Risk assessment on import of Australian redclaw crayfish to Norway Kjetil Hindar, NINA and VKM EFSA-VKM workshop, Oslo, 27 October 2017
Background Australian redclaw crayfish is cultured in tropical and subtropical/temperate regions, and was sought imported to Norway for aquaculture. The Norwegian Food Safety Authority and the Norwegian Environment Agency requested VKM to assess: potential risks to aquatic animal health and biodiversity in Norwegian fauna, associated with import of Australian redclaw crayfish (Cherax quadricarinatus) to Norway for aquaculture. possible risks caused by the introduction of harmful hitchhiker organisms should be included in the assessment. VKM was asked to adopt a 50 years perspective
Australian redclaw (Cherax quadricarinatus) Photo: Dave Wilson
Freshwater crayfish in Norway Noble crayfish (Astacus astacus), is a native species in southeastern Norway (Photo: Børre Dervo) Signal crayfish (Pacifastacus leniusculus)
Signal crayfish Signal crayfish (Pacifastacus leniusculus) Photo: Stein Ivar Johnsen
Comparative biology C. quadricarinatus P. leniusculus A. astacus Geographical distribution Australia and Papua New Guinea USA and Canada Europe Phylogeny Parastacoidea, Gondwanaland Astacoidea, originating in Laurasia Astacoidea, originating in Laurasia Size and growth Maximum 350 mm; rapid Max 170 mm; slow Max 180 mm; slow Life cycle 4-5 yrs; mature 7 mo. - 20 yrs; mat. 2-3 yrs - 20 yrs; 1.5-5 yrs Habitat Turbid water, slow streams Small and large rivers and lakes Small and large rivers and lakes Temperature 23-31 ºC Probably as A. astacus. 15-24 ºC Feeding habits Detrivorous Omnivorous Omnivorous Predators Fish, birds, mustelids Fish, birds, mustelids Fish, birds, mustelids Diseases Susceptible to crayfish plague Carrier/host of crayfish plague Highly susceptible to crayfish plague IUCN category Least concern (LC) Least concern (LC) Vulnerable Harvest Mostly farmed Captured Captured Aquaculture 140 tonnes Yes Yes
Challenges to risk assessment Environmental Risk Assessment and Health Risk Assessment use different procedures and criteria Aquarium import vs Aquaculture production Current vs future temperature regimes Lack of specific knowledge (on Australian redclaw) vs ample general knowledge (on alien crayfish) Scenario 1: unsuccessfull aquaculture (low propagule pressure) Scenario 2: successfull aquaculture (potentially high propagule pressure)
Larson ER & Olden JD 2012. Global Ecol. Biogeogr. 21
Climate projections 50 yrs
Current and future climate in southern Norway Lake Liavatnet, Rogaland County Current and future projected temperature 0.5 meter depth Temperature C 25,0 20,0 15,0 10,0 5,0 0,0 May June July August September October November December January February March April May June C 0.5 meter year 2015/2016 C 0.5 meter year 2065/2066
Ecological risk assessment AS-ISK (FI-ISK) system for screening Copp GH et al. 2016 Fish. Mgmt Ecol. 23 NBIC system for risk assessment Sandvik H et al. 2013 Biodiversity and Conservation 22 «The consistent and general negative effects of nonnative crayfish warrant efforts to discourage their introduction beyond native ranges.» Twardochleb LA et al. 2013 Freshwater Science 32
Vulnerable species Amphibians have been identified as a vulnerable group because of the deadly fungus Batrachochytrium dendrobatidis, which is present in amphibian populations on many continents, and for which crayfish may act as carriers (Photos: Børre Dervo)
VKM Report 2016: 64 Working group/authors: Øivind Bergh (chair), Carlos Goncalo Afonso Rolhas Fernandes das Neves, Kjetil Hindar*, Helga R. Høgåsen#, Anders Jelmert**, Trude Vrålstad#, Angelika Agdestein (VKM staff), Maria G. Asmyhr (VKM staff), Dean Basic (VKM staff) Panel on Animal Health and Welfare *Panel on Alien Organisms **Panel on Microbial Ecology # External experts, Veterinary Institute VKM. (2016) Risk assessment on import of Australian redclaw crayfish to Norway, Opinion of the Panel on Animal Health and Welfare, ISBN: 978-82-8259-254-3, Oslo, Norway.