• Korean Journal of Ichthyology
• /
• v.23 no.3
• /
• pp.242-245
• /
• 2011

This is the first report of Japonolaeops dentatus Amaoka, belonging to the family Bothidae, collected in Korea. Four specimens (152.9~174.7 mm in standard length) were caught in the coastal waters of Jeju Island by using the bottom trawl. This species was characterized by the following morphological traits: 115~120 dorsal fin rays, 96~98 anal fin rays, 105~106 pores in lateral line, upper jaw extending to below anterior margin of lower eye, and teeth presenting on both ocular and blind sides of the jaw. We propose a new Korean name, "Geom-eun-kko-ri-neop-chi-sok" and "Geom-eun-kko-ri-neop-chi" for the genus and species, respectively.

• Journal of Environmental Science International
• /
• v.20 no.12
• /
• pp.1521-1531
• /
• 2011

This study was carried out to determine the characteristics of the marine environment, including nutritional content, in order to clearly understand the outbreaks of Gonyaulax polygramma in the southern coastal areas in August, 2009. Samples were collected at 13 sites and water temperature and salinity were measured using a CTD. Field surveys were twice: the first between August 5-7, the second between August 22-24. The cell density of G. polygramma was 6,500-10,000 cells $ml^{-1}$ during the $1^{st}$ survey, whereas during the $2^{nd}$ survey the range of the cells was recorded from 8,000 to 12,500 cells $ml^{-1}$. Cochlodinium polykrikoides ranged from 0 to 105 cells $l^{-1}$ during the field survey. In water environments, the majority stations during the $1^{st}$ survey showed a nearly homogeneous water column below $1^{\circ}C$ in temperature, as well as similar profiles of salinity. However, the stratification between the surface and bottom was observed in the $2^{nd}$ survey. Regarding nutrients, Dissolved Inorganic Nitrogen (DIN) in the surface ranged from 0.144 to 0.236 mg $l^{-1}$ during the $1^{st}$ survey, and 0.082-0.228 mg $l^{-1}$ during the $2^{nd}$ survey. DIP (Dissolved Inorganic Phosphorus) did not show any difference in concentration between the $1^{st}$ and $2^{nd}$ survey. During August of 2009, the wind speed in the southern waters remained at around ${\leq}2\;m\;s^{-1}$ for about 60% of time, and there was very little precipitation during the month. Irradiance of ${\geq}10$ hr was shown in the late of August. It is thought that a low level of DIN and salinity play an important role as an essential factor for rapid growth, wide distribution and longer duration of red tide in G. polygramma.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.15 no.4
• /
• pp.255-262
• /
• 1982

The data of 37 oceanographic stations in the coastal sea of Jeju island are compiled in terms of temperature, salinity, dissolved oxygen, silicate, nitrate and phosphate to analyge the chelnical characteristics in this region. This work was carried out during June, 1951. The concentrations of nutrients in the layer more than 50 m are generally 0.5-3 times larger than the surface layer. Each constituents in this layer are as follows: temperature ranged 11.8 to $15.4^{\circ}C$ and salinity, 33.8 to $34.8\%_{\circ}$; and also dissolved oxygen and slicate are 5.2 to 5.6ml/l and 5.6 to $9.0{\mu}g-at/l$, respectively. And nitrate and phosphate ranged 1.0 to $6.0{\mu}g-at/l$ and 0.1 to $0.5{\mu}g-at/l$, respectively. The coastal sea of Jeju island is divided into two parts in chemical view point : one is the southeastern sea of Jeju island under the influence of the Tsushima Current, md the other is the northeastern sea of Jejo island under the influence of the Yellow Sea Bottom Cold Water and the south coastal water of Korea. The north-western sea of Jeju island had relatively a cold (about $13^{\circ}C$) and low saline water (about $34\%_{\circ}$), and dissolved oxygen was higher than in the neibouring waters. It seems that in the southern area between Moseulpo and Seogwipo of Jeju island, two different Ivater masses are complicately intermixed and a tidal front is formed.

• Korean Journal of Ichthyology
• /
• v.29 no.4
• /
• pp.272-276
• /
• 2017

This is the first report of Cantherhines pardalis (Tetraodontiformes: Monacanthidae) from Korea. A single specimen (105.4 mm in SL) was collected from the coastal waters of Busan by gill net on 20 June, 2012. This species is characterized by having the following morphological traits: II, 34 dorsal fin rays; 31 anal fin rays; 13 pectoral fin rays; caudal peduncle without large spines; spine row on the lateral side of first dorsal spine distinct; posterior end of pelvic with encasing scales distinctly more protruding than ventral flap. This species is similar to C. dumerilii except for the number of spines on caudal peduncle (none in C. pardalis vs. two pairs in C. dumerilii). Based on morphological and molecular approaches, the specimen was identified as C. pardalis. We add C. pardalis to Korean fish fauna and propose the new Korean names "Yuk-gak-mu-nui-jwi-chi" for the species.

• Journal of Fisheries and Marine Sciences Education
• /
• v.29 no.1
• /
• pp.148-157
• /
• 2017

This study has studied the phenomenon exclusive to the activity of skin scuba among marine sports in Busan region, and such empirical studies are for the development of skin scuba, and even of the entire marine sports, and in order to achieve such objective, the study method centered around qualitative study method of in-depth interview, participatory observation, and documentation study, the results of which are as follows. First is the advantage of the local environment as an open-water location. This study area has beaches of pebbles, and the underwater is also comprised of pebbles up to a certain distance, securing a superior underwater visibility compared to the sand of other Busan regions, and such local environment is thought to be an advantage of skin scuba activity. Second is the satisfaction of accessibility. This study area had an advantage in participant accessibility, which is thought to act as a good strength for the marine sports development of this area in the future. Third is the satisfaction of education. The club instructors of this study area had various marine sports-related licenses such as skin scuba, along with marine lifeguard trainer qualifications to prepare against safety accidents, which are also thought to have positive influences on the education satisfaction for beginners. Fourth is the inconvenient subsidiary facility. This study area has great natural environment for open waters, but the subsidiary facilities of the club for skin scuba activity was found to be very inconvenient by this study, and for the future development of skin scuba, the improvement of subsidiary facilities should be considered. Fifth is the inconvenient parking facilities. The participants in this study area agreed upon the inconvenience of the parking issue alongside the subsidiary facilities. There are always parking issues near the coasts of Busan region, and in order to resolve such issues, active assistance from the City of Busan and each local government, and if such methods are well proposed, the conflict between the marine sports participants and local residents shall be resolved, it would play a great role in the development of marine sports.

• Animal Systematics, Evolution and Diversity
• /
• v.27 no.1
• /
• pp.25-33
• /
• 2011

Three morphospecies of the genus Uronychia, i.e. U. setigera Calkins, 1902, U. binucleata Young, 1922, and U. multicirrus Song, 1997, were collected from the coastal waters of Gumjin-ri on the East Sea and the public waterfront of Incheon on the Yellow Sea in Korea, respectively. These species are described based on live observation, protargol impregnation, silver nitrate impregnation, and their morphometrics. Diagnostic keys for these species are also provided. In addition, their small subunit ribosomal DNA sequences were compared with previously known sequences of Uronychia species. Diagnostics of three Uronychia species are as follows: U. setigera: $50-80\;{\mu}m$ long in vivo, oval-shaped, 2 macronuclear nodules (Ma), 1 spur on the left margin, 11 adoral membranelles (AM) 1, 4 AM2, 1 buccal cirrus (BC), 4 frontal cirri (FC), 3 left marginal cirri (LMC), 2 ventral cirri (VC), 5 transverse cirri (TC), 3 caudal cirri (CC), 6 dorsal kineties (DK), and approximately 23 cilia in the leftmost kinety. U. binucleata: $70-110\;{\mu}m$ long in vivo, oval to slightly rectangular shaped, 2 Ma, 1 micronucleus (Mi), 2 spurs on the posterior region, 11 AM1, 4 AM2, 1 BC, 4 FC, 3 LMC, 2 VC, 5 TC, 3 CC, 6 DK, and approximately 37 cilia in the leftmost kinety. U. multicirrus: $140-200\;{\mu}m$ long in vivo, oval to slightly rectangular shaped, ca. 7 Ma, 1 Mi, 11 AM1, 4 AM2, 1 BC, 4 FC, 3 LMC, approximately 8 VC, 5 TC, 3 CC, and 6 DK. This study presents the first record of this genus in Korea.

• Journal of Environmental Science International
• /
• v.23 no.12
• /
• pp.2015-2028
• /
• 2014

We analyzed with HPLC (High Performance Liquid Chromatography) analysis photosynthetic pigments and environmental factors, microscopic observations of the phytoplankton and zooplankton in the seawater every month from February 2009 to November 2010 in Haengam Bay. The level of dissolved inorganic nutrients was the highest between July and September, when freshwater influx was at its peak, whereas chlorophyll a levels were the highest in April and August. Also, phytoplankton pigment concentration increased when dissolved inorganic nutrients are carried into nearshore waters by rainfall runoff. Based on identification of phytoplankton and photosynthetic pigments results, diatoms were mainly dominant while dinoflagellate populations increased at July and August 2009, May 2010. The zooplankton communities are dominated in terms of Noctiluca scintillans. The contribution of Noctiluca scintillans in 2010 accounts for approximately 77.3% of the total zooplankton. Distribution patterns over time of zooplankton in the seasonal distribution of phytoplankton showed a different pattern.

• Ocean Systems Engineering
• /
• v.3 no.1
• /
• pp.9-34
• /
• 2013

Submarine pipelines encounter significant wave forces in shallow coastal waters due to the action of waves. In order to reduce such forces (also to protect the pipe against anchors and dropped objects) they are buried below the seabed. The wave force variation due to burial depends on the engineering characteristics of the sub soil like hydraulic conductivity and porosity, apart from the design environmental conditions. For a given wave condition, in certain type of soil, the wave force can reduce drastically with increased burial and in certain other type of soil, it may not. It is hence essential to understand how the wave forces vary in soils of different hydraulic conductivity. Based on physical model study, the wave forces on the buried pipeline model is assessed for a wide range of wave conditions, for different burial depths and for four types of cohesion-less soils, covering hydraulic conductivity in the range of 0.286 to 1.84 mm/s. It is found that for all the four soil types, the horizontal wave force reduces with increase in depth of burial, whereas the vertical force is high for half buried condition. Among the soils, well graded one is better for half buried case, since the least vertical force is experienced for this situation. It is found that uniformly graded and low hydraulic conductivity soil attracts the maximum vertical force for half buried case. A case study analysis is carried out and is reported. The results of this study are useful for submarine buried pipeline design.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.38 no.5
• /
• pp.331-341
• /
• 2005

Distribution of anchovy (Engraulis japonica) eggs and larvae was studied in the southwestern sea of Korea in July and November, 2001. Anchovy eggs were found mainly in the oceanic fronts of the northern sea area which were formed in the offshore area of Chuja Is. Bogil Is. and Chungsan Is. from west to east. Anchovy eggs were also found in the surrounding sea of Cheju Is. in the southern sea front area. The waters were highly heterogeneous and the water masses were bordered based on temperature $(10.8-26.4^{\circ}C)$ and salinity (28.9-33.7 psu). The anchovy eggs were mostly found outside of the China Coastal Water, where salinity was below 31 psu. The anchovy eggs were not found in November. Abundance of the anchovy larvae were higher in July than November. Temperature ranged from $10.8^{\circ}C\;to\;25.9^{\circ}C\;and\;15.9^{\circ}C\;to\;20.5^{\circ}C$, and salinity ranged from 28.9psu to 34.1psu and 33.2psu to 34.1psu in July and November, respectively. Non-swimmable larvae were found throughout the whole area of the southwestern sea of Korea. The area beyond the oceanic front had anchovy eggs dispersed from the spawning grounds to offshore. Dispersion pattern showed that the eggs were transported from the spawning grounds with a process of advection and diffusion based on the flow pattern which were caused by winds. Distribution pattern of the anchovy eggs and larvae may be used for the prediction of oceanic currents in each area.

• Strategy21
• /
• s.36
• /
• pp.5-32
• /
• 2015

Geopolitics or Political Geography is an essential academic field that should be studied carefully for a more comprehensive analysis of international security relations. However, because of its tarnished image as an ideology that supported the NAZI German expansion and aggression, geopolitics has not been regarded as a pure academic field and was rejected and expelled from the academic communities starting from the Cold War years in 1945. During the Cold War, ideology, rather than geography, was considered more important in conducting and analyzing international relations. However, after the end of the Cold War and with the beginning of a new era in which territorial and religious confrontations are taking place among nations - including sub national tribal political organizations such as the Al Quaeda and other terrorist organizations - geopolitical analysis again is in vogue among the scholars and analysts on international security affairs. Most of the conflicts in international relations that is occurring now in the post-Cold War years can be explained more effectively with geopolitical concepts. The post - Cold War international relations among East Asian countries are especially better explained with geopolitical concepts. Unlike Europe, where peaceful development took place after the Cold War, China, Japan, Korea, the United States, Taiwan and Vietnam are feeling more insecure in the post-Cold War years. Most of the East Asian nations' economies have burgeoned during the Cold War years under the protection of the international security structure provided by the two superpowers. However, after the Cold War years, the international security structure has not been stable in East Asia and thus most of the East Asian nations began to build up stronger military forces of their own. Because most of the East Asian nations' national security and economy depend on the oceans, these nations desire to obtain more powerful navies and try to occupy islands, islets, or even rocks that may seem like a strategic asset for their economy and security. In this regard, the western Pacific Ocean is becoming a place of confrontation among the East Asian nations. As Robert Kaplan, an eminent international analyst, mentioned, East Asia is a Seascape while Europe is a Landscape. The possibility of international conflict on the waters of East Asia is higher than in any other period in East Asia's international history.