Prioritizing species, pathways, and sites to achieve conservation targets for biological invasion

Abstract

Prioritization is indispensable for the management of biological invasions, as recognized by the Convention on Biological Diversity, its current strategic plan, and specifically Aichi Target 9 that concerns invasive alien species. Here we provide an overview of the process, approaches and the data needs for prioritization for invasion policy and management, with the intention of informing and guiding efforts to address this target. Many prioritization schemes quantify impact and risk, from the pragmatic and action-focused to the data-demanding and science-based. Effective prioritization must consider not only invasive species and pathways (as mentioned in Aichi Target 9), but also which sites are most sensitive and susceptible to invasion (not made explicit in Aichi Target 9). Integrated prioritization across these foci may lead to future efficiencies in resource allocation for invasion management. Many countries face the challenge of prioritizing with little capacity and poor baseline data. We recommend a consultative, science-based process for prioritizing impacts based on species, pathways and sites, and outline the information needed by countries to achieve this. This should be integrated into a national process that incorporates a broad suite of social and economic criteria. Such a process is likely to be feasible for most countries.

Invasive predators and global biodiversity loss

“…Given the many islands on which invasive predators occur and the high costs involved in controlling or eradicating them, prioritization of islands for eradications is an important exercise (30)(31)(32)(33). Facilitation between multiple invasive species (e.g., rodents providing abundant food for cats, thus maintaining high densities of the latter) can exacerbate their respective impacts on native species (1,9).…”

Beyond protocols: improving the reliability of expert-based risk analysis underpinning invasive species policies

“…This requires baseline data on priority species, their pathways of introduction and susceptible and sensitive sites (McGeoch et al 2016). High resolution distribution data as well as survey data on establishment and spread are often lacking or inadequate which can lead to suboptimal conservation investment.…”

“…Several studies have reviewed and compared these tools. Protocols consider different subsets of the major invasion stages (transport, introduction, establishment, spread), impact categories (environmental, health, socio-economic) and domains of impact (human, animal, plant) (Heikkilä 2011;Kumschick and Richardson 2013;Leung et al 2012;Verbrugge et al 2010;Roy et al 2014a;McGeoch et al 2016). They also differ in the possibilities for weighting different components of impact and the way they cover uncertainty (Heikkilä 2011).…”

“…They also differ in the possibilities for weighting different components of impact and the way they cover uncertainty (Heikkilä 2011). In a comprehensive review of risk assessment schemes, McGeoch et al (2016) stated that there is currently no broadly adopted, standard approach to prioritizing invasions. The method and approach that is most relevant for any given risk assessment will differ depending on the objective and scope.…”

Invasive Alien Species Management: A Personal Impasse

“…Although we may like to control all IAS, the full prevention of new introductions across all biomes is an insurmountable aim (Seebens et al, 2017) while the management of already introduced or established IAS is often technically challenging, time consuming, and costly (Courchamp et al, 2017). Due to environmental managers having a limited resource, the hundreds of IAS within each of their jurisdictions and the inevitably of that number increasing, some sort of prioritization process is clearly needed (McGeoch et al, 2016).…”