VKM Report 2017: 33 Assessment of the risk to Norwegian biodiversity from the import and keeping of terrestrial gastropods in terraria Opinion of the Panel on Alien Organisms and Trade in Endangered Species of the Norwegian Scientific Committee for Food and Environment Report from the Norwegian Scientific Committee for Food and Environment (VKM) 2017:33 Assessment of risks to Norwegian biodiversity from the import and keeping of terrestrial gastropods in terraria Opinion of the Panel on Alien Organisms and Trade in Endangered Species of the Norwegian Scientific Committee for Food and Environment 18.12.2017 Authors: Anders Nielsen, Bjørn Arild Hatteland, Martin Malmstrøm, Ted von Proschwitz, Gaute Velle, Hugo de Boer, Jan Ove Gjershaug, Lawrence R. Kirkendall, Eli K. Rueness og Vigdis Vandvik ISBN: 978-82-8259-290-1 ISSN: 2535-4019 Norwegian Scientific Committee for Food and Environment (VKM) Po 4404 Nydalen N – 0403 Oslo Norway Phone: +47 21 62 28 00 Email: [email protected] www.vkm.no www.english.vkm.no Cover photo: ColourBox Suggested citation: VKM, Anders Nielsen, Bjørn Arild Hatteland, Martin Malmstrøm, Ted von Proschwitz, Gaute Velle, Hugo de Boer, Jan Ove Gjershaug, Lawrence R. Kirkendall, Eli K. Rueness and Vigdis Vandvik (2017). Assessment of the risk to Norwegian biodiversity from the import and keeping of terrestrial gastropods in terraria. Opinion of the Panel on Alien Organisms and Trade in Endangered Species of the Norwegian Scientific Committee for Food and Environment. VKM report 2017:33, ISBN: 978-82-8259-290-1, ISSN: 2535-4019, Norwegian Scientific Committee for Food and Environment (VKM), Oslo, Norway. VKM Report 2017: 33 Assessment of risk to Norwegian biodiversity from the import and keeping of terrestrial gastropods in terraria Preperation of the opinion The Norwegian Scientific Committee for Food and Environment (Vitenskapskomiteen for mat og miljø, VKM) appointed a project group to answer the request from the Norwegian Environment Agency. The project group consisted of two VKM members from the VKM Panel on Alien Organisms and Trade in Endangered Species (CITES), two external experst, and a project leader from the VKM secretariat. One VKM member from the Panel on Plant Health and one from the Panel on Animal Health and Welfare evaluated and approved the final opinion drafted by the project group. Authors of the opinion Anders Nielsen – Chair of the project group and member of the Panel on Alien Organisms and Trade in Endangered Species (CITES) in VKM. Affiliation: 1) VKM; 2) Department of Biosciences, University of Oslo. Bjørn Arild Hatteland – Member of the project group. Affiliation: Norwegian Institute of Bioeconomy Research (NIBIO). Martin Malmstrøm – Member of the project group and project leader in the VKM secretariat. Affiliation: VKM. Ted von Proschwitz – Member of the project group. Affiliation: Museum of Natural History Göteborg. Gaute Velle – Member of the project group and member of the Panel on Alien Organisms and Trade in Endangered Species (CITES) in VKM. Affiliation: 1) VKM; 2) Uni Research Environment; 3) Department of Biology, University of Bergen. Hugo de Boer – Member of the Panel on Alien Organisms and Trade in Endangered Species (CITES) in VKM. Affiliation: 1) VKM; 2) Natural History Museum, Oslo. Jan Ove Gjershaug – Member of the Panel on Alien Organisms and Trade in Endangered Species (CITES) in VKM. Affiliation: 1) VKM; 2) Norwegian Institute for Nature Research (NINA). Lawrence R. Kirkendall – Member of the Panel on Alien Organisms and Trade in Endangered Species (CITES) in VKM. Affiliation: 1) VKM; 2) Department of Biology, University of Bergen. Eli K. Rueness – Member of the Panel on Alien Organisms and Trade in Endangered Species (CITES) in VKM. Affiliation: 1) VKM; 2) Department of Biosciences, University of Oslo. VKM Report 2017: 33 Vigdis Vandvik – Chair of the Panel on Alien Organisms and Trade in Endangered Species (CITES) in VKM. Affiliation: 1) VKM; 2) Department of Biology, University of Bergen. Assessed and approved The opinion has been assessed and approved by the Panel on Alien Organisms and Trade in Endangered Species (CITES). Members of the panel are: Vigdis Vandvik (chair), Hugo de Boer, Jan Ove Gjershaug, Kjetil Hindar, Lawrence R. Kirkendall, Anders Nielsen, Eli. K. Rueness, Odd Terje Sandlund, Kjersti Sjøtun, Hans K. Stenøien and Gaute Velle. (Panel members in alphabetical order after chair of the panel) Acknowledgment VKM would like to thank the Great Britain Non-Native Species Secretariat for allowing the use and adaptation of the risk assessment template. VKM would also like to thank the hearing expert, Tarald Stein, for his expert opinion on the species relevant for trade in Norway and the husbandry of these animals, and hearing expert Arne Skorping for valuable input on nematodes and other parasites. VKM would also like to thank Åshild Ergon, VKM Panel on Plant Health, and Øivind Bergh, VKM Panel on Animal Health and Welfare for reviewing and commenting on the manuscript. We are grateful to Lucy Robertson for proofreading the manuscript. Competence of VKM experts Persons working for VKM, either as appointed members of the Committee or as external experts, do this by virtue of their scientific expertise, not as representatives for their employers or third-party interests. The Civil Services Act instructions on legal competence apply for all work prepared by VKM. VKM Report 2017: 33 Table of Contents Summary ................................................................................................................ 7 Sammendrag på norsk.......................................................................................... 10 Abbreviations and glossary .................................................................................. 13 Background as provided by the Norwegian Environment Agency ........................ 16 Terms of reference as provided by the Norwegian Environment Agency ............. 16 1 Introduction ................................................................................................. 18 1.1 Problems related to invasive non-native species...................................................... 18 1.2 Invasive gastropods ............................................................................................. 19 Worldwide ................................................................................................ 19 In Norway ................................................................................................ 20 1.3 Factors controlling invasiveness............................................................................. 20 1.4 Land snails as hobby animals in Norway ................................................................ 21 1.5 Challenges relating to taxonomic uncertainty .......................................................... 22 1.6 Biology and ecology of terrestrial gastropods .......................................................... 23 Habitat ..................................................................................................... 23 Fecundity.................................................................................................. 23 Dispersal .................................................................................................. 23 Diet .......................................................................................................... 24 Pathogens ................................................................................................ 24 1.7 Potential for successful establishment in a 50-year perspective ................................ 26 2 Methodology and data .................................................................................. 28 2.1 Methodology for evaluation ................................................................................... 28 Initial screening phase ............................................................................... 28 Risk assessment scheme ............................................................................ 29 Modified GB-NNRA protocol ........................................................................ 31 Rating and descriptions .............................................................................. 36 2.2 Sources of information ......................................................................................... 38 Scientific literature ..................................................................................... 38 Governmental databases and private websites ............................................. 38 2.3 Considerations of climate ...................................................................................... 39 3 Answers to the terms of reference ............................................................... 41 3.1 Species relevant for trade in Norway ..................................................................... 41 VKM Report 2017: 33 3.2 Biotic and abiotic factors that determine the potential for survival, establishment and spread of terrestrial gastropods in Norway ............................................................. 44 3.3 Biotic and ecological properties of terrestrial gastropods that determine the potential for a negative impact on biodiversity in Norway ...................................................... 45 3.4 Risk of negative impacts on biodiversity in Norway from terrestrial gastropods which are relevant for trade ........................................................................................... 46 3.5