Can the Beach–Dune Ecosystem Be Preserved Without Protecting the Beach? Ecological Assessment with a Focus on Specialized Beetle Fauna as Environmental Quality Indicators

Anthropogenic development has historically concentrated in coastal areas to exploit resources from fishing and commercial navigation. In recent centuries, intensive tourism has added pressure on sandy shorelines, leading to their modification. This development model has led to the disappearance of most coastal sand dunes and their rich biodiversity, which includes specialized plant and animal species adapted to sandy substrates, harsh arid conditions, and variable levels of salinity. The European Community’s conservation policies, particularly the Habitats Directive (Council Directive 92/43/EEC), have facilitated the preservation and restoration of the few remaining dune systems. However, these policies have unfortunately overlooked the protection of the adjacent beaches, which are integral to the coastal ecosystem. The loss of biodiversity typical of the beach–dune ecosystems is examined in relation to the anthropogenic disturbance factors, with particular attention to mechanical beach cleaning. Indeed, the metabolizable energy generated by this decomposer biomass is crucial for supporting a diverse trophic network of predators, ranging from insects to birds. The rapid disappearance of the specialized beetle fauna is examined, and some essential criteria for defining standard biotic indices suitable for monitoring these ecosystems are suggested. This approach aims to support more effective conservation programs for these fragile environments. We recommend revising the regulatory framework for safeguarding beach–dune ecosystems, while also proposing some key management principles to be incorporated into the protection guidelines.