First record of a possibly overlooked impact by alien parrots on a bat (Nyctalus leisleri)

Although its interferences on native biodiversity are still poorly known, the rose-ringed parakeet Psittacula krameri is currently recorded as one of the 100 worst alien species. The impacts on native fauna by this parrot are mainly represented by the displacement of native birds from nesting sites, with direct lethal attacks observed only against little owls and red squirrels. To date, competition with bats for tree cavities has been hypothesized but not documented yet. We recorded a fatal attack of a parakeet towards a Leisler's bat (Nyctalus leisleri), roosting or possibly hibernating in a trunk cavity. Although this is the only report available, the fact that both parrots and many bat species use tree cavities suggests that similar cases may be relatively frequent although sporadically observed. This observation puts emphasis on the need to supporting active monitoring and management of introduced species populations to preserve threatened native fauna. © 2014 Associazione Teriologica Italiana

The role of invasive alien species in the emergence and spread of zoonoses

The role of invasive alien species in the transmission dynamics of zoonotic pathogens is often overlooked, despite the rapid escalation in biological invasions globally. Here we synthesise available information on the influence of invasive alien species on zoonotic pathogen dynamics in invaded ranges, focussing on Europe, and identify key associated knowledge gaps. We identified 272 documented interactions between alien species and zoonotic pathogens within invaded ranges. The majority of these involved invasive alien mammals followed by birds with only a few occurrences of other taxa documented. A wide range of potential interactions between invasive alien species and zoonotic pathogens were identified but few studies considered transmission to humans and so there was limited evidence of actual impacts on human health. However, there is an urgent need to raise awareness of the potential risks posed to human health by the transmission of zoonotic diseases by invasive alien species; the role of invasive alien species in zoonotic disease transmission may exceed that of native wildlife and occur in a relatively short period following the arrival of an invasive alien species within a new region. Ecological and social mechanisms govern the dynamics of zoonotic disease transmission but wildlife diseases are not consistently included within animal, plant and human policies. Rapid advances in the development of systems frameworks that integrate the ecological, economic and social processes promoting spillover in rapidly changing environments will increase understanding to inform decision-making

Invasive alien species – framework for the identification of invasive alien species of EU concern

Invasive alien species (IAS) are considered to be one of the greatest threats to biodiversity, particularly through their interactions with other drivers of change (MEA 2005, GBO 2011). In recent years the European Commission (EC) has intensified their commitment to provide a comprehensive, problem-oriented, well-balanced and manageable solution to IAS in Europe. The text of a European Union (EU) Regulation is expected to be adopted soon. A core component of the Regulation is a list of “IAS of EU concern” that will be drawn up together with European Member States (MS), based on scientifically robust risk assessments as laid down in the Regulation. Risk assessment is the technical and objective process of evaluating biological or other scientific and economic evidence to identify potentially invasive alien species and determine the level of invasion risk associated with a species or pathway and specifically whether an alien species will become invasive. An effective and robust risk assessment method is seen as an essential component of IAS management (Shine, Kettunen et al. 2010) and a fundamental element of an early warning and information system in Europe (Genovesi, Scalera et al. 2010). The purpose of this project was to provide a review of available IAS risk analysis protocols and use this, coupled with expert opinion, to inform the development of minimum standards necessary to ensure effective risk assessment methods for the EU. Additionally we considered gaps in knowledge and scope of existing risk analysis methods. Thus, we provide recommendations for developing existing risk analysis methods within a framework of minimum standards. Methods compliant with the minimum standards will be of value for supporting the development of a draft list of “IAS of EU concern”. Such a list should include species that are already established within the EU but also be extended to a scoping study to consider species that are not yet established but that may present a significant threat to Europe in the near future. Task 1: Literature review and critical assessment of existing risk assessment methodologies on IAS The purpose of the review was to critically assess the scope, robustness and effectiveness of current risk assessment methods and to provide information for their further development in the context of the study particularly underpinning the derivation of minimum standards. More than 100 relevant publications were derived through a literature search. Only 70 publications provided original risk assessment protocols and their applications and of these 29 were selected through filtering to eliminate those which simply described the implementation of an existing protocol to a given geographic region or specific taxonomic groups without modification of the assessment protocol. These 29 protocols were examined further to derive key attributes of the risk assessment method to inform the development of minimum standards. Basic information for all 29 risk assessment methods was provided. Case studies for 14 of these protocols were included to provide further context for subsequent tasks. The 14 protocols included as case studies were selected on the basis of a number of criteria: relevance of the protocol to Europe, taxonomic breadth and/or geographic breadth, likely compliance with minimum standards and availability of experts with key involvement in the protocol to provide the case study. At both the international and regional-level as well as among countries, there is huge variation in how the risks posed by alien species are assessed. Indeed risk assessment protocols vary widely in approach, objective, implementation and taxa covered, the majority are based on qualitative methods, even though the need to develop quantitative risk assessments has been recognised. Major hurdles preventing the use of quantitative risk assessment methods are the lack of data and challenges in interpretation and communication. Two critical gaps were identified through this task: consideration of ecosystem services and evaluation of user-friendliness and consistency of outcomes. Very few risk assessment protocols reviewed specifically considered impacts on ecosystem services. Consistency in risk analysis has been recently discussed and assessed for pest risk analyses in the EU-funded project PRATIQUE and methods to improve consistency have been developed. PRATIQUE only considered the EPPO decision support scheme (EPPO DSS), however this work will be extended through consideration of additional risk assessments within the current EU-funded COST Action Alien Challenge. Task 2: Develop minimum standards for risk assessment methodologies The review of characteristics of risk assessments through task 1 resulted in a long-list of attributes. The derived attributes ranged from broad consideration of general characteristics including description of the species through to criteria relevant to the invasion process including likelihood of arrival, establishment and spread. Impacts were classified broadly and included biodiversity and socio-economic impacts alongside perspectives influencing impacts such as climate change. Additional consideration was given to implementation of the protocol including quality assurance and alignment with agreed international standards and policies such as the World Trade Organisation (WTO) and relevant EU Directives including the EU Marine Strategy Framework Directive (MSFD) and EU Water Framework Directive (WFD). From the long-list the core project team developed and selected a draft short-list of attributes that were considered to be relevant for performing risk assessments of IAS. The short-list of minimum standards was agreed by the project team and preliminarily reviewed through a pre-workshop survey in Task 3. Task 3: Risk assessment workshop The overarching aim of the risk assessment workshop (27-28th March 2014) was to peer-review the derived short-list of minimum standards. The derived minimum standards are required to underpin evaluation of existing risk assessments and ensure they are fit for the purpose of supporting the development of a list of “IAS of EU concern”. We aimed to distil the critical components of a risk assessment that, through expert opinion and consensus, are agreed necessary to achieve overarching, robust and rigorous assessment of the risk of an IAS, regardless of the specific approach taken. Additionally consideration was given to recognized international guidelines and recommendations with relevance to the development of minimum standards for risk assessments. The workshop included participants from the project team (23 experts from nine organisations) and 12 additional invited experts. The invited experts and those from within the team represented a breadth of expertise from a variety of perspectives including taxonomic (all taxa, including pathogens), environmental (freshwater, marine and terrestrial), impacts (environmental, socio-economic and health) and disciplines (ecologists, economist, conservation practitioners, scientists, policy-makers, risk assessors). Many of the experts had been actively involved in the development, testing and implementation of risk assessment protocols for IAS. The experts were invited to review and refine the list of attributes derived through Tasks 1 and 2 for inclusion as potential minimum standards. The long list of attributes of risk assessments derived through Task 1 and 2 were circulated in the form of a pre-workshop survey (using Survey Monkey) in which the experts were asked to rank the importance of each as a potential minimum standard on a scale of 1 (low importance) to 5 (high importance). Experts were also asked to provide additional attributes that were not apparent from the long-list. The pre-workshop survey revealed a high level of consensus between all experts for most of the attributes. However one-third of the experts stated that a totally new EU-wide risk assessment system tailored for the new IAS Regulation should be developed. Attributes aligning with socio-economic aspects also appeared to cause division in responses by the experts. Furthermore, questions relating to cost-benefit led to a high degree of uncertainty with more than a third of participants responding “unsure”. The disagreement or uncertainty expressed by respondents on these specific themes highlighted the need to ensure that socio-economic considerations were included as a substantial component of the workshop programme. Clarity is an overarching requirement of risk assessment protocols to ensure consistency. It is of utmost importance that a protocol asks questions that are sufficiently clear and understandable for assessors. This is essential to ensure that responses (accompanied by an indication of level of uncertainty) deliver similar assessments for the same species in the same area, irrespective of the identity of the assessors – as long as these have the necessary expertise or are provided with the necessary information. Fourteen criteria were agreed, through consensus methods, to represent the minimum standards. The minimum standards are: 1. Description (Taxonomy, invasion history, distribution range (native and introduced), geographic scope, socio-economic benefits) 2. Includes the likelihood of entry, establishment, spread and magnitude of impact 3. Includes description of the actual and potential distribution, spread and magnitude of impact 4. Has the capacity to assess multiple pathways of entry and spread in the assessment, both intentional and unintentional 5. Can broadly assess environmental impact with respect to biodiversity and ecosystem patterns and processes 6. Can broadly assess environmental impact with respect to ecosystem services 7. Broadly assesses adverse socio-economic impact 8. Includes status (threatened or protected) of species or habitat under threat 9. Includes possible effects of climate change in the foreseeable future 10. Can be completed even when there is a lack of data or associated information 11. Documents information sources 12. Provides a summary of the different components of the assessment in a consistent and interpretable form and an overall summary 13. Includes uncertainty 14. Includes quality assurance Task 4: Screening of existing risk assessment methodologies None of the analysed risk assessment protocols were fully compliant with the minimum standards. However, there were a number of protocols that appeared to be compliant with a sufficient number of the minimum standards or with the potential to be modified in accordance with the minimum standards to be included within Task 4. The GB NNRA, EPPO DSS, Harmonia+ and ENSARS were the risk assessment protocols that most closely met the minimum standards, they are further referred to as "substantially compliant risk assessments". The risk assessments undertaken with the GB NNRA and EPPO DSS were accessible and included a range of species. Harmonia+ has potential as a risk assessment protocol with broad taxonomic and geographic applicability. It is a comprehensive risk assessment protocol, however it has only recently been published and currently no species have been formally assessed using this method. ENSARS includes assessments for a number of species but these are not yet formally published. GB NNRA and Harmonia+ both currently lack inclusion of description of socio-economic benefits. However, experts representing these methods acknowledge a willingness to include this aspect as a priority in the future. The EPPO DSS and ENSARS already consider such benefits. Consideration of possible effects on climate change in the foreseeable future was lacking in most protocols. However, the GB NNRA does include climate change considerations. ENSARS, Harmonia+ and EPPO fail to include climate change considerations within their protocols but could easily include this aspect as a priority for updates in the future. Consideration of the effects of IAS on ecosystem services was almost consistently lacking in the risk assessment protocols. This was identified through the literature review (Tasks 1 and 2) but was confirmed through Task 4. IAS impacts on biodiversity, ecosystem patterns and processes, ecosystem services and related socio-economic implications are clearly interlinked. Therefore, there are foreseen to be overlaps in how these different impacts are determined in practice: the identification of impacts on biodiversity and ecosystem characteristics clearly forms the basis for impacts on ecosystem services whereas identifying the impacts on ecosystem services form a key conceptual basis for assessing the foreseen socio-economic impacts of IAS invasion. These overlaps – or synergies - should be taken into consideration when developing these three minimum standards further in the future. It is foreseen that a dedicated guidance on how to assess the impact on ecosystem services, in the context of EU risk assessments for IAS, would need to be developed. Task 5: Screening of potential “IAS of EU Concern” and proposal of a list Prioritisation of potential “IAS of EU concern” is essential to both target IAS interventions at the species constituting the highest risks and for allocating the limited resources available for invasion management based on feasibility of outcomes. The establishment of a risk analysis framework, in consultation with the EC, would ensure a coherent and coordinated response to risks of EU relevance which could be termed “IAS of EU concern”. The main objective of the study was to analyse a set of species that have been risk assessed using protocols meeting the minimum standards to develop the list of “IAS of EU concern”. As a result of the analysis in Task 4, it was apparent that none of the existing protocols screened, tested and discussed within Task 3 meet the full set of minimum standards. We proceeded with the analysis of the list of 80 species provided by the Commission against those protocols for risk assessment that were considered as “substantially compliant”. Due to the lack of risk assessment protocols compliant with the minimum standards, it was not possible to obtain a fully compliant list of proposed “IAS of EU concern” as initially foreseen. However, four risk assessment protocols, namely the EPPO DSS, ENSARS, GB NNRA and Harmonia+, were selected as they meet “most” minimum standards and included a breadth of species in existing assessments. The lists generated from the four selected protocols were thus cross-tabulated against the list of 80 species provided by the EC. It is important to note that some of the existing assessments (most notably within GB NNRA, ENSARS and Harmonia+) apply to a restricted area within Europe and so caution in extrapolating outcomes to a European-scale is required. In total 50 species are included within the draft list of proposed “IAS of EU concern” and these were identified through the “substantially compliant” risk assessments as posing a medium to high risk on biodiversity and/or human health and the economy. Of these 37 are from GB NNRA, 18 from EPPO and one from ENSARS. Seven of the species were assessed within more than one protocol. The list includes 14 species in addition to those within the original list provided by the EC. The draft list of proposed “IAS of EU concern” includes 25 plants, 12 vertebrates, 13 invertebrates of which most are found in the terrestrial and freshwater environments (24 and 20 respectively whereas only six marine species are included). The draft list is constrained by inclusion of only the IAS for which a “substantially compliant” risk assessment is available. Furthermore, there are inherent limitations of a list of proposed “IAS of EU concern” compiled on the basis of risk assessment protocols which do not fully comply with the agreed minimum standards. This is reflected in a number of shortcomings or inconsistencies resulting from the outcomes of the four protocols which were used to draft the list of proposed “IAS of EU concern”. Concluding remarks and key recommendations Available risk assessment protocols that meet the minimum standards are an important step in developing a list of “IAS of EU concern”. Refinements to existing risk assessment protocols are required to ensure they include consideration of ecosystem services, climate change and adverse impacts on socio-economic benefits. As these criteria are encompassed it will be necessary to critically test and evaluate the performance of these modified protocols as it is necessary to improve consistency of outcomes. Support should be given to enable developments to modify risk assessment protocols within their mandate to comply with the new EU Regulation. This should include the development of appropriate guidance on the interpretation and use of minimum standards where required. Additionally the importance of national impact assessment protocols should be recognised with consideration given to modifications of methods to provide a scientific basis for EU assessments. These assessments should serve as source to identify potential additional ‘IAS of EU concern’ and evaluation of the list. Impact assessments are not compliant with the minimum standards because of lack of consideration of mechanisms of introduction and establishment. However, impact assessments provide a detailed basis upon which to quantify the impacts of IAS and include aspects that could be considered for inclusion within full risk assessments. The risk assessment methods based on the protocol devised by EPPO DSS, namely GB NNRA and ENSARS, provide a basis on which to begin developing a list of ‘IAS of EU concern’. However, the breadth of species considered relevant is influenced by the original purposes of both protocols. Harmonia+ is a new and promising risk assessment method. It will be essential to consider the relevance of this protocol as one of the key players going forward. A critical issue exists in the simplification of extrapolating national or regional assessments to the total area of the EU. The EU is rich in biodiversity and is a highly heterogeneous and large territory and so risk assessments of IAS may differ substantially when different regions are considered. Consideration of European biogeographic regions as contex for existing national risk assessments protocols would be appropriate. It is essential to ensure that risk assessments undertaken for restricted regions within Europe (such as the GB NNRA, ENSARS and Harmonia+) have relevance to the EU as outlined above. Review of the applicability of such assessments for EU relevance is unlikely to be trivial for many IAS. Re-assessment of risks identified through national risk assessment protocols at the EU level (with consideration of biogeographic regions) through scientific experts should be prioritised. Further development of the list of proposed “IAS of EU concern” is necessary and should involve scientific experts based on the framework provided by the new EU Regulation. It will be essential to develop a process for consolidating the draft list of proposed “IAS of EU concern” through involvement of scientific experts. The list of proposed “IAS of EU concern” will need to be reviewed on a regular basis to ensure it remains current as the number of new arrivals escalates. Equally the knowledge underpinning our understanding of invasions and environmental change will improve and additional relevant concepts will emerge. Therefore, periodically it will be necessary not only to review the list of proposed “IAS of EU concern” but also the framework of minimum standards upon which it is based as, for example, understanding increases and evidence suggests the need to modify minimum standards or indeed include additional minimum standards. Consideration of the establishment of a formal procedure for evaluating the list of proposed “IAS of EU concern” after 2016 should be prioritised. It will be essential to provide support for cooperation between scientific experts (responsible for the risk assessments) and the Member State and stakeholder experts (responsible for the risk management and communication). Indeed before the final list of “IAS of EU concern” is determined risk management factors should be taken into account, such as how widespread the species is within the EU, what benefits are associated with the species and the cost-benefit of adding the species to the list of “IAS of EU concern"

ARES(2014)2425342 - 22/07/2014. Organisation and running of a scientific workshop to complete selected invasive alien species (IAS) risk assessments

The introduction and spread of invasive alien species (IAS) constitutes one of the most important drivers of global change in biodiversity and ecosystem services. Robust risk assessment methods are required for IAS to provide the foundation upon which to prioritise appropriate action. In a previous study (Roy, Schonrogge et al. 2014) minimum standards were developed to provide an assessment framework for risk assessments and ultimately for underpinning the development of a proposed list of “IAS of EU concern”, in accordance to the provisions of the Regulation (EU) No 1143/2014 of the European Parliament and of the Council of 22 October 2014 on the prevention and management of the introduction and spread of invasive alien species. In practice, of the protocols assessed in detail, only four (GB NNRA, EPPO DSS, Harmonia+ and ENSARS) were sufficiently compliant with the minimum standards to be considered and of these only the GB NNRA and EPPO DSS have published IAS risk assessments. As a result, using the information from such “substantially compliant” protocols, a draft list of approximately 50 species was compiled. It is important to note that this list of species is based on availability of robust risk assessments already completed through methods which are almost compliant with the minimum standards, and it does not constitute the list of “IAS of EU concern”. In view of the application of the forthcoming EU Regulation on IAS (and building-on ENV.B.2/ETU/2013/0026) the Commission hosted a 2-day scientific workshop to examine the selected risk assessments and pool the existing knowledge existing in the EU to complete the missing information, on the basis of robust scientific evidence, in order to make them fully compliant with the minimum standards, wherever possible. The workshop was led by Helen Roy (CEH) and Riccardo Scalera (ISSG). An additional 16 experts from fifteen member states were selected based on their expertise in invasion biology and represented a breadth of expertise from a variety of perspectives including taxonomic (all taxa), environmental (freshwater, marine and terrestrial), impacts (environmental, socio-economic and health) and disciplines (ecologists, conservation practitioners, scientists, policy-makers, risk assessors). In view of the gaps across risk assessments for ecosystem services and climate change two experts were invited to guide the development of approaches for these specific themes. In total the risk assessments for 56 species were considered. The GB NNRA and EPPO DSS have published IAS risk assessments which, when considering species that score medium to high impact, together cover 51 species (noting that Fallopia japonica and F. sachalinensis are separate species). Two further risk assessments were suggested for consideration by the GB Non-Native Species Secretariat which follow the GB NNRA protocol: coati (Nasua nasua) and skunk (Mephitis mephitis), although scored as low impact. Finally an additional three species have been considered through new European–wide risk assessments, with the reported outcome of high impact, for this project which again follow the GB NNRA protocol: Pallas squirrel (Callosciurus erythraeus), grey squirrel (Sciurus carolinensis) and coypu (Myocastor coypus). The main gaps across all risk assessments were in relation to climate change and ecosystem services but additional information was also required on benefits as mentioned with minimum standard “Description (Taxonomy, invasion history, distribution range (native and introduced), geographic scope, socio-economic benefits)” and in some cases information to support the minimum standard “Includes status (threatened or protected) of species or habitat under threat“ was missing. It was agreed that systematic consideration of a list of questions in relation to the minimum standards on ecosystem services and climate change would be useful guidance for experts. An outline of the approaches agreed through the workshop for the minimum standards “Includes possible effects of climate change in the foreseeable future“ and “Can broadly assess environmental impact with respect to ecosystem services” were developed as guidance for documenting information in relation to climate change and ecosystem services. Each species was considered separately with the experts providing an overview of the information available for addressing the identified gaps. After all species had been considered the workshop participants (excluding the EC, Helen Roy and Riccardo Scalera) adopted a consensus approach to confirm whether or not the risk assessment was compliant with the minimum standards and whether the overall score of the risk assessment remained applicable. No changes were made to the scores but any recommendations were noted. There were very few recommendations for change. The outcome for each risk assessment was agreed and summarised as “compliant” or “not compliant” with the minimum standards. Of the risk assessments for the 56 species considered through this project, 53 were agreed to be fully compliant with the minimum standards. However, Pacific oyster, Crassostrea gigas, although compliant with the minimum standards should be excluded as it is not within the scope of the regulation (see art 2.e) because it is listed in annex IV of Council Regulation (EC) No 708/2007 of 11 June 2007 concerning use of alien and locally absent species in aquaculture. Four of the risk assessments were not considered to be compliant because of major information gaps: Elodea canadensis (Canadian pondweed), Heracleum mantegazzianum (giant hogweed), M. mephitis (skunk), N. nasua (coati)

Identifying, reducing, and communicating uncertainty in community science:A focus on alien species

Community science (also often referred to as citizen science) provides a unique opportunity to address questions beyond the scope of other research methods whilst simultaneously engaging communities in the scientific process. This leads to broad educational benefits, empowers people, and can increase public awareness of societally relevant issues such as the biodiversity crisis. As such, community science has become a favourable framework for researching alien species where data on the presence, absence, abundance, phenology, and impact of species is important in informing management decisions. However, uncertainties arising at different stages can limit the interpretation of data and lead to projects failing to achieve their intended outcomes. Focusing on alien species centered community science projects, we identified key research questions and the relevant uncertainties that arise during the process of developing the study design, for example, when collecting the data and during the statistical analyses. Additionally, we assessed uncertainties from a linguistic perspective, and how the communication stages among project coordinators, participants and other stakeholders can alter the way in which information may be interpreted. We discuss existing methods for reducing uncertainty and suggest further solutions to improve data reliability. Further, we make suggestions to reduce the uncertainties that emerge at each project step and provide guidance and recommendations that can be readily applied in practice. Reducing uncertainties is essential and necessary to strengthen the scientific and community outcomes of community science, which is of particular importance to ensure the success of projects aimed at detecting novel alien species and monitoring their dynamics across space and time

Applying the convention on biological diversity pathway classification to alien species in Europe

The number of alien species arriving within new regions has increased at unprecedented rates. Managing the pathways through which alien species arrive and spread is important to reduce the threat of biological invasions. Harmonising information on pathways across individual sectors and user groups is therefore critical to underpin policy and action. The European Alien Species Information Network (EASIN) has been developed to easily facilitate open access to data of alien species in Europe. The Convention on Biological Diversity (CBD) Pathway Classification framework has become a global standard for the classification of pathways. We followed a structured approach to assign pathway information within EASIN for a subset of alien species in Europe, which covered 4169 species, spanning taxonomic groups and environments. We document constraints and challenges associated with implementing the CBD Pathway Classification framework and propose potential amendments to increase clarity. This study is unique in the scope of taxonomic coverage and also in the inclusion of primary (independent introductions to Europe) and secondary (means of dispersal for species expansion within Europe, after their initial introduction) modes of introduction. In addition, we summarise the patterns of introduction pathways within this subset of alien species within the context of Europe. Based on the analyses, we confirm that the CBD Pathway Classification framework offers a robust, hierarchical system suitable for the classification of alien species introduction and spread across a wide range of taxonomic groups and environments. However, simple modifications could improve interpretation of the pathway categories ensuring consistent application across databases and information systems at local, national, regional, continental and global scales. Improving consistency would also help in the development of pathway action plans, as required by EU legislation

Socio-economic impact classification of alien taxa (SEICAT)

Many alien taxa are known to cause socio-economic impacts by affecting the different constituents of human well-being (security; material and non-material assets; health; social, spiritual and cultural relations; freedom of choice and action). Attempts to quantify socio-economic impacts in monetary terms are unlikely to provide a useful basis for evaluating and comparing impacts of alien taxa because they are notoriously difficult to measure and important aspects of human well-being are ignored.Here, we propose a novel standardised method for classifying alien taxa in terms of the magnitude of their impacts on human well-being, based on the capability approach from welfare economics. The core characteristic of this approach is that it uses changes in peoples' activities as a common metric for evaluating impacts on well-being.Impacts are assigned to one of five levels, from Minimal Concern to Massive, according to semi-quantitative scenarios that describe the severity of the impacts. Taxa are then classified according to the highest level of deleterious impact that they have been recorded to cause on any constituent of human well-being. The scheme also includes categories for taxa that are not evaluated, have no alien population, or are data deficient, and a method for assigning uncertainty to all the classifications. To demonstrate the utility of the system, we classified impacts of amphibians globally. These showed a variety of impacts on human well-being, with the cane toad (Rhinella marina) scoring Major impacts. For most species, however, no studies reporting impacts on human well-being were found, i.e. these species were data deficient.The classification provides a consistent procedure for translating the broad range of measures and types of impact into ranked levels of socio-economic impact, assigns alien taxa on the basis of the best available evidence of their documented deleterious impacts, and is applicable across taxa and at a range of spatial scales. The system was designed to align closely with the Environmental Impact Classification for Alien Taxa (EICAT) and the Red List, both of which have been adopted by the International Union of Nature Conservation (IUCN), and could therefore be readily integrated into international practices and policies

A vision for global monitoring of biological invasions

Managing biological invasions relies on good global coverage of species distributions. Accurate information on alien species distributions, obtained from international policy and cross-border co-operation, is required to evaluate trans-boundary and trading partnership risks. However, a standardized approach for systematically monitoring alien species and tracking biological invasions is still lacking. This Perspective presents a vision for global observation and monitoring of biological invasions. We show how the architecture for tracking biological invasions is provided by a minimum information set of Essential Variables, global collaboration on data sharing and infrastructure, and strategic contributions by countries. We show how this novel, synthetic approach to an observation system for alien species provides a tangible and attainable solution to delivering the information needed to slow the rate of new incursions and reduce the impacts of invaders. We identify three Essential Variables for Invasion Monitoring; alien species occurrence, species alien status and alien species impact. We outline how delivery of this minimum information set by joint, complementary contributions from countries and global community initiatives is possible. Country contributions are made feasible using a modular approach where all countries are able to participate and strategically build their contributions to a global information set over time. The vision we outline will deliver wide-ranging benefits to countries and international efforts to slow the rate of biological invasions and minimize their environmental impacts. These benefits will accrue over time as global coverage and information on alien species increases

Seven recommendations to make your invasive alien species data more useful

Science-based strategies to tackle biological invasions depend on recent, accurate, well-documented, standardized and openly accessible information on alien species. Currently and historically, biodiversity data are scattered in numerous disconnected data silos that lack interoperability. The situation is no different for alien species data, and this obstructs efficient retrieval, combination, and use of these kinds of information for research and policy-making. Standardization and interoperability are particularly important as many alien species related research and policy activities require pooling data. We describe seven ways that data on alien species can be made more accessible and useful, based on the results of a European Cooperation in Science and Technology (COST) workshop: (1) Create data management plans; (2) Increase interoperability of information sources; (3) Document data through metadata; (4) Format data using existing standards; (5) Adopt controlled vocabularies; (6) Increase data availability; and (7) Ensure long-term data preservation. We identify four properties specific and integral to alien species data (species status, introduction pathway, degree of establishment, and impact mechanism) that are either missing from existing data standards or lack a recommended controlled vocabulary. Improved access to accurate, real-time and historical data will repay the long-term investment in data management infrastructure, by providing more accurate, timely and realistic assessments and analyses. If we improve core biodiversity data standards by developing their relevance to alien species, it will allow the automation of common activities regarding data processing in support of environmental policy. Furthermore, we call for considerable effort to maintain, update, standardize, archive, and aggregate datasets, to ensure proper valorization of alien species data and information before they become obsolete or lost

Drivers of future alien species impacts: an expert‐based assessment

Understanding the likely future impacts of biological invasions is crucial yet highly challenging given the multiple relevant environmental, socio‐economic and societal contexts and drivers. In the absence of quantitative models, methods based on expert knowledge are the best option for assessing future invasion trajectories. Here, we present an expert assessment of the drivers of potential alien species impacts under contrasting scenarios and socioecological contexts through the mid‐21st century. Based on responses from 36 experts in biological invasions, moderate (20%–30%) increases in invasions, compared to the current conditions, are expected to cause major impacts on biodiversity in most socioecological contexts. Three main drivers of biological invasions—transport, climate change and socio‐economic change—were predicted to significantly affect future impacts of alien species on biodiversity even under a best‐case scenario. Other drivers (e.g. human demography and migration in tropical and subtropical regions) were also of high importance in specific global contexts (e.g. for individual taxonomic groups or biomes). We show that some best‐case scenarios can substantially reduce potential future impacts of biological invasions. However, rapid and comprehensive actions are necessary to use this potential and achieve the goals of the Post‐2020 Framework of the Convention on Biological Diversity