The ‘dirty dozen’: socio‐economic factors amplify the invasion potential of 12 high‐risk aquatic invasive species in Great Britain and Ireland

Abstract

Summary1. Aquatic invasive species are a growing concern to environmental managers because of their diverse impacts on aquatic biodiversity and high eradication costs, necessitating effective management policies. In this study, we evaluate the ability of environmental and socioeconomic factors to predict the risk of invasion in Great Britain and Ireland of 12 potential aquatic invaders covering all major aquatic groups. Despite their potential to inform risk assessments, this is the first time socio-economic factors related to propagule pressure have been specifically integrated in distribution modelling. 2. Species distribution models (SDM, MaxEnt algorithm) were calibrated with a set of environmental factors (e.g. bioclimatic, geographical and geological) and integrated with socioeconomic (e.g. human influence index, population density, closeness to ports) predictors. 3. The inclusion of socio-economic factors in SDM did not affect accuracy scores (AUC already >0Á90), but their effects were more pronounced in spatial predictions, resulting in up to a sixfold amplification of the area predicted suitable for each species. Despite the inclusion of potential surrogates of water chemistry (e.g. geology) and propagule pressure (e.g. population density), temperature-related variables were most important predictors of aquatic species' distributions. 4. According to SDM, the environmental suitability for a suite of invaders belonging to different taxonomic groups and regions of origin is greatest in east and south-east England and decreases towards the north and west. Multiple invasions in this region are of special concern, as species are known to modify their habitat facilitating subsequent invasions, thereby potentially exacerbating their impacts. 5. Major management regions to be prioritized in monitoring programmes include the Humber, Thames and Anglian River Basin Districts. Species of special concern include a mysid (Hemimysis anomala), a gammarid (Dikerogammarus villosus), a plant (Ludwigia grandiflora) and two crayfishes (Procambarus clarkii and P. fallax). 6. Synthesis and Applications. The inclusion of socio-economic factors in species distribution models has the potential to improve predictions of areas under a highest risk of multiple invasions and to help disentangle the complex interplay between biological invasions and global environmental and socio-economic processes. Such understanding is pivotal to prioritize limited resources for the optimum prevention and control of biological invasions.

Corruption, development and governance indicators predict invasive species risk from trade

“…Corruption, though, was the only predictor able to estimate invasive species interception in all three commodity pathways. Corruption is defined as capturing perceptions of the extent to which public power is exercised for private gain, including both petty and grand forms of corruption, as well as the 'capture' of the state by elites and private interests [12]. Across all pathways analysed, a decrease in corruption was linked with an increase in non-native species detections (figure 3), which was the opposite trend to that which we initially predicted.…”

“…The percentage of forest cover (forest) was positively associated with interceptions on vegetable material. The indicator of political stability and freedom from violence (stability) captures perceptions of the likelihood that a government will be destabilized or overthrown by unconstitutional or violent means, including politically motivated violence and terrorism [12]. Political stability was the third most important significant predictor of non-native species incursion risk for the vehicle pathway (figure 3).…”

“…Despite the intent and provisions of these regulatory measures, there is almost certainly variation in their implementation. Socio-economic and development factors can have considerable influence on countries' economic growth and environmental standards [11,12], and probably influence their abilities to effect phytosanitary standards and implement sound biosecurity systems. Previous work has suggested that socio-economic factors such as protected land cover or gross domestic product (GDP) indices are correlated with exotic species invasions [4,13], but have not ascertained the importance of factors such as corruption or the ability of governments to formulate and implement sound policies and regulations [5].…”

Substrate preferences of coexisting invasive amphipods, Dikerogammarus villosus and Dikerogammarus haemobaphes, under field and laboratory conditions

“…In addition, detrital processing efficiency of invasive amphipods has been reported to be lower than that of native amphipod species resulting in a potential modification of energy flows within invaded ecosystems (MacNeil et al 2011;Piscart et al 2011;Constable and Birkby 2016;Jourdan et al 2016). The resulting effects on community structure, resource flow and ecosystem functioning have given rise to D. villosus being regarded as one of the most dangerous invasive species across Europe (DAISIE 2009;Gallardo and Aldridge 2013b).…”

Thermal Tolerance Limits of the Chinese Mystery Snail (Bellamya chinensis): Implications for Management

“…Identifying the thermal limits of aquatic invasive species is important for both managing and preventing their introduction, establishment, and spread (Rahel and Olden 2008, Gallardo and Aldridge 2013, Kelley 2014. Once identifi ed, the upper and lower thermal tolerance temperatures can be used to inform the development and refi nement of invasive species distribution models (Uden et al 2015), which can be used to explain variability and predict changes in invasive species' geographic distributions.…”