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

Abstract

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.Key-words: crayfish, Decapoda, methodology, mapping, education, conservation. NOTE TECHNIQUE UNE NOUVELLE MÉTHODE ÉCONOMIQUE, BASÉE SUR LE VOLONTARIAT, POUR LA CARTOGRAPHIE ZOOLOGIQUE : IDENTIFICATION DES ÉCREVISSES (CRUSTACEA, DECAPODA) D'APRÈS PHOTOS, ET IMPORTANCE DES VOLONTAIRES DANS LA RECHERCHE SUR LES ÉCREVISSES RÉSUMÉLa publication de l'atlas des écrevisses d'Europe dans le cadre du programme CRAYNET est une contribution importante pour la cartographie des Décapodes en Europe. La base de données associée contient des informations sur environ 60-70 % des mailles UTM de 50 km × 50 km couvrant le continent. Une nouvelle méthode permettant l'amélioration de cette situation consiste en l'utilisation de photos fournies via la mobilisation de bénévoles réunissant les données de distribution. La capacité d'identifier les écrevisses de deux groupes, les astacologistes d'une part, et les enseignants et étudiants en biologie d'autre part, a été testée en utilisant le questionnaire de la Figure 2. Une photo (Astacus leptodactylus) a été correctement identifiée par tous et les autres photos par respectivement 59-94 % des astacologistes et 30-38 % des enseignants et étudiants en biologie mais non spécialistes des écrevisses. Ce prem...

Invasive American crayfish Pacifastacus leniusculus (Decapoda: Astacidae) in the Morava River (Slovakia)

“…Given the high abundance of shelters, even significant effort directed to manual searching may not lead to capture in parts of the river where crayfish are only moderately abundant. However, help from the general public may be solicited (Puky 2006) -if properly informed, local fishermen in particular may report any crayfish captures and provide photographs, or even keep the encountered specimens of American species, and in that way efficiently assess the crayfish distribution in the river Morava. The general public in the region should also be informed of the presence of non-native crayfish in the area and their potential impact, so that the further human-mediated spread of these species into additional localities is prevented.…”

An assessment of the use of volunteers for terrestrial invertebrate biodiversity surveys

“…This does not consider the direct contribution that the extra hands of volunteers make to data collection. No studies have been undertaken to assess effectiveness of volunteers in surveys of terrestrial invertebrates (but see FosterSmith and Evans (2003) and Puky (2006) for studies on aquatic invertebrates). Techniques to survey terrestrial invertebrates are generally simple, especially if only passive sampling methods are used, such as pitfall trapping and colour pan traps.…”

Towards a new flora of Liguria: the usefulness of citizen science through the Wikiplantbase floristic surveys

“…In addition, continuous expert supervision ensures that all species are taken into account and limits the tendency of volunteers to focus only on the rarest species (Lepczyk 2005, Lewandowski and Specht 2015, MacKenzie et al 2017, thus avoiding the risk of increasing data imbalance in the Wikiplantbase #Liguria dataset. Similarly to the use of photographs as a tool for recognition and confirmation of identifications, widely used to limit identification errors in several projects (e.g., Puky 2006, Swanson et al 2015, Smith and Davis 2019, apps (e.g., Goëau et al 2013, Kress et al 2018, Nugent 2018) and communities (e.g., Forum Acta Plantarum), during the floristic surveys hundreds of herbarium specimens have been collected (i.e., near the 30% of observed taxa). Despite the use of voucher specimens for the verification of data would require expert time to process (Crall et al 2011), the herbarium samples offer advantages that make them more suitable for our type of data collection than the photographs; for example, some key morphological characters are difficult to be observed in the photos, unless the operator has professional equipment and is adequately instructed on the details necessary for identification (which vary from species to species).…”