2008년 하계 울릉분지에서 관측된 물리·화학적 외압에 대한 플랑크톤 군집의 반응

• Published in: Ocean and polar research Vol. 32; no. 3; pp. 269 - 289
• Main Authors: 노태근, 김윤배, 박정인, 이용우, 임동훈, 강동진, 이동섭, 윤승태, 김태훈, 곽정현, 박현제, 정만기, 장경일, 강창근, 서해립, 박명원, Rho, Tae-Keun, Kim, Yun-Bae, Park, Jeong-In, Lee, Yong-Woo, Im, Dong-Hoon, Kang, Dong-Jin, Lee, Tong-Sup, Yoon, Seung-Tae, Kim, Tae-Hoon, Kwak, Jung-Hyun, Park, Hyun-Je, Jeong, Man-Ki, Chang, Kyung-Il, Kang, Chang-Keun, Suh, Hae-Lip, Park, Myung-Won
• Format: Journal Article
• Language: Korean
• Published: 한국해양과학기술원 01.09.2010
• Subjects: 해양학; Plankton Community Structure; Physico-Chemical Forcing; East Sea; Coastal Upwelling; Ulleung Basin
• ISSN: 1598-141X; 2234-7313

In Summer 2008, a multidisciplinary survey was conducted onboard R/V Haeyang 2000 to understand plankton response to the three distinct physico-chemical settings that developed in the Ulleung Basin of the East Sea. Baseline settings of hydrographic conditions included the presence of the thin (<20 m) Tsushima Surface Water (TSW) on top of the Tsushima Middle Water (TMW). It extends from the Korea Strait to $37^{\circ}N$ along the $130^{\circ}E$ and then turns offshore and encompasses the relatively saline (T>$26^{\circ}C$, S>33.7) Ulleung Warm Eddy surface water centered at $36.5^{\circ}N$ and $131^{\circ}E$. A relatively colder and saline water mass appeared off the southeastern coast of Korea. It was accompanied by higher nutrient and chlorophyll-a concentrations, suggesting a coastal upwelling. Most of the offshore surface waters support low phytoplankton biomass (0.3 mg chl-a $m^{-3}$). A much denser phytoplankton biomass (1-2.3 mg $m^{-3}$) accumulated at the subsurface layer between 20-50 m depth. The subsurface chlorophyll-a maximum (SCM) layer was closely related to the nutricline, suggesting an active growth of phytoplankton at depth. The SCM developed at shallow depth (20-30 m) near the coast and deepened offshore (50-60 m). A fucoxanthin/zeaxanthin ratio was high in coastal waters while it was low in offshore waters, which indicated that diatoms dominate coastal waters while cyanobacteria dominate offshore waters. The community structure and biomass of phytoplanktonare closely related to nitrogen availability. Zooplankton biomass was higher in the coastal region than in the offshore region while species richness showed an opposite trend. Zooplankton community structure retained a coastal/offshore contrast. These suggest that summer hydrography is a stable structure, lasting long enough to allow a hydrography-specific plankton community to evolve.