Sarah Fawcett

Ocean biogeochemist

Sarah Fawcett is an ocean biogeochemist, and has always been interested in the large chemical cycles that make our planet habitable, simply because they’re so elegant. She chose to work on chemical cycles in the ocean because the ocean is the reason we have a habitable planet: it transports heat and gases around the globe, ensuring that the high latitudes don’t get too cold and the equator doesn’t get too hot for life.

“I realised while I was working on my honours thesis that I really enjoy the process of research: asking a question, designing experiments, collecting data in the field and the laboratory and then interpreting the data, which inevitably leads to more questions, ” says Fawcett.

“Mostly I’m intrigued by the way the Earth is able to regulate itself, always returning to some sort of balance. This is true at the level of photosynthesis and respiration over timescales of a day or a season, but also over long timescale cycles such as the ice ages 100 000 years, or even multi-million year timescales. It’s also true across huge space scales. The ocean is the biggest player in these cycles because of its size and because, unlike the atmosphere that mixes rapidly, the ocean takes 1 000 years to completely mix.

“But knowing something about the Earth’s natural cycles is why I find the pressure that we’re putting on our environment, through pollution and overfishing, to be so scary. Human-induced environmental change is happening so rapidly that it’s unclear whether the planet will be able to adapt, and even if it does, will the adaption result in conditions in which we can comfortably live?” she asks.

Fawcett has ongoing research projects in the Southern Antarctic Ocean, which is the most important oceanic region for climate, in part because of its size, and also because it is characterised by high levels of nutrients (nitrogen, phosphorus) that do not get used by the microscopic plants (phytoplankton) living in the surface ocean. She also works in the Benguela Upwelling System off the west coast of South Africa. This is a region that is important for South Africa’s economy and social wellbeing as it supports important commercial fisheries and subsistence fishing, and also increasingly supports mariculture operations.

“My broad goal through my research is to better understand the role of the ocean in making the planet habitable, and to figure out how we can use the ocean to improve the lives of people living in South Africa, which has a vast coastline, in a manner that’s sustainable.”

— Kerry Haggard