ABSTRACT
Worldwide, increase of human pressures and consequent degradation of the ecological quality of aquatic systems have been contributing to the awareness that the integrity of marine ecosystems is under threat (e.g., Crain et al. 2009) and hence, in decline from earlier natural or pristine conditions. In this context, the idea of a ‘natural’ or ‘pristine’ ecological condition that can be linked to a historic past without signifi cant human pressures, leads to the idea of ecological reference conditions, against which the current degraded ecological conditions can be seen in perspective and compared.
