Common deficiencies of actions for managing invasive alien species: a decision-support checklist

Abstract

Despite the increasing number of invasive species, protocols devoted to assess the feasibility (i.e., probability of success or failure) of management actions in the field are scarce, yet success depends on a broad scope of issues beyond the biology of species and the ecosystem to be managed. In this paper we make a retrospective analysis of 90 actions and management proposals developed in Andalusia (southern Spain) in 2004 to 2018. Actions included 59 terrestrial and aquatic taxa. We identified items that in case of deficiency were responsible for either the rejection of action proposals (n = 44) or failure of implemented actions for which the goal was not achieved (n = 22). The most frequent deficiencies included the absence of funding during the necessary time to achieve the goals, the risk of reinvasion and an insufficient removal rate to achieve the specific objective. Based on the deficiencies found, we built a comprehensive, broad-scope compliance checklist to assist decision-makers to identify deficiencies before action. In addition, implemented actions for which the goal was achieved (n = 24) were used for validating the checklist. The checklist contains 40 items related to IAS features, administrative features, methodology effectiveness, efficiency and impacts of the action, and invaded ecosystem features. The checklist is valid across all taxa and habitats. The use of this checklist will help reduce the degree of arbitrariness and subjectivity of actions aimed at managing IAS, and a more efficient use of resources.

Six years of controlling the invasive species Vespa velutina in a Mediterranean island: The promising results of an eradication plan

“…If we check the most important items that had the highest frequency of occurrence in unsuccessful actions for management of IAS, 56 we can verify the viability of the eradication plan presented here. In this plan, (i) the funds are guaranteed during the necessary time frame; (ii) the risk of reinvasion is low because Majorca is an island; (iii) sufficient nest removal rate to achieve the eradication objective; (iv) evidence reporting that the methodology applied is effective; and (v) there is adaptation of the methodology every year since the pest arrived.…”

Traps and netting, better together than alone: an innovative approach to improve Procambarus clarkii management

“…Both the opening diameter and mesh size of fish keeping net used in this study were bigger than other common gears used for zooplankton sampling in order to facilitate the catch of crayfish. The application of netting required the removal of submerged objects as a preparatory action in order to increase accessibility for workers, a key item related to feasibility of action plans (Dana et al, 2019). Netting trialled in this study may be in principle useful in shallow lakes and ponds, which can be forded on foot (depth < 1 m).…”

“…Managing populations of many aquatic invasive alien species remains an unsolved problem today. For many invasive species from inland waters (e.g., crayfish, freshwater mussels, and many fish) there is a lack of effective eradication and control methods compatible with the maintenance of uses (e.g., irrigation or drinking water for humans, livestock or wildlife) and preservation of native accompanying species (Dana et al, 2019). Although prevention and eradication maximises the efficiency of management, once aquatic invasive species have colonized an aquatic ecosystem, eradication seems feasible only for isolated or highly reduced populations (Wizen et al, 2008;Gherardi et al, 2011).…”

Las invasiones vegetales en sistemas agrícolas. Retrospectiva de los últimos 40 años en Cataluña

“…La capacidad predictiva de los diferentes protocolos suele ser elevada cuando se aplican de forma independiente y, de hecho, su aplicación se ha demostrado eficaz a la hora de reducir daños económicos (Keller et al, 2007). Sin embargo, estudios recientes alertan sobre la subjetividad implícita en las valoraciones de dichos protocolos (Dana et al, 2019) al depender del grado de experiencia del evaluador y de la escala espacial de aplicación, lo que puede dar lugar a inconsistencias en las valoraciones de riesgo cuando se analizan, en conjunto, los resultados de diferentes esquemas (González-Moreno et al, 2019). Por otro lado, la limitación en la funcionalidad de dicha metodología también recae en la dificultad en cuantificar objetivamente los daños causados por las especies evaluadas, en medir la variabilidad y la estocasticidad inherente de los hábitats hospedadores (Hulme, 2012) y en la falta de estandarización de los diferentes protocolos de evaluación diseñados hasta ahora (González-Moreno et al, 2019).…”