@article{oai:ir.kagoshima-u.ac.jp:00007713,
 author = {Maung, Maung San and FUWA, Shigeru},
 journal = {鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University},
 month = {2016-10-28},
 note = {To obtain some fundamental suggestions on the gear-efficiency of the two different types of trawl net, the authors carried out the model experiment, and compared them with each other, basing on the physical characters of the net. The one is a six-seam net used on board of the "Keiten Maru" (854.55 GT) for catching the demersal fishes: and here the otter board was rigged between the hand rope and the warp. The other one is shrimp trawl net used on board of the "Satsunan" (116.57 GT): and the otter board was directly rigged to the wing-tip in a traditional type. The results obtained in this study are summarized as follows. (1) In ordinary towing condition, the height of the net mouth of the six-seam net and the shrimp trawl net, marked 3.5m and 1m, respectively. In six-seam net the height of the net mouth (h) can be expressed in the following formula, h= (0.15-0.053 V)l. where l is maximum breadth of the net mouth without shrinkage in (m), and V is towing speed in (m/sec) when the distance between both wing-tips is about 30m. In shrimp trawl net, the maximum height of the net mouth is limited by the otter board height., (2) The bag net and net shape of the six-seam net look like cigar-shaped and in shrimp trawl net it is conical shaped but short. These are concerned with the planning of the net design.  (3) The net resistance of six-seam net is larger than that of shrimp trawl net.  At ordinary towing condition the net resistance of six-seam net, marked in 3.1~7.0 ton. In shrimp trawl net it marked about 105~275 kg. This difference of the net resistance depends on the scale of each net.  Considering from the net shape and other characteristics of net, the six-seam net with V-D type otter board seems to be suitable for catching the demersal fishes, and the shrimp trawl net with one directly rigged to the wing-tip seems to be suitable for shrimps.},
 pages = {47--56},
 title = {Comparison of the Gear-Efficiency of Two Types of Trawl Net},
 volume = {24},
 year = {}
}