Experiments
Timeline of planned experiments throughout the REPAIRS project.
As part of the collaboration, experiments have been carried out at the Ifremer Experimental Site in Argenton, Brittany, France. Besides its magnificent view on the rugged coastline, the Experimental Site in Argenton provides an excellent place for experimentation with natural seawater under controlled conditions.
Ifremer Experimental Site in Argenton, Brittany, France.
In 2024, we ran three major experiments for the project in Argenton, including:
(1) the dissolution of minerals (olivine) in natural seawater to study the effect on alkalinity and determine the release of heavy metals and major elements and
(2) the spawning of early life stage oysters (crassostrea gigas) to (3) examine their growth and development in olivine-treated seawater.
- Investigate olivine dissolution based on collisions with other mineral grains and the effects of low ambient pH.
- Determine the potential change in major ion concentration over the course of the olivine dissolution experiment.
Setup of the mineral dissolution experiment at the Ifremer Experimental Site in Argenton, France.
Experimental setup:
We added different mineral mixtures to natural seawater with three replicates, respectively:
- Treatment 1: olivine only
- Treatment 2: sand only
- Treatment 3: olivine:sand mixture (20:80)
- Treatment 4: olivine:sand mixture (20:80) with algae
Half of the treatments was vigorously bubbled while the water was kept stagnant for the other half of the treatments.
In a a second set of the experiment, the ambient pH was lowered by 0.5 units through the addition of CO2 gas.
Schematic setup of the cones used during the dissolution experiment. Cone functionality (left) and arrangement of eight different treatments (right). ©Lucille Hoogerdijk
Guided research project by Lucille Hoogerdijk
Master student Lucille Hoogerdijk joined the REPAIRS project for her guided research project as part of the Master’s study programme Marine Sciences at Utrecht University. She spent a total of three months in Brittany, helping to set up the experiment, sampling and performing lots and lots of alkalinity measurements. As ‘Cone Master’, she learnt about the development and execution of scientific experiments and how to troubleshoot along the way. Beside the practical knowledge, she also gained insides into the subject of ocean alkalinity enhancement.
“What I like about being part of this project besides learning how to run experiments and perform measurements is that I can produce results to get a first hand insight of what is happening during the experiment.” – Lucille Hoogerdijk
Master student Lucille mastering the cones and the titrator and photographing sunsets over the sea in Brittany.
