Biological invasions are the third largest threat to South Africa’s biodiversity after cultivation and land degradation, and are responsible for 25% of all biodiversity loss.

Current estimates show that if biological invasions on grazing land were not controlled, the country could lose up to 70% of this valuable natural asset.

“This will reduce the capacity of natural rangelands to support livestock production, thereby threatening rural livelihoods and food production,” said the Minister of Forestry, Fisheries and the Environment, Ms. Barbara Creecy.

Speaking at the launch of the Status of Biological Invasions and their Management in South Africa (SBIMSA) in 2019 report, the Minister emphasised the effect biological invasions have in biodiversity, the economy, human health and well-being, and sustainable development in South Africa.

Scientific research has shown that one of the key factors driving the accelerated decline of biodiversity is the invasion of alien species.

The scientific report makes a number of important points in this regard:

Firstly, the number of alien species that have established in South Africa has increased by 15% from 1 637 to 1 880, about a third of which are invasive. Formal assessments of the impact of invasive species are underway using a new United Nations scheme that was developed in collaboration with SANBI and the Centre of Excellence for Invasion Biology scientists.

Current estimates suggest the ecological costs of invasive alien plants and animals to be more than R6,5 billion each year. The main costs associated with losses are a decline in ecosystem services such as water and grazing and in agriculture as a result of invasive pests.

The second finding is that invasive trees use up 3–5% of South Africa’s surface water runoff each year, a serious problem in an already water scarce country which is increasingly prone to drought. Some scientists have calculated that Day Zero in Cape Town was brought forward by 60 days due to invasive trees sucking up water. The same impact occurs in other drought-stricken areas, such as the Eastern Cape.

The third finding is that invasive trees increase the risk and intensity of veld fires, with 15% more fuel burnt in invaded areas. Consequently, fires burn at a higher temperature and containment measures are more difficult.

Most disturbingly, the report highlights that new alien species continue to arrive every year in South Africa.

Among these is the polyphagous shot hole borer beetle which, with its associated fungus, has already killed thousands of trees in South Africa. It looks set to be one of the most damaging and costly biological invasions faced by the country.

South Africa, the Minister said, was recognised as global leader in invasion science. Through regulations promulgated in 2014, and revised in 2021, and permitting and regulations, there is greater control over those who import, grow and trade with invasive species that have commercial value. While new technologies have been developed to support actions to prevent the introduction of listed species, accidental imports will continue to occur.

“It is for this reason that our the Environmental Programmes of the Department of Forestry, Fisheries and the Environment, is spending over a billion Rand a year on projects to control biological invasions and create jobs. Since the adoption of the Working For… programmes in 2005, we have been relentless in our efforts to effectively manage alien and invasive species in the country,” said the Minister.

Removals are of both plant and animal species. A recent programme has successfully removed bass from selected wetlands and stretches of river leading to rapid recovery of native fishes and biodiversity in general.

“The use of biological control against invasive alien plants has also been shown to have very high positive returns on investment. Biocontrol is a critical and well-regulated tool to manage biological invasions, with South Africa recognised as a global leader in the field,” Minister Creecy said.

In recognising that this is a multi-faceted problem that needs a multi-faceted approach, the Minister said there was a need to cut through red tape and the silos of different government departments “so that we deal with this through a common national approach”.

Accordingly, the department is developing a policy on the management of biological invasions. Its implementation will be supported by a 10-year National Invasive Species Strategy and Action Plan.

The aim of the strategy is to facilitate a cohesive and collaborative approach by government, industry and the broader community in identifying and managing biosecurity risks. It will soon be published for public comment and input.

Minister Creecy announced that South Africa, through the financial support from the Global Environmental Facility, under the biodiversity focal window, had secured funds for a project to enhance the efficient and effective management of high risk biological invasions.

The project is aimed at directly mitigating the negative impacts of biological invasions on South Africa’s biodiversity, whilst contributing to the improvement of rural food security and livelihoods.

“It is envisaged that the project will have a significant contribution towards the efforts to mitigate the impact of biological invasions on South Africa’s biodiversity,” said Minister Creecy.

Source: Department of Forestry, Fisheries and the Environment