하계 서태평양의 초미소 식물플랑크톤 분포 특성 연구

Abstract

- The effect of environmental forcing on picophytoplankton distribution pattern wasinvestigated in the tropical and subtropical western Pacific (TSWP) and the East Sea in-ECS) in August, 2003. Theabundance of picophytoplankton populations, Synechococcus, Prochlorococcusand picoeukaryoteswere determined by flow cytometry analyses. Picophytoplankton vertical profiles and integratedabundance (0~ 100 m) were compared with these three physiochemically different regions.Variation patterns of integrated cell abundance of Synechococcusand Prochlorococcusin theseSynechococcusshowed average abundance of 84.5× 1010cells m-2, in the TSWP, 305.6× 1010 cells m-2 in the C-ECS, and 125.4× 1010cells m-2 in the EastSea where increasing cell concentrations were observed in the region with abundant nutrient. Onthe other hand, Prochlorococcusshowed average abundance of 504.5× 1010 cells m-2 in theTSWP, 33.2× 1010 cells m-2 in the C-ECS, and 130.2× 1010 cells m-2 in the East Sea exhibiting adistinctive pattern of increasing cell abundance in oligotrophic warm water. Althoughpicoeukaryotes showed a similar pattern to Synechococcus, the abundance was 1/10 ofSynechococcus. Synechococcusand picoeukaryotes showed ubiquitous distribution whereasProchlorococcusgenerally did not appear in the C-ECS and the East Sea with low salinityenvironment. The average depth profiles for Synechococcusand Prochlorococcusdisplayeduniform abundance in the surface mixed layer with a rapid decrease below the surface mixedlayer. For Prochlorococcus, a similar rapid decreasing trend was not observed below the surfacemixed layer of the TSWP, but Prochlorococcusto 100m depth. Picoeukaryotes showed uniform abundance along 0~ 100m depth in the C-ECS,and abundance maximum layer appeared in the East Sea at 20~ 30m depth.