THE THEMATIC ASSESSMENT REPORT ON INVASIVE ALIEN SPECIES AND THEIR CONTROL
15SUMMARY FOR POLICYMAKERS
making frameworks and tools for inclusively identifying and 
supporting management goals related to (a) management 
of pathways of introduction and spread of invasive alien 
species; (b) management of target invasive alien species 
at either local or landscape scales; and (c) site-based or 
ecosystem-based management. There are many sources 
of accessible literature and information, tools, and novel 
and emerging technologies, including biotechnology, 
bioinformatics, eDNA, remote sensing and data analytics, 
for supporting the management of biological invasions. 
Consideration of both potential benefits and risks of the 
management of biological invasions can improve outcomes. 
A risk assessment and a risk management framework 
in line with a precautionary approach, as appropriate, 
can be effective to guide management actions, including 
the use of novel and emerging and environmentally 
sound technologies. The success of any management 
programme depends on the availability of adequate, 
sustained resources, including for building capacity, which 
is sometimes lacking, especially in some developing 
countries. Multi-stakeholder engagement, including risk 
communication and context-specific application, can 
improve public acceptability and adoption of new tools and 
technologies for managing biological invasions.
KM-C2 Prevention and preparedness are the 
most cost-effective options and thus crucial for 
managing the threats from invasive alien species 
{C15, C17, C18}. Prevention can be achieved through 
pathway management, including strictly enforced import 
controls, pre-border, border and post-border biosecurity, 
and measures to address escape from confinement. 
Prevention is particularly critical in marine and connected 
water systems, where most attempts at eradicating or 
containing invasive alien species have mostly failed. 
Prevention has been particularly effective on islands. 
Preparedness includes border surveillance, early detection 
and rapid response planning, and is critical to reduce 
rates of establishment. Horizon scanning and risk analysis 
can support prevention and preparedness by prioritizing 
emerging invasive alien species. Sustained and adequate 
funding, capacity-building, technical and scientific 
cooperation, transfer of technology, monitoring, relevant 
and appropriate biosecurity legislation and enforcement, 
and quarantine and inspection facilities are necessary for 
effective prevention measures.
KM-C3 Eradication has been successful, 
especially for small and slow-spreading 
populations of invasive alien species in isolated 
ecosystems {C19}. Over the last 100 years, 88 per 
cent of eradication attempts on 998 islands have proven 
successful, especially for invasive alien vertebrates. 
Large-scale eradications have been achieved but in many 
cases are likely to be infeasible. There are also examples 
of eradication of invasive alien plants and invertebrates, 
particularly for those with limited distribution. Adoption of 
appropriate tools and technologies and involvement of 
relevant stakeholders underpin and improve the success of 
eradication programmes. Sustained investment is required 
15SUMMARY FOR POLICYMAKERS
The thematic assessment report on
INVASIVE ALIEN SPECIES
AND THEIR CONTROL
C. Invasive alien species and their 
negative impacts can be prevented 
and mitigated through effective 
management