• Ocean Science Journal
• /
• 제43권2호
• /
• pp.101-106
• /
• 2008

A single specimen of Albula leptocephalus (55.7 mm SL) was collected from the southern coastal waters of Korea using an aquatic lamp. It is characterized by having a ribbon-like body with a small head and a well-forked caudal fin. Although the general appearance was similar to the leptocephalus of A. vulpes including myomere counts and fin ray counts, the melanophore deposition was different from that of A. vulpes. This leptocephalus specimen was confirmed with A. forsteri using the cytochrome b mtDNA (Cytb) analysis. The genetic distance of Cytb between the present leptocephalus and A. forsteri is 0.006-0.038, which falls into the cutoff point separating Albula species into eight deep lineages including the four valid species. Its genetic characteristic have more similarities to those of Fiji than those of Hawaii and the Northern territory of Australia.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 춘계학술대회
• /
• pp.531-533
• /
• 2007

We report and discuss molecular and isotopic properties of hydrate-bound gases from 55 samples and void gases from 494 samples collected during Ocean Drilling Program (ODP) Leg 204 at Hydrate Ridge offshore Oregon. Gas hydrates appear to crystallize in sediments from two end-member gas sources (deep allochthonous and in situ) as mixtures of different proportions. In an area of high gas flux at the Southern Summit of the ridge (Sites 1248-1250), shallow (0-40 meters below the seafloor (mbsf)) gas hydrates are composed of mainly allochthonous mixed microbial and thermogenic methane and a small portion of thermogenic C2+ gases, which migrated vertically and laterally from as deep as 2-2.5 km depths. In contrast, deep (50-105 mbsf) gas hydrates at the Southern Summit (Sites 1248 and 1250) and on the flanks of the ridge (Sites 1244-1247) crystallize mainly from microbial methane and ethane generated dominantly in situ. A small contribution of allochthonous gas may also be present at sites where geologic and tectonic settings favor vertical gas migration from greater depth (e.g., Site 1244).

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제3권2호
• /
• pp.136-140
• /
• 2011

Monitoring of water surfaces through permanent measurement of hydrodynamic and meteorological data is one of the main requirements in safe and sustainable water management. The Caspian Sea, the major surface water body in Iran, significantly affects more than 600 km of urban and industrial coastline. In the present work, an integrated marine monitoring network for the entire southern coastline of the Caspian Sea was developed. The main design concerns centered on the network measuring components and data recording, checking, filtering, gap recognition, and transferring systems. Four coastal monitoring stations were assigned, along with two regional collecting stations and one central data station for gathering, checking and delivering recorded data at different access levels. Applicable guidelines on selection of measuring devices for both shallow and deep water zones are presented herein.

• 한국어업기술학회:학술대회논문집
• /
• 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
• /
• pp.195-196
• /
• 2003

The southern rough shrimp, Trachysalambria curvirostris (Stimpson 1860) (formerly known as Trachypenaeus curvirostris) occur in the East China Sea, Korea and Japan to China(Kubo, 1949; Paulinose, 1982), and is locally abundant species in the coastal areas of Korea(Kim, 1997). The main investigations into diets of shrimps have been on the Penaeidae(Chong ＆ Sasekumar, 1991; Wassenberg ＆ Hill, 1993), Crangonidae(Pihl ＆ Rosenberg, 1984; Allen, 1966; Boddeke et at., 1986). (omitted)

• 한국수산과학회지
• /
• 제47권6호
• /
• pp.895-900
• /
• 2014

The feeding ecology of Doederleinia berycoides from the southern sea of Korea was examined. Specimens were caught monthly from January 2007 to June 2008. The size of the specimens ranged from 6.8 to 39.8cm in total length (TL). The primary prey items of D. berycoides included fishes and shrimps. In autumn, feeding mainly crustacea and fishes feeding mainly in winter. The individuals of smallest size class (less than 15 cm TL) fed mainly on crustacea. The proportion of crustacea decreased as body size increased, whereas the consumption of fishes increased. Fishes accounted for almost (86%) stomach contents of larger individuals (more than 35 cm TL).

• 환경생물
• /
• 제31권4호
• /
• pp.493-498
• /
• 2013

To investigate the historical record of Alexandrium spp. in southern coastal areas of Korea, two sediment cores were collected from Gamak Bay and Yeoja Bay. Germination experiments revealed that the ellipsoidal Alexandrium cysts isolated from Gamak Bay and Yeoja Bay are morphologically identical to a toxic dinoflagellate A. tamarense. The ellipsoidal Alexandrium cysts in Yeoja Bay appeared from 30 to 32 cm depth upwards (ca. 1980s), and their concentration increased around 10 to 12 cm depth (mid-1990s). Similarly, cyst concentration in Gamak Bay also increased from 40 to 44 cm depth (ca. 1990s). These results coincide with the reports of Paralytic Shellfish Poisoning caused by A. tamarense in 1980s and 1990s along the southeast coast of Korea.

• 한국지구과학회지
• /
• 제26권2호
• /
• pp.109-113
• /
• 2005

In this study, the estimation of the temperature distribution of Jeju Island with coastal ocean derived from the thermal band of Landsat 7/ETM+ of January 6, 2003 was carried out. For the computation of the temperature of the island and the coastal ocean based on the thermal band, we used NASA method wiich is the 8 bit Digital Number(DN) converted into spectral radiance. The computed results showed that the land temperature variations were from 0 to 12 Celsius degrees, and a good agreement with the observation ones based on the method. However, the ocean surface temperature was not much changed ground 15 degree since the water was well mixed between the coastal and the offshore ocean. The interesting results were that the temperature distributions of the southern part(Seogwipo City) of Jeju Island were higher than those of the north one(Jeju City) by more than 2 Celsius degree at the same height although the distance between the Jeju and the Seogwipo is only about 35km in winter season. The reason was found that the solar irradiance intensity of the south part was stronger than the north one by Halla mountain in winter season only. From the results, we found that the seasonal variations of solar irradiation and the height of Mt. Halla were an important role of temperature distribution of Jeju Island.

• Ocean and Polar Research
• /
• 제23권4호
• /
• pp.401-410
• /
• 2001

Global climate change will alter many such properties of the Southern Ocean as temperature, circulation, stratification, and sea-ice extent. Such changes are likely to influence the species composition and activity of Antarctic marine microorganisms (protists and bacteria) which playa major role in deter-mining the concentration of atmospheric $CO_2$ and producing precursors of cloud condensation nuclei. Direct impacts of climate change on Antarctic marine microorganisms have been determined for very few species. Increasing water temperature would be expected to result in a southward spread of pelagic cyanobacteria, coccolithophorids and others. Growth rates of many species would be expected to increase slightly but nutrient limitation, especially micronutrients, is likely to result in a negligible increase in biomass. The extent of habitats would be reduced for those organisms presently living close to the upper limit of their thermal tolerance. Increased UVB irradiance is likely to favour the growth of those organisms tolerant of UVB and may change the trophic structure of marine communities. Indirect effects, especially those as a consequence of a diminution of the amount of sea-ice and increased upper ocean stratification, are predicted to lead to a change in species composition and impacts on both trophodynamics and vertical carbon flux.

• Ocean and Polar Research
• /
• 제26권3호
• /
• pp.501-506
• /
• 2004

The observational proxy estimates suggest that the North Atlantic overturning stream function associated with the North Atlantic Deep Water (NADW) production and outflow was substantially weaker during the last glacial maximum (LGM) than that observed under present conditions. The impact of the changes in overturning circulation on the glacial carbon budget is investigated using a box model. The carbon box model reveals that the atmospheric $CO_2$ concentration is more sensitive to change in the overturning circulation of the North Atlantic than that of the Southern Ocean, especially when North Atlantic overturning becomes weaker. For example, when the strength of the North Atlantic overturning circulation is halved, the atmospheric $CO_2$ concentration is reduced by 50ppm of that associated with the accumulation of $CO_2$ in the deep ocean. This result implies that a weaker North Atlantic overturning circulation may play an important role in the lowering of LGM atmospheric $CO_2$ concentration.

• 한국항해학회지
• /
• 제18권3호
• /
• pp.19-30
• /
• 1994

By use of the recent tropical cyclones' data in the Northwest Pacific Ocean, the occurrence frequency and region of typhoon as well as the features of the monthly mean track were analyzed. As the result of this study, (1) mean occurrence frequency of typhoon per year is 27.5, and 68% of total typhoons were formed in July to October and shown the highest frequency in August. (2) The ave-rage duration of typhoons is 8.5 days, and super typhoon which maximum sustained surface wind speeds is more than 130 knots occurs most frequently in October and November. (3) The highest frequency ap-pears around the Caroline, Mariana and Marshall Islands, and in wintertime, typhoon occurs in lower lati-tude comparing with those in summertime. (4) The typhoon track depends upon the distribution of pres-sure system and steering current in neighbouring areas. The mean track of typhoon can be classified into three types such as westward-moving type, northward-moving type and abnormally moving type. The west-ward-moving typhoons make landfall on the southern China by way of the South China Sea in June and July, on mid-part of China in August and September, and on Indo-china Peninsula in October and Novem-ber. The northward-moving typhoons approximately move on north~northwestward track to $20~30^{\circ}N$ from the occurrence region, then recurve to the East Sea through Korean Peninsula and Kyushu Island in June and July, to the Noth Pacific Ocean along the Japanese Islands in August and September and to the North Pacific Ocean through the seas far south off the Japan in October and November.