sim}$</TEX>21.1, 16.2<TEX>${\sim}$</TEX>21.2, 14.0<TEX>${\sim}$</TEX>17.3, 11.7<TEX>${\sim}$</TEX>13.9, 5.4<TEX>${\sim}$</TEX>6.9, 8.2<TEX>${\sim}$</TEX>9.8m respectively, varied in the range of 50<TEX>${\sim}$</TEX>78, 25<TEX>${\sim}$</TEX>36, 24<TEX>${\sim}$</TEX>31, 31<TEX>${\sim}$</TEX>38, 61<TEX>${\sim}$</TEX>73, 71<TEX>${\sim}$</TEX>91, 87<TEX>${\sim}$</TEX>104% of the actual ratio of net opening in each part. Labor saving improved net was performed instant net opening in fore wing net and maintained stable net opening and towing depth by means of attached net pendant. Also, it was minimized as net pocket phenomenon leading to guide anchovy for more catch by means of attached body net. The opening in accordance with distance between catcher boats and towing speed. The catch of labor saving improved net was increased than traditional net due to decrement of net resistance by improvement of bag net leading to increasement of towing speed and reduction of escape anchovy as well as improve nets of whole operation system.

기선권현망 축소형 개량어구의 전개성능

기선권현망어업의 어구 개량과 조업시스템 개선을 목적으로 자루그물을 A, B 2가지로 달리한 축소형 개량어구를 설계, 제작하여 현장조업선에 의한 해상실험을 실시하여 어구의 형상을 관찰한 결과를 요약하면 다음과 같다. 1. 축소형 개량어구의 실제 전개율은 오비기에서 20% 정도로 가장 작았고, 뒤쪽으로 갈수로 커지며, 자루그물에서는 110% 정도로 가장 컸으며, B형이 A형에 비하여 5~10%정도 크게 나타났다. 자루그물 입구와 뒤끝의 망고 변화폭은 A형이 9.0~13.6, 9.3·10.4m이고, B형이 10.9~14.8, 5.8~8.0m로 나타나서 B형이 A형에 비하여 자루그물 입구는 1~2m 크고, 뒤끝은 2~3m 작았다. 2. 축소형 개량어구는 오비기의 수직방향 전개성능이 개선되어 수비에 이르기까지의 예망수층이 완만하게 형성되었으며, 예망수층의 변화폭이 기존어구에 비해 적게 나타났다. 나발 그물이 포켓형상을 개선시켜 그물코의 날림현상 감소와 수비에서 자루그물까지의 어구형상이 완만하게 이루어졌으며, 예망속도가 느린 경우에도 어구의 형상이 안정되었다. 3. 축소형 개량어구 B형은 자루그물의 변화폭이 적었고, 이중깔대기의 부착으로 인해 입망된 어군의 도피율이 감소하였다. This study was conducted in order to improvement of fishing gear and fishing operating system for anchovy boat seine by bag net A-type and B-type was attached with half size modified nets. Field experiments were carried out observe geometry of nets by catcher boats. The obtained results are summarized as follows : The actual ratio of net opening in each part of the half size modified nets was increased from fore part to back part of the nets as shown the smallest value about 20% in wing net and the biggest value about 110% in bag net. In addition, vertical net opening of B-type net as measured as 10.9~11.8m in fore bag net and 5.8~8.0m in after bag net were 1~2m greater than 9.0~13.6m of A-type one, and 2~3m less than 9.3~10.4m of A-type one, respectively. Vertical net opening of half size modified net was shown as less variation of towing depth from wing net to inside wing net than those of traditional nets due to stable vertical performance. The mesh distortion or drift and variation of vertical net opening were decreased by improvement of bag nets in order to minimized shape of net pocket phenomenon whenever towing speed is slow. Bag net B-Type attached with dual flapper was shown as less variation in width of bag net and less escapement of anchovy.