Determinants of rapid response success for alien invasive species in aquatic ecosystems

Alien invasive species (AIS) have received much attention for their harmful effects on health, ecology and the global economy. In response to this threat, many countries have adopted the Convention on Biological Diversity, which requires prevention or eradication of AIS. The best management approach is prevention, however when this fails and AIS establish, it is imperative that cost-efficient, rapid-response (RR) countermeasures be available. We performed a meta-analysis of case studies involving successful and failed RR to AIS in temperate aquatic ecosystems. We examined eight variables including ecosystem type (freshwater vs. marine), method type (chemical vs. mechanical), number of methods (multiple vs. single), taxonomy (animal vs. plant), population abundance (number of organisms), infestation extent (surface area of infestation), habitat size (surface area of management site), and project duration (length of project in number of months). Eradication success was significantly greater for plant (89 %) versus animal AIS (64 %) while suppression of AIS was most successful for projects using chemical versus mechanical methods and when conducted in small habitats. Managers should expect that taxonomy will be highly influential to the success of eradication-based RR, while both method type and management surface area influence suppression outcomes.