Abundances of algae, bacteria, viruses, and heterotrophic nanoflagellates in the Southern Ocean and determination of grazing and viral lysis of the algae

Twenty four stations were sampled in an area between 43 oS to 54 oS and 140 oE to 155 oE. At 3 of the stations designated Process Stations 1, 2 and 3 repeated sampling was completed over a number of days to examine temporal variation.

Process Stations 1 to 3 were located in the SAZ to the southwest of Tasmania, the PFZ and in the productive SAZ region southeast of Tasmania respectively, the latter being potentially representative of the future SAZ. Abundances of algae, bacteria, viruses and heterotrophic nanoflagellates were measured using flow cytometry and viral production was determined by an incubation based method. A dilution method was also used to determine grazing and viral lysis of the algae.