Mapping marine habitats in a shallow beach-reef environment combining direct methods and hyperspectral remote sensing

Abstract

Human occupation of coastal strips generates pressures that can trigger severe degradation processes in marine ecosystems and threaten human livelihoods and the sustainability of the socio-ecological system. In this context, monitoring the conservation status of algal and benthic plant communities, as the basis of coastal ecosystems, is essential for the sustainability of coastal environments. The paper presents a bionomic investigation in a shallow water beach-reef coastal system called Las Canteras, in the Canary Islands (Spain). The work aims to generate a high-resolution mapping, according to standardised rules, of the marine habitats of an area with high ecological value showing signs of severe degradation due to anthropogenic pressure. For this purpose, direct observation techniques were combined with hyperspectral remote sensing techniques. The bathymetric, sedimentological and biological data collected were combined to generate detailed mapping of 13 marine habitats according to the Spanish Inventory of Marine Habitats and Species (IEHEM by its initials in Spanish) classification system. Comparison of these results with previous studies since 1960 shows total regression of the most sensitive species of marine habitats in the Canary Islands, such as Cymodocea nodosa, as well as the decline of sandy substrates which are fundamental for maintenance of the local coastal socio-ecological system.