Environmental changes in foraminiferal shell morphology revealed by synchrotron μCT

Human activities in coastal areas are accelerating in the last 200 years, increasing pressures as warming, oxygen depletion, and ocean acidification on organisms and ecosystems. These environmental changes can lead to multiple social-ecological problems. To better understand these potential future threats, we need to develop tools to compare our present situation and events that happened in the past. Foraminifera are tiny marine microorganisms. Their shells are made of calcium carbonate and abundantly fossilized in marine sediments. Foraminifera are currently used as recorders of the past as the chemical composition of their shells reflects environmental conditions. Their changes in morphology are recently used thanks to the 3D development imagery acquired with microtomography. However, the current method used is time-consuming and allows a few specimens analyzed (one specimen every 24h). This project aims to develop protocols and post-data analysis by using synchrotron facilities, allowing to generate long time series of hundreds of specimens (one specimen every 30min) required to obtain statistically valid conclusions. Thus, we hypothesize that the foraminiferal calcite will respond to the changed environmental conditions by having changed shell morphology (size, weight, volume, pore density).