We know that the ocean covers 71% of the planet's surface and represents more than 90% of the habitable volume for the living world. It is the main reservoir of biodiversity: it is home to 240,000 known species and almost double those not yet recorded. It also plays an essential role in sustaining life on Earth, particularly in terms of climate regulation: each year, it absorbs 30% of the CO₂ emitted by humans into the atmosphere and more than 90% of the additional heat due to greenhouse gas emissions. For this, it needs healthy ecosystems but also urgent political actions, because it warms, acidifies, loses oxygen and suffocates under pollution... Faced with the extent of the disaster, the UN declared last year "a state of emergency for the oceans", recalling that "more than half of marine species could have disappeared by 2100". To change the situation, citizen, economic, technological or biological initiatives will have to converge. Here are five hopeful ones.
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Developing farmed coral
Peter Harrison managed to grow corals on damaged reefs. Press photo
It is about restoring the endangered barriers, essential cogs of biodiversity, and the feat is signed by Australian biologist Peter Harrison. It breeds coral before grafting the larvae onto Philippine reefs or the Great Barrier Reef, the world's largest living structure. Its objective is twofold: to restore it and to help it adapt to climate change to ensure its survival in the decades to come. His technique, the first to operate on a large scale, is potentially replicable and modular according to ecosystems and regions of the globe.
Preventing deep sea mining
Or, in French, seabed mining, which consists of sending machines to plough the seabed and the abyss to extract rare metals, such as manganese, cobalt or nickel, useful for the manufacture of batteries. In passing, these mining machines ravage precious biodiversity, still poorly known. The oceans, and particularly the seabed, capture about a third of our global carbon emissions. Stirring the ocean floor could therefore release millions of tons of greenhouse gases. Real climate bombs dropped into the atmosphere, which would accelerate an already dramatic disruption. While some thirty exploration permits have already been issued by the International Seabed Authority (ISA) attached to the United Nations, extraction remains prohibited. But until when? Its authorization on a global scale could be decreed as early as next July. It is to prevent it that NGOs, activists and scientists have been warning for years. Young activists have taken up the issue with the Look Down campaign, and have already helped convince twelve heads of state, including Emmanuel Macron, once pro-mining, to oppose it. Objective? Let a majority of heads of state imitate him.
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Wastewater is poorly treated in France. Shutterstock / NoonBuSin
This is the challenge of the moment to respond to the problems of drought and crop irrigation, of course. But also to prevent this grey, or used, water from flowing directly into rivers and, therefore, into the oceans. The wastewater reuse rate is only 0.6% in France, against 8% in Italy, 14% in Spain or 90% in Israel... Hence the urgency of accelerating. The water plan unveiled at the end of March by Emmanuel Macron has set itself the goal of increasing this rate to 10% by 2030, through the financing of 1,000 projects. Among them, that of Veolia: the giant of the environment, which has been working for almost twenty years on the issue, has decided to deploy an innovative device in 100 wastewater treatment plants on the national territory. In total, about 3 million cubic metres of drinking water would be preserved. Start-ups are entering the race, such as the Lyon-based structure Tree Water, which has developed a technology for recycling industrial water (such as laundry water) and treating groundwater from industrial sites through action on 40 micropollutants.
Changing the paint of the boats
Polluting, the paint of the boats is replaced by a clever film. Maxime DUC/Finsulate
To protect them from fouling, an Anglo-Saxon term for the fouling by the layer of living microorganisms that settle on the hulls after months in seawater, the boats are covered with chemical paints specially designed to repel them. In total, more than 100,000 tonnes of antifouling paint are used worldwide each year, including 20,000 tonnes in Europe. Each square meter of hull treated in this way contains an average of 15 grams of biocide — a single gram of this polluting product 10,000 cubic meters of water... Hence the brilliant concept invented by the company Finsulate in the Netherlands: to take inspiration from the sea urchin to coat the shells with an adhesive film composed of millions of microfibers of a few millimeters, reproducing the role of quills. And thus preventing mechanically, and no longer chemically, marine organisms from attaching to the hull. The company, now present in several countries including France, has received numerous awards, but 90% of its business is still based on boaters. His challenge: to seduce fishermen and the merchant navy.
Recycling marine litter
The vase transformed into tiles. Instagram screenshot / @gwilen
A pile of clay, sand, algae and shell residues, salt... This is what makes up the sediments that silt up some French ports and the mouths of rivers that flow into the ocean. In France, it is estimated that 40 to 50 million cubic metres of mud need to be dredged each year. This impermeable material is currently often dumped into the sea, which contributes to choking the seabed. This will be banned from 2025, as will the deposit of silt in landfills near ports. So what to do with it? Tiles, answer the founders of the Brest start-up Gwilen. Thanks to a process inspired by nature, they transform the vase into colorful tiles and small decorative objects with a very artisanal aesthetic.