Marine Habitats in an Emerging Eco-Touristical Small Oceanic Island: A Methodological Strategy to Marine Spatial Planning

Abstract

Accurate mapping of marine benthic communities, through acoustic technologies such as the Side-Scan Sonar (SSS), is highly demanded as critical baseline biological database to promote smart management of unknown tropical coastal environments, where rapid anthropogenic development is often occurring. In this study, SSS methodological protocol was developed to describe subtidal marine seabed’s (3 to 30 m depth) in four areas around Principe Island (Republic of São Tomé and Príncipe, Gulf of Guinee, Africa). A list of 6 habitats, within three main typologies (sandy bottoms, rocky reefs and biogenic seabed’s), was generated using a post-processing software and then corroborated with SCUBA diving and video transects. Sandy bottoms with ripple marks and small biogenic areas (rhodolith seabeds and Scleractinian corals) predominated in the north, east and south of the island. The southwestern sites concentrated most of the biogenic seabed’s, with greater variability and richness of the habitat and should be considered for future conservation purposes, according to Marine Spatial Planning policies. In the eastern zone of Principe Island, with an important local fishermen community, it is foreseen the implementation of sustainable marine resources management policies to support long-term exploitation. Geo-referenced habitat maps elaborated through SSS are an efficient tool for marine management and conservation.