• Title/Summary/Keyword: fishing lamp

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Change of fishing power index by technological development in the offshore squid jigging fishery (근해오징어채낚기어업에서 어로기술발달에 따른 어획성능지수 변동)

  • OH, Taeg-Yun;SEO, Young-Il;CHA, Hyung-Kee;JO, Hyun-Su;AN, Young-Su;LEE, Yoo-Won
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.54 no.3
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    • pp.224-230
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    • 2018
  • Squid is one of the important fisheries resources in Korea. Therefore, squid has been designated and managed as a target species of total allowable catch (TAC) since 2007, but the catch amount is gradually decreasing. The analysis was conducted to identify the change of relative fishing power index to develop the vessel and gear technology that may have improved the fishing efficiency of the offshore squid jigging fishery from 1960s to 2010s. Gross tonnage per fishing vessel increased with the increase in size until 1990, but then gradually decreased to 41.0 tons in 2000 and 37.1 tons in 2010. The illuminating power (energy consumption) by fishing lamps increased to 180 kW in 2005 and stabilized to 120 kW in 2015. Jigging machine started to be supplied to fishing vessels from the early 1970s, and fish finders began to be supplied in the early 1980s and gradually increased. Therefore, the relative fishing power index in the offshore squid jigging fishery increased from 1.0 in 1980 to 1.1 in 1990, to 3.5 in 2000 and to 2.5 in 2010, but the increment rate slowed down gradually. The results are expected to contribute to reasonable fisheries stock management.

Development of the silver-white decoy for squid automatic jigging machine and fishing performance (오징어채낚기용 은백색 유인체 개발과 어획성능)

  • An, Young-Il;Jang, Ung-Jeong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.49 no.3
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    • pp.208-217
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    • 2013
  • Decoys for automatic jigging machines, the body part of a squid hook, have been developed in small and existing sizes in consideration of squid food, color blindness, and retinomotor responses and in utilization of pearl pigment, PP of high transparency, and combined mixture. In comparison of the developed silver-white decoy and existing decoys, the optical characteristics were examined, and the fishing performance of small size silver-white squid hooks was assessed in application of 4 fishing boats with the squid automatic jigging machine and metal halide fishing lamp in July, 2012. The luminances of the three squid hook colors-green, dark green and silver-white-increased as the intensity of illumination increased. Among these, the increase of silver-white was particularly distinguished. As to the average contrast of squid hooks, that of silver-white was 10.33, which was the highest, and then green 1.86 and dark green -0.10 in the order. As to the fishing performance of the silver-white hook, that of the 202 Geumyeong-ho and 101Yongjin-ho which caught squids were similar to that of the existing green hook and was relatively low in the case of the Dongbu-ho. However, that of the Haengbok-ho which caught relatively small squids whose average length was 19.9cm and installed silver-white hook in all automatic jigging machines was significantly excellent. In order to enhance the fishing performance of small size silver-white hooks, therefore, it would be effective to install in every automatic jigging machines of fishing boat and to start fishing before July by which small squids are caught.

Radiation and Underwater Transmission Characteristics of a High-luminance Light-emitting Diode as the Light Source for Fishing Lamps (집어등 광원으로서 고휘도 발광 다이오우드의 방사 및 수중투과 특성)

  • Choi, Sok-Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.39 no.6
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    • pp.480-486
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    • 2006
  • The radiation characteristics of a high-luminance light-emitting diode (LED) light source were studied to evaluate its potential as an energy-saving light source for fishing lamps. The angle of the LED light source with 50% illuminance was $8-15^{\circ}$, and it had strong directional characteristics. The wavelengths at which the radiance and irradiance were maxima were 709, 613, 473, 501, 525, and 465 nm for red, orange, blue, peacock blue, green, and white light, respectively. The underwater transmission characteristics of the LED light source were superior in the order blue, white, peacock blue, and green in optical water type I: blue, peacock blue, white, and green in optical water type II; and blue, peacock blue, green, and white in optical water type III. Setting the underwater transmission characteristics of the LED light source in optical water type I at 100%, the transmission of water types II and III decreased to 67 and 17%, respectively. Based on the underwater transmission characteristics calculated in optical water types I-III, the blue and peacock blue LED light sources can be used as an energy-saving light source for fishing lamps.

Relationship Between the Boat Sizes, tight Source Output for Fishing Lamps and the Catch of Squid, Todarodes pacificus STEENSTRUP, in Coastal Squid Jigging Fishery of Japan (일본 소형 오징어 채낚기 어선의 톤수 및 집어등 광원 출력과 어획량과의 관계)

  • Choi Sok Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.6
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    • pp.644-653
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    • 2002
  • Sizes of coastal squid jogging boats, their light source output for fishing lamps and daily catch data were collected, for a purpose of evaluating factors on fishing boats, which affect to the squid catch, from four fishing ports (Hakodate, Sado Island, Noto and Tsushima) in Japan. The catch amount was increased as boat sizes and their light source output of fishing lamps were increased up to 100$\~$200 kW class and 11$\~$15 gross tonnage class. The relationship between catch per unit efforts y (box/machine/day), gross tonnage x_{1}, (GT) and light source output for fishing lamps x_2 (kW) is expressed as following formula; $y=4.091+0.18x_1+0.0019x_2$. Thus, 0.1819 boxes of squid catch can be expected, when light source output for fishing lamps increases for 1 kW $(x_2{\leq}200)$ and boat size 1 GT ($x_1\leq15$). It is considered that the boat size which created a shadow area under the jigging boat, is important factor affecting to catch amount, Because larger shadow area created by bigger boat has a possibility to let more squid stay there.

Relationship between the Catch of Squid, Todarodes pacificus STEENSTRUP, According to the Jigging Depth of Hooks and Underwater Illumination in Squid Jigging Boat (소형 오징어 채낚기 어선의 낚시 깊이별 조획량과 수중 조도)

  • CHOI Sok-Jin;ARAKAWA Hisayuki
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.6
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    • pp.624-631
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    • 2001
  • The relationship between the catch of squid, Todarodes pacificus, according to the jigging depth and underwater illumination by fishing lamps was investigated during nighttime operations off-Tusima Islands in November 1994 and off-Oki Islands in November 1995. We used echo sounder to observe the distribution of squid. Echo images on the echo sounder showed the distribution of squid at the water layer of 50 meter depth at the beginning of jigging operation. After the time elapsed, a continuous dense image had moved to the layer of 60-80 meters jigging depth. A larger number of squid were caught by jigging machines set at a lowest depth of 90 meters, when it compared with machines set at a 60 meters. However, Catch increased around 60 meters jigging depth, when fishing lamps output were switched to 24 kW halogen lights:.The underwater illumination, under the each light power of fishing lamps of squid jigging boat was continuously measured with an underwater illuminometer. Values of the underwater illumination, when schools were distributed from 60 to 80 meters, ranged from $3.0\times10^{-2}lx\;to\;3.4\times10^{-3}lx$ in average at $80\~360$ kW fishing lamps output of squid jigging boat.

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Irradiance Distribution Analysis of a Squid Jigging Vessel Using an LED Plus Metal Halide Fishing Lamp Combination Under Optimized Conditions (메탈할라이드와 엘이디 오징어 집어등의 겸용시 배치조건에 따른 수중조도분포 비교분석)

  • Jung, Mee Suk;Lee, Ki Dae;Ko, Jae Seok;Bae, Jae Hyun
    • Korean Journal of Optics and Photonics
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    • v.25 no.6
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    • pp.315-325
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    • 2014
  • A combination of MHL and LED fish-luring light is used in this study. Its yield, characteristics, and irradiance distribution are evaluated and analyzed. To obtain an irradiance distribution similar to that of an MHL, we suggest the optimal arrangement of MHL and LED.

Distribution patterns of the Japanese common squid, Todarodes pacificus attracted around the luring lamp on the jigging boat (채낚기 집어등 어선 주변에 유집된 살오징어, Todarodes pacificus의 분포 패턴)

  • BAE, Jae-Hyun;LEE, Kyounghoon;JO, Hyeon-Jeong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.52 no.3
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    • pp.276-280
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    • 2016
  • This study investigated luring distributions by water layer of common squid which were targeted by angling fishing vessels equipped with LED and metal-halide lamps using a scientific echosounder with a 120 kHz frequency in order to develop energy-effective underwater fish aggregation devices. In the analysis, angles of a transducer were changed from $0^{\circ}$ to $45^{\circ}$ and were rotated every $10^{\circ}$ horizontally. It was shown that common squid were densely distributed from the surface to 40 m and they were also distributed in directions of $10^{\circ}{\sim}+30^{\circ}$, $-30^{\circ}{\sim}-60^{\circ}$, and $-120^{\circ}{\sim}-130^{\circ}$with the head of vessel as the center. Comparative results of angles of transducer on acoustical densities of common squid distributing in 21~40 m water depth showed an average $101.8m^2/nm^2$ in vertical direction of $0^{\circ}$, $12.3m^2/nm^2$ in angle of $30^{\circ}$, and $42.4m^2/nm^2$ in angle of $45^{\circ}$, respectively. It implied that more considerations on acoustic scattering strength by incidence angle direction of the transducer and swimming oriental angle direction of common squid would be required.

The study on the Anchovy's (Engraulis japonica) reaction to several light colors in a tank (수조에서 여러 가지 색광에 대한 멸치의 반응 연구)

  • Bae, Bong-Seong;Cho, Sam-Kwang;Cha, Bong-Jin;Park, Seong-Wook;An, Heui-Chun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.4
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    • pp.327-337
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    • 2011
  • This study was conducted to develop energy-efficient LED lamps with an excellent fishing performance for an anchovy scoop net by comparing the functions of 6 different lamps- incandescent, blue LED, green LED, white LED, yellow LED and red LED lamp. We used incandescent and red LED lamps only for the initial test and then excluded because those showed the lowest herding capacity. According to the result, yellow LED showed lower herding capacity in comparison with the blue, green and white one. Although the herding performance of the blue, green and white LED was similar in almost tests, herding speed to the each light was different. The anchovies were gathered into the blue LED as the speed of 39.88cm/s that was the fastest. Green LED was the second as the speed of 33.28cm/s. White LED was the slowest as the speed of 26.73cm/s. We will have field tests because we found the result that yellow LED's herding performance was better than green LED's for 5 seconds comparing after starting in some tests.