• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.10 no.1
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• pp.1-18
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• 1974

Some coastal oceanographic investigations in Kwang Yang Bay were carried out bimonthly from April to September (The first half period of the research project) in 1974. The behaviour of the waters, distributions of water temperature and salinity and diffusion characteristic by dye release experiments in the bay are studied for the problems of practical importance in connection with water pollution. Velocities and directions of tidal currents at five fixed stations were observed. And dye diffusion experiment was also carried out on the sea. According to the results from this study, the salinity of the water is lower, ranging from about $28\;\textperthousand\;to\;32\textperthousand$, on all over the surface in the bay with the cause that the fresh water flows in from the Sumjin river. Diffusivities in this sea by means of Rhodamine B diffusion elliperiment were $785.6\;{\times}\;10^2\;\textrm{m}^2/sec$ in major axis, $15.6\;{\times}\;10^2 \;\textrm{m}^2/sec$/sec in minor axis in the direction on patch after 30 minutes from the dye release.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.3
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• pp.150-159
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• 2008

The marine litter generated as by-products of human activities and economic development enters to the sea through rivers or stream Indirectly, and through sea-based activities directly. It is commonly comprised of materials that degrade very slowly, such as various plastic products, polystyrene, glass, rubber, metal, wood, derelict fishing nets, wire, rope and so on. Such litter is found in the water column and on the seafloor as well as coastal areas In the Northwest Pacific region. It causes injury or death of human and other living organisms and also accident or damage of the vessel. It is not only a problem of country but also regional and/or global problem because it is transported by currents and winds from one country to another. In this regard, Northwest Pacific Action Plan (NOWPAP) Marine Litter Activity (MALITA) project had been carried out during 2006-2007 biennium and NOWPAP Regional Action Plan on Marine Litter (RAP MALI) has been also continuously implemented in the 2008-2009 biennium as next phase step of MALITA. MERRAC, one of four Regional Activity Centres (RACs) of NOWPAP, has developed monitoring guidelines, sectoral guidelines, and brochures related to sea-based marine litter and port reception facilities and services through MALITA project. Based upon these output, MERRAC will continuously implement relevant activities of RAP MALI in order to help to establish and improve a regional mechanism to deal with the sea-based marine litter problem. This paper aims to introduce MERRAC activities under MALITA and RAP MALI, and to suggest several recommendations to reduce marine litter in the NOWPAP region.

• Journal of the Mineralogical Society of Korea
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• v.32 no.4
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• pp.235-247
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• 2019

The Central South Sea Mud (CSSM), developed in the Seomjin River estuary, is known to be supplied with sediments from Heuksan Mud Belt (HMB) and Seomjin River. However, in order to form a mud belt, more sediments must be supplied than supplied in the above areas. Therefore, research on additional sources should be conducted. In this study, clay minerals, major elements analyzes were performed on cores 16PCT-GC01 and 16PCT-GC03 in order to investigate the transition in the provenance and transport pathway of sediments in CSSM. The Huanghe sediments are characterized by higher smectite and the Changjiang sediments are characterized by higher illite. Korean river sediments contain more kaolinite and chlorite than those of chinese rivers. Korean river sediments have higher Al, Fe, K concentraion than Chinese river sediments and Chinese rivers have higher Ca, Mg, Na than those of Korean rivers. Therefore, clay minerals and major elements can be a useful indicator for provenance. Based on our results, CSSM can be divided into three sediment units. Unit 3, which corresponds to the lowstand stage, is interpreted that sediments from Huanghe were supplied to the study area by coastal or tidal currents. Unit 2, which corresponds to the transgressive stage, is interpreted to have a weaker Huanghe effect and a stronger Changjiang and Korean rivers effect. Unit 1, which corresponds to the highstand stage when the sea level is the same as present and current circulation system is formed, is interpreted that sediments from Changjiang and Korean rivers are supplied to the research area through the current.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.2
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• pp.153-165
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• 1995

The fluctuations of catches in set nets around Kyeongbuk Province, the eastern coast of Korea, were analyzed and investigated by on the values of CPUE(Catch Per Unit Effort per hauling), and composition of dominant species caught from 1985 to 1989. Annual CPUE values were fluctuated every year, but their trends were decreased year by year, When the values were evaluated by species, the trends of annual catches were shown decreasing in file fish(Auteridae), mackerel(Scomber japonicus), tuna(Thunnus Thynnus), rock fish(Sebastes schlegelid) and yellowtail(Seriola quinqueradiata), increasing in sardine(Sardinops melanosticta), jack mackerel(Trachurus japonicus), and herring(Clupea pallasi), and similar in squid(Todarodes pacificus) and cuttle fish(Sepiidae). The main fishing season evaluated by monthly CPUE was estimated from August to November with a little difference by regions : from August to November at Chukpyon and Kanggu, from September to November at Chuksan and Kampo, and August to December in Hupo. When the DPUE values were analyzed by species, the main fishing seasons were quite different by species. Mackerel, jack mackerel, tuna, yellowtail, and rock fish were caught mainly from September to October, file fish and squid from November to January, sardine from April to May, herring in May, and cuttle fish in April. Annual catches were shown highest level in file fish and revealed higher by sardine, jack mackerel, mackerel, squid, tuna, and yellowtail in order. But the highest catches among each species were different with seasons, and that from January to July was sardine, from November to December file fish. The main migrating seasons of file fish, mackerel, squid, tuna, and cuttle fish at Chukpyon were a little earlier than at other regions. Though the migrating seasons of jack mackerel and tuna were almost same in every regions, that of sardine were shown 3 month's difference according to regions. In the year when the warm currents were stronger than those of the normal year and their isotherms were formed from the north to south along the eastern coastal line, the annual fish catches in set net were show higher levels.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.1
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• pp.13-19
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• 2024

An analysis of the coastal water temperature in the Tongyeong waters, the eastern sea of the South Sea of Korea, revealed that the water temperature rose sharply before the typhoon made landfall. The water temperature rise occurred throughout the entire water column. An analysis of the sea surface temperature data observed by NOAA(National Oceanic and Atmospheric Administration) satellites, indicated that sea water with a temperature of 30℃ existed in the eastern waters of the eastern South Sea of Korea before the typhoon landed. The southeastern sea of Korea is an area where ocean currents prevail from west to east owing to the Tsushima Warm Current. However, an analysis of the satellite data showed that seawater at 30℃ moved from east to west, indicating that it was affected by the Ekman transport caused by the typhoon before landing. In addition, because the eastern waters of the South Sea are not as deep as those of the East Sea, the water temperature of the entire water layer may remain constant owing to vertical mixing caused by the wind. Because the rise in water temperature in each water layer occurred on the same day, the rise in the bottom water temperature can be considered as owing to vertical mixing. Indeed, the southeastern sea of Korea is a sea area where the water temperature can rise rapidly depending on the direction of approach of the typhoon and the location of high temperature formation.