Water hyacinth, Eichhornia crasses
is a serious aquatic pest in many parts of the world. The menace of the weed
has reached alarming proportions in many countries. Its rapid growth has
clogged major waterways and created problems associated with navigation,
national security, irrigation and drainage, water supply, hydroelectricity and
fishing in many countries. Its home base is the Amazon
Basin in South
America. Water hyacinth regarded as the most troublesome weed of
the world has since been willingly or unintentionally aided by man in its
dispersal and present distribution (Gopal and Sharma, 1981; Jayanth, 1987).
The first surge of the weed in Nigeria was noticed in September 1984 along the
Badagry Creek in Lagos
State where it formed a
'mat' over the water surface. By January 1985, it has spread to the creeks and
lagoons in Lagos
and its environs. Investigations by the University
of Lagos team of scientists revealed
that
the surge of the weed entered Nigerian water via the Porto Novo Creek (Benin Republic)
which is connected to and flows into the Badagry Creek. Our prediction then was
that if the immediate and adequate steps were not taken to check the weed, the
Lagos Lagoon system would become the avenue for spreading the weed into other
parts of the Nigerian waterways including Epe, Lekki and Mahin, Lagoons
(Kuserniju ci al, 1985).
By 1986, the weed had crossed the
Lagos lagoon and has since covered most of the intricate system of waterways
made up of lagoons and creeks along the coast of south-western and south-eastern
parts of Nigeria. Water hyacinth rapidly became a major problem in the ECOWAS
region. The problem was most pressing in Nigeria,
Benin, Ghana and Cote
d 'Jvoi re. However, the interdependence of the water network especially the
River Niger system facilitated the spread of the weed to other countries in the
region.
Water hyacinth infestations have now
covered Senegal, Guinea, Burkina Faso, Mali and Niger. In 1988, the Nigerian
Federal Ministry of Science and
Technology organised an international workshop in Lagos on "Water
hyacinth, Menace and Resource". By 1992, the occurrence of water hyacinth
iii the River Niger and the Kainji
Lake was confirmed. The
weed entered Nigeria via the
Niger Republic at Lob, a border village on the
River Niger (Kusemiju and Chizea, 1992).
The presence of water hyacinth in
Kainji Lake posed a major threat to the Kainji dam which supplied
hydro-electricity to Nigeria and the Niger Republic. The economic cost to
Nigeria if water hyacinth in the Kainji Lake was not immediately brought under
control would be incalculable in terms of hydro-electricity, fishery and
communication.
Recognizing the need for an
integrated approach, ECO WAS (the Economic Community of West African States)
with financial support from the African Development Bank (ADB) engaged
EUROCONSULT, a consultancy firm from the Netherlands to conduct a study on
"Control of floating weeds in the ECO WAS member countries". The
study dealt with the investigation of degree of infestation of floating weeds
in the member countries, and the preparation of projects for their control.