Microbial plankton across Drake Passage

2020-03-30 06:22:47

10 passage PF biomass Drake

责任者: PedrosAlio, C;CalderonPaz, JI;Guixa, N;Navarrete, A;Vaque, D 单位: 来源出处: POLAR BIOLOGY, v 16, OCT 1996, p 613- 622 摘要: We determined biomass and activity of microbial plankton across the Polar Front (PF) in Drake Passage during January 1994. Temperature was around 0 degrees C south and between 3 and 5 degrees C north of the PF. Both biomass and activities of microorganisms were significantly lower in the Antarctic waters south of the PF than in the sub-Antarctic waters north of it. Thus, values of chlorophyll alpha, integrated between 0 and 200 m, reached 150 mg m(-2) north, but only 25 mg m(-2) south of the PF. Likewise, bacteria varied between 10(14) and 4 x 10(13) cells m(-2). However, the abundance of heterotrophic nanoflagellates was extremely low throughout Drake Passage (around 3 x 10(10) cells m(-2)). Bacterial doubling times were long (mean of 25 days). Bacterivory was estimated from the abundance of predators and prey and from temperature. The grazing impact on bacterioplankton biomass was insignificant (less that 0.05% per day) and low on bacterial heterotrophic production (15% per day). Neither biomass nor the activities of microorganisms were found to increase at the PF. The microbial food web was uncoupled and the bacteria did not seem to be controlled by predation. 关键词: telechelic ionomers; light scattering; transient network; w/o microemulsions microemulsions; ANTARCTIC CIRCUMPOLAR CURRENT; LATE AUSTRAL WINTER; SOUTHERN-OCEAN; BACTERIAL PRODUCTION; DIVIDING CELLS; BIOMASS; BACTERIOPLANKTON; BACTERIAL PRODUCTION; DIVIDING CELLS; BIOMASS; BACTERIOPLANKTON; PHYTOPLANKTON; FREQUENCY; ZONATION PHYTOPLANKTON; FREQUENCY; ZONATION