Pathways and gateways of freshwater invasions in Europe

Abstract

Taking into account the continuous increase in freshwater introductions, and to support the recent European legislation on invasive alien species, the identification of priority pathways and gateways of introductions is of utmost importance to develop adequate control strategies. The aim of this paper was to analyse the main pathways and gateways of introductions of freshwater alien species in Europe. Based on a thorough review of the scientific and grey literature, information on pathways, country and year of initial introduction of all freshwater alien species in Europe, was retrieved. The spatial and temporal patterns and trends of biological invasions in freshwater ecosystems in Europe, in relation to different pathways, were assessed. Our results pinpoint the major importance of aquaculture, pet/aquarium trade and stocking activities as pathways of introduction of freshwater alien species in Europe. For species native to some European countries, shipping and inland canals were the most important pathways, highly responsible for the entry of many harmful species. Germany, the United Kingdom and Italy were the main entry gateways of freshwater alien species in Europe. We found a geographical pattern related to some pathways of introduction in Europe: introductions through inland canals were concentrated in Central/North-eastern Europe, while introductions through pet/terrarium/aquarium trade were mainly observed in Central/Western Europe. While Chordata species entered Europe mainly through the three major above mentioned pathways, many harmful Arthropoda and Mollusca entered through shipping and inland canals. The information gathered in this study clearly indicates the entry routes that should be prioritised by Member States, for which stronger control and management actions should be implemented and prevention efforts concentrated under the scope of the related new EU Regulation.

Climatic niche shift of aquatic plant invaders between native and invasive ranges: a test using 10 species across different biomes on a global scale

“…2). Due to their negative impact on aquatic and wetland ecosystems, both the prevention and control of API invasions are vitally important for maintaining ecosystem stability (Warfe et al, 2013;Kaufman and Kaufman, 2013;Luque et al, 2014;Svirčev et al, 2014;Nunes et al, 2015). Our results provide novel insights for risk assessments of API invasions.…”

“…A variety of factors, including human activity and climate change, may promote the adaptation of plant species to novel climatic conditions in non-native regions, resulting in a climatic niche shift between native and invasive ranges (Nunes et al, 2015). Hence, the transferability of ENMs supports the necessity for an accurate determination of climatic niche distributions of APIs in invasive ranges based on observed habitat suitability in both native and invasive ranges (Mainali et al, 2015;Wan et al, 2017).…”

“…The expansion and evolution of APIs in non-native ranges, and their propagation along barriers may instill an environmental niche shift. Previous studies have also shown that environmental niche shift is related to human influence (Riis et al, 2012;Hussner, 2012;Donoghue and Edwards, 2014;Svirčev et al, 2014;Nunes et al, 2015). API seedlings have been imported to non-native regions for ecological restoration, agricultural production, or even as ornamental plants (De Groot et al, 2002;Leppäkoski et al, 2013;Riis et al, 2012;Kaufman and Kaufman, 2013).…”

“…Plasticity is the ability of an individual plant species to alter its physiology or morphology in response to changes of environmental conditions (Nunes et al, 2015;Donoghue and Edwards, 2014;Guisan et al, 2014). Hence, some degree of plasticity allowing at least the temporarily establishment of individual plants enables subsequent climatic niche evolution (Zhu et al, 2013;Guisan et al, 2014;Nunes et al, 2015). The interaction between the climatic niche shift of APIs and their expansion into invasive ranges is rather complex (Petitpierre et al, 2012;Guisan et al, 2014;Larson et al, 2014).…”

“…Additionally, a period of repeated human colonization in relation to plasticity, establishment, and genetic evolution can result in a successful niche shift. Plasticity is the ability of an individual plant species to alter its physiology or morphology in response to changes of environmental conditions (Nunes et al, 2015;Donoghue and Edwards, 2014;Guisan et al, 2014). Hence, some degree of plasticity allowing at least the temporarily establishment of individual plants enables subsequent climatic niche evolution (Zhu et al, 2013;Guisan et al, 2014;Nunes et al, 2015).…”