An ACE CRC researcher has secured funding to undertake the world’s first polar sea-floor carbon dioxide enrichment experiment. Dr Donna Roberts, a marine biologist who specialises in the impacts of rising CO2 on tiny shell-forming organisms, has received an Australian Research Council Large Infrastructure, Equipment & Facilities (LIEF) Grant and will lead the collaboration with enthusiastic University of Tasmania (UTAS), Australian Antarctic Division (AAD) and Monterey Bay Aquarium Research Institute (MBARI) researchers and engineers. As the amount of CO2 has risen in the atmosphere there has been a corresponding rise of CO2 in the ocean, changing its chemistry and making it more acidic – a process known as ‘ocean acidification’. Ocean acidification has serious implications for the resilience of marine ecosystems in a future high CO2 ocean, and as CO2 is more soluble in cold water it is expected that our polar ecosystems will bear the heaviest burden of this acidification. Free Atmosphere Carbon Enrichment (FACE) experiments are commonplace tools for terrestrial ecosystem scientists to be able to make predictions about the effects of high CO2 emissions on forests, soils and associated processes. But only recently have marine scientists had access to the same technology to be able to determine community-wide responses to future high CO2 emission oceans. Free Ocean Carbon Enrichment (FOCE) experiments were first developed by MBARI in 2005 and have since been deployed in tropical (e.g. Heron Island, Australia, 2010) and temperate (e.g. Monterey Canyon, USA, 2011) waters to date.  ACE CRC, AAD, UTAS and MBARI engineers and researchers, aka “Team Acid”, will deploy the world’s first polar FOCE system in Australian Antarctic waters in 2014. “Basically we are going to build a bio-dome with a future ocean inside it,” Dr Roberts said. “Instead of taking the ecosystem to the lab, which is what happens when experiments are set up in labs back home, we are taking the lab to the ecosystem.” Dr Roberts said three possible sites for the lab have been identified, all of them just off the Antarctic coastline at Casey station. The lab will be in situ for four months, during which time ocean water with increasing levels of CO2 will be pumped through (offset with known natural pH fluctuations). Probes into the unit will measure changing properties and time lapse photography will record observations. This polar CO2 enrichment experiment will assess the vulnerability of Southern Ocean sea-floor, or benthic communities, to continuing, and increasing, CO2 emissions. These communities are often overlooked, but are the world’s best recyclers, releasing essential nutrients back into the water to support the plankton that drive ocean productivity. Dr Roberts said taking FOCE technology into polar waters was not without its challenges – this will be the first FOCE unit deployed under ice, and will be at risk of being struck by the ‘‘bergy bits’’ of ice that break off over the summer. “Our FOCE chambers will need to be firmly entrenched in the sea-floor and built with materials that can withstand extreme cold and inquisitive penguins,’’ Dr Roberts said. Read more about the bio dome here: Building a future ocean. Donna Roberts features in the documentary Acid Ocean.

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