PLENARY SPEAKERS

Prof. Andrew McMinn

Institute for Marine and Antarctic Studies, University of Tasmania (UTAS)

Biography:
Prof McMinn was one of the foundation staff members at the Institute for Marine and Antarctic Studies (formerly known as the Institute of Antarctic and Southern Ocean Studies) at the University of Tasmania in May 2002 he was appointed as Director of that institute. Prof McMinn is a very prominent Polar scientist and has spent 14 field seasons in the Antarctic, 3 at the Australian station, Davis, 3 Marine Science voyages and 8 seasons at the New Zealand station, Scott Base. He has also had 4 field seasons in the Arctic with the Norwegians and 5 on sea ice in northern Hokkaido. Prof McMinn’s research work has been focused on sea ice ecology and environmental change. This includes the ecology, biochemistry, production, and photo physiology of the sea ice microbial communities. He is known to be a pioneer in the in-situ use of micro sensors in polar environments. Prof McMinn’s work also included an examination of the effects of UV, a work that was subsequently published in Nature. Prof McMinn is now an Emeritus Professor of Antarctic Science at the Institute for Marine and Antarctic Studies, the University of Tasmania. He also serves as a Distinguished Professor at The Ocean University of China.

Title:
The role of viruses in marine polar environments and their response to change

Abstract:

Background: Viruses are the most abundant life form on earth with an estimated total abundance in the oceans of ~1030. They are responsible for 10-30% of bacterial mortality, known to control harmful algal blooms and can reduce photosynthesis by up to 78%. In Prydz Bay, eastern Antarctica, their abundance at all depths is closely correlated with both chlorophylla and bacterial abundance. Metagenomic analyses of surface seawater from the Scotia Ridge and Prydz Bay, identified bacteriophages of the Caudovirales, especially the Podoviridae, as the most abundant. Microalgal viruses belonging to the Phycodnaviridae family, which contains most microalgal viruses, especially Phaeocystis viruses, were also identified.

Sea ice algae communities comprise a globally significant photosynthetic biofilm. While their microalgal and bacterial constituents are well characterized, there is very little information on their associated viral communities or the virus-bacteria and virus-algae interactions within them. While high levels of interaction might be expected because of the high density of cells, infection rates, particularly of microalgae, have been found to be low. It remains unclear whether this is a result of environmental characteristics, developed resistance or because of the small number of studies. However, research to date has focussed exclusively on DNA viruses. Recent research has shown that key eukaryote group, including diatoms, are mostly infected with RNA viruses. Our most recent research shows that RNA viruses are abundant and diverse in sea ice

We are investigating how projected global change, including ocean acidification temperature and nutrient availability, will change infection rates in ice edge blooms and sea ice ecosystems.