Dynamics of bacterioplankton activities after a summerphytoplankton bloom period in Terra Nova Bay

[摘要] A late summer study of marine bacteria activities, and the interrelationships with the microbialloop and the microbial food chain was carried out from 22 January to 10 February 2000 in a coastal area ofTerra Nova Bay (Ross Sea). The objective was to investigate the transition from the end of a phytoplanktonicbloom to the start of winter. Intense bacterial activities, comparable to those of temperate marineenvironments, were observed. The carbon potentially mobilized from proteinaceous matter wasquantitatively the most important source of carbon for the bacterioplankton. The leucine aminopeptidaseactivity was higher in January samples and decreased towards 10 February whereas an opposite trend wasobserved for alkaline phosphatase and �-glucosidase activities. The bacterial production was supported byc. 0.2% of the amounts of dissolved organic carbon mobilised by hydrolytic activities and by 7% ofinorganic phosphate mobilised by alkaline phosphatase activity. A sharp reduction in the bacterial biomass,possibly due to zooplankton grazing or viral lysis, was observed for the first time in Terra Nova Bay.

[学科分类] 自然科学（综合）