Erosion Control through Mangrove Biomimicry: Creating Ecologically Functional Artificial Reefs to Enhance Biodiversity

Shallow coastal ecosystems offer rich habitats for marine life, providing feeding, breeding, and sheltering grounds for numerous species, including crabs, mollusks, and juvenile fish. In response to beach erosion at Cape of Agde, a nature-inspired solution called PEGASE has been deployed as an alternative to traditional breakwaters. PEGASE structures, designed to biomimic mangrove forests, are placed on a sandy seabed flanked by two large quays with small breakwaters. Beyond its primary function of erosion control, PEGASE has demonstrated a remarkably positive impact on biodiversity.

After three years, the structures are fully colonized by mollusks, crustaceans, and macroalgae. Species such as oysters, mussels, barnacles, and dictyota algae attract various fish, predominantly sea breams and cryptic species like gobies and blennies, as well as crabs. PEGASE seems to offer suitable habitats for both juvenile and adult fish, including gilt-head seabreams.

Additional nighttime observations reveal that up to one octopus per structure, along with diurnal fish seeking shelter, frequent PEGASE. This rapid colonization and high abundance of mobile species have created a vibrant environment with increased macrofauna diversity compared to the surrounding sandy seabed.

The project demonstrates that PEGASE can serve as a viable alternative to breakwaters, fostering habitats for coastal marine macrofauna and flora. A joint abstract outlines PEGASE's design approach and its effectiveness in coastal protection. This study suggests that biomimicry, often requiring less material and offering aesthetic benefits, presents a compelling alternative to conventional methods for enhancing biodiversity. For coastal protection, such solutions can simultaneously support erosion control and biodiversity enhancement.

Keywords: Biomimicry, erosion, PEGASE, artificial reef, biodiversity, field monitoring, ecodesign, mangrove