PROJECT DESCRIPTION
BACKGROUND
The river Dora Baltea (150 km) and its 15 major tributaries (300 km) represent the north-western limit of the range of both the marble trout (Salmo marmoratus) and the grayling (Thymallus thymallus). S. marmoratus is included in Annex II of the EU Habitats Directive and, according to the IUCN’s criteria, it is critically endangered in Italy and endangered in Europe. T. thymallus is included in Annex V of the Habitats Directive; the species’ Adriatic lineage is listed as critically endangered. The main threats are: hybridisation and introgression; lack of knowledge on the residual populations’ status; alterations of both longitudinal connectivity (i.e. connections between upstream and downstream sections of a river network) and natural hydrologic regimes; water abstractions and insufficient minimum viable flows; and a lack of suitable hatcheries, guidelines and specific regulations on the management of both fish species and their habitats.
OBJECTIVES
The main goal of LIFE GrayMarble is to improve the conservation status of the marble trout and the grayling from unfavourable to favourable in the project area. This will be achieved by eliminating or mitigating major threats and through restocking, improving habitat quality and updating fishing regulations.
The project is in line with a range of EU policy and legislation, including the Habitats Directive, the 2030 biodiversity strategy, the Invasive Alien Species Regulation and the Water Framework Directive (WFD).
RESULTS
Expected results:
- Identification of “Evolutionary Significant Units” and “Management Units” which will provide different source populations for artificial reproduction;
- Improvement of the infrastructure for rearing genetically identified breeders of the 2 species, by modernising an existing hatchery in Aosta Valley and constructing a new hatchery in Piedmont;
- Development of pure-bred stocks for the reinforcement of residual natural populations and reintroductions(2 for T. thymallus and 2 for S. marmoratus). In the fourth year, about 100 pure breeders of marble trout and 30 of Adriatic graylings are expected;
- Removal of 17 barriers to fish movement, reconnecting a 20 km-long stretch of the river Dora Baltea (a core area for the species), including a Natura 2000 site;
- Immediate stop to inter-fertile trans-Alpine trout and grayling releases in the whole original range of the 2 target species. Complete eradication in the 11 nursery areas inside or outside Natura 2000 sites (24 km);
- Achievement of favourable conservation status for both species in 21 stretches of river (63 km), and reinforcement of residual wild populations occurring along 25 km of rivers in 9 Natura 2000 sites and 38 km of other river stretches;
- Creation of at least 2 new populations of Adriatic grayling in a 5 km-long stretch (an increase of 200%) and at least 7 populations of marble trout along a river stretch of 20 km (450% increase);
- Enhancement of regional conservation policies for the target species and Natura 2000 sites, by promoting a regional protocol for fish management, long-term protocols and regulations for sustainable management of aquatic fish ecosystems; guidelines for the development and monitoring of fish passes;
- Involvement of stakeholders, ensuring they play an active role in the project activities via a citizen science approach (iNaturalist.org): 300 students per year engaged; 3 anglers' associations involved; 4 sustainable marketing initiatives organised; 40 anglers trained in eradication actions and 30 volunteers in surveillance;
- Development of a viability study for transferring the project to the rivers Sesia and Tanaro (Italy) and River Nestos (Eastern Macedonia and Thrace - Greece);
- Achievement of good ecological status (under the WFD) for at least 7 water bodies; and
- Improvement of habitat quality, by regulating water withdrawals and restoring suitable flow conditions for fishes, for 6 watercourses (with updating of hydro-electric concessions by specific deliberations of regional councils within the end of the project).
