Investigating the effects of the implementation of artificial frames on the reefs’ structural complexity in the St. Anne Marine National Park, Seychelles.

Coral reefs are essential for marine biodiversity and provide ecosystem services that are threatened by natural and anthropogenic pressures. The Saint Anne Marine National Park (SAMNP), located within the Inner Islands of Seychelles, allows conservation actions aiming to restore the damaged reefs. This study was set in the same line of work and aims to investigate the effect of artificial reef structures on the complexity of restored coral reefs. Cement-coated steel frames were used for the transplantation of corals in the SAMNP. Analysis of the live coral cover and the structural complexity of the restoration plot before and after the deployment of the frames showed encouraging results. The frames permitted the growth of transplanted corals and created a complex habitat by increasing elevation, roughness and rugosity, on which a number of ecosystem services depend. The use of photogrammetry to create digital reconstructions of the plot for analysis has proven itself as a powerful tool to monitor coral reefs when restoration actions have been undertaken. This limits human error and confirms in-field observations.