Scientific Opinion on the environmental risk assessment of the apple snail for the EU

At EFSA‘s request, the Plant Health Panel (PLH) performed an environmental risk assessment (ERA) of the apple snail for the EU and validated the ERA approach presented in the PLH ERA guidance document. Improvements and suggestions for simplification of the ERA are provided. One service-providing unit—shallow fresh water areas—was identified for this ERA. The effects of resistance, resilience and management on snail population dynamics in the short (5 years) and the long term (30 years) were estimated. In line with the PLH ERA guidance rating system, expert judgement was used to evaluate separately the impacts on (i) ecosystem traits, (ii) ecosystem services and (iii) biodiversity components. Snail biomass values were predicted to be higher in the short term than in the long term. For ecosystem services, moderate risk was estimated for genetic resources, climate regulation, pest and disease regulation and pollination in both the short and long term; for food, risk was assessed as moderate in the short term and major in the long term; for water and erosion regulation, risk was assessed as major both in the short term and in the long term; for fresh water, risk was assessed as massive both in the short term and in the long term; and for nutrient cycling and photosynthesis and primary production of macrophytes, risk was assessed as massive in the short term and as major in the long term. For biodiversity components, risk for genetic diversity and native species diversity was estimated as major in both the short and the long term; risk for native habitats was assessed massive in the short term and major in the long term; and for threatened species and habitats of high conservation value, risk was determined as massive in both the short and the long term.