Maintaining or restoring connectivity among protected areas is widely recognised as a strategy to improve ecosystems resilience and populations viability. The recent emphasis of international policies on increasing protected surface worldwide offers a unique opportunity to embed connectivity into the spatial planning of new sites, thereby maximising the effectiveness of conservation investments.
In the context of the marine conservation project “Reconnect”, using the dusky grouper Epinephelus marginatus as a model species, we assessed connectivity patterns in the central Mediterranean Sea, with particular focus on Sicilian coasts. We used Lagrangian simulations with an individual-based bio-physical model to simulate larval dispersal throughout the region with the aim of (1) identifying priority areas for protection, i.e. connectivity hotspots; (2) evaluating to what extent the existing network of marine protected areas (MPAs) is well connected; and (3) assessing how the designation of candidate MPAs (“aree marine di reperimento” as defined by the Italian legislation) would contribute to improve network connectivity. The overall performance of the protection network as well as the role of each node within it were quantified by global (i.e. efficiency) and local (i.e. degree and strength) network metrics. Finally, we integrated the connectivity analysis with spatial data on fish abundance and suitable habitats for dusky grouper into a spatially explicit metapopulation model, enabling scenario-based evaluation of different fishery restriction policies and their effects on population persistence.
We believe that such an approach can offer useful insights into spatial conservation planning and site prioritisation, at a time when national authorities are required to make crucial management decisions that will impact long-term ecosystem health.