Students on the blue marble - Shlomit Sharoni

Shlomit Sharoni has successfully completed her PhD at the Department of Earth and Planetary Sciences on August 2020, and is currently a postdoctoral researcher at Prof. Itay Halevy’s group. She is a modern-day Renaissance woman, in addition to to her research career, she is also an aerial acrobatics instructor and a bass guitar player. She has an adorable 3-year old daughter, and currently lives in Eilat with her family.

During her PhD, Shlomit investigated the impact of the elemental composition of microscopic algae on the oceanic environment, both in the present and in the geological past.

Shlomit joined the department of Earth and Planetary Sciences at the Weizmann Institute after completing her BSc in chemistry at the Hebrew University in Jerusalem. Before starting her MSc studies, she worked with Prof. Dan Yakir at the department. As part her research, Shlomit worked in the Yatir forest on a study about tree mortality. During her MSc studies in Prof. Assaf Vardi’s lab at the department Plant and Environmental Sciences, in collaboration with Prof. Ilan Koren from the EPS, Shlomit explored the effect of oceanic microalgae and viruses on the composition of marine atmospheric aerosol. After completing her MSc, Shlomit became interested implementing a mathematical model as a tool for understanding how the ocean functions, and approached Prof. Itay Halevy for a PhD.

The core of Shlomit’s research is focused on changes in the chemical composition of microalgae in present-day and past oceans. The importance of microalgal chemical composition stems from the substantial impact of their relative carbon content on Earth’s climate; Organic compounds produced by oceanic microalgae during photosynthesis trap atmospheric carbon dioxide (CO₂), a known greenhouse gas. In addition, when microalgae die and sink to the bottom of the ocean, they undergo decomposition, which consumes oxygen. Therefore, their chemical composition affects the oxygen concentration of the oceans, which, in turn, impacts the marine food chain. Shlomit used statistical tools and mathematical models to determine the interaction between oceanic microalgae and the Earth’s climate today and in the geological past.

One of Shlomit’s main findings during her PhD research, recently published in the journal Science Advances, demonstrates that the chemical composition of the organic matter in the oceans is determined by the structure of microalgal communities, which varies across the oceans, depending on temperature and nutrient availability.

Shlomit used the main conclusions of her research to explore the geological past and discovered that the chemical composition of microalgae differed substantially from the present-day composition, due to major differences in environmental conditions.

This research, together with other environmental studies conducted at the Weizmann Institute, allows to address fundamental questions regarding the current climate change and its various implications. Since Earth’s atmosphere and oceans are warming, we expect (and already observe) that nutrient poor areas will expand, altering oceanic microalgal compositions, impacting the ocean’s carbon content, chemical composition, and consequently the entire food chain.

Shlomit has had many unique experiences during her time at the Weizmann Institute, including taking part in a research cruise in the North Atlantic Ocean, and presenting her research in international conferences. In the future, she intends to conduct her postdoctoral research abroad, where she hopes to combine mathematical modeling tools with experiments, in order to further explore how microscopic organisms drive the biogeochemistry of the oceans.