The distribution and abundance of viruses in the Southern Ocean during spring

• Published in: Antarctic Science
• Main Authors: Marchant, Harvey, Davidson, Andrew, Wright, Simon, Glazebrook, John
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2000
• Subjects: Geology; Ecology, Evolution, Behavior and Systematics; Oceanography; Southern Ocean; Antarctic Science; Sea ice
• Online Access: http://dx.doi.org/10.1017/s0954102000000481; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102000000481

The concentrations of viruses, bacteria, chroococcoid cyanobacteria and chlorophyll a were determined in surface waters of the Southern Ocean during spring. Viral concentrations declined southward from around 4 × 10 6 ml −1 near Tasmania to a minimum of around 1 × 10 6 ml −1 at the Polar Front. South of the Front, virus concentrations increased again, reaching around 4 × 10 6 ml −1 in the sea-ice zone south of 60°S. Bacterial concentration decreased southwards across the Southern Ocean from around 6.5 × 10 5 ml −1 near Tasmania to < 1.0 × 10 5 ml −1 in the sea-ice zone. Cyanobacteria accounted for < 8% of the prokaryotes. There was no significant relationship between viral abundance and eithercyanobacterial or chl a concentration. Viral and bacterial concentrations were not significantly correlated north ( P {0.10 < r < 0.20}) or south ( P {0.20 < r < 0.5}) of the Polar Front. The virus to bacteria ratio (VBR) was between 3 and 15 in the open ocean but varied between 15 and 40 in the sea-ice region. These virus concentrations and VBRs indicate that viruses are no less important in Southern Ocean ecosystems than elsewhere in the world's oceans.