Wednesday, January 24, 2007

WATER HYACINTH AND ITS INVASIVENESS

Water hyacinth is the plant which floats freely in the water. The plant is indigenous in
the continent of South America. Globalisation, International trade and transportation lead to the spread of Eichhornia Crassipes in the continents of Africa, North America, Asia and Australia. In South Africa, Water hyacinth first came into existence in the province of KwaZulu-Natal in 1910 (Coetze, 2007).

The species is now spreading in the Eastern part of South Africa. The plants serve as habitats for small invertebrates animals such as Fish and Frogs. The modes of dispersal include movement of People and Ships all across the boundaries. The species has been found to be a problem in Kenya where it suppresses other aquatic plants (Coetze, 2007). The plants float on the water and prevent sunlight from reaching other aquatic plants.

The prevention of the sunlight from reaching other aquatic organisms mean that other organisms will die because of the absence of the oxygen and the process of photosynthesis is reduced greatly. In countries such as Australia and Papua New Guinea, the plant destroys native plants. The killing of the native plants by water hyacinth is encouraged by the fact that, there are no preventive measures in place in the above mentioned two countries (Wikipedia contributors, 2007).

The dying of other aquatic organisms means that the aquatic ecosystem is disturbed because of the reduction in the quality of water. The other problem in which Eichhornia Crassipes possesses is that the species acts as a vector in which Mosquitoes build their nests. This means that Mosquitoes will be able to carry their diseases to the People who are living near to the area where the plants are available (Wikipedia contributors, 2007).

Water hyacinth forms fibrous roots which are thick, branched and dark in colour under the water. On top of the water, the species forms a thick mat which prevents many water activities such as swimming, fishing and canoeing. When the species dies, decomposers such as bacteria and fungi are responsible for the decaying of the dead organic matter. The dead organic matter provides other aquatic organisms in the water.

REFERENCES

Coetzee, J. 2000. Animals, Plants and the Environment [Online]. [cited 2007 January 18]. Available from: http://sunsite.wits.ac.za/ape/hyacinth.htm

Wikipedia contributors. Water hyacinth [Online]. Wikipedia, The Free Encyclopedia; 3 January 2007, 09:23 UTC (cited 2007 January 23]. Available from:
http://en.wikipedia.org/wiki/Water_hyacinth


Peter Muvhali
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