The risk is « critical, » according to the journal Nature. These ecosystems, however, are essential to biodiversity and provide us with numerous services.
From the Camargue to the Nile Delta, coastal marshes are gradually being eaten away by the sea, a « critical risk, » warns a study published in Nature. Taking a middle-ground scenario, neither too pessimistic nor too optimistic, the Earth is projected to warm by 2.5 degrees by the end of the century, according to the IPCC’s « intermediate » projection. In this case, coastal marshes would recede by at least 70% by 2100 in many Mediterranean regions.
French, English, German, and Spanish researchers even predict their near-total disappearance in Algeria, Egypt, and France if no action is taken to save these wetlands. This confirms a study from last year by the National Museum of Natural History, which had already raised concerns about the imminent submersion of the Camargue. Why such alarming predictions? Because in the Mediterranean, and especially in France, coastal marshes are very vulnerable, victims of what is known as « coastal compression. » In fact, they are trapped on one side by the advancing sea, and on the other by the inability to expand due to natural terrain and also because of houses, roads, and dikes.
Essential Preservation
It is therefore necessary to « de-artificialize » in order to make room for these marshes. Creating « retreat zones »—space to allow marshes to retreat—is one of the solutions. Another option is to restore the natural flow of rivers, as dams, such as on the Rhône River, trap sediments (clays and sand). As a result, these sediments do not reach the coasts, which accelerates the erosion of these wetland areas.
Nevertheless, these marshes must be protected, firstly because they shelter a very rich biodiversity, including over a hundred species of water birds, such as the iconic pink flamingos. And secondly, because these wetlands provide many services. They act as buffers by absorbing heavy rainfall or storm shockwaves. They purify water by filtering certain pollutants (pesticides and heavy metals). They are also carbon sinks, meaning they capture part of the CO2 we release into the atmosphere.
Source: france tv info
