Marine protected areas (MPAs) and their coverage have increased worldwide, including EU waters. Natura 2000 (Nat2000) sites are at the core of the EU biodiversity conservation strategy and have been established to protect habitats and species included in two EU directives.

This study assessed the biomass of whole fish assemblages and of ecologically important species to evaluate the potential ecosystem-wide effectiveness of Nat2000 marine sites located along the coasts of Sardinia (Italy). This assessment was performed in six fully protected MPAs, in 12 Nat2000 sites established or extending at sea, and in 18 adjacent unprotected control sites.

The obtained results showed that the highest fish biomasses were observed in fully protected MPAs. It is stated that the values observed at Nat2000 sites do not differ or only slightly differ from those observed at control sites, meaning that these sites may not presently contribute to effectively protect fish and the related rocky reef ecosystems.

The authors note that these results do not dismiss the role of Nat2000 sites relative to the objectives for which they have been established. However, they show that to achieve ecosystem-wide benefits it is crucial to rethink and broaden the scope of Nat2000 sites and adapt their management to that.

It is concluded that by providing sounder and more comprehensive management plans, and implementing more consistent ecosystem-wide conservation measures, Nat2000 marine sites could become an extraordinary tool at EU scale, capable of delivering wider ecological benefits.

Guidetti et al. (2019) Assessing the potential of marine Natura 2000 sites to produce ecosystem-wide effects in rocky reefs: A case study from Sardinia Island (Italy). Aquatic Conservation: Marine and Freshwater Ecosystems 29:537-545.