Consistency of impact assessment protocols for non-native species

Pablo González-Moreno, Lorenzo Lazzaro, Montserrat Vilà, Cristina Preda, Tim Adriaens, Sven Bacher, Giuseppe Brundu, Gordon H. Copp, Franz Essl, Emili García-Berthou, Stelios Katsanevakis, Toril Loennechen Moen, Frances E. Lucy, Wolfgang Nentwig, Helen E. Roy, Greta Srėbalienė, Venche Talgø , Sonia Vanderhoeven, Ana Andjelković, Kęstutis Arbačiauskas, Marie-Anne Auger-Rozenberg, Mi-Jung Bae, Michel Bariche, Pieter Boets, Mário Boieiro, Paulo Alexandre Borges, João Canning-Clode, Federico Cardigos, Niki Chartosia, Elizabeth Joanne Cottier-Cook, Fabio Crocetta, Bram D’hondt, Bruno Foggi, Swen Follak, Belinda Gallardo, Øivind Gammelmo, Sylvaine Giakoumi, Claudia Giuliani, Guillaume Fried, Lucija Šerić Jelaska, Jonathan M. Jeschke, Miquel Jover, Alejandro Juárez-Escario, Stefanos Kalogirou, Aleksandra Kočić, Eleni Kytinou, Ciaran Laverty, Vanessa Lozano, Alberto Maceda-Veiga, Elizabete Marchante, Hélia Marchante, Angeliki F. Martinou, Sandro Meyer, Dan Minchin, Ana Montero-Castaño, Maria Cristina Morais, Carmen Morales-Rodriguez, Naida Muhthassim, Zoltán Á. Nagy, Nikica Ogris, Huseyin Onen, Jan Pergl, Riikka Puntila, Wolfgang Rabitsch, Triya Tessa Ramburn, Carla Rego, Fabian Reichenbach, Carmen Romeralo, Wolf-Christian Saul, Gritta Schrader, Rory Sheehan, Predrag Simonović, Marius Skolka, António Onofre Soares, Leif Sundheim, Ali Serhan Tarkan, Rumen Tomov, Elena Tricarico, Konstantinos Tsiamis, Ahmet Uludağ, Johan van Valkenburg, Hugo Verreycken, Anna Maria Vettraino, Lluís Vilar, Øystein Wiig, Johanna Witzell, Andrea Zanetta, Marc Kenis

Standardized tools are needed to identify and prioritize the most harmful non-native species (NNS). A plethora of assessment protocols have been developed to evaluate the current and potential impacts of non-native species, but consistency among them has received limited attention. To estimate the consistency across impact assessment protocols, 89 specialists in biological invasions used 11 protocols to screen 57 NNS (2614 assessments). We tested if the consistency in the impact scoring across assessors, quantified as the coefficient of variation (CV), was dependent on the characteristics of the protocol, the taxonomic group and the expertise of the assessor. Mean CV across assessors was 40%, with a maximum of 223%. CV was lower for protocols with a low number of score levels, which demanded high levels of expertise, and when the assessors had greater expertise on the assessed species. The similarity among protocols with respect to the final scores was higher when the protocols considered the same impact types. We conclude that all protocols led to considerable inconsistency among assessors. In order to improve consistency, we highlight the importance of selecting assessors with high expertise, providing clear guidelines and adequate training but also deriving final decisions collaboratively by consensus.

Link to publisher