Are the EU biosecurity legislative frameworks sufficiently effective to prevent biological invasions in the Natura 2000 network? – A case study in Mediterranean Europe

•Efficacy of EU biosecurity frameworks for protecting Natura 2000 network is unknown.•EU legislative frameworks on invasive alien species (IAS) are reviewed and compared.•Connections of IAS regulations and EU Nature Directives are explored.•Analysis on IAS regulations efficacy is conducted from EU to state and local levels.•Regulatory aspects that need to be optimized are discussed.