The Port of Marseille Fos and Avignon University are removing concrete foundations to breathe new life into an exceptional ecosystem: the Crau "coussouls".

News Research news 5 December 2023

Photo: Hervé Ramone, IMBE-Avignon University.

From 4 to 8 December 2023, the Grand Port Maritime de Marseille will for the first time be removing a concrete slab that used to support a workshop built in 1971 to service the Ventillon industrial estate in Fos-sur-Mer.

Unsealing is a renaturation operation that involves removing a layer of concrete or bitumen to allow the underlying soil to recover its functions (infiltration and water storage, fixing of atmospheric carbon) and its biodiversity (flora, fauna). Today, these operations are particularly important in the fight against global warming and the extinction of biodiversity. While this type of operation is currently widely used in towns and cities to recreate islands of fresh air, this will be a first for the Crau plain. The aim is to restore its unique ecosystem, the 'coussouls de Crau', a large part of whose surface area has been lost as a result of intensive industrial, military and agricultural development.

In order to measure the precise impact of this original operation, a collaboration has been set up with scientists from the CNRS, INRAE and Avignon University to monitor different restoration techniques on the soil, its fauna and its vegetation in the years following the unsealing.

The worksite will begin with the fracturing of the slab (450 m²) using a jackhammer mounted on a hydraulic excavator, followed by the removal and placement in a recycling centre of the inert spoil collected. Several restoration techniques will then be tested in place of the old slab (decompacting, restoring the layer of pebbles that originally existed on the surface). The soil, its seeds and insects will then be sampled by scientists on the same day and in the years that follow.

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The Mediterranean Institute of Biodiversity and Marine and Continental Ecology (IMBE) is developing an integrative approach to the study of biodiversity and socio-ecological systems.
The IMBE provides fundamental and applied knowledge on the functions and historical and evolutionary dynamics of biodiversity in all types of Mediterranean ecosystems, from the construction of paleo-ecosystems to their future in the context of global change. These contributions also include links with civil society on the one hand and human health issues on the other. Through its involvement in research, training and scientific development, the IMBE plays an active role in environmental transition and sustainable development, helping to define local, national and international environmental policies. The majority of IMBE's staff are biologists specialising in the various fields of ecology, but it also includes chemists, lawyers and specialists in the medical and pharmaceutical sciences. The IMBE is interested in marine, terrestrial and aquatic biological systems, from mountain environments to coastal ecosystems, at different scales of living organisation. The transition to a more resilient and less vulnerable state for these ecosystems, their conservation and restoration, and the effects of their degradation on human health are at the heart of our interdisciplinary research and our various training activities.

The IMBE is a member of the Tersys Federative Research Structure. In 2024 and 2025, the "UNDERGROUND - Under the concrete, the steppe" project, led by Thierry DUTOIT (CNRS), Annette BERARD (INRAE), and Claude DOUSSAN (INRAE), will receive funding from the SFR Tersys via its annual call for projects.

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A major player in international trade, the Port of Marseille Fos welcomes nearly 10,000 ships every year, handles 80 million tonnes of goods and develops 10,400 hectares of land in an environmentally excellent way.
With an area the size of Paris, the Port of Marseille Fos has the space and infrastructure to accommodate maritime, logistics and industrial activities. It can handle a wide range of activities, from import to export of all types of goods (bulk liquids, containers, minerals, food products, etc.). The port has large-scale logistics platforms that cater for international players supplying the French and European markets. Industrial activities such as refining, steelmaking, the chemical industry and ship repair, including the world's third largest "Form 10", illustrate the diversity of the port's ecosystem. The Port of Marseille Fos also meets the international standards required for passenger, cruise and ferry activities. The Port of Marseille Fos places environmental excellence at the heart of its strategy. It is banking on sustainable economic growth through responsible and innovative industrial development that promotes the circular economy. It is taking action to considerably reduce the impact of maritime activities on air quality by connecting ships to the quayside electricity supply and LNG fuelling.

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Contacts :

Grand Port Maritime de Marseille: Nicolas Sire
CNRS / INRAE / Avignon University: Thierry Dutoit :