This study examined the power consumption of angling boats during entry, departure, and fishing operations using a black box-type storage device. Through this analysis, it determined the energy consumption and carbon emissions of small fishing boats used for catching the largehead hairtail. The energy consumption and carbon emissions were calculated using formulas provided by the Korea Energy Agency, which incorporated updated emission coefficients from 2022. The findings revealed that the average power consumption of small fishing boats for the largehead hairtail was 546.3 kWh, with a total energy consumption of 0.1164 TOE and carbon emissions of 24.057 CO2. The average energy consumption was calculated at 0.0006 TOE per kilogram, and the carbon emissions were determined to be 0.135 CO2/kg.

연구는 갈치 Trichiurus lepturus의 성 성숙과 생식생물학적 기초 정보를 제공하기 위해 수행하 였다. 난자형성과정 동안 난모세포와 핵의 크기는 증가하였으나 핵에 대한 인의 비율은 감소 하였다. H-E 염색 결과, 세포질의 염색성은 호염기성에서 호산성으로 변하였다. 난황형성개시 기 난모세포의 난경은 약 63.2 (±12.7) μm였다. 세포질에서는 호산성의 난황핵이 관찰되었다. 성숙기 난모세포의 난경은 216.6 (±24.7) μm였으며, GVBD (germinal vesicle breakdown)가 관 찰되었다. 완숙기 난모세포의 난경은 317.9 (±80.9) μm였으며, 방사대의 두께는 4.2 (±1.7) μm 였다. 난모세포의 발달형태는 난군동기발달형에 속하며, 난황 축적은 대부분의 경골어류와 마 찬가지로 외재적 방법과 내재적 방법에 의한 것으로 판단되었다.

본 연구는 얼음결정체의 형성을 막고자 step-cooling 알고리즘을 적용하여 갈치를 과냉각 저장하였다. 저장의 신선도 유지효과를 확인하기 위해 냉장 및 냉동 저장된 갈치와의 신선도 비교평가를 실시하였다. 과냉각 저장은 냉장 저장과 비교하였을 때, 일반세균수와 단백질 부패로 인해 그 함량이 증가되는 VBN, TMA 값에서 비교적 작은 값을 보여 품질 유지에 효과를 나타내었다. 또한, 냉동 저장과 비교하였을 때, pH, VBN 및 TMA에서는 저장이 종료된 12일을 기준으로 차이를 크게 나타내지 않았다. 일반 세균수에서는 9일차까지 비슷한 값을 유지하였으며, 12일 차에서는 과냉각 시료가 높은 값을 보였다. 이를 통해, 과 냉각 저장이 미생물 생장을 최소화하고 단백질 부패를 지연시키는데 효과가 있다고 사료된다. 장기저장에서는 크게 영향을 미치지는 않았으나, 단기저장 관점에서는 냉장 저장보다 과냉각 저장이 갈치의 품질을 유지하는데 많은 장점을 가질 것으로 판단된다.

The mesh selectivity of hairtail (Trichiurus lepturus) caught by coastal drift gill net was examined in field experiments with three different mesh sizes (45, 50 and 55 mm) from October to November, 2013 in the coastal areas of south-west of Jeju province. The mesh selectivity tests were conducted with the experimental net to be set middle part of conventional driftnets. The mesh selectivity tests were carried out the total of four times. The selectivity curve was estimated by the Kitahara’s and Fujimori’s method. In the results, the catch number of hairtail was 653 (125.8 kg) and occupied 34.8% in total catches weight. The optimal mesh size for 50% selection on the minimum landing size (180 mm, AL) and the first maturity size (260 mm, AL) of hairtail were estimated as 47.2 mm and 64.5 mm by master selectivity curves, respectively.

Yield-per-recruit (YPR) analysis is used to provide management guidance for the efficient use of a fish cohort. However, the individual fish price per unit weight of small yellow croaker (Larimichthys polyactis) or hairtail (Trichiurus lepturus) increases dramatically by size in Korea. Therefore, age-based production value-per-recruit (PPR) analysis has recently been developed (Zhang et al., 2014). Since age determination requires a substantial amount of money and time and it is even impossible for some fish species, it is difficult to obtain age information to apply the age-based PPR model. Thus, we attempted to develop an alternative method, which uses length data rather than age information, called the length-based PPR analysis. The results revealed that length-based PPR analysis was much more conservative for stock management than the YPR analysis. Furthermore, the PPR analysis was more economically beneficial than the YPR analysis, which can prevent the fish stock from the economic overfishing. In conclusion, the length-based PPR analysis could be a proper approach for stock assessment in the case that the individual fish price per unit weight increases dramatically by size, and this analysis is useful to obtain vital management parameters under data-deficient situation when traditional stock assessment methods are not applicable.

1. 제주해협에서는 6월에 가장 낮은 생물량 분포를 나타내었고, 가을철(11월)에 가장 높은 생물량 분포를 보이면서 높은 2차 생산력을 보이는 것으로 사료된다. 2. 해황 및 습중량과의 관계에서 가장 높은 분포를 나타내는 정점은 각각 정점 14와 11로 그 출현위치는 해협의 중앙부분이고, 한국남해연안역 및 제주도 북부연안역에는 다소 낮은 생물량분포를 보이고 있으며, 생물량 분포가 높게 나타나는 해역의 특징은 patch의 형태로 분포하였다 반면 한국남해연안역에 비하여 제주도 북부연안역에높은 생물량 분포를 나타냄으로써 제주해협에서의 갈치어장 형성위치와 생물량 분포와의 관계가 밀접하게 나타날 것으로 판단된다. 그리고, 가을 의 해황 특성인 서로 다른 이질수괴의 경계역인 안상부 해황의 중심에 높은 생물량을 나타냈다. 3. 제주해협에서 patch의 형태로 생물량 분포가 높게 나타나는 해역의 외측에 좋은 갈치어장이 형성되었다.

The study on the Assembling Mechanism of the Hairtail, Trichiurus lenpturus, at the Fishing Grounds of the Cheju Strait had been investigated by analyzing the relationship of the oceanographic conditions and the fishing ground of the Hairtail in the Cheju Strait. 1. The fishing grounds of the hairtail at the Cheju Strait are formed at the bottom of a high temperature of the tidal front at the coast. area of northern Cheju Island, the tip of the linguiform is high in salinity at the eastern and western entrances of Cheju Island, low salinity eddy on the surface and its surrounding front, various water masses in the Strait and coastal waters of the South Sea in Korea. 2. The fishing grounds of the Hairtail at the Cheju Strait begins with the sea surface temperature higher than 15℃ and the incoming of low salinity water now from the East China Sea. 3. Estimation of optimum temperature and salinity per season based upon analysis for relationship between temperature of water and salinity of the bottom layer and the catch is : 15.2~16.4℃, 34.20~34.40‰ in spring(June); 14.4~ 17.0℃, 33.70~34.30‰ in summer(July~September); and 15.7~ 18.6℃, 33.70~34.50‰ in autumn(October~December). Hairtail are mostly caught at the Yellow Sea Warm Current and Tsushima Current with temperature over 14.5℃ and salinity over 33.70‰ at the bottom layers of the Cheju Strait. 4. Considering the relationship between the amount of hairtail catch and the water temperature of bottom layer, when the bottom water being above 14.0℃ flowed into Cheju Strait through the western entrance of the strait in summer, the ca-h appears to have been abundant. In contrast, the catch has been poor when the temperature of such water was recorded to be below 13℃ Therefore, distribution patterns of water at the bottom layer can be used as a forecast index whether the catch of a certain year will be good or poor.

PCR analysis generated on the genetic data showed that the geographic hairtail (Trichiurus lepturus) population from Korea in the Yellow Sea was more or less separated from geographic hairtail population from China in the South Sea. The average bandsharing value (mean±SD) within hairtail population from Korea showed 0.859±0.031, whereas 0.752±0.039 within population from China. Also, bandsharing values between two hairtail populations ranged from 0.470 to 0.611, with an average of 0.542±0.059. As compared separately, the bandsharing values of individuals within hairtail population from Korea were comparatively higher than those of individuals within population from China. The hierarchical dendrogram resulted from reliable oligonucleotides primers, indicating two genetic clusters composed of cluster 1 (KOREANHAIR1~KOREANHAIR11) and cluster 2 (CHINESEHAI12~CHINESEHAI22). The genetic distances between two geographic populations ranged from 0.038 to 0.476. Individual No. 11 within hairtail population from Korea was genetically closely related with No. 10 (genetic distance=0.038). The longest genetic distance (0.476) displaying significant molecular difference was also between individual No. 01 within hairtail population from Korea and No. 22 from Chinese. In the present study, PCR analysis has revealed significant genetic distances between two hairtail population pairs (P<0.05).

Hairtail, Trichiurus lepturus, ecologically warm water fish species, belonging to family Trichiuridae, widely distributed on the coast of the West Sea, South Sea and Jeju island in the Korean Peninsula and the several sea areas in China under the natural ecosystem. The food consumption of this species has increased considerably in various types of restaurants (including restaurants specializing in serving hairtails roasted and soy-sauce glazed cutlass fish with radish or other vegetables) for a long time. However, in spite of their economic and scientific consequences, a little information currently exist regarding the physiological and ecological levels only of hairtail species in Korea. Only the biological fisheries feature, distribution and migration of hairtail, Trichiurus lepturus, in Korean waters were in vestigated (Kimatal, 1998; Parketal, 2002). Lately, imported hairtail have been changed into endemic hairtail because of high margin. In the present study, to elucidate the genetic distances and differences among geographical hairtail, Trichiurus lepturus, populations, we performed a clustering analysis of two hairtail populations collected from Korea and China. Muscle tissues were collected separately from hairtail, Trichiurus lepturus, in dividuals from Korea in the Yellow Sea and China in the East Sea, respectively. RAPD-PCR analysis was performed on DNA samples extracted from a total of 44 (specimen numbers for duplicate experiments) individuals using eight arbitrarily selected primers of two decades of different decamer primers. Hairtail muscle was collected in sterile tubes, immediately placed on dry ice, and stored at －40℃ until the genomic DNA extraction. Genomic DNA was extracted and purified under the conditions described previously (Yoon and Kim, 2004). The degree of variability was calculated by use of the Dice coefficient (F), which is given by the formula: F = 2 nab/(na+nb), where nab is the number of bands shared between the samples a and b, na is the total number of bands for sample a and nb is the total number of bands for sample b (Jeffreys and Morton, 1987; Yoke-Kqueen and Radu, 2006). Euclidean genetic distances within- and between-populations were also calculated using the hierarchical dendrogram program Systat ver.10 (SPSS Inc., Chicago, IL, USA). The random primers OPA-07, OPA-20, OPB-14, OPB-15, OPB-17, OPB-18, OPD-16 and URP-07 showed common, polymorphic and specific bands produced using each primer to amplify genomic DNA isolated from the muscle of individuals. Accordingly, PCR analysis generated on the RAPD data showed that the geographic hairtail population from Korea in the West Sea was more or less separated from geographic hairtail population from China in the South Sea. The hierarchical dendrogram resulted from reliable four primers, indicating three genetic clusters composed of group 1 (Korean No. 1～11) and group 2 (Chinese No. 12～22). The genetic distances between two geographic populations ranged from 0.038 to 0.476. Individual No. 09 within hairtail population from Korea was genetically closely related with No. 06 (genetic distance = 0.104). The longest genetic distance (0.476) displaying significant molecular difference was also between individual No. 01 within hairtail population from Korea and No. 22 from Chinese. In the present study, RAPD-PCR analysis has revealed significant genetic distances between two hairtail population pairs. High levels of genetic polymorphisms and the existence of population differentiation between two hairtail populations showed RAPD-PCR approach is one of the suitable tools for individuals and/or population biological DNA studies.