The purpose of this study is to select a fishing gear deposit marking method for the gear deposit system implemented for gillnet. The fishing gear deposit system was implemented in Korea for the first time in the world in January 2024 for fish trap, and it is scheduled to be expanded to gillnets and buoys by 2026. In this study, an AHP (Analytic Hierarchy Process) survey was conducted with 34 experts. The AHP analysis method was used to calculate the weights of each criterion that influence the selection of the deposit marking method, in order to determine the optimal marking method that considers both qualitative and quantitative criteria. Experts prioritized the label-type marking and preferred the weight-based deposit unit for its ease of application and ability to measure multiple gear widths at once. This study quantitatively reflects the opinions of experts on the selection of the gillnet deposit system. Future research should examine the impact of marking method on fishing performance, durability, and institutional improvements.

This study sought various ways to prevent the occurrence of waste fishing gear and promote the recovery. It is expected that the problem of waste fishing gear can be effectively solved through measures such as strengthening education and publicity, technical measures, establishment of recovery infrastructure, and provision of incentives. In particular, introduction of the waste fishing gear recovery promotion point system gives fishermen practical motivation. It can be an important means of inducing leisure and sustainable fishing activities. In addition, by inducing the participation of private companies, it is expected to promote the recovery and recycling of waste fishing ports and contribute to the protection of the marine environment and fisheries resources. The government or local government should actively review the measures suggested in this study and prepare related laws and policies. In addition, it is necessary to establish a system to induce the participation of various stakeholders and support sustainable fishing activities through public-private cooperation. Through this, we will be able to achieve carbon neutrality goals in the fishing sector in response to climate change. This study suggests an early stage plan, and in future research, it is necessary to evaluate and find and improve practical effects through pilot projects. Moreover, it is necessary to study the management of closed fishing gear and carbon neutrality practice measures at the global level by seeking international cooperation measures. Consequently, more effective and sustainable marine environment and fishery resource protection measures can be prepared.

This study aims to estimate the trawl net width based on the design drawing and towing condition of sampling trawl used in past surveys to improve the accuracy of estimation for fishery resources. To this end, the trawl gear was modeled as a flexible structure and numerically analyzed, and the analysis results were subjected to multiple regression analysis. As a result, a model was derived to calculate the net width by the towing conditions. When the towing conditions from past surveys were input into this model, it was confirmed that the net width increased in a natural logarithmic manner with the increase in the warp length and that decreased linearly as the water depth increased at the same warp length. For verification of the model, the theoretical formula of other study and this model were compared. As a result, despite the values of the two were slightly different, the tendency of changing net width by increasing warp length was consistent each other. Therefore, it is thought that the derived model can obtain the net width according to various towing conditions and can contribute to improving the accuracy of fishery resources estimation.

In response to the global interest and efforts towards reducing plastic use and promoting resource recycling, there is a growing need to establish methods for recycling discarded fishing gear. In Korea, various technologies are being developed to recycle discarded fishing gear, but significant technical and policy challenges still remain. In particular, biodegradable gill nets require a pre-treatment process to separate biodegradable materials from other substances and to remove salt before recycling. Therefore, this study aims to develop a pre-treatment device for recycling biodegradable gill nets and to evaluate the feasibility of recycling them.

Most fishing nets used in fish cage aquaculture are made of synthetic fibers such as polyamide (PA) and polyethylene (PE). Therefore, it is challenging to maintain the internal volume of the fish cage due to biofouling, which can increase the load on the cage or reduce dissolved oxygen levels by impeding smooth current flow. To address this issue, research has been conducted to replace conventional synthetic fiber cage nets with brass nets, demonstrating certain benefits such as improved productivity and ease of fish cage management. However, given the need for a more thorough examination of brass fishing net weaving technology and performance, this study assessed the optimal weaving method for brass fishing nets to be used in fish cages. Additionally, it provided essential data for the practical application of brass fishing nets by evaluating their weight, tensile strength, elongation, fatigue resistance, and wear resistance. The study concluded that weaving brass fishing nets using the chain link method ensures durability, ease of installation, and compact storage in a scroll-like form. Moreover, due to their superior fatigue and wear resistance properties, brass nets can offer increased utility if appropriate net diameter and length are selected to compensate for their higher weight per unit area and relatively higher cost compared to existing fiber fishing nets.

In this study, the risk factors of coastal purse seine fisherman were analyzed through a survey of fishery workers of coastal purse seine fishery and the accident compensation insurance data of the fisheries workers of the National Federation of Fisheries Cooperatives (NFFC). The classified fishing operation accident data was analyzed through 4M (Man, Machine, Media, Management) model of the National Transportation Safety Board (NTSB) and the accident prevention measures were presented using Harvey's 3E (Engineering, Education, Enforcement) model. The rate of accidents on coastal purse seinens each year was 75.8‰, 36.7‰ and 74.8‰ from 2015 to 2017. The accident frequency resulting from slipping was the highest, and the risk of a contact with gear was low. When comparing each insurance data, the average value of the contact with gear accident was the highest. This research result is expected to be important data in identifying and preventing safety hazards of coastal purse seiner fisherman in the future.

Recently, as the global problem of marine debris and marine plastics is getting serious, various ways to solve them have been proposed, and the use of the biodegradable fishing gear is proposed as an alternative. Currently, 13 types of biodegradable fishing gears are available, but their penetration rate is only 8.7%. However, the need for the use of the biodegradable fishing gear is growing as awareness of protecting marine ecosystems is growing. Therefore, in this study, the economic effects of the expansion of biodegradable fishing gear distribution in Korea's coastal areas were analyzed through the conservation of marine ecosystems, augmentation of fisheries resources, and augmentation of fishing efficiency. According to the analysis, the economic effects of 52,795 million won, 105,590 million won, and 158,385 million won was generated as the distribution of biodegradable fishing gear were expanded to 10%, 20% and 30% across all gill net and trap.

The concern on the greenhouse gas emissions is increasing globally. Especially, the greenhouse gas emission from fisheries is an important issue from the Paris Climate Change Accord in 2015. Furthermore, the Korean government has a plan to reduce the GHG emissions as 4.8% compared to the BAU in fisheries until 2020. However, the investigation on the GHG emissions from Korean fisheries rarely carried out consistently. Therefore, the quantitative analysis of GHG emissions from Korean fishery industry is necessary as a first step to find a relevant way to reduce GHG emissions from fisheries. The purpose of this research is to investigate which degree of GHG emitted from the major offshore fisheries such as offshore gillnet fishery, offshore longline fishery, offshore jigging fishery and anchovy drag net fishery. Here, we calculated the GHG emissions from the fisheries using the Life Cycle Assessment method. The system boundary and input parameters for each process level are defined for the LCA analysis. The fuel use coefficients of the fisheries are also calculated according to the fuel type. The GHG emissions from sea activities by the fisheries will be dealt with. Furthermore, the GHG emissions for the unit weight of fishes are calculated with consideration to the different consuming areas as well. The results will be helpful to understand the circumstances of GHG emissions from Korean fisheries

본 연구는 우리나라의 Holstein 암소의 주요 번식형질과 305 일 산유량과의 상관관계를 알아보고자 실시했다. NRR 56d 와 305 일 산유량과의 상관관계를 알아보기 위해 2003 년부터 2013 년사이에 분만한 농협중앙회 젖소개량사업소 검정자료 경산우 479,331 두를 이용하였으며, 분만계절, 산차 및 유량그룹을 고정효과로 하는 Yijkl= u + seasoni + parityj + yieldgroupk + eijkl 선형모형을 적용하여 분석을 실시했다. NRR 과 305 일 산유량의 단순상관 및 오차상관은 각각 –0.089 및 –0.018 로 분석되어 산유량이 증가할수록 NRR 은 감소하는 것으로 나타났다. 이는 고능력우의 저수태 발생율이 높다는 주장을 뒷받침 한다. 다음은 최근 인공수정의 횟수가 증가하고 있는 현상이 유생산과 어떠한 관계가 있는지 알아보기 위해 수정횟수와 305 일 산유량과의 관계를 분석했다. 자료는 젖소개량사업소의 동일한 자료를 이용했다. 305 일 유량이 6000kg 미만, 6,000~7,000kg, 7,000~8,000kg, 8,000~9,000kg, 9,000~10,000kg, 10,000~11,000kg, 11,000~12,000kg, 12,000kg 이상, 8 개 그룹으로 나누어 305 일 유량에 따른 수정횟수를 분석했다. 각 그룹별로 평균 수정횟수는 각각 1.57, 1.59, 1.62, 1.66, 1.72, 1.78, 1.83, 1.91 회로 나타났으며 수정횟수 3 회 및 4 회 이상의 저수태우 발생비율 역시 산유량이 증가함에 따라 증가하는 것으로 나타났다. 다른 주요 번식형질인 분만간격과 305 일 산유량과의 상관관계를 알아보기 위해 젖소개량사업소 검정자료인 2010 년부터 2013 년 사이에 분만한 2 산차 이상 경산우 42,550 두를 데이터 분석에 이용했다. 분만간격은 361 일 미만, 361~400 일, 401~450 일, 451~500 일, 501~550 일, 551~600 일, 601~650 일 및 651 일 이상, 총 8 개 그룹으로 나누어 분석을 하였다. 305 일 추정유량은 분만간격이 길어짐에 따라 유의적으로 증가하는 것을 나타났다. 다음으로는 초산차 홀스타인 젖소에서 분만계절과 305 일 유량의 관계를 분석했다. 조사에 이용된 데이터는 2009 년부터 2011 년까지 분만한 1 산차 14,189 두의 농협중앙회 검정자료를 이용했다. 305 일 추정유량은 봄, 여름, 가을, 겨울이 각각 9,684, 9,413, 9,805, 10,084 kg 으로 여름철 분만이 겨울철 분만우보다 약 6.3% 낮은 것으로 나타났다. 유량 위주의 개량은 젖소의 번식형질을 저하시킨다는 연구가 다수 있었지만, 낙농 선진국과는 달리 국내에서는 아직 번식형질에 대한 유전평가는 실시하지 않고 있다. 이러한 국내 기초자료를 근거로 우리나라도 산유량 위주의 유전평가가 아닌 번식형질에 대한 유전평가도 필요한 시점이라 생각한다.

In this study, we tested Japanese trolling lines in the Jeju fishery. This fishery simulates the natural marine environment with many seabed rocks, and has been redesigned and manufactured it to be suitable for the Jeju fishery. In order to ensure that the trolling lines were deployed at the inhabitation depth of hairtails, the conditions required for the fishing gear to reach the target depth were determined for use during the experiment. The experimental test fishing was conducted at the depth of 120 m water in front of Jeju Seongsanpo and in the offshore area of Jeju Hanlim. The fishing gear used in the test fishing is currently used in a variety of field operations in Japan. However, several problems were identified, such as twisting of the line during its deployment and excessive sinking of the main line. The fishing gear was, therefore, redesigned and manufactured to be more suitable for the Jeju fishery environment. For the fishing gear to accurately reach the target depth, depth loggers were installed at the starting point of the main line and at the 250 m and 340 m points of the line. Depth and time were recorded every 10 seconds. According to the daytime positioning of hairtails in the lower water column, the target depth of the fishing gear was set at 100-110 m, which was 10-20 m above the sea floor. At a speed of 1.9 knots and with a 9 kg sinker attached, the main fishing line was deployed and catch yields at depths of 100 m, 150 m and 180 m were recorded and analyzed. When the 180 m main line was fully deployed, the time for the hairtail trolling lines to arrive at the appropriate configuration had to be 5 minutes. At this time, the depth of the fishing gear was 16-23 m above the sea floor, in accordance with the depths at which the hairtails were during the day. In addition, in order to accurately place the fishing gear at the inhabitation water depth of hairtails, the experimental test fishing utilized the results of the depth testing that identified the conditions required for the fishing gear to reach the target depth, and the result was a catch of up to 97 kg a day.