Effectiveness of the “Ecological Beach” Model: Beneficial Management of Posidonia Beach Casts and Banquette

Alice Rotini,Stefania Chiesa,Tiziana Mezzetti,Loredana Manfra,Alfonso Scarpato,Sergio Cappucci,Saverio Devoti,Carla Creo,Patrizia Borrello,Luca Parlagreco,Raffaella Piermarini,Luciana Migliore,Marco Pisapia,Cecilia Silvestri

doi:10.3390/w12113238

Abstract

The accumulation of Posidonia oceanica dead leaves on the beaches of the Mediterranean shores is a natural phenomenon. They are either temporary or permanent structures (banquettes) and represent a valuable resource, with important ecosystem functions including coastal protection against erosion. Nevertheless, the perception of these plant accumulations by the different stakeholders (beach managers, local administrations and tourists) is often negative; they consider these deposits a malevolent waste to be removed, rather than a natural and valuable component of the coastline. We propose an integrated/beneficial management model for posidonia deposits, called ECOLOGICAL BEACH, firstly proposed in France, and recently implemented and applied in Italy. The model promotes the preservation of posidonia beach casts on site, with a balanced coexistence of natural and anthropic elements. The model fosters the several important ecosystem services of the beach casts and contributes to coastal preservation. To successfully spread the model, several activities must be implemented: a regulatory framework, the collection of data about the occurrence of beach casts, management protocols and educational programs. The most important activity is the educational one, based on the dissemination of the ecological and economic value of the beach casts, aimed at switching the perception of this phenomenon towards positive appraisal.

Highlights

Posidonia oceanica (Linnaeus) Delile is a seagrass (Magnoliophyta) endemic to the MediterraneanSea
A rich macrofauna inhabits the banquette, especially the “aged” ones, established for some years, and the residual nutrient content of P. oceanica dead matter represents an important input of nitrogen and carbon, contributing to the formation of the dune and its colonization by psammophilous vegetation
In the Mediterranean countries, a critical issue is the lack of specific legislation at the basin scale and the implementation of already-existing local regulations

Summary

Introduction

Posidonia oceanica (Linnaeus) Delile is a seagrass (Magnoliophyta) endemic to the Mediterranean. Turkey), the northern Adriatic Sea, most of the shores of Languedoc (France) and the vicinity of the Gibraltar Straits. It dwells from the sea surface down to a 20–40 m depth (more rarely, down to 45 m), depending upon water transparency and upon water movement [1]. The presence of Posidonia meadows is marked by the presence of banks mainly made of dead leaves called banquette, which may include broken rhizomes with leaf bundles. A rich macrofauna (gastropods, crustaceans, annelids and insects) inhabits the banquette, especially the “aged” ones, established for some years, and the residual nutrient content of P. oceanica dead matter represents an important input of nitrogen and carbon, contributing to the formation of the dune and its colonization by psammophilous vegetation

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