Comparison of fishing efficiency on octopus traps to reduce bycatch in the East Sea

This study aims to reduce the bycatch of young fishes and other species in the octopus(Octopus vulagris, Octopus dolfleini) trap fishery on the East Sea, Korea. We carried out field experiments and tank experiments to verify the fishing efficiency and bycatch with the different 8 types of trap. 4 of them had mesh size 20, 35, 55 respectively and 75mm, 2 of them with escape ring of diameter 30mm and 50mm and 2 of them with escape device. The gap was 20 and 40mm respectively. The mesh sizes of the traps with ring and frame were 20mm. The traps with mesh size 20 and 35mm were not reasonable because it could fish under 300g octopus as bycatch which is not permitted by the Korean fisheries regulations. The catch number of octopus over 300g by traps with escape ring of diameter 30mm was 53. The catch of trap with mesh size 20mm was 54. The catch of trap with mesh size 35mm was 53. There is no significant difference among them. The catch number of octopus over 500g that is fishermen's favorite one was 46 in the trap with escap ring. The diameter of was 30 mm and the catch of trap with mesh size 20mm was more 3 catch and the catch of trap with mesh size 35mm had 6 more catch. Fishermen wanted to catch over 500g octopus because the octopuses had commercial value. The traps with escape ring can be replaceable with he traps with mesh size 20 or 35mm because the trap is suitable to conserve the octopus resources and keep the fishermen's fishing substantiality.

혼획저감형 동행안 문어통발의 어획효율 비교