Rapid tool for assessing potential ecological changes in littoral rocky shores

The coastline is one of the most densely populated and exploited areas globally, positioning it as a "vanguard system" for assessing the impacts of global change. This status has led to the development of numerous indicators that provide insights into its ecological condition and the human pressures it faces. However, few studies directly evaluate the role of human pressure as a driver of ecological change compared to other environmental variables, and even fewer assess the vulnerability of these systems to potential shifts in ecological status. In this study, a rapid assessment approach was employed to evaluate the influence of human pressure—quantified through cumulative human pressure indices—and geomorphological variables as drivers of the ecological status of the littoral fringe along a sector of the western Mediterranean, an area characterized by high variability in both geomorphology and human impact. The findings indicate that cumulative human pressure is the primary determinant of ecological status, especially when the pressure gradient associated with each human activity was categorised in distance ranges and land uses were characterised for their respective watershed. The non-linear relationship between cumulative human pressure and ecological status enabled the identification of tipping points revealing vulnerable coastal areas that, irrespective of their current ecological status, could experience rapid degradation with increased human pressure but also hold potential for recovery if pressures are alleviated. By integrating this comprehensive dataset (ecological status, cumulative human pressures, and vulnerability) into a digital cartographic platform (GIS), a tool with significant potential for coastal management was developed, which is adaptable and applicable to coastal regions worldwide. • Cumulative human pressure (CHPI) is the primary driver of ecological status (ES). • A non-linear relationship exists between cumulative human pressure and ES. • Identified tipping points revealed coastline sectors vulnerable to deterioration. • Integrating ES, CHPI and vulnerability can enhance coastal management. • This approach is applicable to rocky coastlines worldwide.