Invasive alien species (IAS) have become a major threat to sustainable development in Africa, forcing governments to divert millions of dollars a year to fight the spread of such species. In South Africa, for example, it has been estimated that invasive alien trees and shrubs, which consume about 7 per cent of the country's freshwater, will double in 15 years if they are not controlled. It has been estimated that economic losses due to IAS amount to about 5 per cent of the world economy or about US$1.4 million million annually. This is about three times the gross national product of all countries in Africa (National Botanical Institute and Global Invasive Species Programme 2004).

Invasive alien species pose a serious threat to ecosystems and biodiversity, and are second only to habitat loss as a cause of biodiversity loss. The loss of biodiversity presents a serious threat to the sustainability of human society, as it undermines the provision of essential ecosystem functions and reduces the availability of environmental goods.


Invasive alien species will not be eradicated, at least in the foreseeable future. The only options available to policymakers are to control and manage the species which are already creating havoc for people's livelihoods, economies and ecosystems. The costs of managing IAS will continue to be high.


Urgent action is required to undertake a comprehensive inventory of both floral and faunal IAS, including spatial extent in the region and impacts on people, various economic sectors such as agriculture and forestry, and on endemic species.

Policymakers should also undertake the following:

  • Develop a list of IAS and facilitate its publication and distribution on a regular decadal period.
  • Mount a massive public campaign across the region to inform people about the impacts of IAS on biodiversity, economic activity and their livelihoods.
  • Implement stringent measures to control the export and import of living organisms from one territory to another, particularly where information on a particular organism is lacking.
  • Introduce regulatory measures which control the marketing and distribution of GMOs whose impact on biodiversity is unknown, and for which comprehensive information on their properties is lacking.
  • Fund research on various IAS and encourage the development of technology that could assist in controlling the further spread of such species.
  • Introduce measures to comprehensively cost the impacts of IAS on the environment and on socioeconomic development.
  • Make the eradication and control of IAS the first focus of government policy. To achieve these objectives innovative ways of engaging with the private sector, including micro-, small- and medium-scale enterprises, should be considered. This may include encouraging the use of IAS in manufacturing, provided that this investment does not lead to the continued propagation of IAS. Additionally, it must be recognized that the control of IAS is crucial for restoring ecosystem well-being and enhancing environmental services; this may serve as an important basis for engaging with the private sector.


Governments, the public, the private sector, research organizations and regional and sub-regional organizations have a stake in ensuring that the issue of IAS is high on the agenda. The sharing of information among and between these stakeholders is important.

Result and target date

IAS is an ongoing challenge for policymakers at different levels, and cannot really be tied down to a specific date in terms of control. However, the development of strategies and programmes for individual national and collective sub-regional and regional action is critical. It is important that such strategies and programmes be fully operational by the beginning of the next decade.