• 한국패류학회지
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• 제29권3호
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• pp.225-232
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• 2013

본 연구는 저염분 해수에 노출된 전복의 폐사 원인을 구명하고자, 수온별 (15, 20 및 $25^{\circ}C$) 염분별 (30, 25, 20 및 15 psu) 노출시간별 (3, 6, 12, 24 및 48 h) 북방전복, Haliotis discus hannai 치패의 회복률 및 아가미의 조직학적 변화를 조사하였다. 모든 수온조건에서 20 psu 이하의 저염분 해수에 6시간 이상 노출시킨 전복은 회복기간 동안 생존율이 감소하였으며, 15 psu 해수에 24시간 이상 노출시킨 전복은 회복되지 못하고 전량 폐사하였다. 이를 조직학적으로 관찰한 결과, 20 psu 이하의 저염분 해수에 6시간 이상 노출시킨 전복의 아가미 조직은 팽창 또는 손상되었으며, 15 psu 해수에 24시간 이상 노출시킨 전복의 아가미 조직은 대부분 파괴되었다. 이와같은 결과는 수온이 높을수록, 염분이 낮을수록, 노출시간이 길수록 확연히 나타났다. 따라서 저염분 해수에 노출된 전복이 폐사하는 직접적인 원인 중의 하나는 아가미 조직의 손상으로 인한 질식으로 판단된다.

• 한국수산과학회지
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• 제48권4호
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• pp.507-528
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• 2015

The Fish Collection Project collected 356 fish species from the Southern Sea of Korea during 2010-2012, 55 more than previously collected. The fishes belonged to 3 classes, 29 orders and 128 families. The 5 dominant orders, Perciformes, Scorpaeniformes, Pleuronectiformes, Tetraodontiformes, and Clupeiformes, accounted for ~80% of the identified species. Additionally, 126 species were collected from the Southern Sea for the first time, while 85 species that had been found in previous collections were not seen. The species variety of fish in the Southern Sea may be influenced by its unique oceanographic conditions such as increased water temperatures in coastal areas, so regular surveys would assist our understanding of the fish community. We suggest that various collection methods, including diving, be used to collect fish species inhabiting rocky shore or deep-sea areas, where commercial fishing gear is difficult to deploy.

• 한국환경과학회지
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• 제18권10호
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• pp.1171-1179
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• 2009

The solitary ascidian, Halocynthia aurantium, which is commonly called the sea peach because of its coloration and general shape, is a valuable organism of benthic marine population in the northern region of the East Sea, Korea. It is seldom found at a depth of less than 10 meters and the sea peach is frequently observed in large populations between 20 and 100 meters. It appears to prefer attachment to vertical rocks faces and artificial cement blocks exposed to the currents. Mass mortality and reduction of resources in sea peach, H. aurantium, were occurred in the benthic area of the northern region of the East Sea because of the rapid fluctuation of environmental factors such as temperature and salinity due to mass rainfall in summer and going up north of a strong warm current in winter. Therefore, we examined the effects of temperature and salinity on embryonic development of fertilized eggs, tadpole larva to metamorphosis, and attachment to siphon development. Laboratory-raised larvae were studied using a two-factorial experimental design with four levels of temperature(8, 12, 16 and $20^{\circ}C$) and four levels of salinity(20, 25, 30 and 34 psu). The ascidian larvae of H. aurantium survived environmental conditions between temperature of $8{\sim}20^{\circ}C$ and salinity of 25~34 psu and exhibited positive growth at $8{\sim}16^{\circ}C$ and 30~34 psu. Fertilized eggs have not developed at lower salinity of 20 psu irrespective of temperature range tested and have showed an abnormal development at the salinity of 25 psu between higher temperatures of 20 and $24^{\circ}C$. This result suggests that temperature increase and salinity reduction depending on environmental fluctuation may have significant impacts on population variation of H. aurantium in the northern region of the East Sea.

• 한국수산과학회지
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• 제36권6호
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• pp.619-624
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• 2003

Genital organs and gonad development in kishi velvet shrimp (Metapenaeopsis dalei) were studied based on morphological and histological observations. The samples were collected monthly around the Ochongdo area on the western coast of Korea, from April 1997 to December 1998. Thelycum appear structurally complete after females reach a length of about 12.0 mm CL. Petasma rarely Join after males reach a length of 10.6 mm CL and a fully developed petasma shows up to a length of 12.0 mm CL. The ovaries lie on the dorsal side of the female shrimps thorax. The ovary cavity is located below the heart and above the hepatopancreas. The anterior part of the ovary is round and fused, and the posterior part shows a pair of tubule-like structures. Testes are bilaterally symmetrical, the anterior part shows a convoluted tubule, and the posterior part consists of a pair of tubules. In histological observations, ripe eggs and spermatozoon show when mature females and males reach a length of about 12.0 mm CL.

• 한국해양바이오학회지
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• 제3권1호
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• pp.54-60
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• 2008

Compared to other North African countries, Tunisia has reached a significant level of fish consumption. The only relevant historical dimension of aquaculture in Tunisia are traditional lagoon management (80,000 ha of lagoon and coastal lakes) and culture of shellfish. Semi-intensive and intensive cultures are relatively new concepts in Tunisia and only recently also the public sector is involved. The Tunisian fishing industry has expanded over the last 20 years and annual catches at present are more than four times those registered in mid-fifties. Production of the year 2007 reached 105 thousand tons against 111 thousand tons during the same period of 2006 thus recording a fall of 5%. Unfavorable weather conditions mainly during the last quarter year had the effect to reduce the number of days out at sea. Exports reached 24.3 thousand tons for one value 240.5 MD against respectively 22.2 thousand tons and 234.1 thus recording MD at the end of the past year a rise of 9% in volume and from 3% in value. Commercial value such as shellfish - consequence of one regression of the production - with in parallel raises blue fish exports. The imports were stabilized in volume of 39.1 thousand tons and increased from 6% in value with respectively 67.4 MD in 2007 against 63.7 MD at the end of 2006. The importation in larger quantities of intended fish to the fattening of tuna in floating cages explains partly this rise. Nevertheless, the pay of balance import/export of produced fishing remains positive with a surplus of 173.1 MD against 170.4 MD in 2006.

• 한국패류학회지
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• 제27권2호
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• pp.143-148
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• 2011

연구는 양질의 피조개 수정란 확보와 안정적 종묘생산을 위하여 피조개 모패의 먹이생물로 미세조류 3종 (Isochrysis galbana, Tetraselmis tetrathele, Phaeodactylum tricornutum) 을 단독 또는 혼합 공급하여 먹이생물에 따른 피조개 모패의 비만도, 생식소발달, 성숙유도율 및 생존율을 조사하였다. 사육 45일 경과 후 피조개 모패의 완숙기 출현율, 성숙유도율 및 생존율은 3종의 미세조류를 혼합 공급하거나 T. tetrathele를 단독공급한 실험구에서 가장 높았다.

• 수산해양기술연구
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• 제59권4호
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• pp.290-300
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• 2023

This study aimed to identify the actual catch situation of offshore dredge gear which is newly regulated in the legislation. It's also conducted to identify the species composition, weight of the catch including the target species and incidental catches, and to provide the basic information necessary for the resource management of aquatic organisms caught by offshore dredge. During the investigation period (from September 2022 to May 2023), a total of 61 species appeared in the test operation sea of Boryeong, Chungcheongnam-do and Gunsan, Jeollabuk-do, with 31 species of fishes, 11 species of malacostraca, six species of gastropoda, five species of bivalvia, three species of cephalopoda, three species of asteroidea, one species each of asteroidea and holothuroidea appeared. According to the results of the test operation conducted in September and November 2022, the non-catch season of Atrina (Servatrina) pectinata, 1,203 shellfishes were caught out of 2,979 caught in number, showing a bycatch rate of 59.6%, and by weight, 157.9 kg of shellfish was caught out of the total catch of 448.4 kg, showing a bycatch rate of 64.8%. On the other hand, in February and May 2023, the catch season for Atrina (Servatrina) pectinata, 3,692 fishsells were caught out of the 4,232 catches in total, showing a bycatch rate of 12.8%, and by weight, 1,185.0 kg of shellfish was caught out of the total catch of 1,293.2 kg, showing an 8.3% bycatch rate.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.334-334
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• 2015

The results of flow feature around two circular cylinders in various arrangements are carried out using two-dimensional simulation at Reynolds number of 200. In this work, time-averaged fluid force acting on the upstream and downstream cylinders were calculated for staggered angle ${\alpha}=0{\sim}90^{\circ}$ in the range of L/D = 1.1~5, where ${\alpha}$ is the angle between the free-stream flow and the line connecting the centers of the cylinders, L is centre-to-centre distance and D is cylinder diameter. The dependence of magnitudes and trends of fluid force coefficient on the spacing ratio L/D and ${\alpha}$ are discussed. In all arrangements of two cylinders, tandem arrangement (${\alpha}=0^{\circ}$) is the case produced a minimum drag coefficient for downstream cylinder. Moreover, the locations of separation and stagnation points or pressure coefficient on surface of the cylinder were examined. Acknowledgement: "This research was a part of the project titled 'Development of integrated estuarine management system', funded by the Ministry of Oceans and Fisheries, Korea."

• 한국해양환경ㆍ에너지학회지
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• 제20권1호
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• pp.45-54
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• 2017

최근 취업애로 계층이 100만명을 넘어서는 등청년 고용의 어려움이 지속되고 있다. 해양수산 분야도 예외가 아니어서 수요 측면에서는 우수한 인재 부족으로, 공급 측면에서는 양질의 일자리 부족으로 인력 수급 상의 미스매치가 발생하고 있다. 미스매치는 양적인 면도 중요하지만 질적인 측면이 더욱 중요하다. 이러한 문제를 해소하기 위해서는 현장과 미래 수요에 부응한 전문인력을 집중적으로 양성하고, 실습장비 등과 같은 교육 인프라와 교원의 역량 강화, 산학연 협력 체계 구축 등이 필요하다. 나아가 학교교육에서 재교육까지 아우르는 인력양성 통합관리 시스템을 구축하고 일반 국민의 해양수산에 대한 이미지 제고를 위한 사업들이 추진되어야 한다.

• 한국수산과학회지
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• 제36권4호
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• pp.389-401
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• 2003

The changes in structure and abundance of taxon or species groups in the East Sea ecosystem were compared between pre- and post-Climatic Regime Shift (CRS) occurred in the mid 1970s using an ECOPATH model. Although the East Sea ecosystem consisted of primary producers, primary consumers, secondary consumers and terminal consumers most species groups were classified as secondary consumers. The mean trophic level between pre- and post-CRS increased from 3.09 during the pre-CRS period to 3.28 during the post-CRS period. Total biomass of the species groups in the East Sea ecosystem increased by $9\%$ due to the CRS, and total catch increased by $48\%.$ The most significant differences between pre- and post-CRS models occurred at the mid/high trophic levels occupied by fishes and cephalopods. Relative contribution of the different species groups to the total energy flow was calculated for the trophic level III. As a result, the status by the dominant species in the East Sea ecosystem shifted from cephalopods to walleye pollock due to the CRS. Relative contribution of 5 species, which were commercially important, such as Pacific saury, Pacific sardine, filefish, walleye pollock and sandfish in trophic level III, were also changed due to the CRS. Finally, the CRS turned out to cause large variations in biomass and catch of fisheries resources as well as the status and role of the major species.