THE THEMATIC ASSESSMENT REPORT ON INVASIVE ALIEN SPECIES AND THEIR CONTROL
36SUMMARY FOR POLICYMAKERS
management approach, including ecosystem restoration, 
depends on long-term monitoring to assess management 
efficacy using ecological and social indicators (established 
but incomplete) {5.5.2, 6.6.3}. Long-term monitoring of sites 
ensures early detection of new introductions, reintroductions 
and re-emergence of invasive alien species (e.g., from a 
seed bank that includes invasive alien plants) and can inform 
further management actions (well established) {5.4.3.3.b, 
5.5.6}. However, most studies failed to quantify the 
effectiveness of ecosystem restoration since they failed to 
measure the initial status of native vegetation. This has led 
to inconsistent conclusions regarding the best invasive alien 
plant control option which may lead to the most effective 
ecosystem restoration {5.4.3.3b; 5.5.6}. Regarding 
freshwater ecosystems, monitoring biodiversity using 
macroinvertebrate-based indices is a widely used method 
globally. However, knowledge is lacking on how invasive 
alien species may affect the metric scores and therefore 
classification of a river's status (established but incomplete)
{5.6.2.3}. In marine and connected water systems, 
ecosystem restoration has so far proved to be largely 
ineffective because the systems are open, leading to 
difficulties in implementing and evaluating management 
actions (established but incomplete) {5.5.6, 5.6.1.1}.
C22 Tools and technologies increase efficiencies 
when managing biological invasions and controlling 
invasive alien species, with many new options 
emerging (established but incomplete) {5.4}. The 
development of tools and technologies ranging from 
biotechnology to bioinformatics and data analytics is ongoing 
for managing pathways, surveillance and detection, rapid 
response and eradication, local containment and control of 
widespread invasive alien species (well established) {5.4.1, 
5.4.2, 5.4.3}. eDNA-based approaches have been used for 
detection and identification of invasive alien, mostly aquatic, 
species such as Orconectes rusticus (rusty crayfish) (well 
established) {5.4.2.1}. New approaches can be integrated 
with existing management actions to support site- and 
ecosystem-based management and restoration (established 
but incomplete) {5.4}. Multi-stakeholder engagement, 
including risk communication and context-specific 
application of approaches through local communities, can 
improve public acceptability and adoption of new tools and 
technologies for managing biological invasions and the 
control of invasive alien species (well established) {5.2.1, 
5.4.3, 5.6.2.1, 6.4.1}. Potential benefits and risks of novel 
technologies can be assessed using a risk assessment and 
risk management framework in line with a precautionary 
approach, as appropriate (well established) {5.4.3.2.f}. Using 
this framework in consultation with regulators, stakeholders 
and Indigenous Peoples and local communities can limit the 
potential for unintended consequences (well established)
{5.4.3.2}. However, most countries do not have the 
regulatory frameworks and/or technical capabilities needed 
to guide and support development and implementation of 
new tools and technologies (established but incomplete)
{5.4.3.2, 6.3.3.4}. Access to modern tools and technologies 
and the ability to utilize them can be limited, particularly in 
developing countries, meaning greater capacity-building is 
required and improved technical and scientific cooperation 
(well established) {5.6.2.4, 6.7.2.7}.
C23 Stakeholder engagement, capacity-building 
and sustained resourcing are critical to the 
success of adaptive management (well established)
{5.2.1, 5.6.2.1, 5.6.2.2, 5.6.2.4, 6.4.1, 6.5.3, 6.5.6, 
6.5.7}. Access to adequate and sustained financial and 
other resources, including international funding to support 
developing countries, underpins and improves the 
effectiveness of actions for long-term management of 
biological invasions, including eradication, control and 
ongoing monitoring, by, for example, providing access to 
modern tools and enhancing capacity to deploy them (well 
established) {5.3.1, 5.5.7, 5.6.2.1, 5.6.2.2, 5.6.2.4, 6.5, 
6.5.7}. Engagement by all stakeholders, governments and 
the private sector helps to optimize management of 
biological invasions in terms of economic, environmental 
Box SPM 4 Working for Water programme: an example of management of invasive alien 
species leading to recovery of nature's contributions to people.
Control of widespread invasive alien species requires sustained, 
large-scale efforts but can lead to improvement in the provision 
of a range of nature's contributions to people {Box 5.19}. 
Certain invasive alien plants, such as shrubs and trees, can 
reduce water availability, especially in scenarios of increasing 
drought caused by climate change {Box 5.4}. In South Africa, 
the Working for Water programme, an Expanded Public 
Works Programme, was introduced in 1995 and targeted 
historically disadvantaged communities, primarily women, 
youth and disabled people, creating jobs to reduce poverty 
nationally through the removal of widespread woody invasive 
alien species threatening water conservation {Box 5.19}. The 
programme generated 20,000 jobs per year over the first 
15 years and has helped to improve nature's contributions 
to people by improving water security {Box 5.19}. It has 
contributed to rural development by providing training in 
entrepreneurial and management skills while encouraging a 
sense of community and dignity among workers, especially 
women. The Working for Water programme shows how 
partnerships with rural communities to manage invasive 
alien species can bring both ecological and social benefits 
{Box 5.19}.
SUMMARY FOR POLICYMAKERS
19SUMMARY FOR POLICYMAKERS
BACKGROUND
Box SPM 3 Classical biological control of Mikania micrantha (bitter vine): an example of 
effective suppression of a widespread invasive alien species.