Professor Rick Cavicchioli Leads Third Antarctic Expedition

Date: 
01/10/2013

Intrepid environmental microbiologist Professor Rick Cavicchioli is setting out on 7 October on his third expedition to Antarctica. Rick’s group has been running expeditions most years since 2006, with summer trips to Antarctica in 2006/7 and 2008/9, and voyages to the Southern Ocean in 2007/08, 2010/11 and 2011/12. This new expedition is by far the biggest, an over-wintering expedition that will run for more than 12 months.

The two previous Antarctic trips were focused on studies of lakes in the Vestfold Hills region near Davis Station. Building on knowledge gained from the use of omics to interrogate microbial samples from the previous expeditions, the purpose of this trip is to monitor ecosystem stability in model marine-derived Antarctic lake and near-shore systems; in essence, addressing the question of what do microorganisms do season by season, year after year in the frigid Antarctic wilderness.

The specific aim of this latest expedition is to determine how microbial communities change throughout a complete annual cycle in three climate-sensitive Antarctic lakes – Ace Lake, Organic Lake and Deep Lake – and in a near-shore marine location. The group’s research to date reveals that Antarctic microbial communities are very delicate, with indications that environmental perturbation, including climate change, may prevent such communities from recovering, thereby altering the lake biogeochemistry forever. Establishing what the microorganisms do in different seasons will reveal which microbial processes change, and how environmental perturbation will impact on normal ecological cycles in the Antarctic. This essential evidence-based knowledge will form the underpinnings for evaluating the effects of climate change on sensitive ecosystems in the Antarctic.

Rick will undertake pre-departure training in Hobart, and is scheduled to depart on the RV Aurora Australis on 15 October. The trip to Davis is expected to take 12 days, where he will conduct fieldwork before flying to his ultimate destination, Casey Station, returning in early January 2014.

Sarah Payne (left) and Alyce Hancock (right), who both have Masters in Antarctic Science from the University of Tasmania and are now employed by UNSW, will expedition with Rick, but will remain at Davis for a little over 12 months until Oct/Nov 2014. Rick then plans to travel to Davis in late 2014, overlapping with Sarah and Alyce so that sampling can continue during Summer 2014/15.

The estimated value of logistics support that the Australian Antarctic Division (AAD) plans to provide for this project is $1,504,732 in 2013/14. The AAD also plans to provide an additional allocation of approximately $775,000 for the final part of the expedition in summer 2014/15. The budget takes into account costs associated with transport to and from Antarctica, in addition to support while the team is in Antarctica. Rick has also been awarded an Australian Antarctic Science grant of $107,662.

This is Rick’s first wintering expedition, and he has found the logistics and costs to be considerable and risky. His postdoc Dr Tim Williams has shipped off about 50 cases/items representing 1,200 kg of gear that has gradually been put together since about February this year. Critical to making the expedition a success, Rick and Tim have been forecasting, detailing, and engaging in long-term planning of activities associated with logistics and supplies (e.g. ~5,000 sampling tubes, 3 full sampling rigs with petrol compressors). It has also proven essential to have clever advice and expertise from Jean Matossian from the Faculty of Science workshop, who has engineered custom equipment and defined a range of solutions for the fieldwork. 

PhD students Tahria Najnin & Bernhard Tschitschko, Dr Tim Williams, BABS Professional Officer Geoff Kornfeld

Rick’s research has been described by the AAD as a showcase project, and due to the current limited capacity to support Antarctic logistics, this project is the only one being funded within the Antarctic science stream ‘Vulnerability and Spatial Protection’. Reflecting on what may be expected from this work, Rick states that the scientific findings will be extremely valuable, but will not be immediate, taking much time and effort to be realised over many years. To put this in perspective, the first paper published from work during the 2006 expedition was not published until 2010.

Rick’s group was the first to publish findings based on the use of shotgun metagenomics and metaproteomics to describe Antarctic microbial communities, and has now published more of this type of work than any other group in the world. One of the strengths of this approach is letting the data empirically describe the system, thereby discovering what is present and important – discoveries which do not necessarily match preconceived expectations. For example, Ace Lake and Organic Lake revealed unexpected roles for viruses (e.g. virophages and phage-resistant bacteria) and dominant cellular species (e.g. green sulfur bacteria), and Deep Lake exhibited an extraordinary level of inter-genera gene exchange. As a result, unanticipated and important roles for specific components of the microbial loop and the apparent peculiarities of polar ecosystems were revealed.

The use of omics techniques, multidisciplinary teams of researchers and access to long-term data records powerfully highlight just how much the scientific community can learn about these unique systems. However, it has also made researchers realise just how little is really understood and how much remains to be learned, and hence, why Antarctica needs real protection so that society can continue to learn and prosper from it for years to come. Clearly, and in view of the global changes arising from climate change and the particularly sensitive nature of polar environments, we need to rapidly improve our understanding of Antarctic biology.

To emphasise the trajectory of the group’s work at UNSW, the following papers have just been published in Nature Communications and Proceedings of the National Academy of Sciences USA:

  • Wilkins, D., van Sebille, E., Rintoul, S.R., Lauro, F.M. & Cavicchioli, R., 2013, ‘Advection shapes Southern Ocean microbial assemblages independent of distance and environment effects’. Nature Communications. 16 September, doi:10.1038/ncomms3457
  • DeMaere, M.Z., Williams, T.J., Allen, M.A., Brown, M.V., Gibson, J.A.E., Rich, J., Lauro, F.M., Dyall-Smith, M., Davenport, K.W., Woyke, T., Kyrpides, N., Tringe, S.G. and Cavicchioli, R. 2013. High level of inter-genera gene exchange shapes the evolution of haloarchaea in an isolated Antarctic lake. Proceedings of the National Academy of Sciences USA.
    doi 10.1073/pnas.1307090110 http://www.pnas.org/content/early/2013/09/25/1307090110.full.pdf+html

Recent published findings from this research have today received wide media coverage, with articles in The Australian Higher Education section, Science Codex, and on the US Dept of Energy Joint Genome Institute website. Rick has also written a piece for The Conversation.

RV Aurora Australis