An invasive species is a species which is non- native , usually dominant, highly competitive with native species can cause damage to plants, animals and livelihoods of humans (ISAC 2006)
Many invasive species were introduced intentionally or by accident. Some species were used with good intentions such as to restore degraded lands but turned out to be problematic. The Water Hyacinth also scientifically known as Eichhornia crassipes is an invasive plant species on the Volta lake(Appenteng, 2014). The plant is originally from Amazonas, Brazil and was introduced to Africa because of it ornamental purpose. Water Hyacinth grows fast and forms a dense cover on the surface of water.These characteristics of the plants hinders transportation of boats, serves as breeding grounds for mosquitoes and blocks channels for irrigation( FAO 2002). Invasive species cost lots of money to control and can affect the livelihood of local people.
Invasive species are often overlooked by policy makers, for example there are instances where an exotic plant species used for reafforestation programmes became invasive. Scientist must be careful to select plant species that do not become invasive. Native species are best plants to use for re vegetation( Aradóttir 2017)
Some countries have employed mechanic and biological control in reducing the spread of the water Hyacinth. For instance in Benin, weevils were used as a biological control to feed on water hyacinth(Atser 2010).
A native plant of a country could be invasive when introduced in a different part of the same country.
What are the invasive species in your country?
A Aradóttir ,6 April 2017, United Nations University Land Restoration Training Programme, Keldnaholt, Iceland, personal power point presentation lecture.
Appenteng I (2014)Water lily on the Kpong stretch of Volta River in Ghana. http://fishconsult.org/?p=11213.( Accessed 11 May 2017)
Atser G (2010) Scientist send weevils after water hyacinth. https://www.modernghana.com/news/292529/scientists-send-weevils-after-water-hyacinth.html. (Accessed 21 May 2017)
Food and Agriculture Organization (FAO) (2002) Management of problematic aquatic weeds: FAO efforts and achievements during 1991-2002. ftp://ftp.fao.org/docrep/fao/005/y4270E/y4270E00.pdf . (Accessed 11 May 2017)
Invasive Species Advisory Committee (ISAC) (2006) National Invasive Species Council (2006)Invasive Species Definition Clarification and Guidance White Paper. https://www.invasivespeciesinfo.gov/docs/council/isacdef.pdf. (Accessed 11 May, 2017)