Presented during the 2018 MedPAN experience sharing-workshop.
In the context of a large seaside resort (Cap d’Agde), with an important fishing activity (trawlers and coastal and offshore small scale fisheries) and with the presence of many recreational activities at sea, the city of Agde has immersed for more than 30 years (since 1985) several types of artificial reefs in the MPA of the Agathoise Coast, a Natura 2000 marine site.
The main objective was initially to find solutions to the depletion of the local fishery resource and to support coastal fisheries.
To this primary socio-economic objective have gradually been added objectives to resolve conflicts of use / maritime actors and ecological objectives to preserve marine biodiversity, create new habitats and corridors with natural rock.
Between 1985 and 2009 a total of 429 modules or 4,500 m3 were submerged for a total of 2.4 million euros.
Rigorous scientific monitoring has been undertaken on physical and biological parameters (diving) as well as by experimental fisheries with the support of the fishers, based on natural control areas and areas with different types of artificial reefs (nozzles, carpet nozzles, double nozzles, baskets).
The objectives of the first immersions in 1985 and 1995 by the nozzle system were achieved for protection against trawling but a strong burial was observed.
For the immersion in 2009, the most important in terms of volume and new basket-type reefs and which differentiated between protection and production reefs, the objective of supporting professional fishing was achieved. The yield proved to be better with the basket system.
The objective of resolving conflicts of use is partially achieved with a better relationship between professional fishers. However, the relationship need be strengthened with recreational activities (especially recreational fishing) that would require an appropriate management plan.
The objective of preserving and restoring biodiversity has been partially achieved, in particular with the creation of new artificial habitats, with very significant concretion, with a significant production effect on the commercial lobster species and with the creation of ecological corridors in the MPA.
However, better management and protection of artificial reefs would contribute to supporting professional coastal fisheries on the Agathoise coast.
The results show that natural habitats remain the main production areas and that it is necessary to consider natural habitats for the effectiveness of immersion. Artificial reefs are not an isolated system.
Contact: Renaud Dupuy de la Grandrive, City of Agde , MPA of the Agathoise Coast, France (please contact MedPAN secretariat for details)