THE THEMATIC ASSESSMENT REPORT ON INVASIVE ALIEN SPECIES AND THEIR CONTROL
26SUMMARY FOR POLICYMAKERS
specifically on invasive alien species (well established)
{6.1.3}, which also increases the risk of biological invasions 
for neighbouring countries (well established) {6.3.2.1}. Only 
17 per cent of countries have national legislation for 
biological invasions, whereas an estimated 69 per cent have 
biological invasions-specific legislation as part of legislation 
in other sectors (well established) {6.1.2, 6.1.3}. Although 
many agribusinesses do not manage the risk of the plants 
they trade (established but incomplete) {5.6.2.1}, in some 
cases the business sector has developed voluntary codes of 
conduct in tandem with government regulations (Box 
SPM.1) (well established) {5.4.1, 6.3.1.4(4), Box 6.7}. It 
should be noted, however, that voluntary codes of conduct 
are intended to complement, not replace, obligations within 
national legislation that regulate activities that transport, sell 
or use alien species (well established) {6.3.1.4(4)}. The 
transport of invasive alien species along trade supply chains 
(e.g., in shipping containers) may be poorly managed and 
consequently may constitute a biosecurity risk (well 
established) {5.6.2.2}. There are many reasons for the 
limited adoption, implementation and efficacy of policy 
instruments, including varying capacity and resources 
across regions (well established) {6.2.2(7), 5.6.2.2} and lack 
of coordination, with unclear roles and responsibilities 
among government agencies, stakeholders and Indigenous 
Peoples and local communities (well established) {6.2.2(3), 
6.2.2(7), 6.2.3, 6.7.2.5}. Nearly half of all countries (45 per 
cent) do not invest in management of biological invasions 
(Sustainable Development Goal indicator 15.8.1) 
(established but incomplete) {6.1.3}. Lack of awareness of 
the need for collective and coordinated responses can also 
hinder implementation {6.1.1, 6.2.2(9)}.
B. Globally, invasive alien species and their impacts are 
increasing rapidly and are predicted to continue rising in 
the future
B9 Intentionally or not, many human activities 
facilitate biological invasions globally (well 
established) {3.1.1, 3.2, 3.3, 3.4}. The transport and 
introduction of an invasive alien species can be intentional or 
unintentional, or in some cases both (well established) {3.2, 
3.3}. Historically, many invasive alien species have been 
intentionally introduced outside their natural range around 
the world for their perceived benefits to people, without 
consideration or knowledge of their negative impacts (well 
established) {3.2.1, 3.2.3, 3.3.1, 3.3.2}. For example, 
invasive alien species are often used in forestry, agriculture, 
horticulture, aquaculture and as pets (well established)
{3.2.3.2, 3.3.1.1}.9
 In the Mediterranean basin alone, more 
than 35 per cent of alien freshwater fish have arisen from 
aquaculture (well established) {3.3.1.1.1}. Invasive alien 
species have also been intentionally introduced for 
recreation and amenity (well established) {3.2.1, 3.2.3.3} 
and for soil stabilization (well established) {3.3.1.1.2, 3.3.1.6, 
3.3.4.6}. Many invasive alien species have also been 
introduced unintentionally, including as contaminants of soils 
and traded goods, stowaways in shipments (well 
established) {3.2.3.1, 3.2.3.2, 3.2.3.4}, stowaways in ballast 
water and sediments, and as biofouling organisms that 
attach themselves to ships' hulls and other surfaces on 
vessels (well established) {3.2.3.1, 3.2.5, 3.3.2.3, Box 3.7}. 
Additionally, online trade in animals, plants and other 
organisms is contributing to the introduction of invasive alien 
9. IUCN. 2017. Guidance for interpretation of CBD categories on 
introduction pathways. Technical note prepared by IUCN for the 
European Commission. Available at: https://www.cbd.int/doc/
c/9d85/3bc5/d640f059d03acd717602cd76/sbstta-22-inf-09-en.pdf
species worldwide (well established) {2.1.2, 3.2.4.2}. 
Progressive degradation of nature, including from pollution 
and fragmentation of ecosystems, has facilitated the 
establishment and spread of invasive alien species (well 
established) {3.3.1.2, 3.3.1.3, 3.3.1.5, 3.3.1.6, 3.3.3}. 
Demographic drivers10 also facilitate the introduction and 
spread of invasive alien species, although it is acknowledged 
that drivers differ across regions (well established) {3.2.2}. In 
the last 50 years, the number of people in the world has 
more than doubled, consumption has tripled, and global 
trade has grown nearly tenfold, with shifting patterns across 
regions (well established) {3.1.1}. This acceleration of the 
world economy is increasing the rate and magnitude of 
many direct and indirect drivers, particularly those related to 
trade, travel and land- and sea-use change,11 leading to 
further biological invasions (well established) {3.1.1, 3.2.2}.
B10 The number of alien species is rising globally 
at unprecedented and increasing rates (Figure 
SPM.4) (well established) {2.2.1}. Thirty-seven per cent 
of all known alien species have been reported since 1970 
10. Demographic drivers have been identified by the IPBES Global 
Assessment Report on Biodiversity and Ecosystem Services of 
the Intergovernmental Science-Policy Platform on Biodiversity and 
Ecosystem Services as one of the indirect drivers of change in nature, 
as described in Table 3.1
11. IPBES (2022). The Thematic Assessment Report on the Sustainable 
Use of Wild Species of the Intergovernmental Science-Policy Platform 
on Biodiversity and Ecosystem Services. Fromentin, J.M., Emery, 
M.R., Donaldson, J., Danner, M.C., Hallosserie, A., Kieling, D., 
Balachander, G., Barron, E.S., Chaudhary, R.P., Gasalla, M., Halmy, 
M., Hicks, C., Park, M.S., Parlee, B., Rice, J., Ticktin, T., and Tittensor, 
D. (eds.). IPBES secretariat, Bonn, Germany. https://doi.org/10.5281/
zenodo.6425599
SUMMARY FOR POLICYMAKERS
19SUMMARY FOR POLICYMAKERS
BACKGROUND
Box SPM 1 Voluntary codes of conduct can complement legislation for managing the risks 
of transport and the introduction of invasive alien species through trade. 