Interdisciplinary evaluation of the impacts of offshore renewable energies to support an ecosustainable approach to the marine environment

The rapid expansion of offshore renewable energy installations, particularly floating offshore wind farms, raises critical questions about their environmental impact in marine ecosystems. One key concern is the acoustic impact of operational wind turbines on marine mammals and turtles, species that rely heavily on sound for communication, navigation, and foraging. Despite the growing number of offshore wind projects, research on the underwater noise produced by these structures and its potential consequences remains limited. This dissertation adopts an interdisciplinary approach to assess the possible impacts, combining acoustic modeling, passive acoustic monitoring (PAM), and ecological investigations. The first two studies focus on characterizing the underwater noise emitted by floating wind farms in the Strait of Sicily, modeling sound propagation under different environmental conditions. These studies estimate the potential exposure of marine species to turbine-generated noise and assess whether sound levels exceed established behavioral and physiological thresholds. The findings highlight the importance of considering species-specific sensitivities and ecological contexts in environmental impact assessments. The following studies shift focus to marine mammal monitoring, utilizing PAM to investigate bottlenose dolphin (Tursiops truncatus) presence and behavior. By analyzing echolocation clicks recorded over an eight-month period, these studies provide insights into temporal variations in dolphin activity, emphasizing diel and seasonal patterns. Additionally, novel approaches to density estimation using cue-counting techniques are explored, improving methodologies for long-term population monitoring. The research underscores the importance of refining acoustic-based density models to account for variations in click rates and environmental influences. Together, these studies contribute to a more comprehensive understanding of the interactions between floating offshore wind farms and marine species, bridging gaps in knowledge necessary for effective conservation and management. By integrating acoustic impact assessments with ecological monitoring, this research supports a sustainable approach to offshore renewable energy development that aligns with marine biodiversity protection goals. The findings provide valuable guidance for policymakers and stakeholders, advocating strategic turbine placement, mitigation measures, and continued monitoring to minimize anthropogenic disturbances in the marine environment.