When the ocean advances… – It’s in your nature

The Moëze-Oléron Nature Reserve, on the Atlantic coast, is one of the main sites for migrating birds in France. But since the storm Xynthia, in 2010, we understood that the rising waters were inevitable. How will living species adapt? If the sea advances, it will be necessary to retreat.

“Where we are, we had water up to our waist, up to 1.50m! ” We are in the heart of the Moëze-Oléron National Nature Reserve, a few kilometers from Rochefort and the Ile d’Oléron, on the Atlantic coast, and that day, the wind blows a little less strongly on the meadows. salt, reeds and canals than 11 years ago, when Storm Xynthia pushed the ocean far inland. The dike, built at the edge of the water, to protect this artificial marsh which had been taken over the water a few centuries ago to collect salt, the gold of the Middle Ages, had given way. Rebuilt, it cracked again, revealing a breach in the horizon which “Shaped like the battlements of fortified castles”, shows Nathalie Bourret, in charge of the animations of the Moëze-Oléron Reserve, managed by the LPO, the League for the protection of birds. Through the breach, between land and ocean, “We can guess the island of Oléron. It forms a passage, in fact. ”

A passage for water. The rise of the ocean is inexorable, under the effect of global warming which swells the water molecules, and could threaten the incredible biodiversity sheltered by the nature reserve, one of the most important in France for birds of migratory water. Here, there are some 300 species, more than 80,000 individuals, and even 200,000 throughout the basin. “The nature reserve was created in 1985, recalls Nathalie Bourret. And little by little, thanks to this protected area, with the ban on hunting and fishing, where no one can enter, migratory birds have come in more and more. They know they can have food, shelter, and above all peace. “ Relative tranquility, to be heard at 6 am, even before the birds and the rising sun offer a peaceful and flaming spectacle, gunfire. The hunters are on the hunt. Authorized outside the reserve. A practice “Heritage”, according to a resident.

A privileged stopover for migrants

On the north-south migratory route, the great “East-Atlantic” route, between the Arctic and Africa, the Moëze-Oléron nature reserve accommodates over 6,000 hectares of maritime surface and 220 hectares of land surface all types of travelers. Those who are just stopping off, passerines for example, before reaching Africa, from Morocco to Senegal via “The Banc d’Arguin national park in Mauritania, specifies Nathalie Bourret. Between the Arctic Circle and the African continent, there is us, a tiny bit on this migratory path. “ Others will stay there all winter, like the Brent Goose from Siberia, “And for some species, this wintering can last 10 months”.

The Moëze-Oléron reserve is one of ten sites selected by the European Union’s Life Adapto program, which is experimenting with the resilience of natural environments in the face of rising sea levels. Birds are on the front line. shorebirds, which represent a quarter of the species present in the reserve. “These are birds that will live to the rhythm of the marshes. Six o’clock at low tide: they are going to eat in the mudflat. Six hours of high tide: they are looking for areas to rest. So if we offer these birds pond areas with too high water, they will no longer be able to be present. “

The elegant avocet, the emblematic shorebird of the Charente marshes, will be on the front line in the face of rising sea levels.

Climate refugee frogs

This is to support species in climate change. Freshwater plants and animals are directly threatened. This is particularly the case with amphibians, frogs, toads and other newts. “If we choose to let these freshwater ponds salinize, when these species are already threatened at the national level due to the disappearance of wetlands and their pollution, they will no longer be able to survive,” warns Nathalie Bourret. At some point, therefore, it will be necessary to recreate ecological corridors behind them, so that these species can also begin to migrate, quite simply. Like all climate refugees ”

Here the trauma of Xynthia is on everyone’s mind and has sparked awareness. The breach in the dike is only the harbinger of a shattered future. “Of course, things have to move forward, because the sea is moving forward! “, summarizes Nathalie Bourret for the LPO. The dike seems condemned. Options are being considered. One of them would be to buy land inland. This is the role of the Coastal Conservatory, created in the 1970s to avoid the outrageous concreteization of 20,000 kilometers of French coast.

” It can not be helped ”

Move, move back the reserve. A problem that also concerns farmers and oyster farmers, such as Auréliano Moissenot, busy in the early morning harvesting his oysters matured in a salt water basin, a clear one, which he rents in the reserve at the Conservatoire du littoral. “Here we are at 0 at sea level, he notes, wearing rubber waders. We will soon have to invest in land to make oysters! “ The oyster farmer is fatalistic and, like everyone here, has understood that he will have to adapt. ” It can not be helped. The fire, you stop. Water, you don’t stop it. Oh yes… it’s a crazy thing! “