Scientific Opinion on the assessment of the potential establishment of the apple snail in the EU

Abstract

EFSA requested the PLH Panel to review the current state of the art of the biology and ecology of apple snails, reported in this opinion, and to perform an environmental risk assessment for validation of the Plant Health environment guidance document, which will be provided in a second opinion. The Panel presents in this opinion the current state of the art of the biology of apple snails, and develops and uses a population dynamics model to assess the potential establishment of apple snails in the EU. A thorough review of the literature on the biology of Pomacea canaliculata and P. maculata was performed to collect information and data on life history characteristics related to temperature, which was used in the population dynamics model. Although uncertainties on the systematics and taxonomy of the genus Pomacea remain, it is now acknowledged that Pomacea insularum is a synonym of P. maculata and can be undoubtedly differentiated from P. canaliculata. Natural spread occurs via rivers and canals, in which the snails crawl, drift, float and raft. Flooding increases spread. In addition, attachment to animals (e.g. birds, cattle, horses, deer and aquatic invertebrates) results in spread. Human assistance results in spread through cultivation transport of rice seedlings, aquaculture, aquaria, boats, and agricultural field machinery. The potential distribution of P. canaliculata in Europe was obtained by calculating with the population dynamics model, the average snail abundance per year in each node of a grid of 0.25 × 0.25 degrees covering Europe, which resulted in the following conclusions: (1) the area of potential establishment 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, (2) the potential area of establishment includes the rice production areas in Europe. SUMMARYThe European Food Safety Authority (EFSA) asked the Plant Health Panel (hereinafter referred to as the Panel) to deliver a scientific opinion on the risk posed to the environment in the European Union (EU) by the apple snail. In this document the Panel presents a review of the current state of the art of the biology and ecology of the apple snail and performs the assessment of the potential for the apple snails to establish in the EU territory using a population dynamics model. The environmental risk assessment of the apple snail for the EU territory, including an evaluation and update of the risk assessment methodology will be presented in a second scientific opinion.In a previous opinion on Pomacea spp. (EFSA Panel on Plant Health (PLH), 2012b) the Panel concluded, based on a preliminary climate matching exercise, that (a) climate is not a limiting factor for spread and further establishment in the risk assessment area, (b) vast areas of Europe have climatic conditions very similar to those in areas within the current distribution of Pomacea spp., and (c) the recognised importance of natural spread, as well the availability of suitable hab...

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

“…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.…”

“…In this scientific opinion the Panel uses the data on biology and ecology of the apple snail and the results of the population dynamics model, presented in EFSA PLH Panel (2013), to perform an ERA following the guiding principles detailed in the PLH ERA guidance document. This task has been performed considering the possible simplification and adjustments to the Panel's environmental risk assessment guidance document.…”

“…In EFSA PLH Panel (2013), the Panel presented the current state of the art of the biology of apple snails, and developed and used a population dynamics model to assess the potential establishment of apple snails in the EU in terms of the spatial distribution of the snail's population density.…”

“…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 the approach and to make it more flexible.In this opinion, the results obtained by the population dynamics model developed for P. canaliculata (EFSA PLH Panel, 2013) are summarised to describe the potential establishment and population density of the apple snail in different areas of Europe. However, in the current opinion, the Panel assessed snail population densities not in terms of number of eggs, juveniles and adults, but instead using a snail biomass index to represent density, which combines the fresh weights of the snail stages and supports the evaluations of the impacts on ecosystem services and biodiversity.…”

Dieta de Pomacea canaliculata (Gastropoda: Ampullariidae) en su hábitat natural basada en análisis de contenidos digestivos e isótopos estables

“…The favorable weather conditions, the availability of food resources (crops or macrophytes), a high reproductive potential and the lack of natural predators have contributed to its success as an invader (Damborenea and Darrigran, 2002;Joshi, 2007;Hayes et al, 2008). In consequence, this species is actually distributed in several countries of Asia and Oceania, North America (Hawaii and other states of the United States) (Rawlings et al, 2007;Hayes et al, 2008;Tran et al, 2008;Cowie and Hayes, 2012) and it was even recently reported in some regions of Spain (EFSA PLH Panel, 2013), Pakistan (Baloch et al, 2012) and Russia (Yanygina et al, 2010). The impacts of P. canaliculata are not restricted to agricultural economics, but they are also a serious concern for public health as they are a known carrier of the Rat Lung Worm (Angiostrongylus cantonensis), the causative agent of eosinophilic meningoencephalitis (Lv et al, 2009;Yang et al, 2013).…”