Project 4315

The Antarctic marine ecosystem is an important 'hot spot' of productivity, supporting global marine biodiversity through photosynthesis performed by microscopic marine plants (phytoplankton). Antarctic phytoplankton produce organic sulphur compounds that drive many marine food-web interactions and link ocean chemistry to global climate through the release of aerosols that influence cloud formation. Marine sulphur cycling is governed by cell-cell interactions between phytoplankton and bacteria. This project examines the role of sulphur compounds in Antarctic phytoplankton-bacteria associations and explores how changes in environmental condition, such as those expected from global warming, influence these fundamental relationships. This is important, because marine microbes perform invaluable ecosystem services, and any shift in their interactions and collective function will profoundly affect ocean productivity (fisheries yields) and chemical cycling (which control our climate).

Project 4315 was not supported logistically in 2015/16 and has subsequently been extended to the 2016/17 season. The project relies on the collection and processing of samples from the field. However, since no field work has been undertaken yet, scientific progress to date has been minimal. We have however obtained various pieces of specialised equipment and have begun testing and optimising our techniques. Our team meet regularly to discuss and further plan the project to ensure the best possible outcomes from our trip, should it be supported this season. We have also started our data management plan, which will be finalised before the December 2016 deadline.

This season, our research team spent three weeks sampling coastal waters and conducting laboratory experiments at Davis Station, Antarctica. We were able to sample >500L of seawater and complete a series of laboratory experiments to elucidate the role of the sulphur molecule DMSP in the interaction between bacteria and algae in the Antarctic marine environment. Having only recently returned from Antarctica, we are now in the process of analysing our samples to reveal the processes and physiologies that underpin these interactions and how they may affect the Antarctic marine sulphur cycle.

In the late summer of 2017, our research team spent three weeks sampling coastal waters and conducting laboratory experiments at Davis Station, Antarctica. We were able to sample >500 L of seawater and complete a series of laboratory experiments to elucidate the role of the sulphur molecule DMSP in the interaction between bacteria and algae in the Antarctic marine environment. In consolidating our findings, our data are starting to reveal processes and physiologies that underpin the role of this sulphur molecule and uncover distinctive phytoplankton-bacteria interactions in the Antarctic marine environment. The work from our project contributes new information on DMSP producers and users and sheds light on how these lower trophic interactions affect Antarctic marine sulphur cycling.