The DISCO project is now finished
Since the industrial age, the concentration of carbon dioxide (CO2) has strongly increased in the atmosphere, mainly due to human activities. A third of this CO2 has been captured by oceans, by simple gas dissolution. After a range of chemical reactions, the pH value of the oceans decreases. This pH decrease can lead to the dissolution of calcium carbonate (CaCO3), the element that is mostly used by marine organisms to build their shells. As the majority of marine ecosystems is composed of shelled organisms, ocean acidification makes their future uncertain.
Coastal environments are especially affected by this phenomenon becasue the pH, which already naturally varies according to tides, season and climate, is also modified by additional processes such as eutrophication, land run-off or erosion.
Drivers and Impacts of Coastal Ocean Acidification (DISCO)
In this context, the DISCO project (Drivers and Impacts of Coastal Ocean Acidification) suggested to study benthic ecosystems and their environment along the Skagerrak, Kattegat, and Baltic Sea areas (see sampling stations on the map on the left). My PhD project focused on a ubiquitous single-celled organism called foraminifera. Thanks to their small size, their large number in the oceans and their shell that can easily fossilise, they are excellent recorders of past environmental conditions, such as ocean acidification events for example.
The aim of this thesis was to study the response of benthic foraminifera under the impacts of varying environmental parameters (salinity, temperature...) combined with a decreasing pH. I first implemented a field study in a natural environment, and then culture experiments in the laboratory. Changes in the composition of foraminiferal fauna in these area on the last 200 years were also observed.
To understand past and present reactions of coastal ecosystems facing modifications in their environment allow us to better predict their response and evolution in the context of current climate disruptions.
This PhD was based on the collaboration between the Centre for Environmental and Climate Research (CEC) and the Department of Geology (Quaternary Sciences), Lund University.
The project was funded by the Swedish Research Council FORMAS, the Royal Physiographic Society in Lund and Oscar and Lili Lamm's Foundation. It was a part of the Strong Research Environment "Managing Multiple Stressors in the Baltic Sea" (Multistressors) and the Linnaeus environment "Lund University Centre for Studies of Carbon Cycle and Climate Interactions (LUCCI)".