Assessment of the loss of natural capital in priority marine habitats as a result of environmental changes

Marine and coastal ecosystems are among the most productive environments in the world and contribute to the economic value generated by the biosphere offering a wide variety of services. Posidonia oceanica and some organisms of coralligenous biocenosis are key species listed among the priority habitats in the European Habitat Directive 92/43/ECC and they are considered as important bioindicators to define quality of coastal marine ecosystem in order to reach the good environmental status (Marine Strategy Framework Directive, 2008/56/EC). In this study P.oceanica meadows and coralligenous are used as indicator for their sensitivity to environmental changes in Portofino Marine Protected Area (Ligurian coast). Aims of this study are 1) to quantify and characterize Natural Capital (NC) value of both P.oceanica and coralligenous habitats (considering Paramuricea clavata and Eunicella Cavolini) and 2) to evaluate changes in NC value due to increasing effects of anthropogenic disturbances and exceptional meteorological phenomena (e.g. heavy sea-storms that hit the Ligurian coast on October 2018). The NC has been assessed through emergy analysis (Odum, 1988; 1996), a biophysical approach able to study the ability of the system to stock natural capital. This methodology quantifies resources directly or indirectly used up to generate or maintain a system and its functioning. Environmental accounting can be used as a tool to assess both the biophysical and economic value of NC and ecosystem services. The ecological value of natural resources is linked to the role that they play in the functioning of the biosphere at different scales and in support of different species, as such must be maintained and guaranteed.