The Indian Ocean is the second-largest tuna fishing ground in the world, accounting for approximately 1.2 million tonnes (23%) of the estimated 5.2 million tonnes of global commercial tuna catch in 2023. This study examined the relationship between tuna catches, specifically skipjack, bigeye, and yellowfin tunas, and prey biomass (Nautical Area Scattering Coefficient, NASC) estimated from acoustic surveys conducted in the southwestern Indian Ocean from 20 April to 15 May 2019. Environmental variables were derived from the Copernicus Ocean Model, and tuna length data from the IOTC. The estimated total tuna catch in the study area was approximately 166,400 tonnes, with the northwestern region showing the highest catches and NASC values. Tuna catches increased with NASC; however, the relationship was non-linear. While skipjack showed no significant correlation with NASC, bigeye and yellowfin tunas exhibited weak but significant positive correlations. Environmental analysis revealed that the northern waters had high surface temperatures, low salinity, and low oxygen levels, with mid and deep layers characterized by low temperature, salinity, oxygen, and chlorophyll. These findings offer a foundation for understanding tuna distribution in relation to prey and environmental conditions, highlighting the need for future species- and fishery-specific studies to support sustainable tuna resource management.

This study aimed to enhance the operational efficiency and safety of offshore eel trap fisheries by developing six types of automated fishing equipment: a bait crusher, bait cutter, main line arranging device, trap cleaning device, eel sorting device, and fish pump system. Sea trials demonstrated that the bait crusher and bait cutter significantly reduced manual labor and processing time while maintaining bait quality. The main line arranging device improved productivity and safety by automating the sorting of looped cords. The trap cleaning device effectively removed fouling organisms using high-pressure water and rotating brushes. The eel sorting device enabled automatic size-based selection, improving resource management and operational efficiency. The fish pump system transferred eels rapidly with minimal physical damage, reducing unloading time by over 80% and decreasing labor requirements. A satisfaction survey of fishery participants confirmed that all developed devices were highly effective in reducing workload, enhancing safety, and improving operational performance. The automated equipment developed in this study is expected to contribute to the sustainable management of offshore eel trap fisheries and to offer potential applicability to other coastal and offshore fisheries.

This study examined the offshore eel trap fishing process using one year of fishing logs and fishermen’s insights to identify key operational challenges and propose equipment improvement for greater efficiency and safety. Conger eel catches varied significantly by season, depth, and temperature, peaking in winter at 85–90 m and 23°C. The western waters of Jeju Island were identified as a major fishing ground, with the highest catch recorded in November and the lowest in July, reflecting seasonal trends. Each fishing operation deployed about 10,000 traps, with an average loss of 38 traps, posing economic concerns. The process involved intensive manual labor in bait preparation, trap retrieval, catch separation, line loading, and unloading, leading to high physical demands and safety risks. To address these issues, the study proposed automation through the development of a line loading device, trap cleaning device, bait processing machine, and automatic catch separator. These innovations could reduce the labor force required by one to two workers per process, alleviate workloads, and enhance resource management. By integrating quantitative logbook analysis with field-based knowledge, this study offers practical value. Further research is recommended on automation development, cost-effectiveness, and field validation to support safer and more sustainable eel trap fisheries.

세친은 유식삼십송 마지막 다섯 게송에서 유식오위설을 설명한다. 아뢰야식은 자체(自體, ātma-bhāva)를 만들고, 유식성을 향하여 나간다. 유식성은 아뢰야식이 의타기성의 잡염분인 변계소집성을 벗어나서, 진여 와 무분별지인 원성실성을 이룬 것을 의미한다. 유식삼십송의 주관적 측면의 아뢰야식은 자체를 의미하며, 자체가 유식성을 성취한다는 것은 번뇌 제거를 의미한다. 세친의 오위설은 아뢰야식을 자체의 개념으로 바 라보고 번뇌의 유기적 관계를 체계적으로 기술한다. 자체는 아뢰야식 일기(一期)의 생을 유지하는 유근신이며, 아뢰야식의 집수에 의한 것이며 종자와 함께 만들어진다. 유신근은 주관에 해당하며, 종자는 소연경(대상)에 의해 형성된 명언종자이다. 오위설은 아뢰야식 내 부의 근본적인 분별의 양상을 이취(二取)라고 하는데, 유식성이 전개되는 단계에서는 이취의 명칭이 달리 사용된다. 자량위는 이취가 남아 있다. 가행위는 미세한 대상이 나타나야만 이취가 나타난다. 가행위의 이취는 수면(隨眠)이라고 하며 유부무기의 번뇌이다. 통달위는 이취가 사라짐으 로써 진여와 무분별지가 성취된다. 수습위는 아뢰야식 내부의 이취를 제 거하는데, 세친은 수습위의 번뇌를 추중(麤重)이라고 한다. 추중은 아뢰야 식 내부의 이장(二障), 즉 번뇌장과 소지장이다. 번뇌장은 아뢰야식 내부 의 주관이며, 소지장은 아뢰야식 외부의 객관이다. 이장은 아뢰야식의 최 초 분별이며, 이취의 또 다른 이름이며, 아・법(我・法)의 형태이다. 이장 은 보살십지에서 무분별지의 수행과 중생구제의 이타행을 통해 제거된다.

We presented foundational findings regarding the occurrence and acoustic characteristics of the finless porpoise through passive acoustic and visual surveys conducted on the southern coast of Korea, specifically at Hadong Jungpyeong Port. Over a survey period spanning from July 8 to August 16, 2023, totaling 40 days, we observed peaks in the number of clicks produced by this species on July 15, July 24, August 4, August 11, and August 16. The highest count, totaling 18,924 clicks, was recorded on July 15th, while the lowest count, at 3,888 clicks, occurred on August 8th. Examining the acoustic characteristics throughout the diurnal cycle, we found that the peak activity in terms of DPM (detection positive minute for one hour), DP10M (DPM for ten minutes), and overall number of click sounds was observed between 05:00 and 08:00, with a secondary peak occurring from 17:00 to 18:00. The quietest period was noted between 23:00 and 02:00. Furthermore, there was a significant increase in the number of clicks from sunrise, with the maximum count of 21,581 clicks recorded at 6 AM. This count gradually decreased until noon, experienced a slight increase thereafter, peaked again at sunset, and then declined. The dominant frequency mode of this species was 126 kHz, with a concentration ranging from 112 to 136 kHz. The average duration of a click sound was 127 ㎲, with approximately 16 sinusoids (cycles) within each click sound and an average cycle length of approximately 7.9 ㎲. These findings from our study are anticipated to serve as foundational data for the development of a Korean pinger and acoustic warning system.

Recently, domestic fishing production of Japanese horse mackerel has been continuously decreasing. To achieve sustainable fishing of this species, it is essential to acquire its target strength (TS) for accurate biomass estimation and to study its ecological characteristics. To date, there has been no TS research using a broadband echosounder targeting Japanese horse mackerel. In this study, for the first time, we synchronized an underwater camera with a broadband frequency (nominal center frequency of 200 kHz, range: 160-260 kHz) to measure the TS according to the body size (16.8-35.5 cm) and swimming angle of the species. The relationship between Japanese horse mackerel length and body weight showed a general tendency for body weight to increase as length increased. The pattern of the frequency spectra (average values) by body length exhibited a similar trend regardless of body length, with no significant fluctuations in frequency observed. The lowest TS value was observed at 243 kHz while the highest TS values were recorded at 180 and 257.5 kHz. The frequency spectra for the swimming angles appeared to be flat at angles of –5, 0, 30, 60, 75, and 80° while detecting more general trends of frequency spectra for swimming angle proved challenging. The results of this study can serve as fundamental data for Japanese horse mackerel biomass estimation and ecological research.

This study investigated the species composition and community structure of aquatic organisms captured using coastal beam trawling in Gomso Bay, Jeollabuk-do, from January to December 2022. Throughout the experimental period, a total of 20,246 individuals belonging to 94 marine species were captured, with a combined biomass of 602,828 g. Fish exhibited the highest abundance, comprising 56 species, followed by crustacea (21 species), bivalvia (8 species), cephalopoda (5 species), gastropoda (3 species), and holothuroidea (1 species). The dominant species was Leiognathus nuchalis, constituting 14.0% of the total individuals, followed by Portunus trituberculatus at 12.1%, Oratosquilla oratoria at 10.4%, Crangon hakodatei at 9.9%, and Metapenaeus joyneri at 7.9%. The diversity index ranged from 1.72 to 2.55, with the lowest diversity observed in March and the highest in July. Cluster analysis based on species composition of the 27 most common species showed that aquatic organisms were divided into three groups: spring and summer organisms (Group A) and summer organisms (Group B) and autumn and winter organisms (Group C).

The United States enforces the seafood import regulations so-called the Marine Mammal Protection Act (MMPA), and by 2023, all exports of aquatic products and processed fish products by fisheries which have not obtained an “Comparability Finding” from the National Oceanic and Atmospheric Administration will be completely banned. Therefore, to respond to the US MMPA, it is critical to identify technologies and methods used in worldwide for reducing bycatch of marine mammals. In particular, marine mammals are frequently caught in five fisheries (trawl, gill net, trap, stow net and set net) in Korea, which is facing a great challenge. This study presented bycatch reduction methods by five fisheries, classified the methods by country, and suggested appropriate reduction methods which can be applied in Korea.

The swimming behavior of pacific bluefin tuna (Thunnus orientalis) in the offshore sea cage of the brass fishing net was observed and analyzed by imaging sonar techniques. The cultured fish spent most of the time swimming a circular path along the circular cage wall and continued to swim only clockwise direction without completely changing the swimming direction during the 23-hour observation time. In addition, changed swimming behaviors were divided into four categories: (a) the behavior of a large group temporarily swimming in the opposite (counter clockwise) direction, (b) the behavior of a small group temporarily swimming in a small circular path, (c) the behavior swimming small circular path in the center of the cage, and (d) the behavior of a large group swimming across the center of the cage. The maximum swimming speed of the cultured fish was from 3.5 to 3.8 TL/s, the mode was from 1.2 to 1.4 TL/s and the swimming speed during the day time was faster than at night time. It was confirmed the cultured fish swam not only on the surface but also near the bottom net of the cage during the day, but swam mainly at the upper part of the cage at night.

Recently, wideband acoustic technology has been introduced and started to be used in fisheries acoustic surveys in various waters worldwide. Wideband acoustic data provides high vertical resolution, high signal-to-noise ratio and continuous frequency characteristics over a wide frequency range for species identification. In this study, the main characteristics of wideband acoustic systems were elaborated, and a general methodology for wideband acoustic data analysis was presented using data collected in frequency modulation mode for the first time in Republic of Korea. In particular, this study described the data recording method using the mission planner of the wideband autonomous acoustic system, wideband acoustic data signal processing, calibration and the wideband frequency response graph. Since wideband acoustic systems are currently installed on many training and research vessels, it is expected that the results of this study can be used as basic knowledge for fisheries acoustic research using the state-of-the-art system.

In September and October 2020, combined acoustic and trawl surveys were conducted in the northwestern sea of Jeju Island. In the survey area, a region, so called Jeju region, was designated to esimate the biomass of chub mackerel and jack mackerel using a trawl survey method and frequency difference method. In the September survey, the weight ratios of jack mackerel and chub mackerel to the total catch were 24.6% and 2.8%, respectively, and in the October survey, those ratios were 24.9% and 20.7%, which were used to calculate their biomass (trawl survey). Using the frequency difference range (–8 to –3dB) corresponding to two species in 120 and 200 kHz, their biomass was estimated (frequency difference method). As a result, the biomass of two species from the trawl method was 3252.3 tons in September and 5777.0 tons in October. The estimated biomass by the frequency difference method was 4926.6 tons in September and 7521.5 tons in October. It was the first trial to estimate the biomass of two species using the trawl and frequency differencing methods in South Korea although there were some differences between two methods. In addition, horizontal distributions of acoustic backscattering strength over the entire survey area were mapped.

Using environmental DNA (eDNA) in the fisheries and oceanography fields, research on the diversity of biological species, the presence or absence of specific species and quantitative evaluation of species has considerably been performed. Up to date, no study on eDNA has been tried in the area of fisheries acoustics in Korea. In this study, the biomass of a dominant species in the northwestern waters of Jeju Island was examined using 1) the catch ratio of the species from trawl survey results and 2) the ranking ratio of the species from the eDNA results. The dominant species was Zoarces gillii, and its trawl catch ratio was 68.2% and its eDNA ratio was 81.3%. The Zoarces gillii biomass from the two methods was 7199.4 tons (trawl) and 8584.6 tons (eDNA), respectively. The mean and standard deviation of the acoustic backscattering strength values (120 kHz) from the entire survey area were 135.5 and 157.7 m 2 /nm 2 , respectively. The strongest echo signal occurred at latitude 34° and longitude 126°15’ (northwest of Jeju Island). High echo signals were observed in a specific oceanographic feature (salinity range of 32-33 psu and the water temperature range of 19-20℃). This study was a pilot study on evaluating quantitatively aquatic resources by applying the eDNA technique into acoustic-trawl survey method. Points to be considered for high-quality quantitative estimation using the eDNA to fisheries acosutics were discussed.

세친은 『유식삼십송』의 제1게송에서 가설의 ‘아(我)와 법(法)’은 식에 의존하여 전변한다고 선언한다. 제2게송에서 전변하는 식의 이름으로 이숙(異熟)과 사량(思量)과 요별경식(了別境識)을 거명하며 초전변식의 이름으로 아뢰야식, 이숙식, 일체종자식을 나열한다. 이숙은 초전변(初轉變)의 대표 이름으로 설정되며, 제19게송에서 이숙은 업과 2취(二取) 습기에 의해서 유전한다고 밝힌다. 제19게송은 세친이 『유가사지론』의 이숙의 유전설을 요약한 것으로 파악된다. 『유가사지론』은 이숙에 대하여 여러 교문에 의해서 설명한다. 먼저 구유의(俱有依), 등무간의(等無間依), 종자의(種子依)의 관계를 설정하여 5근과 의(意)와 이숙식의 연결을 시도한다. 또한 이숙이 생명을 받는 과정을 아애(我愛), 희론 종자, 업에 의해서 설명하는데, 이는 아집습기와 명언습기와 업습기를 의미한다. 아뢰야식은 초전변식의 자상(自相)에 해당하지만 이숙은 수없이 분별하여 만든 희론의 종자를 원인으로 품으며, 선악 등의 업 세력의 도움을 받으며 4생 6도와 같이 마음의 결과적 산물을 창출한다. 또한 이숙은 과보식의 명칭으로 중유(中有)에서 생유(生有)에 이르게 한다. 그럼에도 불구하고 이숙식은 청정한 진여 본성을 지니며 무루업에 의해 전변한다.

본 연구는 장기간의 태권도 수련프로그램과 태권도수련과 복합운동프로그램이 초등학생의 신체구 성과 기초체력에 미치는 영향을 알아보고자 실시하였으며, 연구대상자는 주5회 태권도수련프로그램에 참여한 30명, 태권도수련과 복합운동프로그램에 참여한 30명, 규칙적인 신체활동에 참여하지 않는 30 명을 선정하였다. 자료처리는 IBM SPSS 24.0 통계패키지를 사용하였으며, 기술통계를 산출하였으며, 집단 간 비교를 위해 일원변량분석(one-way ANOVA)를 실시하였다. 통계학적 유의수준은 p<.05로 설정하였다. 본 연구결과는 태권도 수련프로그램에 참여한 초등학생은 신체구성의 키(p<.001), 기초체 력의 근력(p<.001), 근지구력(p<.01)이 유의하게 증가하였으며, 태권도수련과 복합운동프로그램에 참여 한 초등학생은 신체구성의 키(p<.001), 체중(p<.05), 기초체력의 근력(p<.001), 민첩성(p<.05), 평형성 (p<.05)이 유의하게 증가하였다. 결론적으로 규칙적인 신체활동은 초등학생의 신체발달에 효과가 있었 으며, 태권도수련과 복합운동프로그램은 신체의 성장과 기초체력 요인에 효과가 있는 것으로 나타났 다.