• 한국해양학회지:바다
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• 제18권3호
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• pp.131-141
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• 2013

본 연구는 2011년 9월에서 12월까지 동해(북부, 중부, 남부), 서해, 동중국해의 해구에서 각각 채집된 살오징어의 계군을 형태 및 유전학 차이를 이용하여 구분하였다. 형태학적 차이에 따른 계군분석은 평균성숙외투장(20-22 cm)을 기준으로 하여 발생시기를 구분하였고, 유전학적 특성에 따른 계군은 mtDNA COI 영역의 염기변이에 의한 유전자 다양성을 이용하여 확인하였다. 본 연구 결과 평균성숙외투장을 기준으로 동해 북부는 발생시기가 하계군, 나머지 집단(동해 중부, 동해 남부, 동중국해 북부, 서해 북부)은 추계군으로 크게 2개의 계군으로 추정되었다. 유전자 분석결과 살오징어 mtDNA COI 영역에서 총 49개의 haplotype을 확인하였다. TCS 분석결과 haplotype 유전자형 네트워크가 star-like형태이며, 모든 집단에서 유전적 다양성(haplotype diversity, h)이 높고(h=0.661~0.841), 반면에 염기 다양도(nucleotide diversity, ${\pi}$)가 낮게 나타난 점으로 미루어보아 국내 서식 살오징어의 경우 최근에 급속한 집단의 분화가 이루어진 것으로 판단된다. Pairwise Fst를 이용한 집단분석결과 비록 모든 집단간의 유전적 차이가 낮게 나타났지만(Fst = 0.001~0.043) 평균성숙외투장 기준으로 같은 추계군으로 분류된 집단(동해 중부, 동해남부, 서해 북부)간에는 유전적 차이를 확인할 수 있었다(P<0.05).

• Ocean and Polar Research
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• 제33권2호
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• pp.135-147
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• 2011

Zooplankton is an important constituent in assessing ecosystem responses to global warming. The northern East China Sea is an important ecosystem for carbon cycling with a net sink of carbon dioxide. Despite their importance as a major component in carbon cycling, relatively little is known about zooplankton biomass structure and its regulating factors in the northern East China Sea. This study examined zooplankton biomass distribution pattern in the region from multiple cruises encompassing various seasons between 2004 and 2009. Results showed that zooplankton biomass exhibits less cross-shelf gradient in general with declining biomass to the eastern shelf towards the Tsushima Current Water. Size-fractionated biomass showed that the 1.0~2.0 mm size group, mostly copepods, dominated zooplankton biomass, comprising 38 to 48% of total biomass. Smaller zooplankton (0.2~1.0 mm) biomass, consisting mainly of Paracalanus spp, a particle eating herbivorous copepod, was positively related to chlorophyll-a concentration, but no relationship was established for larger zooplankton (1.0~5.0 mm). Spatially-averaged mean total zooplankton biomass was also highly related to chlorophyll-a concentration. These result suggest that the long-term trend of zooplankton biomass increase in this region is partly accounted for by the increases of phytoplankton biomass and productivity underway in the region. However, the underlying mechanisms of how sea surface warming in the study area leads to increased phytoplankton biomass and productivity remains unclear.

• Ocean and Polar Research
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• 제23권1호
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• pp.35-49
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• 2001

An ichthyofauna analysis of the East Sea using quantitative investigation procedures for latitudinal variations of the species richness and clustering of the species list is presented to illustrate the application of the adopted geographical scaling (less than 1:10,000,000) which provides a principal opportunity for common benthic and pelagic biogeographical zonation. The distribution of both pelagic and benthic marine fish biota at a scale of biosphere (or its major sections) was highly influenced by spatial nonuniformity of hydrological structure associated with the various water circulations and frontal zones. Following zoogeographical zonations were established for the East Sea: Osaka, East Korea, Primorye, North Primorye, Northern East Sea, Uetsu, Tsugaru, Soya and West Sakhalin.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.918-921
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• 2006

The short-term variation of sea surface temperature before and after typhoons and increase of chlorophyll a concentration that accompany with the typhoons during summer in the East/Japan Sea were explored by satellite. Four typhoons (NAMTHEUN, MEGI, CHABA and SONGDA) and a typhoon (NABI) passed over the East/Japan Sea in 2004 and 2005, respectively. Decreasing of SST was observed in the every five typhoons, however the magnitude of SST decreasing were various from 1 to $5^{\circ}C$. Chlorophyll a increases were found after the typhoons (0.1-3 ${\mu}g$ $l^{-1})$ except NAMTHEUN, and the area was approximately included in SST decreasing area by the typhoons. It suggests that chlorophyll a increase was caused by nutrient input from subsurface layer by strong mixing. On the other hand, rarely chlorophyll a increase was observed in northern area of polar frontal zone, which is located in $38-41^{\circ}N$, than northern area, and chlorophyll a increase in coastal area was higher (more than 3 times) than offshore area. It might suggest that chlorophyll a increase in the East/Japan Sea is also related with the depth or nitracline depth that affects the amount of nutrients supply to the upper layer by typhoon mixing.

• Ocean and Polar Research
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• 제27권3호
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• pp.251-263
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• 2005

In order to study changes in the marine ecosystem of the East China Sea derived by the global warming and construction of the Three Gorges Dam in the middle of the Changjiang, temperature, salinity, nutrients, and chlorophyll-a were studied intensively in the northern part of the East China Sea during the summer of 2003 and spring of 2004. According to the previous studies, the upwelling of the Kuroshio Current and the Changjiang resulted in a major inputs of nutrients in the East China Sea, but these two inputs may not contribute gently to a build up of nutrients in the northern East China Sea. In spring, relatively high concentrations of nitrates and phosphates were observed in the western part of the study area, which resulted from the supply of high concentrations of nutrients showing up in the surface waters as a result of vertical mixing from the ocean bottom. The concentrations of nitrates and phosphates observed in summer were lower than those in spring, since the surface waters were well stratified by the larger discharge of fresh water from the Changjiang in summer. The surface nitrate/phosphate ratios ranged from 1.3 to 16 in spring and from 1.1 to 15 in summer and were lower than the Redfield ratio of 16, indicating that the growth of phytoplankton is limited by nitrogen. This results are contrary to the previous results, in which the growth of phytoplankton was limited by phosphate in the East China Sea. The reason for this contrary result is that most nutrients in the surface waters are supplied by vertical mixing from the bottom waters with low nitrate/phosphate ratios, not directly influenced by the Changjiang with high nitrate/phosphate ratios. The depth-integrated chlorophyll observed in summer was similar to the previous results, but those measured in spring were almost twice as high as those found in previous results. The depth-integrated chlorophyll in spring was higher than that of summer, which results from high concentrations of nitrates and phosphates in the surface waters in spring due to active vertical mixing.

• 한국작물학회지
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• 제68권4호
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• pp.285-293
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• 2023

한반도 남부지방(진주)에서 콩 생태형에 따라 생육단계별 생육일수를 적산온도로 환산하여 한반도 북방지역 7개 농업기후지대의 콩 생육예측을 실시하였다. 그 결과는 아래와 같다. 1. 수양산 이남, 수양산 이북, 동해 남부, 중부 내륙, 북부내륙 지역들은 모든 생태형에서 정상적인 생육과 수확이 가능할 것으로 예측되었다. 2. 북부 고산지대는 모든 생태형에서 정상적인 생육이 불가능한 것으로 나타났고, 동해 북부지역은 조생종, 중생종은 정상적인 생육이 가능하지만 중만생종은 생육일수가 부족한 것으로 나타났다. 3. 파종 한계기는 수양산 이남, 수양산 이북, 동해 남부 지역은 생태형에 따라 6월 6일~26일까지, 중부 내륙 6월 2일~17일, 북부 내륙은 5월 24~6월 12일, 동해 북부는 5월 16일~6월 7일경인 것으로 조사되었다. 그러나 북부고산지대는 9℃기준인 4월 30일 파종하여도 생육일수가 부족한 것으로 나타났다.

• 한국수산과학회지
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• 제50권2호
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• pp.207-218
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• 2017

Seawater with salinity of 32.5 psu or less is observed in the southern Japan/East Sea (JES) every autumn. It is confined to a surface layer 30-45 m in depth that expands to cover the entire JES in October. Two sources of "autumn low-salinity water" have been identified from historical hydrographic data in the western JES: East China Sea (ECS) water mixed with fresh water discharge from the Yangtze River (Changjiang) and seawater diluted with melted sea ice in the northern JES. Low-salinity water inflow from the ECS begins in June and reaches its peak in September. Low-salinity water from the northern JES expands southward along the coast, and its horizontal distribution varies among years. A rare observational study of the entire JES in October 1969 indicated that water with salinity less than 33.0 psu covered the southwestern JES; the lowest salinity water was found near the Ulleung Basin. In October 1995, the vertical distribution of salinity observed in a meridional section revealed that water with salinity of 33.6 psu or less was present in the area north of the subpolar front.

• 한국수산과학회지
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• 제44권3호
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• pp.267-275
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• 2011

The common squid Todarodes pacificus is an ecologically and commercially important species in Korea and Japan. However, the distribution pattern of its eggs and larvae in Korean waters has not yet been clarified. To determine the horizontal and temporal distribution of common squid larvae in the northern East China Sea, samples collected using paired, 60 cm diameter Bongo nets from the three surveys conducted in August 2003, May 2004 and November 2005 were examined. In addition, the vertical distribution was examined from the samples collected using a $1\;m^2$ MOCNESS in April 1999 (20 m interval down to 100 m). A total of 218 larvae ranging in mantle length (ML) from 1.2 to 17.0 mm were counted at 27 stations. Larval abundance was highest in May 2004. The larvae mainly occurred in the southeastern area of Jeju Island, where the water temperature and salinity at 50 m deep ranged from $15-23^{\circ}C$ and 34-34.6 psu, respectively. Most larvae were collected in the frontal zone, where the Tsushima Warm Current and inshore waters meet. The results from the MOCNESS samples showed that the larvae occurred mostly in 20-80 m depth ranges (about 90%), although collections were only conducted above 100 m. No significant differences in larval mantle lengths (ANOVA, P>0.05) were found among each depth interval. Given the occurrence sites of the larvae <2.0 mm ML, the spawning ground of this species appears to be within the northern East China Sea, mainly to the southeast and northeast of Jeju Island, in early spring.

• 한국수산과학회지
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• 제45권2호
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• pp.173-179
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• 2012

The common squid $Todarodes$ $pacificus$ is a dominant species in Korean waters, where it is captured preponderantly by the angling fishery. The spawning and nursery grounds of $T.$ $pacificus$ extend from the southern East Sea to the northern East China Sea. Consequently, the environmental conditions in this area during the spawning and nursery seasons might affect the abundance of $T.$ $pacificus$. This study, analyzed the relationship between the distribution of zooplankton and the abundance of $T.$ $pacificus$ and variation in the squid angling fishing grounds in Korean waters. There was a positive relationship between the fluctuations in zooplankton and the catch per unit effort (CPUE; $kg{\cdot}day^{-1}{\cdot}person^{-1}$) of the angling fishery in the East Sea of Korea. The main fishing season is from July to December and the CPUE was closely related to the zooplankton biomass in April in the East Sea. Recently, the center of the squid jigging ground has moved drastically from the area around Ulleung Island to the northern East Sea. We postulate that the fishing grounds of the squid angling fishery will move farther north with climate change.

• Journal of the korean society of oceanography
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• 제37권3호
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• pp.187-195
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• 2002

The characteristics of surface circulation in the Yellow Sea and the East China Sea are discussed by analyzing a great deal of current data observed by 142 sets of mooring buoy and 58 sets of drifters trajectories collected in the Yellow Sea and the East China Sea through domestic and abroad measurements. Some major features are demonstrated as bellow: 1) Tsushima Warm Current flows away from the Kuroshio and has multiple sources in warm half year and comes only from Kuroshio surface water in cold half year. 2) Taiwan Warm Current comes mainly from the Taiwan Strait Water in warm half year and comes from the intruded Kuroshio surface water and branches near 27N in cold half year. 3) The Changjiang Diluted Water turns towards Cheju Island in summer and flows southward along the coastal line in winter. 4) The study sea area is an eddy developing area, especially in the southern area of Cheju Island and northern area of Taiwan.