PROJECT DESCRIPTION
BACKGROUND
The Southern European nase (Protochondrostoma genei), a fish also known as the lasca, is only found in Slovenia and Italy, and it is considered close to extinction in Slovenia. All its populations are in drastic decline. For this reason, timely deployment of measures was due to save the species. Informed by the IUCN guidelines for reintroduction, a preparatory check on the main subjects was performed in 2015 and 2016 and followed a multidisciplinary approach, with genetic analysis of Italian (Ticino) stock compared with Slovenian specimens. The results supported the reintroduction programme including the release of the Ticino specimens.
OBJECTIVES
As a first step, it was necessary to ensure backup of Lasca genetic material in captivity (modification of a fish farm), which served as a source of specimens for its reinforcement in the wild. Species reintroduction was carried out in the Vipava river basin (where the species was extinct) and substantially improved the conservation status of the species in Slovenia. As a next step, the long-term plan for the conservation of the species was established via a Lasca conservation management plan, considering all threats in the wild, especially the reduction of its competitor, the invasive fish Common Nase (Chondrostoma nasus). The objectives of the actions were thus strongly linked to the Annex II of the Habitats Directive and the EU regulation (1143/2014) on invasive alien species.
RESULTS
The ultimate goal of the project was achieved in full, namely, to establish Lasca broodstock in Slovenia as a source of Lasca juveniles for the reintroduction into Natura 2000 site Vipava basin. The fish farm in Kobarid was modified as an alternative solution, because the building permission linked to the original plan had not been issued. The project was foreseen to release at least 150 000 Lasca specimens in three years, but actually 136 052 specimens were released after four spawning seasons. As a best practice, older specimens were released to avoid higher mortality in wild, so the overall effect is roughly equivalent or even better.
Monitoring showed that Lasca spread across suitable sections of Vipava tributaries. Successful habitat occupancy (more than 1 000 specimens recorded during monitoring) and reproduction in wild (within 2 consecutive seasons) have been confirmed. Action plan for Lasca conservation was issued and adopted within the official legislative Fisheries management plans in Slovenia and by Parco Ticino in the Po River basin in Italy. In the Vipava river basin monitoring sites, the number of Common Nase specimens decreased by 80%. The amount of non indigenous fish release by angling clubs decreased by 20%. Project visibility and awareness had good results for a non-charismatic target species and in light of several COVID19 restrictions. Reception in traditional and digital media was very good, and activities with schoolchildren were numerous. In total, 2 "final" events were organised – one targeting local population and anglers, and another one tailored to a scientific audience with participation of international speakers and invitees.
