Artificial Reefs in the Cote Bleue Marine Park: Assessment After 25 Years of Experiments and Scientific Monitoring

Abstract

The Côte Bleue Marine Park (PMCB) was one of the precursors in France concerning the deployment of artificial reefs (AR). For 25 years, the Park has led several varied operations by using different kinds of modules: between 1983 and 2004, seven types of architecture for production reefs and five architectures for protection reefs were studied, for a total AR volume of 4,884 m³, and represent an investment of €480,000.

The purpose of the AR deployment policy of the Park was to experiment and test various types of modules, during small-scale operations, but including several phases of immersion and scientific field surveys. These experiments allowed development of the conception of modules and adapting them to the local context, targeting several objectives. Moreover, they are used to support small-scale artisanal coastal fishing by two complementary aspects:

• (1) The promotion of biological production in impoverished seabeds and sustaining professional artisanal fishing, with 2,684 m³ of modules arranged in chaotic heaps in five areas, and increasing the biodiversity and the available fishing resources.

• (2) The protection of priority natural habitats (Posidonia meadows and coralligenous rocks) and to manage and share both resources and fishing grounds among fishermen, with 326 heavy obstacles designed to protect against illegal trawling within the 5.5 km offshore limit. These 2,200 m³ of antitrawling reefs are spread along 17.5 km, creating barriers perpendicular to the coast. Since they have been installed, a significant decrease in illegal trawling has been observed.

In the Côte Bleue Marine Park, the two categories of AR (production and protection reefs) are interrelated in the two protected marine areas (integral reserves of 295 ha where all kinds of fishing activities, scuba diving, and mooring are prohibited).

These management tools have worked in an additional way and contributed to the preservation of the traditional small-scale fisheries in the Côte Bleue territory (for about 60 fishermen) at a time when these fishing activities are decreasing in the nearby zones.