한국남해안의중앙부에위치하는장수만의식물플랑크톤군집의시ㆍ공간적분포특성과생물해양학적환경특성을파악하기위한현장조사를2006년봄부터겨울까지계절별로장수만과인근해역을대상으로하는31개의정점의표ㆍ저층해수를대상으로실시하였다. 장수만에서출현이확인된식물플랑크톤은47속83종으로규조류가65.1%, 와편모조류가30.1%를차지하였고, 유해성조류도3종출현하였다. 세포밀도로표시한식물플랑크톤현존량은봄3.1cellsㆍmL-1에서겨울521.0cellsㆍmL-1의범위로겨울과여름에높고, 봄과가을에낮았다. 현존량은정점평균으로표층에서봄7.6cellsㆍmL-1,여름68.0cellsㆍmL-1, 가을8.1cellsㆍmL-1, 그리고겨울은220.2cellsㆍmL-1를나타내었다. 표층에서우점종은봄에Chaetoceros affinis, Paralia sulcata, Bacillaria pax-illifera, 여름에Chaetoceros didymus, Ch. affinis, Octactisoctonaria, 가을에Skeletonema costatum유사종과B. pax-illifera이10% 이상의우점률을나타내었고, 겨울은S.costatum유사종에의해극우점되었다. 주성분분석에의한장수만의생물해양학적특성은봄과여름의수온상승기에는봇돌바다등개방해역에서유입되는해수영향으로높은생물생산을유지하고있고, 가을과겨울의수온하강기에는생물량은수심의얕은천해해역에서높고, 현존량은수로부에서높은밀도를나타내었다. 특히 겨울은해수혼합의원활한천해해역에높은식물플랑크톤생산을나타내었다.

This study describes about the spatio-temporal distributions in phytoplanktoncommunity such as species composition, standing crop and dominant species from May 2006 toFebruary 2007 in the Jangsu bay and the northwestern parts of Gamak bay. Based on theprincipal component analysis(PCA) of the environmental factors as well as biological parameters,the bio-oceanographical characteristics were analysed. A total of 83 species of phytoplanktonbelonging to 47 genera were identified. Whereas diatoms and dinoflagellates occupied more than65% and 30% of total species, respectively. The annual dominant species were Chaetocerosaffinis, Paralia sulcataand Bacillaria paxilliferain spring, Chaetoceros didymus, Ch. affinisandOctactis octonariain summer, Skeletonema costatum-like species and B. paxilliferain autumn.Moreover phytoplankton cell density was ranged between 3.1cellsㆍㆍmL--1in spring and 521.0cellsㆍㆍmL--1in winter. It fluctuated with an annual mean of 76.0cellsㆍㆍmL--1between the lowestvalue of 7.6cellsㆍㆍmL--1in spring and the highest value of 220.2cellsㆍㆍmL--1by Skeletonemacostatum-like species in winter. Briefly, the phytoplankton cell density in the mixing seasons washigher in comparison with the other seasons. According to the PCA, the biological oceanographiccharacteristics of the Jangsu bay was affected by the introduction of outside seawater particularlyin temperature increasing seasons, and the other seasons, it may be described the light intensity,and mix between inner and outer bay sea waters.

• 윤양호(전남대학교 해양기술학부) | Yang Ho Yoon Corresponding author