Effect of Thermal Stratification and Mixing on Phytoplankton Community Structure in the Western Channel of the Korea Strait

다국어 초록 (Multilingual Abstract)

The profile of a fixed site at station M (34.77oN, 129.13oE) in the Korea Strait was studied from March 2006 to February 2007. The aim was to understand the relationship between the annual thermal stratification pattern and seasonal variation in phytoplankton community structure. Physicochemical factors including temperature, salinity and nutrient concentrations, which strongly influence the proliferation and diversity of phytoplankton, were measured. The study period was divided into three due to the characteristic of thermohaline structures; mixed I (March-May 2006), stratified (June-November 2006) and mixed II (December 2006-Feburuary 2007). Diatoms dominated during the mixed I (89%) and II (48%) periods, while nanoplankton group occupied over 83% of total population during the stratified period. The dominant species during the mixed I and II was Chaetoceros socialis (47% and 29%, respectively), while during the stratified period Gyrodinium sp. (4%) was the most dominant. Averaged total chl a concentrations during the mixed I and II periods were 0.61 mg m-3 and 0.72 mg m-3, respectively, which were at least two-fold higher than that during the stratified period (0.30 mg m-3). The vertical mixing and convection process of the water column induced nutrient supply from the bottom layer to the euphotic zone. It also led to the dominance of diatoms during the mixed periods, whereas small phytoplankton prevailed over large phytoplankton as stratification blocked the upward movement of nutrients to subsurface during the stratified period. During the mixed I and II periods, microplanktonic chl a dominated concentrations (50% and 48%, respectively), while picoplanktonic chl a occupied over 37% of total chl a during the stratified period.

참고문헌 (Reference)

1 노재훈, "현미경, Flow Cytometer, HPLC 색소자료 및 원격탐사를 이용한 이어도 관측기지 주변수의 식물플랑크톤 연구" 한국해양연구원 27 (27): 397-417, 2005

2 김일남, "하계 대한해협 저층냉수의 물리·화학적인 특성 및 기원" 한국해양연구원 26 (26): 595-606, 2004

3 Lim, C.H., "he comparison of volume transport in the Korea Strait and in the Middle of the East Sea (Japan Sea)" 20 : 50-55, 1985

4 Kim, C.H., "and origin of the cold water mass along the east coast of Korea" 18 : 73-83, 1983

5 Fang, G., "Water volume transport through the Taiwan Strait and the continental shelf of the East China Sea measured with current meters, In: Oceanography of Asian Marginal Seas" Elsevier 1991

6 Byun, S.K., "Two branches of Tsushima Warm Current in the Western Channel of the Korea Strait" 19 : 200-209, 1984

7 Kiørboe, T., "Turbulence, phytoplankton cell size, and the structure of pelagic foodwebs" 29 : 1-73, 1993

8 Takikawa, T., "Tsushima Warm Current through Tsushima Straits estimated from ferryboat ADCP data" 35 : 1154-1168, 2005

9 Park, M.J., "Tidal nontidal fluctuations of currents in the Western Channel of the Korea Strait" 34 : 133-143, 1999

10 Lee, J.C., "Thermohaline structure of the shelf front in the Korea Strait in early winter" 19 : 56-57, 1984

11 Lim, D.B., "The movement of the cold water in the Korea Strait" 8 : 46-52, 1973

12 McQuoid, M.R., "The diatom paralia sulcata as an environmental indicator species in coastal sediments" 56 : 339-354, 2003

13 Young-Ju Kim, "The Seasonal and Interannual Variability of the Volume Transportthrough the Western Channel of the Korea Strait" 한국해양연구원 39 (39): 155-162, 2004

14 Guo, X., "The Kuroshio onshore intrusion along the shelf break of the East China Sea: The origin of the Tsushima Warm Current" 36 : 2205-2231, 2006

15 Arin, L., "Spatiotemporal variability of size fractionated phytoplankton on the shelf adjacent to the Ebro river (NW Mediterranean)." 25 : 1081-1095, 2005

16 Baecena, M.A., "Planktonic response to main oceanographic changes in the Alboran Sea (Western Mediterranean) as documented in sediment traps and surface sediments" 53 : 423-445, 2004

17 Shim, J.H., "Plankton study in the Southeastern Sea of Korea (I)-Phytoplankton distribution in September" 18 : 91-103, 1981

18 Choe, S., "Phytoplankton studies in Korean Waters. III. Surface phytoplankton survey of the North-eastern Korea Strait in May of 1967" 4 : 1-8, 1969

19 Sournia, A., "Phytoplankton Manual" Unesco 337-, 1978

20 Shim, J.H., "Phytohydrography and the vertical pattern of nitracline in the southern waters of the Korean East Sea in early spring" 24 : 15-28, 1989

21 KORDI, "Pacific Ocean Study on Environment and interactions between Deep Ocean and National Seas" KORDI 553-, 2006

22 Seung, Y.H., "On the response of coastal water to the intensification of East Korea Warm Current along the East Coast of Korea - A theoretical consideration" 21 : 229-235, 1986

23 Isobe, A., "On the origin of the Tsushima Warm Current and its seasonality" 19 : 117-133, 1999

24 Lie, H .J., "On the origin o f the T sushima Warm Current" 99 : 25081-25091, 1994

25 Lim, D.B., "On the cold water mass in the Korea Strait" 4 : 71-82, 1969

26 Johnson, D.R., "Observations of the Korea Strait bottom cold water" 22 : 821-831, 2002

27 Bao, R., "Mesoscale distribution patterns of diatoms in surface sediments as tracers of coastal upwelling of the Galician shelf (NW Iberian Peninsula)" 144 : 117-130, 1997

28 Teague, W.J., "Low-frequency current observation in the Korea/Tsushima Strait" 32 : 1621-1641, 2002

29 Margalef, R., "Life-forms of phytoplankton as survival alternatives in an unstable environment" 1 : 493-509, 1978

30 Eilertsen, H.C., "Investigation of the phytoplankton community of Balsfjorden, Northern Norway: The phytoplankton 1976-1978." 66 : 129-141, 1978

31 Tomas, C.R., "Identifying marine phytoplankton" Academic press 858-, 1997

32 Han, Y.H., "Heat budget over the south-western part of the Japan Sea in the month of January and cold water mass in the Korea Strait" 7 : 19-23, 1972

33 Park, M.O., "HPLC method for the analysis of chlorophylls and carotenoids from marine phytoplankton" 32 : 46-55, 1997

34 Booth, B.C., "Dynamics of Chaetoceros Socialis blooms in the North Water Polynya, Baffin Bay, Canada" 2 (2): 5003-5025, 2002

35 Kang, J.H., "Distribution of plankton related to the mesoscale physical structure within the surface mixed layer in the south western East Sea" 26 : 1515-1528, 2004

36 Lee, W.H., "Distribution of phytoplankton standing crop and associated T-S properties in the Southwestern East Sea (Sea of Japan)" 25 : 1-7, 1990

37 Park, M.O., "Distribution of phytoplankton pigments in the Korea Strait" 34 : 95-112, 1999

38 Beardsley, R.C., "Discharge of the Changjiang (Yangtze River) into the East China Sea" 4 : 57-76, 1985

39 Norrbin, M.F., "Differences in fine-scale structure and composition of zooplankton between mixed and stratified regions of Georges Bank" 2 (2): 1905-1924, 1996

40 박미옥, "Composition and Distribution of Phytoplankton with Size Faction Results at Southwestern East/Japan Sea" 한국해양연구원 41 (41): 301-313, 2006

41 Lee, M.O., "Characteristics of algal blooms in the southern coastal waters of Korea" 65 : 128-147, 2008

42 Kawabe, M., "Branching of the Tsushima current in the Japan Sea. Part 1." 38 : 95-108, 1982

43 Nitani, H., "Beginning of the Kuroshio, In: Kuroshio" University of Tokyo Press 353-369, 1972

44 Booth, B.C., "Autotrophic flagellates and diatoms in the Northeast Water Polynya, Greenland: Summer 1993." 10 : 241-261, 1993

45 Strickland, J.D.H., "A practical hand book of sea water analysis" 167 : 1-310, 1972

46 Yentsch, C.S., "A method for determination of phytoplankton chlorophyll and phaeophytin by fluorescence" 10 : 221-231, 1963

47 Chung, I.K., "A marine picoplankton from Korea: Pycnococcus provasoli Guillard" 31 : 150-154, 1996

48 Parsons, T.R., "A manual of chemical and biological methods for seawater analysis" Pergamon Press 173-, 1984