My latest research was part of a project on hydrothermal vents at the world’s deepest sea floor spreading centre (Mid-Cayman Rise), in the context of astrobiology and potential life on Jupiter’s moon Europa. I used the stable isotope composition of minerals, water, and biota around these vents to disentangle the food web, and trace carbon, nitrogen and sulphur pathways. Recent results show that a shrimp species that was until now considered bactivorous, is probably carnivorous.
Much of my previous and on-going work focussed on biogenic carbonates of terrestrial, freshwater and marine origin. I studied earthworm secreted calcite granules, in order to construct a new terrestrial palaeo-environment thermometer and to quantify carbon sequestration potential, and ran experiments with earthworms living under different environmental conditions and determine their influence on the chemistry of carbonate granules they produce. I developed the first palaeotemperature equation for earthworm produced calcium carbonate and am currently applying it to granules from archaeological finds.
In addition, I did very similar work on growth increments of bivalve shells. I sampled growth lines from mussel shells, and analysed them for different chemical components like stable isotopes of oxygen, carbon and nitrogen, or trace elements like strontium, magnesium and barium. Within the CALMARs project, I pursued several lines of research, the two most important were: Mytilus edulis shell chemistry as a proxy for past dynamics in the Scheldt estuary; and the potential of shell chemistry of the same species as a palaeoenvironmental proxy in the Arctic.
During my PhD I did this type of work on freshwater mussels from the rivers Rhine and Meuse in the Netherlands. I investigated if oxygen and carbon stable isotopes compositions of these shells can serve as a proxy for past river discharges, floods or droughts. This resulted in the thesis: “Silent witnesses – Freshwater bivalves as archives of environmental variability in the Rhine-Meuse delta“.