If it wasn’t yet obvious from the name of my blog, I study phytoplankton and how they might be affected in the future by climate change, focussing specifically on ocean acidification. Our oceans naturally absorb CO2 from the atmosphere, but as we burn more and more fossil fuels, they take up more CO2. Because of how quickly this is happening, the increase in CO2 is actually changing the very chemistry of seawater, making it more acidic and decreasing the concentration of calcium carbonate, a compound that many marine organisms use to make shells. Organisms that have shown negative impacts from these changes include corals, bivalves (like mussels or scallops) and even baby fish.
Phytoplankton are an interesting group of living things to look at here because they could benefit from the increase in CO2 (they’re photosynthetic), but at the same time there are cellular processes that might be disrupted by the change in pH. In addition, some groups of phytoplankton make shells, and might find it difficult to continue doing so in the future. It’s important to understand exactly how phytoplankton might respond to these changes over the next century as they form a key part of marine ecosystems by being the bottom of the food web, but also contribute to global chemical cycles and are involved in climate feedback systems.
My work has been looking at how the physiology of a group of phytoplankton called coccolithophores is affected by ocean acidification. These guys are bloom forming phytoplankton, with one particularly important species called Emiliania huxleyi (or EHUX for short) that is found all over the world, but is ecologically important in places like the temperate Atlantic. I’ve been lucky enough to not only study these organisms in the lab, but in the field too, travelling to the Arctic and Antarctic to look at local plankton communities. The polar regions are particularly vulnerable to ocean acidification because gases dissolve much more easily in cold temperatures. Hopefully my work can help inform us about the consequences of burning so much fossil fuel.