14 January 2013C3 Environmental Honours student Kirralee Baker took out the award for the Best Honours talk at the recent Australasian Society for Phycology and Aquatic Biology (ASPAB) held in Adelaide.
Kirralee's Honours project used selection experiments with dinoflagellates to better understand climate change adaptation in these microalgae. Despite 30 years of research on the effects of environmental stressors on microalgal performance, and the global significance of climate change, there are still significant knowledge gaps.
While drivers of ecological impacts of climate change operate globally, they vary in their intensity depending on region and habitat. Tropical benthic microalgae living amongst sediment grains may be well buffered from changes in ocean pH, but are potentially exposed to changes in light brought about by sea level rise. Pelagic dinoflagellates in temperate estuaries undergo large daily variations in temperature due to their vertical migrations but may be exposed to steeper thermal gradients due to surface warming.
Kirralee's examined fitness traits of two dinoflagellate species selected for tolerance to high temperature, that were then exposed to different light levels or thermal gradients. The resutlts showed that microalgae grown under long-term conditions of elevated temperature perform differently to those grown under short-term conditions of elevated temperature, which suggests potential adaptation to future ocean-warming scenarios. These results also demonstrates the ability of cells to adjust to changes in light regimes associated with sea-level rise or water column stratification, acclimating to decreased and increased irradiance, respectively.
"This study shows the need for long-term experiments and indicates that elevated temperatures associated with sea surface warming may not be as detrimental as previously thought, " Kirralee said.
"Further research should be directed into maintaining cultures for many generations under multiple selective conditions. This would give more insight into the effect of environmental clusters on the long-term performance of phytoplankton and therefore the consequences of global climate change on future oceanic primary productivity," she said.
Kirralee's Honours supervisor was Dr Martina Doblin who leads the Aquatic Processes Group - Coastal Oceanography Team