Taming the terminological tempest in invasion science

Standardised terminology in science is important for clarity of interpretation and communication. In invasion science – a dynamic and rapidly evolving discipline – the proliferation of technical terminology has lacked a standardised framework for its development. The result is a convoluted and inconsistent usage of terminology, with various discrepancies in descriptions of damage and interventions. A standardised framework is therefore needed for a clear, universally applicable, and consistent terminology to promote more effective communication across researchers, stakeholders, and policymakers. Inconsistencies in terminology stem from the exponential increase in scientific publications on the patterns and processes of biological invasions authored by experts from various disciplines and countries since the 1990s, as well as publications by legislators and policymakers focusing on practical applications, regulations, and management of resources. Aligning and standardising terminology across stakeholders remains a challenge in invasion science. Here, we review and evaluate the multiple terms used in invasion science (e.g. ‘non-native’, ‘alien’, ‘invasive’ or ‘invader’, ‘exotic’, ‘non-indigenous’, ‘naturalised’, ‘pest’) to propose a more simplified and standardised terminology. The streamlined framework we propose and translate into 28 other languages is based on the terms (i) ‘non-native’, denoting species transported beyond their natural biogeographic range, (ii) ‘established non-native’, i.e. those non-native species that have established self-sustaining populations in their new location(s) in the wild, and (iii) ‘invasive non-native’ – populations of established non-native species that have recently spread or are spreading rapidly in their invaded range actively or passively with or without human mediation. We also highlight the importance of conceptualising ‘spread’ for classifying invasiveness and ‘impact’ for management. Finally, we propose a protocol for classifying populations based on (i) dispersal mechanism, (ii) species origin, (iii) population status, and (iv) impact. Collectively and without introducing new terminology, the framework that we present aims to facilitate effective communication and collaboration in invasion science and management of non-native species

Nativeness is a binary concept —Invasiveness and its management are not

In interdisciplinary fields such as biodiversity conservation or invasion science —where multiple perspectives from diverse disciplines often need to converge for effective environmental management, it is crucial to minimise terminological confusion in order to understand and transmit concepts accurately. The diversity of perspectives can exert a substantial influence on defining key terms in those interdisciplinary fields, potentially resulting in confusion. A lively topic within invasion science concerns the definitions of nativeness, non-nativeness, and invasiveness. While some academics dismiss the nativeness concept because it cannot be objectively defined, others advocate for its categorization, and a third perspective posits it as a binary term. Here we argue the inherent binary nature of nativeness, even when our capacity to observe is challenging. Nativeness (and consequently, non-nativeness) is an intrinsic and binary property of a species (i.e. the set of populations of a species) in a place, which should remain a central piece of information in biodiversity conservation and ecosystem restoration. In contrast, invasiveness, which relies on quantitative metrics (including abundance, spread, or impacts), should not be defined on binary terms. This underscores the importance of offering diverse, context-specific management strategies to deal with it. We illustrate the consistency of nativeness' binary nature and the need to rely on diverse management options to address different invasion scenarios with the example of the freshwater crayfish in the Iberian Peninsula

To ban or not to ban, is it the only option to regulate biological invasions? Prohibir o no prohibir, ¿no hay más opciones para legislar sobre invasiones biológicas?

Biological invasions are one of the major causes of biodiversity loss. To mitigate the impacts of invasive alien species (IAS) that pose a serious threat, the Spanish Catalogue of Invasive Alien Species was created; this was a dynamic tool in its creation but rigid in its application. Although it is subject to continuous modifications, the inclusion of an IAS in the Catalogue generally entails a generic ban on its possession, transport, traffic and trade. However, such rigidity often generates social conflict when IAS are economically exploitable resources. In this review, we exemplify the difficulties of implementing generic bans and propose that, to be effective, IAS regulation should expand the range of available tools (i.e. be flexible), beyond the dilemma of banning or not banning everything. To this end, we propose the creation of categories of IAS involving different levels of restriction and management strategies. In the case of widely distributed species with no technical possibilities for large-scale population control or prevention of their expansion, we bring up the permissibility of their commercial exploitation under certain restrictions, and point out the difficulties associated with banning such exploitation where it is already taking place. While simple solutions (i.e. to ban or not to ban) may be easier to understand and implement, they are not always the most effective. We therefore encourage the introduction of flexibility in legislation, which, while introducing greater complexity, it would facilitate the decision-making in the management of IAS, improve resource efficiency and reduce social conflicts associated with such management

Rigid laws and invasive species management

Conservation conflicts arise frequently in the management of non-native invasive species (NIS) when such species provide socioeconomic benefits and have negative environmental impacts (van Wilgen & Richardson 2014). For example, when restrictions on exploitation of NIS are applied in response to demands from the public or agencies, NIS users may believe conservation interests take precedence over their interests (Fig. 1). These restrictions are justified by the benefits to biodiversity, but the absence of such benefits may generate a loss of social support for conservation, potentially leading to deregulation. To illustrate, we considered management of the red swamp crayfish in Spain and the European rabbit in New Zealand

Lista de especies exóticas acuáticas de la Península Ibérica (2020)

Se presenta una lista actualizada de las especies exóticas que se encuentran en etapa de establecimiento o de propagación de la invasión en aguas continentales de la península ibérica. La lista está basada en la evaluación sistemática de los datos en colaboración con un amplio equipo de expertos de España y Portugal. Esta lista de actualización es un instrumento de apoyo importante para la aplicación del Reglamento de la Unión Europea (UE) sobre las especies exóticas invasoras (EEI) y también proporciona una base objetiva para el examen de su aplicación. En última instancia, la información incluida puede utilizarse para supervisar el cumplimiento del objetivo de la Estrategia de la UE sobre diversidad biológica hasta 2030 para combatir las EEI, pero también para la aplicación de otras políticas de la UE con requisitos sobre especies exóticas, como las Directivas de Hábitats y Aves, la Directiva Marco sobre la Estrategia Marina (DMEM) y la Directiva Marco del Agua (DMA)

A horizon scan exercise for aquatic invasive alien species in Iberian inland waters

As the number of introduced species keeps increasing unabatedly, identifying and prioritising current and potential Invasive Alien Species (IAS) has become essential to manage them. Horizon Scanning (HS), defined as an exploration of potential threats, is considered a fundamental component of IAS management. By combining scientific knowledge on taxa with expert opinion, we identified the most relevant aquatic IAS in the Iberian Peninsula, i.e., those with the greatest geographic extent (or probability of introduction), severe ecological, economic and human health impacts, greatest difficulty and acceptability of management. We highlighted the 126 most relevant IAS already present in Iberian inland waters (i.e., Concern list) and 89 with a high probability of being introduced in the near future (i.e., Alert list), of which 24 and 10 IAS, respectively, were considered as a management priority after receiving the highest scores in the expert assessment (i.e., top-ranked IAS). In both lists, aquatic IAS belonging to the four thematic groups (plants, freshwater invertebrates, estuarine invertebrates, and vertebrates) were identified as having been introduced through various pathways from different regions of the world and classified according to their main functional feeding groups. Also, the latest update of the list of IAS of Union concern pursuant to Regulation (EU) No 1143/2014 includes only 12 top-ranked IAS identified for the Iberian Peninsula, while the national lists incorporate the vast majority of them. This fact underlines the great importance of taxa prioritisation exercises at biogeographical scales as a step prior to risk analyses and their inclusion in national lists. This HS provides a robust assessment and a cost-effective strategy for decision-makers and stakeholders to prioritise the use of limited resources for IAS prevention and management. Although applied at a transnational level in a European biodiversity hotspot, this approach is designed for potential application at any geographical or administrative scale, including the continental one

A horizon scan exercise for aquatic invasive alien species in Iberian inland waters

As the number of introduced species keeps increasing unabatedly, identifying and prioritising current and potential Invasive Alien Species (IAS) has become essential to manage them. Horizon Scanning (HS), defined as an exploration of potential threats, is considered a fundamental component of IAS management. By combining scientific knowledge on taxa with expert opinion, we identified the most relevant aquatic IAS in the Iberian Peninsula, i.e., those with the greatest geographic extent (or probability of introduction), severe ecological, economic and human health impacts, greatest difficulty and acceptability of management. We highlighted the 126 most relevant IAS already present in Iberian inland waters (i.e., Concern list) and 89 with a high probability of being introduced in the near future (i.e., Alert list), of which 24 and 10 IAS, respectively, were considered as a management priority after receiving the highest scores in the expert assessment (i.e., top-ranked IAS). In both lists, aquatic IAS belonging to the four thematic groups (plants, freshwater invertebrates, estuarine invertebrates, and vertebrates) were identified as having been introduced through various pathways from different regions of the world and classified according to their main functional feeding groups. Also, the latest update of the list of IAS of Union concern pursuant to Regulation (EU) No 1143/2014 includes only 12 top-ranked IAS identified for the Iberian Peninsula, while the national lists incorporate the vast majority of them. This fact underlines the great importance of taxa prioritisation exercises at biogeographical scales as a step prior to risk analyses and their inclusion in national lists. This HS provides a robust assessment and a cost-effective strategy for decision-makers and stakeholders to prioritise the use of limited resources for IAS prevention and management. Although applied at a transnational level in a European biodiversity hotspot, this approach is designed for potential application at any geographical or administrative scale, including the continental one

Lista de especies exóticas acuáticas de la Península Ibérica (2020)

Se presenta una lista actualizada de las especies exóticas que se encuentran en etapa de establecimiento o de propagación de la invasión en aguas continentales de la península ibérica. La lista está basada en la evaluación sistemática de los datos en colaboración con un amplio equipo de expertos de España y Portugal. Esta lista de actualización es un instrumento de apoyo importante para la aplicación del Reglamento de la Unión Europea (UE) sobre las especies exóticas invasoras (EEI) y también proporciona una base objetiva para el examen de su aplicación. En última instancia, la información incluida puede utilizarse para supervisar el cumplimiento del objetivo de la Estrategia de la UE sobre diversidad biológica hasta 2030 para combatir las EEI, pero también para la aplicación de otras políticas de la UE con requisitos sobre especies exóticas, como las Directivas de Hábitats y Aves, la Directiva Marco sobre la Estrategia Marina (DMEM) y la Directiva Marco del Agua (DMA)

Lista actualizada de las especies exóticas acuáticas introducidas y establecidas en las aguas continentales ibéricas

62 páginas. IlustradoSe presenta una lista actualizada de las especies exóticas que se encuentran en etapa de establecimiento o de propagación de la invasión en aguas continentales de la península ibérica. La lista está basada en la evaluación sistemática de los datos en colaboración con un amplio equipo de expertos de España y Portugal. Esta lista de actualización es un instrumento de apoyo importante para la aplicación del Reglamento de la Unión Europea (UE) sobre las especies exóticas invasoras (EEI) y también proporciona una base objetiva para el examen de su aplicación. En última instancia, la información incluida puede utilizarse para supervisar el cumplimiento del objetivo de la Estrategia de la UE sobre diversidad biológica hasta 2030 para combatir las EEI, pero también para la aplicación de otras políticas de la UE con requisitos sobre especies exóticas, como las Directivas de Hábitats y Aves, la Directiva Marco sobre la Estrategia Marina (DMEM) y la Directiva Marco del Agua (DMA). Esta publicación es un informe técnico del Proyecto Europeo LIFE INVASAQUA (LIFE17 GIE/ES/000515). Ha sido redactado por un equipo de expertos en el marco del proyecto y tiene por objeto proporcionar apoyo, basado en pruebas científicas, al proceso de formulación de políticas europeas. La información científica aportada no implica una posición política de la Comisión Europea. Ni la Comisión Europea ni ninguna persona que actúe en nombre de la Comisión es responsable del uso que pueda hacerse de esta publicación.Este estudio fue apoyado económicamente por el proyecto LIFE INVASAQUA (Especies exóticas acuáticas invasoras de agua dulce y sistemas estuarinos: sensibilización y prevención en la Península Ibérica) (LIFE17 GIE/ES/ 000515) financiado por el Programa LIFE de la UE.Contiene: Prólogo 9 Autores y colaboradores 10 Agradecimientos 11 Acrónimos y abreviaturas 12 Resumen ejecutivo 13 1. Introducción y objetivos 16 1.1. Antecedentes 16 1.2. Objetivos de la lista y propósito del informe 17 2. Alcance y metodología de evaluación 20 2.1. Ámbito geográfico 20 2.2. Alcance del concepto de biota exótica acuática 20 2.3. Evaluación y selección de especies 22 3. Resultados 3.1. Lista 3.2. Enfoque taxonómico 4. Recomendaciones y necesidades de actualización 38 Referencias bibliográficas 39 Lista de afiliaciones de los autores 43 Lista de colaboradores 47 Apéndice A Lista de especies exóticas acuáticas definidas como establecidas (naturalizadas) en las aguas continentales ibéricas Apéndice B Lista de especies exóticas acuáticas definidas como de estado incierto y criptogénico en las aguas continentales ibéricas Apéndice C Número de especies exóticas acuáticas definidas por grupos taxonómicos (Filo, Clase y Orden) Material complementario (http://www.ibermis.org/) (http://www.lifeinvasaqua.com/