Abstract:

The ice algal and phytoplankton assemblages were monitored from April to December,1992 in Nella Fjord near Zhongshan Station (69°22′24″S,76°22′40″E),east Antarctica.The abundance of algae in the ice and water column (0～50 m) were higher in April and mid November mid December,which could reach 10 8-10 9cells/m 2. Amphiprora kjellmanii、Berkeleyarutilans、Navicula glaciei、Nitzschia barkleyi、N.cylindrus、N.lecointei and Nitzschia sp.were dominant in the ice column in one season or throughout the study.Although the dominant species could maintain in some ice layers,succession occurred in most sections following the changes of the environmental factors.The dominant species in the vertical profiles of ice in the spring and summer couldn't reflect the seasonal succession of blooms in the bottom layer of ice. The comparison of algal composition and abundance between bottom layer of ice and surface layer of water suggests that it is different except in late November when the spring ice algal bloom occurred.Both autumn and spring ice algal blooms occurred mainly by the in situ growth rather than physical collection.The seeding of ice algae to phytoplankton was not significant after they released from ice in early December.