TECHNICAL NOTE A NEW, VOLUNTEER-BASED, COST EFFECTIVE METHOD FOR ZOOLOGICAL MAPPING: THE PHOTO IDENTIFICATION OF FRESHWATER CRAYFISH (CRUSTACEA: DECAPODA) SPECIES AND THE IMPORTANCE OF VOLUNTEERS IN CRAYFISH RESEARCH

The publication of the European Crayfish Atlas within the framework of the CRAYNET programme is a major breakthrough in Decapoda mapping in Europe. The current data base contains information from approximately 60-70% of the 50 km × 50 km squares covering the continent. A new method to improve this situation further is the use of photo identification involving volunteers in the collection of distribution data. The crayfish identification ability of two potential user groups, astacologists and biology teachers/students, was tested using the questionnaire given in Figure 2. One picture (Astacus leptodactylus male) was correctly identified by everyone, the others were recognised by 59-94% (astacologists) and 30-88% (non-crayfish specialised biology teachers and students). The first European Decapoda photo identification survey proved that the necessary expertise exists in the continent to determine crayfish species from pictures and also that the quality of the pictures is less important than the presence of key details. Photo identification is a low cost and environmental-friendly approach but it also needs special considerations. Volunteers need to be supported in several ways, such as by providing precise and interesting educational material in an easily understandable language describing e.g. the key parts of the body to photograph. However, the general use of digital cameras and even mobile phones/cameras and the Internet is an effective way to launch such surveys as it gives, on one hand, an opportunity for the specialists to check, and if necessary correct, the field identification of less experienced people and, on the other hand, it provides a much larger data base than what is available now by using the data collected by students, conservationists, scouts or other volunteers.