• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.28 no.1
• /
• pp.93-103
• /
• 1992

The hydrodynamic interaction characteristics between multiple floating bodies of semisubmersible type are examined for presenting the basic data for the design of huge offshore structures supported by a large number of the floating bodies in waves. The numerical approach is based on combination of a three-dimensional source distribution method and interaction theory which is exact within the context of linear potential theory. The method is applicable to an arbitrary number of three-dimensional bodies having any individual body geometries and geometrical arrangement with the restriction that the circumscribed, bottom-mounted, imaginary vertical cylinder for each body does not contain any part of the other body. The validity of this procedure was verified by comparing with numerical results obtained in the literature.

• ALGAE
• /
• v.26 no.1
• /
• pp.41-50
• /
• 2011

Yellow Sea surface sediment samples collected on October 15-31, 2003 were analyzed using the palynological process to investigate the spatial distribution of dinoflagellate resting cysts. The sampling areas comprised four latitudinal transects, the northernmost of which was located off the Shandong Peninsula, China and the southernmost off Jeju Island, Korea. Each transect line was composed of six to nine stations, spanning the distance between the Chinese and Korean coasts. Twenty-five different types of dinoflagellate cysts were identified. Gonyaulax scrippsae, Alexandrium spp. (ellipsoidal type), and G. spinifera were the most dominant at all stations surveyed. Dinoflagellate cysts belonging to the Gonyaulacales comprised over 50% of all cysts collected. The latitudinal distribution trend showed that cyst concentrations along the two middle transects were much higher than those along the two northern and southern transects. Cyst concentrations in the offshore central areas reached their highest values within each transect and gradually decreased toward the Chinese and Korean coasts. Overall, cyst concentrations were markedly elevated in the offshore central Yellow Sea areas and gradually decreased outward in all four directions. This concentric cyst distribution pattern was consistent with the hydrographic features of the Yellow Sea, such as circular current systems, sedimentary properties, and water depth.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.35 no.2
• /
• pp.170-177
• /
• 1999

In order to research the relationship between distribution of fish and the ocean environment in Southern Sea of Korea, echo survey and oceanographic observation were carried out from July 27 to 31 in 1998. The DSL(Depth Scattering Layer) and high density of fishes were appeared in northeastern Cheju Island and offshore of Karnak bay by color echo sounder. The relative Sa(area backscattering coefficient) in offshore of Karnak bay was 5,500 at 28KHz, 12,500 at 200KHz and Northeastern Cheju Island was 6,000 at 28KHz, 20,000 at 200KHz. During the acoustic survey period, Ocean environment of high density of fishes area were as the follows. The surface Northeastern Cheju Island were ranged 20~$26.5^{\circ}C,\;31.5~32.5\perthousand$ and that bottom were ranged 16~$20^{\circ}C,\;35.4~34\perthousand$. The shallow water area in offshore of Karnak bay were ranged 24~$26.5^{\circ}C,\;30.0~31.5\perthousand$

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.6 no.3
• /
• pp.164-179
• /
• 2001

Spatio-temporal variation in species composition, abundance and distribution of fisheries resources caught by large purse seine off Korea from 1991 to 1994 was analysed. Out of 19 species, Scomber japonicus (54.7%), Sardinops melanostictus (20.4%), Trachurus japonicus (9.1%), and Scomberomorus niphonius (6.2%) were predominated in catch. These 4 pelagic fishes occupied 90% of total catch. Major pelagic fishes caught by large purse seine were dispersed to northward from spring to summer, and migrated to the southern wintering ground during winter. Fishing effort (number of haul) was high in summer, but catch per unit effort showed a peak in winter. The high CPUE in winter seemed to be related to aggregation of the pelagic fish to the wintering ground in the southern sea. After spawning, they were widely dispersed for feeding in warm months.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.1
• /
• pp.78-82
• /
• 2010

Vessel numbers and fuel consumption by South Korea's offshore and coastal fisheries have continuously declined since 2000. Using the 2006 Intergovernmental Panel on Climate Change Guidelines, $CO_2$ emissions by South Korea's fishery industry (fishing and aquaculture, excluding deep-sea fishing) were calculated by the default $ CO_2$ emission factor and fuel consumption by fuel type, Emission of $CO_2$ was estimated to be 3.22 million $tCO_2$/year in 2007 for fisheries (excluding deep-sea fishing); when including deep-sea fishing, the estimated value increased to 4.11 million $tCO_2$/year. Fuel consumption per tonne of fishery production was 498 L, and the amount of $CO_2$ emission per tonne of production was 1.62 $tCO_2$. To calculate $CO_2$ emission more exactly, we must develop a system to compile energy balance statistics and introduce life-cycle assessment for the fishery industry.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.46 no.4
• /
• pp.406-415
• /
• 2010

The forming of fishing ground and the population ecological characteristics of yellowtail, Seriola quinqueradiata, in the coastal waters off Gim-nyeong of Jeju Island were investigated. The stock of yellowtail, Seriola quinqueradiata, between Jeju Island and coastal areas of the East Sea is probably the same. Water temperature probably is a major factor for controlling distribution of yellowtails in deeper, offshore areas off Jeju Island. However, the major factor that determines aggregation of yellowtails in coastal areas of Jeju Island, especially off Gim-nyeong is probably strong tidal currents driven by distribution of yellowtails rather than hydrological conditions such as Yellowtails collected off Jeju Island were from 1 to 4yrs old and about 50% of them were $1^{-yr}$ old, probably indicating overfishing. Jack mackerel was the major prey item for yellowtails off Gim-nyeong from October to March, suggesting concurrence of the two species.

• Journal of Fisheries and Marine Sciences Education
• /
• v.25 no.4
• /
• pp.991-997
• /
• 2013

Distribution and occurrence of swimming crab, Portunus trituberculatus larvae were investigated in the mid-western coast of Korea in the Yellow Sea. P. trituberculatus larvae were collected in July and August from 2010 to 2012. Bongo net with 303 mesh was deployed once with a double oblique tow. Zoea I (ZI) densities were highest in all sampling months. Then densities of later larval stages decreased dramatically. In general, larval densities at the stations in northern parts and coastal areas were higher than those at the southern and offshore area. Because egg bearing seasons of P. trituberculatus in the study area are between April and August, larval densities, particularly, of ZI may be underestimated. Considering higher densities of ZI and lower ones of later stages, larvae may be transported to growing area and returned to the parental populations. Larval densities and sea surface temperature were not correlated.

• Journal of Fisheries and Marine Sciences Education
• /
• v.28 no.4
• /
• pp.1031-1041
• /
• 2016

Interests in the Polar Regions have been growing due to various factors such as depletion of natural resources and advanced resource development technologies, accelerated rate of polar ice melting as a result of global warming, etc. In particular, demand for the workforce related to vessel passage using the Northern Sea Route and polar studies is still expanding. The International Maritime Organization adopted the Polar Code in 2015 for the safety of ship operation in polar waters and it will enter into force from 2017. But education and training section in the code has been prescribed only for the safe navigation in the ice covered waters intended for navigational offices. There is no basic safety training requirement that applies commonly for all personnel exposed to the risk of the polar regions and the relevant study or discussion has not been made so far. Therefore, this study provides basic data for developing safety training courses for crew and other personnel by analyzing relevant regulations on polar safety training and the contents of relevant safety training in offshore industry required by the costal states adjacent to arctic ocean.

• Journal of the Society of Naval Architects of Korea
• /
• v.54 no.3
• /
• pp.196-203
• /
• 2017

In general, the installation of offshore wind turbine have been carried out by a jack-up barge or wind turbine installation vessel. In case of using jack-up barge, an additional barge is required to transport offshore wind turbines. During the transportation, barge is affected by environmental conditions such as wave, wind etc. So, it is important to secure the static and dynamic stability of the barge. In this study, fundamental research was performed to evaluate the stability of barge due to use the guide frame. The analysis for static stability of barge was performed under the two loading conditions with or without wave and those results were evaluated according to the Ministry of Oceans and Fisheries rules. Also motion analysis was performed under the ITTC wave spectrum using buoy data and evaluated based on NORDFORSK guideline by using commercial software Maxsurf Motions.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.50 no.4
• /
• pp.567-582
• /
• 2014

Coastal fisheries in Korean waters have highly complexity with a variety of fishing gears, and scale of those fisheries is smaller than that of offshore fisheries. As a result, important spawning and nursery grounds for many species of fish has been destroyed. The pragmatic ecosystem-based approach was developed for the assessment of fisheries resources in Korean waters by Zhang et al. (2009; 2010). As for the species risk index (SRI), common squid caught by coastal gillnet in the Uljin region had the highest risk. As for the fisheries risk index (FRI), coastal gillnet in the Uljin coastal waters had the highest risk. For the common squid which had the highest SRI, resources management strategies must be established such as catch prohibition of length and period with TAC. For the coastal gillnet in the Uljin region which had the highest FRI, it is judged to need management plans for conserving biodiversity as reducing the catch of non-target species and discards. Also to protect existing habitat, illegal fishery should be prohibited, and fishing gears should be designed in the environmental-friendly way considering when fishing gears lost.