Eco-hydrological and morphological restoration of coastal lagoons and decommissioned salt works through targeted nature-based engineering
Project Title
Start Date
End Date
Project Summary
LIFE MC-SALT (LIFE10 NAT/IT/000256) is a LIFE+ Nature and Biodiversity project, coordinated by the Po Delta Regional Park (Emilia-Romagna, lead partner, comprising the Valli di Comacchio and the Salina di Cervia), in partnership with the Molentargius-Saline Regional Natural Park (Sardinia), the Parc Naturel Régional de Camargue (with the Tour du Valat), the Compagnie des Salins du Midi et des Salines de l'Est, and the NGO Green Balkans (Bulgaria). The project, with a total value of approximately €1.8 million for the Sardinian component (UE co-financing of around €900,000), aimed to develop a shared system for the management and conservation of Mediterranean salt works and coastal lagoons, tailored to the specificities of each partner site but oriented towards creating a lasting network among sites with similar environmental characteristics.
Biogeographical Region
- Mediterranean
Habitats Type
Categories
- Ecological Restoration
- Conservation of habitats and species
Context
The Molentargius-Saline Regional Natural Park preserves a system of ponds and salt works of artificial origin, whose existence is closely linked to salt production activities, which were interrupted in 1985. Following the production halt, the Bellarosa Maggiore basin - the first evaporation pond of the salt works and a crucial node in the water circulation system of the district - had not been subject to any maintenance interventions, leading to a progressive deterioration of banks, sluice gates, and supply channels. This situation of abandonment, common to many decommissioned Mediterranean salt works, motivated the construction of a trans-national project capable of pooling experiences and management solutions among similar sites in Italy, France, and Bulgaria.
Problems and Threats Faced
- Severe degradation of the embankments of the Bellarosa Maggiore pond, resulting in the alteration of the physical and chemical characteristics of water and sediments
- Inadequate seawater supply to the pond, due to the lack of the inlet channel embankment and the disappearance of internal banks, compromising the salinity gradient
- Limited knowledge of the lithological and chemical characteristics of bottom sediments, essential for understanding ecosystem dynamics
- Inadequate water exchange and lack of a continuous monitoring system for hydrological and mesological parameters
- Strong eutrophication and progressive freshening of waters, caused by the ingress of fresh waters contaminated by urban waste, resulting in very poor water quality status
- Concrete risk of compromising saltwater environments and the entire ecosystem, with direct consequences on populations of South European toothcarp (Aphanius fasciatus, Habitats Directive Annex II species) and nesting and wintering waterbirds (particularly the flamingo)
Objectives and Results
- Restore and conserve the priority habitat 1150* "coastal lagoons" in the Bellarosa Maggiore basin
- Restore the original morphological conditions of the first evaporation pond, with a view to a potential eco-compatible restoration of salt-working activities
- Remove the causes of eutrophication and improve water quality, preventing the release of nutrients from bottom sediments
- Increase nesting and roosting sites for colonial waterbirds, favouring in particular the nesting of the flamingo
- Maintain and improve the consistency of the South European toothcarp population and deepen knowledge regarding its biology, abundance, and demographic structure
- Characterise the pond sediments from a lithological and chemical perspective
- Create, at the end of the project, a stable network among sites with active or decommissioned salt works for sharing environmental management and development models
Good Practice Description
The value of LIFE MC-SALT lies in having demonstrated how targeted natural and hydraulic engineering interventions, accompanied by a robust multi-year ex-post monitoring programme, can reverse the degradation of a brackish lagoon ecosystem derived from the cessation of a traditional productive activity (salt production) .
The core intervention, Action C2 "Restoration of hydraulic circulation", concerned the restoration of the marine water inlet channel coming from the Poetto coast, the maintenance of the shallow-water bank, and the creation of new internal embankments for pond compartmentalisation, with the objective of returning the morphological and hydraulic characteristics the Bellarosa Maggiore pond possessed when it was functional for salt production. This approach - restoring the ecological functionality of a site by acting on the hydro-morphological processes underlying its operation, rather than on single isolated elements - constitutes a replicable model for many Mediterranean wetlands dependent on active human management .
Particularly significant was the integration between infrastructural works and species conservation objectives: within the framework of the same action, two nesting islets for waterbirds were created, obtained by reusing the bases of decommissioned high-voltage pylons, an example of converting pre-existing anthropogenic structures for conservation purposes at low impact and low cost .
The ex-post monitoring programme, continued for several years beyond the formal closure of the project, allowed for the documentation of the effects of interventions on water, sediments, fish fauna, bird fauna, and vegetation with solid data, providing an evidence-based foundation for future replications of the model. The trans-national dimension of the partnership -which linked management realities in Italy, France, and Bulgaria united by the presence of salt works - also laid the foundations for an exchange of experiences between sites with similar issues.
Impact and Results
- Restoration of the seawater inlet channel originating from the Poetto coast, with a substantial improvement in the water exchange of the Bellarosa Maggiore pond
- Maintenance of the shallow-water bank and creation of new internal embankments for the hydraulic compartmentalisation of the pond, functional for achieving the correct salinity gradient
- Creation of two nesting islets for bird fauna, obtained from the reuse of removed high-voltage pylon bases
- Installation of a continuous monitoring station for mesological parameters (temperature, pH, dissolved oxygen, conductivity-salinity, chlorophyll "a") and water levels
- Multi-year ex-post monitoring (2014-2016) on water, sediments, fish fauna, bird fauna, and vegetation, which recorded a general improvement in environmental quality: overcoming hyper-eutrophic conditions, better water oxygenation, and progressive differentiation of salinity, favourable to creating diversified mesohabitats
- Significant increase in nesting and migratory bird fauna in the Bellarosa Maggiore basin, particularly colonial species (greater flamingo, avocet, slender-billed gull, gull-billed tern, little tern)
- Increase in populations of South European toothcarp (Aphanius fasciatus) and Boyer's sand smelt (Atherina boyeri), with data collected on the abundance and demographic structure of fish populations
- Production of a floristic checklist for the entire sector, verifying species of Community interest, endemics, rare, or threatened species, and production of GIS mapping of the ex-ante state
