• 한국수산과학회지
• /
• 제49권3호
• /
• pp.393-403
• /
• 2016

A steady, strong southward flow was observed in the lower layer beneath the Tsushima Warm Current in the deepest trough of the Korea Strait. Known as the Korea Strait Bottom Cold Water (KSBCW), this bottom current had a mean velocity of 24 cm/s and temperatures below 8–10℃. The direction of the bottom current was highly stable due to the topographic effects of the elongated trough. To determine the path of the southward bottom current, ADCP (Acoustic Doppler Current Profiler) data from 14 stations between 1999 and 2005 were examined. Persistent southward flows with average speeds of 4–10 cm/s were observed at only three places to the north of the strait where the bottom depths were 100–124 m. The collected data suggest a possible course of the southward bottom current along the southeast Korean coast before entering the deep trough of the Strait.

• 한국해안해양공학회:학술대회논문집
• /
• 한국해안해양공학회 1995년도 정기학술강연회 발표논문 초록집
• /
• pp.9-12
• /
• 1995

The Korea Strait becomes deeper than 200 m from south to north in general except coastal area, whereas its southern part is shallower than 125 m except for a deep trough (Fig.1). The flow in the Korea Strait could be simplified as two layers (Isobe, 1995)； the Tsushima Warm Water in the upper layer and the Korea Strait Bottom Cold Water (KSBCW) in the lower layer (Fig.2). (omitted)

• 한국어류학회지
• /
• 제19권4호
• /
• pp.378-386
• /
• 2007

대한해협의 서수도에서 출현하는 앨퉁이 어란의 발생 단계별 구성비를 연구하기 위해 수온, 염분, 난 자치어를 조사하였다. 조사해역에서 $10^{\circ}C$ 이하의 대한해협 저층냉수는 대한해협의 서수도에 위치한 울산 연안의 사면과 부산 근해의 저층에서 발견되었다. 어란은 조사해역의 모든 정점에서 출현하였다. 이들 정점에서 발생 단계별 어란의 구성비는 발생 초기가 37.7~89.5%, 중기가 8.5~37.8%, 후기가 0.0~24.7%였다. 어란의 출현량이 많은 곳은 대한해협 저층냉수의 세력이 강한 곳이었다. 이 해역을 포함한 인접해역에서는 발생 초기 어란의 비율이 73.3~89.5%로 매우 높았다. 이 어란들은 동해서남부 대륙붕단 주변해역의 산란장에서 울릉분지 내 $10^{\circ}C$ 이하의 냉수에 의해 대한해협의 서수도로 수송되어 누적된 것들로 추정된다. 반면 대한해협 저층냉수가 없는 대마도 북동 해역에서는 어란의 발생 초기의 비율이 37.5%로 매우 낮은 대신 중기와 후기의 비율이 각각 37.8%와 24.7%로 매우 높았다. 이러한 현상은 대한해협 저층냉수에 분포한 어란들이 상층의 대마난류수에 의해 다시 북쪽으로 수송되는 동안 발생이 진행되어 발생 초기보다는 중기나 후기단계의 어란들이 이 해역으로 가입되기 때문일 것이다. 이때 어란들의 일부가 부화하여 전기자어가 조사해역의 중부와 북부해역에 나타나는 것으로 보인다.

• Animal Systematics, Evolution and Diversity
• /
• 제32권4호
• /
• pp.272-280
• /
• 2016

Most scyphomedusae jellyfishes recorded in Korean waters are temperate and subtropical species. In the present study, two cold-water jellyfishes from Korean waters are first described. Scyphomedusae were collected from the coasts of Gangneung and Ulsan of the East Sea, and Boryeong, and the eastern area of the Yellow Sea from June 2006 to May 2015. Scyphomedusae collected in Ulsan and Gangneung were identified morphologically as Aurelia limbata Brandt, 1835. Their umbrella was 250-500 mm in width and 30-50 mm in height; the exumbrella was white and the subumbrella was dark brown in color. The vascular system was complex with anastomosed branches. Individuals of this species lived at about 6.6-9.9℃ and 30-50 m depth in Korean waters. Scyphomedusae collected from the center of the Yellow Sea and from Boryeong were identified as Parumbrosa polylobata Kishinouye, 1910. Their umbrella was disc-shaped, 80-200 mm in width and 20-40 mm in height. Its milky white gonads could be seen through the transparent exumbrella. The stomach cavity was round and flat with four interradial cavities connected by subgenital cavities, and the four oral arms were bifurcated and spear-head shaped. Individuals were found at about 6.4-10.0℃ and 40-90 m depth in Korean waters. The identities of both species were confirmed by molecular analysis using nuclear ribosomal DNA sequences.

• 한국수산과학회지
• /
• 제46권2호
• /
• pp.186-194
• /
• 2013

We compiled and analyzed long-term time-series data collected in Korea to evaluate changes in oceanographic conditions and marine ecosystems near Jeju Island ($33^{\circ}00^{\prime}-34^{\circ}00^{\prime}\;N$, $125^{\circ}30^{\prime}-127^{\circ}30^{\prime}\;E$) from 1981 to 2010. Environmental data included depth-specific time series of temperature and salinity that have been measured bimonthly since 1961 in water columns at 175 fixed stations along 22 oceanographic lines in Korean waters by the National Fisheries Research & Development Institute, and time series of estimated volume transport of the Tsushima Warm Current (TWC) and Korea Strait Bottom Cold Water (KSBCW) for the period from 1961 to 2008. We analyzed the species composition in terms of biomass of fish species caught by Korean fishing vessels in the waters near Jeju Island (1981-2010). Data were summarized and related to environmental changes using canonical correspondence analysis (CCA). The CCA detected major shifts in fish community structure between 1982 and 1983 and between 1990 and 1992; the dominant species were a filefish during 1981-1992 and chub mackerel from 1992 to 2007. CCA suggested that water temperature and salinity in the mixed layer and the volume transport of the TWC and the KSBCW were significantly related to the long-term changes in the fish community in the waters off Jeju Island. Fish community shifts seemed to be related to the well-established 1989 regime shift in the North Pacific. Further studies are required to elucidate the mechanisms driving climate change effects on the thermal windows and habitat ranges of commercial species to develop fisheries management plans based on reliable projections of long-term changes in the oceanographic conditions in waters off Jeju Island.