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

Abstract

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. In this scientific opinion, when the Panel refers to the apple snail, it refers specifically to Pomacea maculata and to P. canaliculata. As these species are closely related, their population dynamics pattern and potential impacts are assumed by the Panel to be similar.In this document, the Panel presents the ERA of the apple snail for the EU territory, including an analysis and evaluation of the risk assessment methodology applied to the apple snail. In EFSA PLH Panel (2013), the Panel reviewed the current state of the art of the biology and ecology of the apple snail and used a population dynamics model to assess its establishment in terms of density distribution in Europe. The Panel used these results as a starting point for performing the ERA. Conclusions concerning the methodological approach and its simplificationThe PLH ERA guidance includes a detailed procedure with different consecutive steps to assess the impacts of plant pests on ecosystem traits, ecosystem services and biodiversity components. In the current opinion, when performing the assessment, the complete PLH ERA approach was tested to evaluate the different steps described in the ERA guidance. Some aspects of the guidance were modified to improve it, and suggestions were made to simplify th...

Guidance to develop specific protection goals options for environmental risk assessment at EFSA, in relation to biodiversity and ecosystem services

“…• Prior to the first operational meeting of the WG, the topics of the mandate were openly discussed with experts representing a wide variety of stakeholders. The summaries and outcomes of the discussions from the 19th EFSA Scientific Colloquium on 'Biodiversity as Protection Goal in Environmental Risk Assessment for EU agro-ecosystems' are published on EFSA's website (EFSA, 2014). The collection of views on how to make protection goals operational in ERA served as an information source for the WG.…”

“…The following example (Table A.11) is based on the assessment of the invasive species apple snail Pomacea sp. (EFSA PLH Panel, 2014).…”

“…In crop/fieldedge of field/field marginnearby off-cropprotected areawatershedlandscaperegioncontinent SPG: specific protection goals. Panel, 2014), the EFSA PLH panel defined the entity as shallow fresh water areas containing macrophytes, such as wetlands, shallow lakes, river deltas and the littoral zone of deeper lakes and rivers. This choice was made on the basis of expert knowledge on the kind of ecosystems likely to be invaded by the snail and on the basis of the likely impacts of the snail on ecosystem structure and functioning, and the services provided by those systems Attribute Abundance -Biomass -Process -Within and between species diversity The snail feeds on macrophytes, reducing their abundance, biomass, and associated functions such as nutrient uptake.…”

“…Temperature-dependent population dynamics modelling was used to delineate the areas of potential high snail biomass, where impacts are likely. According to calculations with a population dynamics model (EFSA PLH Panel, 2014), the area of potential establishment of Pomacea comprises wetlands of southern Europe (i.e. Spain, southern France, most of Italy and Greece) and the Balkans up to the latitude of the Danube River…”

Coverage of endangered species in environmental risk assessments at EFSA

“…In the proposed risk assessment approach, one central question to be answered is the extent to which rare or vulnerable species (defined as all species classified as rare, vulnerable or endangered in official national or regional lists within the risk assessment area) are expected to be affected as a result of invasion. Once the relevant traits are acknowledged for the environmental components directly or indirectly affected by the IAS, their connections with biodiversity and ecosystem services are identified, via the selection of the main traits-services clusters (De Bello et al, 2010) and traits-biodiversity clusters (EFSA PLH Panel, 2014). One peculiarity of the ERA for plant pests is that the PLH Panel does not use thresholds for impact assessment.…”