Geospatial analysis for fish farming across Tyrrhenian coast (Tuscany, central Italy)

Aquaculture represents an important source of food and it plays an important role in terms of contribution to economic development. Offshore farming offers considerable advantages, especially in terms of production costs (lower than those of onshore facilities) and of farmed product quality. Suitable areas for aquaculture activities are still available in Italy but are increasingly limited and the demand for new farms is high. The lack of coastal areas allocated to aquaculture and the complex regulatory and legal framework constitutes the major constraints for further development of the sector. Zoning is the process that can allow to sustainably identify and allocate suitable areas for aquaculture. Several aspects, such as effective legal framework and procedures, collection of bio-geochemical, physical and socio-economical information, are crucial for a correct aquaculture zoning process in order to identify the Allocated Zones for Aquaculture (AZAs). In the present work, a spatial multi-criteria decision analysis (SMCDA) was applied for the individuation of potentially suitable marine areas for fish farming across the southern Tyrrhenian coast of Tuscany (Italy). The spatial model was developed by collecting and processing Earth Observation (EO) data, oceanography in situ measurements, and infrastructural and environmental constraints. Excluding areas of constrains, obtained results highlight that 96% of the total investigated area is characterized by medium (62%) and high (34%) suitability. In particular, the highest suitability areas occur in the Talamone gulf and offhore the Argentario promontory at water depth between 15 and 30 m and 30 50m, respectively. Other high suitability areas occur northern of Piombino town between 30 and 100 m depth. Environmental data at higher spatial resolution are needed to improve aquaculture zoning and further process of site selection in order to ensure the sustainability of fish farming in the study area.