Scientific program
2020 expedition
A study of microplastic transport in the Mediterranean. A closer look at the influence of big rivers and cities.
A sampling campaign will be carried out along the route of the 2020 expedition on the coasts of France, Spain and the Balearic Islands. Samples will be collected every morning, and a first analysis will take place on the ship to obtain real-time data on the concentration of micro-plastics.
A sampling campaign will be carried out along the route of the 2020 expedition on the coasts of France, Spain and the Balearic Islands. Samples will be collected every morning, and a first analysis will take place on the ship to obtain real-time data on the concentration of micro-plastics.
Phase 1: Sampling
On the surface
Surface sampling is carried out using a Manta net (mesh size 125 μm). The net is pulled behind the boat for 10 minutes at a speed of 2 knots. A current meter attached to the net let us know the quantity of water filtered by the net. The micro-plastics recovered measure between 125 μm and 5 mm.
In the water column
The protocol for sampling in the water column has been validated by the 2017, 2018 and 2019 expeditions. It uses a closing net which can be dove up to 150 m deep. It is then trawled back to the surface. A mechanism allows us to close the net at any depth. Expedition 2020 uses this protocol to sample micro-plastic between 30 m and 80 m depth. The micro-plastics recovered measure between 100 μm and 5 mm.
Phase 2: Analysis on board the sailboat
1
After rinsing the nets and filtering the contents through a 125 μm sieve, the samples are stocked in glass bottles, until we return to shore.
3
Samples are scanned and analyzed using ImageJ software.
2
Plastic micro-particles are sorted under a binocular magnifying glass.
4
Data is extracted from every micro-plastic of a sample. The information obtained is size, circularity, color, enumeration.
Phase 3: Additional analyses
Surface sampling is carried out using a Manta net (mesh size 125 μm). The net is pulled behind the boat for 10 minutes at a speed of 2 knots. A current meter attached to the net let us know the quantity of water filtered by the net. The micro-plastics recovered measure between 125 μm and 5 mm.
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