Ocean acidification and warming
Acidification of the world’s oceans from rising atmospheric carbon dioxide levels reduces the availability of carbonate required by some marine organisms to build shells and skeletons, and potentially affects their ability to maintain existing structures.
In cold Antarctic waters, carbonate availability is already very low, and effects on key species have the potential to alter entire ecosystems. Our laboratory based investigations of adult bivalves has shown negative impacts of ocean acidification on various aspects of their functioning and health (with colleague Victoria Metcalf, Lincoln University), and later modelling work revealed potential population-level consequences.
The underside of Antarctic sea ice provides a platform for often high concentrations of ice algae. When this algae settles down to the seafloor below it provides one important primary food resource for benthic organisms (including the bivalves mentioned above). Ocean warming and acidification threaten the success of these different parts of the coastal ecosystem, yet how overall functioning and dynamics may be affected is not known. We have recently begun some in situ experimental investigations, to help determine potential implications to the benthos, and to linkages between these important ecosystem components.
- Guy, C.I., Cummings, V.J., Lohrer, A.M., Gamito, S., Thrush, S.F. 2014. Population trajectories for the Antarctic bivalve Laternula elliptica: identifying demographic bottlenecks in differing environmental futures. Polar Biology 37(4): 541-553.
- Cummings, V., Hewitt, J., Van Rooyen, A., Currie, K., Beard, S., Thrush, S., Norkko, J., Barr, N., Heath, P., Halliday, J., Sedcole, R., Gomez, A., McGraw, C., Metcalf, V. 2011. Ocean acidification at high latitudes: potential effects on functioning of the Antarctic bivalve Laternula elliptica. PLoS ONE 6(1): e16069 .
- Proffit, F. 2010. Ocean acidification and Antarctic shellfish. Aquatic Biodiversity & Biosecurity 30, June 2010.
- Cummings, V.J. 2010. Antarctic marine calcifiers and increasing ocean acidification. Antarctic 28(1):14-15.
- Bulleid, J. 2010. Simulating the effects of ocean acidification. Instrument Systems Update 14. March.
- Royal Society of New Zealand. 2009. Ocean acidification, emerging issues.