This expedition is part of Margot THIBAULT PHD project, on plastic pollution accumulated in the subtropical gyre of the Indian Ocean. (UMR ENTROPIE, Université de la Réunion - UMR IMRCP - The Ocean Cleanup)
The accumulation area in this gyre is very little studied.
This is why, in order to better understand concentrations and circulations of plastic debris in the Indian Ocean, we boarded the expedition schooner ANTSIVA for an offshore sailing that will take us to 30 to 35° South. A large loop of nearly 3000 miles (5500 kms) starting from Reunion which will allow us to sample different sizes of plastic debris throughout his area.
Operations focus on 3 axes
1/ Picture Capture A daily watching (via GoPros cameras installed on each side of the vessel) to capture mega (> 1m) and macro (2,5cm - 1m) pastics in image.
2/ Visual Observation : To complete GoPro captures, we daily prospected and noted plastic debris visible from the deck of the boat. In partnership with GLOBICE association, we also noted marine megafauna : seabirds and cetaceans.
Manta Net Lastly, to better know microplastic concentration, we used a Manta Net. This net is named Manta thanks to its two large wings which allow it to navigate and collect plastic on surface. (mesh of 500 µm). At the end of the net, a detachable collecting bag collects microplastics and small living organisms.
We have done several sampling stations in the supposed accumulation area. The contents of the collecting bags are then directly frozen onboard.
This 100% Ocean expedition lasted 21 days and made it possible to carry out 25 Manta sampling stations i.e 76 collected bags.
The shipping route :
Starting from Reunion, a large loop of nearly 3000 miles that will take us along the 33rd parallel South, in microplastic footsteps.