최근까지 우리나라 연근해어업에 있어서 불법어업은 대부분의 업종에서 매 우 다양하게 지속적으로 발생되고 있다. 이러한 불법어업의 유형 중에서도 조업중 수산관계법령상 어업규제 조치를 위반하는 통발어업, 문어단지어업, 자망 어업 등 정치성·부설형어업의 경우 문제가 되는 것이 폐어구를 많이 발생시키 고 있다는 것이다. 특히 통발어업이나 문어단지어업은 거의 대부분 어업규제 조치를 위반한 불법어업으로 유실어구를 많이 발생시키고 있다. 이렇게 발생되 는 폐어구는 연약한 해양생태계 환경을 파괴하고 유령어업을 유발시켜 수산자 원 감소로 이어지고 있기 때문에 수산자원의 보호ㆍ관리 측면에서도 많은 문제 가 있고, 연간 어획량의 10%인 약 3,800억원의 수산업 피해가 발생되고 있다는 점이다. 또한, 어구용 스티로폼, 플라스틱, 나일론 그물망 등으로 제조된 폐어구가 바 다에 장시간 방치될 경우 미세플라스틱이 발생된다. 이를 해양생물들이 섭취하 고 결국 우리의 식탁에 오르게 되면, 인체에 매우 유해한 물질을 최종적으로 인간이 섭취하게 된다. 이런 사유로 세계식량농업기구, 유엔환경계획 등 국제 기구를 비롯한 어업 선진국에서는 해양생태계 환경 오염, 유령어업으로 유발되 어 수산자원 감소로 이어지고 있는 폐어구 발생 저감을 위한 적극적인 관리대 책을 강구하고 있다. 본 연구는 불법어업으로 폐어구를 발생시켜 해양생태계 오염 및 유령어업을 유발함으로써 수산자원을 감소시키고 있는 통발어업과 문어단지어업에 대한 어업규제 위반행위를 근절시킴으로써 폐어구 발생 저감을 위한 방안을 모색하 였다. 따라서 현행 어업규제 관련 법령을 검토, 그 문제점을 고찰하여 폐어구 발생 저감을 위한 법적 개선방안을 제시하고자 한다.

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.

Estimating fishing capacity is one of current hot issues in the international fisheries. It is because that increased fishing capacity has caused not only fish stocks to be reduced, but also additional fishing costs to be incurred without additional incomes, which resulted in decrease of economically viability of fisheries. In order to solve this problem, FAO adopted 'the International Plan of Action for the Management of Fishing Capacity' in 1999 and recommended that member countries to measure fishing capacity and to implement the domestic action plan to reduce excess fishing capacity. This study is aimed at assessing fishing capacity of the octopus coastal trap fishery(OCTF) using data envelopment analysis(DEA) which is a method recommended by FAO. The DEA results on 10 individual OCTF vessels showed that the capacity utilization(CU) was a 0.93 on average, indicating some differences in CU among vessels(0.79-1.0). In addition, results of the sensitivity analysis revealed that under the current level of catch, the gross tonnage, horse power, days fished, and traps per trip could be reduced by 35%, 33%, 16%, and 18% on average, respectively.

Fishing power, which means performance of fishing vessel or catchability of fishing gear, can explain using by fishing power index(FPI) to compare fishery efficiency among uniformity types of fishery that work during the fixed period in specific fishing ground. This research analyzed on their fishing power and catchability using comparing each sampled vessels of coastal trap fishery for common octopus. The results showed that they were no difference in amount of used trap and immersed time etc. in CPUE among sampled vessels, and had no correlation of catch production due to vessel's tonnage. Most vessel's FPI estimates but 3 vessels were higher than the averaged, and showed similar fishing power in general. And then, CPUE and FPI showed that 4 to 5 tonnage vessels would be superior to another, 4 tonnage vessels had also good catchability. Therefore, we estimated that 4 tonnage vessels had the most efficiency work for coastal trap fishery for common octopus.

The behavior patterns of common octopus, Octopus minor to a cylindric trap were examined in the water tank using a video camera in order to know entering mechanism to the trap and to improve it. Fishing efficiency by 2 kinds of traps(A: 3 entrances, B: 2 entrances) was investigated in the coastal area of Deugryang Bay from May to July, 2005. Common octopus tends to approach by swimming more than walking towards trap. When they approached to the trap, they showed much more behaviors that sate at the around than upper part of it. Approaching behaviors of common octopus was more vigorous at nighttime than daytime on the trap, they showed the most vigorous action between 2 am and 4 am of the day. The rate of staying 30 seconds over around the trap was 41.5% in the nighttime. CPUE(g/trap) of common octopus caught by A type trap was 21.4% higher than the B type trap but there was no difference on the significance level of 5% by the ANOVA. Catch rate of common octopus and by-catch species caught by the A type trap were 97.2%, three and 98.7%, two for B type trap, respectively.