Applying a multi-methodological framework to assess natural capital and ecosystem services in the Strait of Sicily (Southern Italy)

Marine ecosystems are recognized as among the most productive ecosystems in the world. The interactions between biotic and abiotic components of marine ecosystems are able to generate ecosystem functions providing a wide range of Ecosystem Services (ES) vital for human well-being. Nonetheless, marine ecosystems are among the most heavily exploited ecosystems worldwide. Within the context of the Mediterranean Sea, the largest and productive semi-enclosed basin in the world, human activities are undermining its ecological integrity. The Strait of Sicily (SoS) is identified as a Mediterranean biodiversity hotspot able to provide multiple ES, supporting human life at different scales. Nevertheless, the SoS is one of the most threatened areas in the Mediterranean basin. Stressors and anthropogenic pressures are degrading the SoS natural capital and its ability to provide ES, negatively affecting human well-being. In this context, the study and conservation of the SoS marine ecosystem represents an urgent need. Although several studies on the SoS have been conducted over time, there is a gap of studies adopting a multi-methodological approach to comprehensively assess natural capital stocks and ecosystem services flows. The present study aims to implement a multi-methodological assessment framework combining environmental accounting methods and conventional ecological indicators. In particular, the eco-exergy method is proposed to account for the complexity and organizational level of the SoS marine ecosystem, coupled with a biomass-based Shannon diversity index. In addition, an ecosystem accounting framework is applied to assess a set of ES provided by the SoS, in both biophysical and monetary terms. The results of this study will be useful to policy makers in charge of developing strategies to achieve impelling conservation actions and sustainability goals