Problems posed by Water hyacinth
have been extensively reviewed by Gopal and Sharma (1981) and Jayanth (1987).
They are summarized as follows:
(a) It impedes the flow of water in
irrigation systems. 40-95% reduction has been reported.
(b) Prevents the free movement of
boats and other navigation vessels.
(c) It interferes with hydroelectric
power generation. That in very clear language means that with infestation of
Kainji Lake by water hyacinth, hydro-electric power from the Kainji Dam is now
threatened.
(d) It reduces the volume of
available freshwater by increasing losses through evapotraspiration. Various
authors recorded 1.26 to 9.48% 16 increase in water loss, compared to The
States of Florida, Louisiana
and open water surface.
(e) It impairs the quality of water.
The plant cover imparts obnoxious smell, colour and suspended particulate
matter to water, making it unfit for human consumption.
(f) Dense growth of water hyacinth
causes serious disruptions to other aquatic life like pliytoplankton and fish. According to Gopal and Sharma (1981), in West
Bengal about 45 million kg of fish were annually lost due to water hyacinth in
early i950s.
(g) It provides suitable habitat or
food or both for niolluscan and insect vectors of diseases like schistosomiasis
and malaria. It gives shelter to adults and also prevents mosquito larvae and
adults from being preyed upon by their natural predators like insects, frogs,
fishes etc.