The project - Life Claw

The project in a nutshell

Life Claw is a project to conserve and enhance the stock of the endangered crayfish Austropotamobius pallipes in North-Western Apennine area of the Italian regions Emilia Romagna and Liguria, by a long-term conservation programme.

It is coordinated by Ente Parco nazionale dell’Appennino tosco-emiliano and the duration is 4 years (October 2029-September 2023).

It will carry out conservation actions which include the breeding of juvaniles of A. Pallipes to be reintroduced, the restoration of crayfish habitat, the sanitary control to avoid the spread of the crayfish plague, the construction of artificial barriers and the trapping of invasive alien crayfish in order to limit their spread.

In parallel, communication and awareness-raising activities will be carried out to spread the themes of the project and encourage sustainable behaviours.
During all the project duration, stakeholders will be involved in order to build a participatory process.

It is expected to reduce of 60% the invasive alien crayfish populations after trapping activities, to restore 33 kiolometers of waterways sections and to release 10.500 rared hatchery- juveniles of A. pallipes.

The context

The main species directly targeted by the project is the cray fish Austropotamobius pallipes (Lereboullet, 1858) listed in Annexes II and V under the EU Habitats Directive. Native populations of A. pallipes have undergone a remarkable contraction and decline over the last 50 years on a widespread basis in Europe (Souty-Grosset et al. 2006, Atlas of Crayfish in Europe).

In Italy the decline has been about 74% over the last 10 years (Holdich et al. 2009, KMAE). This species is also listed as ‘endangered’ by the IUCN (Füreder, 2013). Residual populations of A. pallipes are now confined to small high gradient streams and headwater, where the crayfish IAS have not yet expanded and the habitat is less influenced by human activities (Ghia et al. 2013, Freshw Crayfish).

These populations are nowadays isolated reproductive units, often confined to single mountain streams or to separate basins. The conservation status for A. pallipes populations in the Italian continental biogeographic region (including north-Western Apennine) has been reported as “unfavourable-inadequate” and in “considerable decline”, thus with a negative trend in the short term (Genovesi et al. 2014, ISPRA).

However, northwestern Italy is a hotspot for A. pallipes where high nucleotide diversity was detected and different groups overlap (Trontelj et al. 2005, Mol Phylogenet Ev.). So, conservation strategy for A. pallipes in northern Italy, must take into account the complexity of the biogeographic pattern and the progressive isolation of local demes (Bernini et al. 2016, Conserv Genet).

In the project area, according to the 2014 Natura 2000 SDFs and Specific Measures of Conservation (MSC) the species is still present in 24 out of 28 sites. An estimation of 50 A. pallipes populations is plausible, but often they are relict, appear low-density and are confined to small streams.

Quantitative data are deficient within the overall project area. For the first time in Italy, 2 newly established populations of the invasive cold-water crayfish Pacifastacus leniusculus have been recently detected within project site “Lago del Brugneto” (IT1331019), placed at the headwater of Trebbia river basin (1.070 km2), and at the edge (about 3 km) of the site “Rocca dell’Adelasia” (IT1322304) (Capurro et al. 2007, Aquat Invas; Bo et al. 2016, Natural Hist Sci); both sites still host some residual A. pallipes.

P. leniusculus(American signal cryfish) populations are still restricted, this species is the most successful crayfish IAS (Invasice Alien Species) in Europe and its bioecological attributes leave no doubt that many more Italian lakes and streams (still populated by the native species) will become occupied by signal crayfish, causing strong negative impacts on freshwater biodiversity and ecosystem functioning. Moreover, the most widespread other two invasive America Italy, Procambarus clarkii (red swamp crawfish)and Orconectes limosus (spiny-cheek crayfish), are spread overall the Po river plain area and represent a potential threat overall the project area, especially in the hill area, i.e. within “Basso Trebbia” (IT4010016) A. pallipes has disappeared recently due to P. clarkii colonization of the area.

All 3 Inivasive Alien Species of Union concern represent strong competitors for the native crayfish and the carriers of the crayfish plague, which is responsible of the rapid extinction of A. pallipes populations and they represent one of the most dangerous threats to the native species as well as an excessive release of salmonids for repopulation with possible spread of pathogens.

Objectives

The project main objective is to conserve and enhance the stock of the endangered crayfish A. pallipes in north-Western Apennine area of the Italian regions Emilia Romagna and Liguria by a long-term conservation programme. Specific objectives of the project are:

(1) to establish four ex situ breeding facilities for restoration of A. pallipes populations during the project and after the end of the project, in order to ensure the long-term survival of this species against major threats such as population isolation as well as crayfish Invasive Alien Species (IAS) invasion and crayfish plague;

(2) to protect and increase the stocks of A. pallipes populations most significant for the conservation of the species’ genetic variability in north-western Apennine;

(3) to counteract the dispersal of crayfish IAS (and crayfish plague, consequently), which constitutes one of the main causes of native species extinction in freshwater ecosystems, by intensive and continuous removal of crayfish IAS along the invaded areas as well as by construction of physical crayfish barriers at the invasion fronts to stop the spread upstream of signal crayfish P. leniusculus within the two involved sites and to protect native crayfish populations still living upstream of the same watercourses;

(4) to establish a “Crayfish zonation map” in order to identify the watercourses suitable for crayfish as well as to promote the ban of the continuous release of salmonids that alters the ecosystem balance; it will be integrated with the Conservation Measures or/and Management Plans of project SCIs and will contribute to develop an integrated management of the aquatic ecosystem, implementing the European Water Framework

(5) a broad communication campaign by social media involvement and engagement will be fundamental to create an open dialogue with the stakeholders, not only to increase awareness, but also to discourage inappropriate introduction of IAS and to reduce the probability of deliberate translocation into other rivers caused by illegal capture;

(6) to constitute a network among local stakeholders and communities for the conservation of the species, coherent with the aims of the Habitats Directive. One more objective of the project is to transfer “best practice” techniques and develop a concrete conservation strategy plan for native crayfish, which could be exploited in other contexts in Italy and Europe.