National Invasive Species Week (NISW) 11 to 15 October 2021

Event date: 
2021-10-11 (All day) to 2021-10-15 (All day)

introduction -the beginning            
Introduction / background
Purpose and objectives
Implementation of AIS Regulations 
Get involved



South Africa’s water resources are being invaded by a range of exotic water weeds. While terrestrial invasive plants such as pines, gums, hakeas and wattle have detrimental effect on water in terms of consumption, our water resources are also being invaded by a wide range of invasive aquatic plant species. These plants came into the country through the ornamental garden and aquarium trade where they are used to decorate and plant garden ponds, fish ponds and aquariums.  Species like water hyacinth, water lettuce, salvinia, parrot’s feather, hydrilla etc. are responsible for invasions in our rivers, wetlands and dams. 

Threats posed by invasive species

  • They can pose significant threat to agriculture, environment, tourism, economy and/or human health.
  • Due to their aggressive growth, they choke out native vegetation thus negatively impacting on biodiversity
  • Can cause rivers to dry up completely, if left to spread and grow;
  • Have a negative impact on water quality as they tend to form dense mats that reduce water flow;
  • Are causing restrictions to the use of boats for fishing and river transport; 
  • Are preventing sunlight penetrating the water and this affects the entire food chain, causing the deterioration of aquatic biodiversity and provide breeding sites for mosquitoes and snails that carry diseases such as malaria and bilharzia.


Purpose and objectives of the 2021 National Invasive Species Week


The National Invasive Species Week (NISW) awareness campaign is set to take place during the week of 11 to 15 October 2021. The purpose of the campaign is to inform the public and our stakeholders about invasive species, their negative impacts on natural ecosystems and livelihoods. The campaign will create awareness on what can be done by our stakeholders and the public at large in safeguarding South Africa from invasive species. It will also increase awareness among people about the importance and benefits of controlling invasive species. It is crucial to have an understanding of invasive species and to work towards the effective management of these invaders to protect and restore our ecosystems.  


Implementation of Alien and Invasive Species Regulations


Alien and Invasive Regulations are aimed at mitigating the destructive and negative impacts of such invasive species through an informed policy framework, which in turn, will free up much-needed water resources to the benefit of agriculture and other equally important industries as well as for human use.

The AIS Regulations list 4 different categories of invasive species that must be managed, controlled or eradicated from areas where they may cause harm to the environment, human health, agriculture and economy.


Four categories of listed invasive species:

  1. Category 1a: Invasive species which must be eradicated.
  2. Category 1b: invasive species in which a permit is required to carry out a restricted activity.
  3. Category 3: lnvasive species which may remain in prescribed areas or provinces.

It is expensive and challenging to eradicate invasive species successfully once they are well established. Therefore, management activities to prevent their introduction and establishment are of vital importance and must be prioritised. The management of invasive species must also focus on minimisation of the risk of new incursion, and ensure effective rapid response. Monitoring process should be part of the management activities to prevent re-invasions and such process must begin as early as possible upon rehabilitation.



The theme for 2021 is, “Protect our waters from invasive species”.


Get involved/How can you help?

  • Get involved in invasive species awareness initiatives
  • Comply with the law
  • Plant indigenous species
  • Know what you grow/keep                           
  • Prevent the spread of invasive species
  • Remove invasive species from our watercourses
  • Don’t release or dump invasive species into our waters
  • Do not give invaders a free ride to a new location, so cleaning your hiking boots, boats and trailers, off-road vehicles and other gear.


NB: We must all comply with the duties of care:

  • Take all the required steps to prevent or minimise harm to biodiversity
  • Take steps to control and eradicate the invasive species and prevent it from spreading.
  • Apply for a permit to conduct restricted activities
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