Tell us a bit about yourself. Hi everyone! I am a doctoral candidate at the Leibniz Centre for Tropical Marine Research in Bremen, Germany. After graduating in Ecology at the University of Belgrade in Serbia, I finished a MSc in Marine Environment and Resources (MER Erasmus Mundus) at the University of Southampton, University of Liege, and University of Basque Country. Finally, I decided to pursue research in paleoclimate reconstructions in order to improve our knowledge of modern climate change and ocean acidification. I am a part of the Coral Climatology group led by my supervisor Dr. Henry Wu, and funded by the Make our Planet Great Again research initiative, a joint project of France and Germany to tackle modern climate change through research related to Earth system science, climate change and sustainability, and energy transition.
What research are you doing for your PhD? For our research, we use cores drilled from massive tropical corals like Porites (but don’t worry, they are not hurt by this). Only the top few millimeters of the coral is alive, the rest is all skeleton – an intricate rock made of aragonite, as coral polyps keep growing. Cores we work on were drilled during past expeditions so our project is kept more sustainable. After the cores are drilled, the holes are filled so the coral can keep growing safely without fears of other animals infesting it. My project is focusing on the South Pacific area which is home to the South Pacific Convergence Zone (SPCZ), the largest persistent precipitation band in the Southern Hemisphere. The climate of this area is modulated by large-scale ocean-atmospheric interactions (El Niño/Southern Oscillation, Interdecadal Pacific Oscillation), which also impacts regional seawater CO2 absorption and pH variability.
The cores are transported to our coral climatology lab in Bremen, slabbed and washed, X-rayed and CT-d. The scans help us see the annual bands, similar to tree rings, that help us determine how old the corals are to connect our data to points in time, but also help us establish the best sampling path so our data isn’t impacted by corals turning sideways or protruding from the slab etc. Coral skeletal microsamples are then drilled continuously and analyzed for many trace elements and isotopes for hydroclimate and sea surface temperature reconstructions (δ18Oc and sw, Sr/Ca, Li/Mg, U/Ca, Sr-U), while δ13C, B/Ca, and δ11B analysis allows for the reconstruction of surface seawater carbonate chemistry changes and pH variability. It’s truly a lot of work, one core has approximately around 2000 mm samples to be analyzed with two different methods, and then around 250-350 annual samples with a third method.
In this geologically short period of only 300 years or so, important changes have happened in how us humans use natural resources and affect the environment. Our coral-based reconstructions provide monthly to annual data to describe this change as corals have lived through it for hundreds of years, one of them dating back to 1770AD, much before the first instrumental measurements started!
What advice do you have for up and coming scientists? Working in science is not a straight line and not easy. When you love what you do, it’s easy to lose boundaries and let it consume you too much. Science is also not only academia, and I am learning myself that there are many options out there. The pressure of short contracts in academia, multiplying deadlines and no work-life separation has led me to burn out before.
I like to balance my work life with doing sports and running (I am a proud two-time half marathon finisher so far, but I am no stranger to an occasional Netflix marathon either). I am also a big foodie, and whenever work gets a bit too much, baking a cake fixes it. Try to keep in mind that you’re in for a marathon and not for a short race.
Learn more about Sara and her lab’s research on their website here!