PROJECT DESCRIPTION
BACKGROUND
The Venice lagoon holds several Annex I-listed habitats of the Habitats Directive. In particular, the habitat type “coastal lagoons”, in some part of the lagoon, is of an unfavourable conservation status according to the latest Article 17 report on the conservation status of the EU. In fact, over the past few decades, coastal lagoons have receded significantly because of human activities (e.g., clam digging with mechanical excavation, eutrophication, pollution, and erosion caused by marine traffic). The coastal lagoon habitat plays a crucial role in supplying ecosystem services, for example, by supporting numerous biological communities and increasing the stability of the tidal flats.
OBJECTIVES
The LIFE LAGOON REFRESH project foresaw the restoration, in an area of the Northern Lagoon of
Venice, SCI IT3250031, of the ecotonal environment and improvement of costal lagoons habitat. In particular, it aimed at conserving coastal lagoon to leverage the ecosystem services provided by this habitat to:
- recreate typical estuarine ecological characteristics, so as to counteract the depletion of lagoon bottom and fish communities;
- reduce eutrophication thanks to the phytoremediation function of reed beds, favouring the presence of sensitive species and aquatic plants of high ecological value;
- improve the conservation status of bird species including those listed in Annex I of the Birds Directive, that use the reed beds during the winter period and/or for breeding and foraging;
- increase the presence of the fish species, Canestrini's goby (Ninnigobius canestrinii, previously classified as Pomatoschistus canestrinii), listed in Annex II of the Habitats Directive.
The improvement of nutrient levels in the priority coastal lagoons habitat contributed to the achievement of a good environmental status according to the Water Framework Directive for the area. The restoration of salinity gradients and reed bed surfaces contributed to an increased biodiversity in the Natura 2000 network site and helped achieve targets defined by the 2020 Biodiversity Strategy.
RESULTS
The project managed to improve the conservation status of the target habitat (1150* Coastal Lagoons for a total of 1 250 ha) by re-establishing the salinity gradient (from an initial discharge of 300 l/s up to a maximum of 1 000 l/s) through the implementation of a freshwater input from a river flowing next to the Venice Lagoon. This improvement favoured the target fish and bird species as per initial plan. Ninnigobius canestrinii, the fish target species of the project, increased from 0.1 ind/100 m2 in ante operam up to 18-20 ind/100 m2 right after the opening of the freshwater input up to 1 000 l/s. Moreover, the restoration of salinity gradient has led to an increase in the abundance of juveniles of migratory species with commercial interest (e.g., mullets). Positive response of some species of waterbirds like gulls and scythers were registered as well: among the target species, Alcedo atthis and Ixobrychus minutus showed some positive signals after the freshwater input. Some species like Larus ridibundus, Calidris alpina, and Larus melanocephalus have increased their presence in the intervention area. After surveying the relative abundances of passerines, a total of 66 species (51 passerines) were identified, with 1 548 record and 3 347 individuals contacted. Among the target species associated to the reed, only Emberiza schoelnicus was regularly found in the area. With the absolute census for waterfowl, a total of 62 species were identified and 2 568 records and 29 290 individuals contacted. Among them, 25 species of conservation interest and 6 target species (Ardea purpurea, Circus cyaneus, Circus aeruginosus, Phalacrocorax pygmeus, Alcedo atthis) were contacted.
The reed beds expanded in the lagoon border and in those salt marshes that are closest to the freshwater input (the total number of sods transplanted was 2 789 out of the foreseen 1 000) and the halophytic species changed in terms of coverage and composition (the total number of clumps transplanted was 1 757, out of the foreseen 1 560). At the end of the project, the mapping activities showed a significant presence of the reed bed in the lagoon border and in the salt marshes that are closest to the freshwater input, in a lagoon area of about 11 hectares (including salt marshes).
The project has involved over 20 managing bodies of coastal lagoons in networking activities, with 6 of them selected following a European Call for Interest. Exchanges of visits and knowledge sharing were carried out with these projects (3 in Italy and 3 in France, Spain and Greece), to facilitate replication of best practices in other contexts. The project has also had a significant socioeconomic impact, by involving relevant stakeholders in field operations (hence increasing their environmental awareness) and by creating business opportunities for environmental engineering companies. On the policy side, the local hunting regulation was modified (3 fixed hunting spots were removed from the project area). Moreover, the project developed a preliminary indicator to quantify the Conservation Degree status of habitat 1150* coastal lagoons, improving the methodology built within the framework of the previous LIFE12 NAT/IT/000331 LIFE SERESTO project. This method could support the implementation of the Habitats Directive both at regional and national scale, and at EU level.
