• 중국학논총
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• 제63호
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• pp.343-362
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• 2019

During the traditional periods when there were exchanges among Korea, China and Japan based on ocean currents or seasonal winds, the southwestern coastal areas including Yeosu held an important position since the route would not have been complete without them. Armed with its advantages including the marine environment, the Yeosu area in the southwestern coast on the Korean Peninsula engage in active maritime exchanges and activities as a base along the sea route since the Neolithic or Bronze Age. It was the same later when Baekje and Gaya had exchanges with China and Japan, when Unified Silla had exchanges with China, and when Goryeo had exchanges with China and Japan. In Joseon, the Yeosu area gained fame as a marine defense base. In short, the Yeosu area in the southwestern coast on the Korean Peninsula during the traditional periods not only engage in active maritime exchanges and activities, but also serve as an important base that could not be left out in the maritime history of East Asia.

• Journal of Ecology and Environment
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• 제38권2호
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• pp.229-239
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• 2015

The southwestern islands of Japan, especially southward from Amamioshima Island, have distinguished sets of nature and culture. However, various problems are arising on those islands. This report first introduces island characteristics as well as, their status briefly. Then it introduces conservation efforts. Since nature and culture are closely connected in the island system, conservation of the set of nature and culture is essentially important. From this point of view, this report focuses on two efforts. The first example is the effort for designation of a new national park with a new concept of "environmental culture type" and "ecosystem management type" in the Amami Gunto Islands. This effort is a new challenge to focus on the importance of cultural aspects. The second example is the unique effort of the national park visitor center to conserve as one set of integrated nature and culture with an alliance of all stakeholders in Taketomijima Island, Iriomote-Ishigaki National Park. The visitor center serves not only visitors, but also islanders. These two cases are good models that suggest hints for future conservation measures.

• Ocean and Polar Research
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• 제21권2호
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• pp.87-97
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• 1999

To estimate absolute transports by advection in the southwestern East Sea (Japan Sea), an inverse method was applied to CTD data obtained in July 1993. The relative velocities are calculated using the thermal wind equation. The inverse model was formulated to obtain a reference velocity based on the mass conservation in each of four vertical layers within a region enclosed by hydrographic sections and the coastal boundary. The flow patterns in the surface layer are clockwise and anti-clockwise in the regions south and northwest of Ulleung Island, respectively, and a strong northward flow appears in between them. In the second layer, the flow fields are generally weak. The inverse calculation yields the southward flow along the coast, and this suggests that the subsurface low salinity water in the Ulleung Basin is supplied by the southward transport along the east coast of Korea.

• Ocean Science Journal
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• 제41권4호
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• pp.301-313
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• 2006

Abundance and distribution of phytoplankton in seawater at southwestern East/Japan Sea near Gampo were investigated by HPLC analysis of photosynthetic pigments during summer of 1999. Detected photosynthetic pigments were chlorophyll a, b, $c_{1+2}$ (Chl a, Chl b, Chl $c_{1+2}$), fucoxanthin (Fuco), prasinoxanthin (Pras), zeaxanthin (Zea), 19'-butanoyloxyfucoxanthin (But-fuco) and beta-carotene (B-Car). Major carotenoid was fucoxanthin (bacillariophyte) and minor carotenoids were Pras (prasinophyte), Zea (cyanophyte) and But-fuco (chrysophyte). Chl a concentrations were in the range of $0.16-8.3\;{\mu}g/land$ subsurface chlorophyll maxima were observed at 0-10m at inshore and 30-50 m at offshore. Thermocline and nutricline tilted to the offshore direction showed a mild upwelling condition. Results from size-fraction showed that contribution from nano+picoplankton at Chl a maximum layer was increased from 18% at inshore to 69% at offshore on average. The maximum contribution from nano+picoplankton was found as 87% at St. E4. It was noteworthy that contribution from nano+picoplanktonic crysophytes and green algae to total biomass of phytoplankton was significant at offshore. Satellite images of sea surface temperature indicated that an extensive area of the East/Japan Sea showed lower temperature ($<18\;^{\circ}C$) but the enhanced Chi a patch was confined to a narrow coastal region in summer, 1999. Exceptionally high flux of low saline water from the Korea/Tsushima Strait seemed to make upwelling weak in summer of 1999 in the study area. Results of comparisons among Chi a from SeaWiFS, HPLC and fluorometric analysis showed that presence of Chi b cause underestimation of Chi a about 30% by fluorometric analysis but overestimation by satellite data about 30-75% compared to HPLC data.

• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.514-520
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• 2006

An abandoned mandarin orange orchard in southwestern Japan was set-stocked by Japanese Black cows at two stocking rates (1.0 and 2.0 animals/ha), and vegetation dynamics and diet selection by cattle were monitored for two years, in an effort to obtain information on effective use of abandoned agricultural fields for low-cost animal production and environmental conservation. Two dominant species at the commencement of grazing, kudzu (Pueraria lobata Ohwi) and tall goldenrod (Solidago altissima L.), showed different responses to grazing during the two years; the composition of kudzu decreased, contrasting with that of tall goldenrod which increased at both stocking rates. This was caused by high preference for kudzu and avoidance or low preference for tall goldenrod by cattle. Retrogression of vegetation due to cattle disturbances occurred at both stocking rates, with the high stocking rate leading to a lower degree of succession than the low stocking rate. It was shown that cattle grazing, particularly at a high stocking rate, was effective in the management of vegetation of an abandoned orchard.

• 한국해양학회지
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• 제22권1호
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• pp.34-42
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• 1987

동해 西南海域의 식물플랑크톤의 분포와 환경요인의 상관관계를 연구하기 위해 Canonical Correlation 분석을 실시하였다. 조사된 7가지의 환경요인 가운데서 식물플랑크톤의 분포에 가장 중요한 영향을 끼친 것은 봄철에 수온 가을철에 염분이었다. 이 두가지 환경요인의 계절적인 변화와 연구 수역의 해양 물리학적 현상에 대하여 논하였다. 쿠로시오 指表種들과 Protoperidinium 속의 두종들은 높은 수온 및 높은 염분과 量的인 연관성을 나타낸다. 소형 우주주조류와 無色 質鞭毛 類들은 낮은 수온역을 선호하여, 서로 규산염에 대해 생태적인 경쟁 관계에 있는 것으로 보인다. 그 결과 無色 質鞭毛類가 보다 규산염농도에 대하여 더 낮은 값 을 보인다. 질소 고정 난조류의 一種인 Oscillatoria erythraea 는 인산염 농도와 陽 的인 연관성을 나타내었다.

• Fisheries and Aquatic Sciences
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• 제10권3호
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• pp.150-158
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• 2007

Data on squid catches, water temperature, and climatic factors collected for the Northwest and subtropical North Pacific were analyzed to examine the influence of oceanic and climatic conditions in spawning grounds on catches of Japanese common squid, Todarodes pacificus, in the East (Japan) Sea. The main spawning ground was divided into four sub-areas: the South Sea of Korea (R1), the southern waters off Jeju, Korea (R2), the southwestern part of Kyushu, Japan (R3), and the northern part of Okinawa, Japan (R4). Interannual and decadal fluctuations in water temperatures correlated well with squid catches in the East/Japan Sea. In particular, water temperatures at a depth of 50 to 100 m in sub-areas R3 and R4 showed higher correlation coefficients (0.54 to 0.59, p<0.01) in relation to squid catches in the East/Japan Sea than for R1 and R2, which had correlation coefficients of 0.40 or less (p>0.05). Air temperature and wind velocity fluctuations in each sub-area are correlated with water temperature fluctuations and were closely connected with variations in the surface mixed layers. Water, air temperatures and wind velocities at the main spawning grounds are linked to the Southern Oscillation Index (SOI) with higher signals in the ca. 2-4-year band. Strong changes in a specific band and phase occurred around 1976/77 and 1986/87, coincident with changes in squid catches.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2003년도 International Symposium on Clean Environment
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• pp.145-150
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• 2003

16 APEX floats, autonomous profiling floats deployed as part of the Array for Real-time Geostrophic Oceanography (ARGO) program, are used to understand the currents at 800 m underwater in the southwestern East Sea. The flow penetrates into the Ulleung basin (UB) through two paths： an extension of the southward flowing the North Korean Cold Water along the east coast of Korea and between Ulleung Island and Dok island. Flows at 800 m are observed range 0.2 to 4.29 cm/sec and the variability in the north in the DB is stronger than that in the south. The eddy kinetic energy is found a few $cm^{2}$ $S^{-2}$. In the UB, cyclonic flows from 0.3 - 1.6 cm/see are observed with the bottom topography.

• 한국환경과학회지
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• 제12권9호
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• pp.943-948
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• 2003

Variation of the polar front in the East Sea is studied using temperature and dissolved oxygen data obtained from Japan Meteorological Agency from 1972 to 1999. Variation of the polar front in the East Sea has a close relation to the variation of the Tsushima Warm Current (TWC). When the TWC spreads widely in the East Sea, polar front moves northward. The spatial variation of the polar front is greater in the southwestern area of the East Sea and the northern area of Tsugaru Strait where the variation of the TWC's distribution area is greater than those in others of the East Sea. Hence, in the southeastern area of the East Sea, that is, between near Noto peninsula and Tsugaru Strait, the spatial variation of the polar front is not so wide as in the southwestern area because the flow of TWC is stable.

• 한국수산과학회지
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• 제26권6호
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• pp.538-548
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• 1993

한국 동해 연안역 해수순환 및 수온분포에 대한 바람응력의 효과에 관하여 검토하였다. 동해상의 바람응력은 국립수산진흥원 정선관측 바람자료 및 일본기상청 Buoy No. 6에서의 10년간($1978{\sim}1987$)의 약 5,100개의 바람 관측자료를 사용하여 계산하였다. 여름과 겨울의 계절풍의 전환에 따른 에크만 수송의 변화가 대한해협에서의 대마난류 수송량에 미치는 영향을 정량적으로 평가하였다. 특히 동해에서의 평균적인 바람응력의 회전성(wind stress curl) 값이 음이 되는 사실에서 울릉도 근해의 난수층의 형성에 부분적으로 도움이 됨을 알았다. 한편, 동해 난수층의 분포를 단순화된 3층 경계면모델을 적용하여 설명하였다.