“I am very happy to be leaving. “ A few days before the start for the Vendée Globe, around the world sailing alone and without assistance, Fabrice Amedeo feels carried by a mission that goes beyond the sole sporting feat: he will put his boat, the Imoca Newrest-Art & Windows, in the service of scientific research. For the first time, it will travel the world’s oceans with a sensor of microplastics, these particles almost invisible to the naked eye, which are causing more and more concern for the marine balance. The objective of this mission is twofold: to hunt them down in the waters of the Southern Hemisphere, very little explored until now, and to collect several sizes.
This sensor, designed by the company SubCtech, has three filters capable of continuously collecting microplastics smaller than 300, 100 and 50 microns in seawater (one micron corresponding to one thousandth of a millimeter). “When you are offshore, the pollution is not very visible, underlines this former journalist, who gradually became a full-time sailor (1). For my first Vendée Globe, I had a somewhat romantic approach to the profession of a navigator: leaving the earth and human pollution to travel immaculate spaces far from any civilization. “
But the big fires in Australia or South America made him aware of the dangers which weigh on the whole planet. For the Transat Jacques-Vabre, between Normandy and Brazil, he first equipped his boat with sensors measuring the consequences of global warming on the oceans (temperature, salinity, CO2), in conjunction with Ifremer (French research institute for the exploration of the seas) and two German laboratories. This year, he chose to focus on microplastics. “As a former journalist, I like going to seek information where scientific boats cannot go”, says the navigator, who now works with three partners: Ifremer, the University of Bordeaux and the Research Institute for Development (IRD).
Three filters to change every 24 hours
For Christophe Maes, researcher in the physical and spatial oceanography laboratory (Lops) of IRD in Brest, this partnership will allow him to supplement his digital cartography models with ground truth. “We still have a lot of unexplored areas like the South Atlantic, the South Pacific or the Indian Ocean, he explains. It is not clear whether these areas are contaminated with microplastics. “ Especially since most of the sampling campaigns are carried out in coastal areas, which represent only 10% of the surface of the oceans.
→ MAINTENANCE. “Microplastics can be a problem for the consumption of shellfish”
Upstream of the Vendée Globe, Fabrice Amedeo was able to test this equipment last July, during the Vendée-Arctic race, from Sables-d’Olonne to Iceland. Unlike other sensors, which operate autonomously, this microplastics collector requires you to change the three filters every 24 hours, and to note the time and the position of the boat at sea. “It’s a manipulation that takes about fifteen minutes”, describes the navigator, who took advantage of this trial run to train in the most rigorous protocol possible. “Care must be taken when opening and closing the filter boxes, do not use a cloth to wipe them and provide a transport bag adapted to the movements of the boat”, explains Christophe Maes.
A wind turbine on board
Can this extra time devoted to science affect its performance? “It’s more the weight that can penalize me, answers the skipper. The sensor weighs 30 kg and the filters 25, which is not nothing when we do everything to lighten up. “ To compensate for the energy expenditure of the sensor, the navigator installed a wind turbine on board. “This project gives meaning to my race, he adds. During the Vendée Globe, we go through moments of absolute discouragement. But knowing that a whole team of researchers is counting on me can only encourage me. “
On land, the scientists embarked on the adventure do not hide their enthusiasm. “It’s galvanizing to work with him, confides Catherine Dreanno, researcher at Ifremer, in Brest. He put us on his boat, which is very impressive. It has nothing to do with our scientific fleet! ” This specialist in the chemical analysis of plastic molecules, which makes it possible to determine their origin (polyethylene, polystyrene, polyamide, etc.), promises to “Follow the Vendée Globe as it has never followed it”. Above all, she will be present when the skipper arrives to collect the precious samples.
Measure contamination by other pollutants
“Their analysis will take at least six months, she warns. Because in the filters, we will find a very complex environment, made of phytoplankton and zooplankton which will hide the microplastics. ” This is why two laboratories at the University of Bordeaux (Epoc and CBMN) will also collect samples. “It would be too tedious for a single team”, confirms Jérôme Cachot, professor at the Epoc laboratory, who is delighted to have such a material: “Usually, we track down microplastics using manta nets that only concern water from area. There, we will have continuous filtration of the water three meters below the hull, over all the seas of the globe. We will go further in terms of the fineness of the particles collected. “
His team will try to measure the contamination of microplastics by other pollutants, such as heavy metals, for example, but also additives, pesticides, viruses or bacteria which are not without consequences on marine fauna. “This collaboration is a great human adventure, continues the scientist. With its aura of a navigator, it can also convey a message to the general public that we would not carry so widely. “
Once this work is done, these teams will hand over to cartographer Christophe Maes. “I’m going to be able to place this data on a map and compare it with ocean conditions, to find out, for example, if we can explain a concentration of microplastics by the presence of eddies. ” The navigator takes with him 85 sets of three filters for 85 days of racing. “But I hope to be faster”, he smiles. In 2017, the winner of the Vendée Globe, Armel Le Cléac’h, completed his round the world trip in… 74 days.
Sail for science
Unesco’s Intergovernmental Oceanographic Commission (IOC) and the International Association of Open Monohulls (Imoca) signed a new partnership in January 2020 to support marine scientific research.
More and more skippers are thus equipped with sensors to collect data on the oceans (weather information, water temperature, salinity, etc.). For this Vendée Globe 2020, half of the 33 sailors will leave with scientific instruments on board.