REPIC

REPIC : AN EXPERIMENTAL PROGRAM FOR THE RESTORATION OF POSIDONIA MEADOWS !

The REPIC programme (« REstaurer la Posidonie Impactée par les anCres », Restore posidonia impacted by anchors) was initiated in 2019 by Andromède Océanologie in partnership with the Rhône Méditerranée Corse Water Agency and NAOS. It allows the replanting of posidonia meadow fragments on workshop sites particularly impacted by anchoring and, thus, to initiate a restoration dynamic (reinforcement of populations) of these meadows. REPIC uses a sampling technique that has no impact on the seagrass beds: the planting of floating bundles torn off by anchors during the summer season (or broken off naturally). These fragments have the following advantages: high availability, moderate collection effort, no impact on existing populations. These fragments are transplanted into areas of dead matte using biodegradable staples specially designed for the project.

Transplanting is done by hand on predefined areas after the fragments have been surrounded by a biodegradable staple.

Since the program was set up three years ago, two restoration sites (Golfe Juan and Rade de Beaulieu sur Mer, between 1.5 and 30 meters deep) have been defined. Due to the former degradations suffered by the Posidonia meadow and the new protection measures put in place (especially anchoring regulations), these geographical sites of the REPIC program are now suitable areas to test new methods of restoration of these meadows.

Each year, scientific monitoring is carried out on the restored areas: individual monitoring of fragments in permanent quadrats, visual monitoring of all the restored areas by photogrammetry, monitoring of the carbohydrate reserves of the fragments and monitoring of the evolution of the temperature of the area. The geographical site effect is also tested by analyzing different environmental conditions at each site (salinity, currentology, surface temperature and surface concentration of chlorophyll a).

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The areas are gridded and made up of circles of different densities. @Andromède Océanologie

In 2022, with the support of new partners, the Fondation de la Mer and the Artelia Foundation, 28 days at sea on two missions were carried out for the REPIC program between July and September 2022. These missions allowed the planting of a total of 28,000 beams on new areas to be restored and then to carry out the scientific monitoring.

Between 2019 and 2022, professional divers and marine biologists collected and transplanted during 515 h, a continuous area of about 1000 m² from 18,671 fragments bearing 94,205 bundles.

The success rate of the REPIC operation is now estimated at 80%. The scientific monitoring data will be processed and made available on the online mapping platform for monitoring Mediterranean coastal waters and ecosystems MEDTRIX (http://plateforme.medtrix) in the RESTAU-MED project which presents ecological restoration projects. For more information on this network you can visit the RESTAU-MED project page.