TARGET: Targeted Strategies for Safeguarding the Noble crayfish against alien and emerging threats

Summary

The noble crayfish (Astacus astacus) is an ecologically and economically important fresh water species that is red-listed throughout Europe. The main threat is spread of alien invasive North-American crayfish that carry and transmit the crayfish plague pathogen (Aphanomyces astaci) that is lethal to European crayfish. We have recently demonstrated the application of A. astaci DNA monitoring directly from lakes and rivers, and the use of environmental DNA (eDNA) is a rapidly growing field with a great potential for streamlined inventory- and monitoring purposes. The TARGET project aims to implement eDNA approaches for rapid and reliable "all-in-one-water-sample"-monitoring of the noble crayfish and its threats, including alien invasive disease-carrying freshwater crayfish and crabs, the crayfish plague pathogen A. astaci, and possibly toxin-producing cyanobacteria that during blooms may pose a risk to crayfish health and crayfish as a secure food source. The eDNA approach will be tested in vitro and on real-life water samples from relevant sites in Norway and Europe comparing (CPUE) data and eDNA quantities in order to identify eDNA predictor values for 1) relative crayfish population densities and 2) relative prevalence and infection load of A. astaci in the infected crayfish population. Such approaches may allow effective non-invasive surveillance programs that monitor noble crayfish and/or its threats. TARGET will further elucidate how toxin-producing cyanobacteria may affect crayfish health and crayfish as food-source. Finally, we will explore innovative environmental measures for mitigation and prevention of the crayfish plague agent in water and in carrier crayfish through pilot studies using ultrasonic technology.