Massive clumps of the notorious water hyacinth, Eichhornia crassipes, are responsible for the partial “sealing” of the Ogun River at Kara on the Lagos-Ibadan Express Road, near the boundary between Ogun and Lagos states, an investigation by The Nation has confirmed.
But the massive weed infestation has raised fears of a possible massive locust-type attack of farmlands in and around Lagos and Ogun states.
The uncommonly heavy clogging of the river surface by the water weeds, has virtually turned the surface of the river near the Lagos-Ibadan Express Way into a massive land of green vegetation.
Environmental journalist O’seun Ogunseitan, who spoke to The Nation in Lagos, last night said the clogging could get worse and cause massive flooding of land areas west of the river.
Ogunseitan, who incidentally broke the story of the first water hyacinth infestation in Nigeria 30 years ago at The Guardian, has been to the Ogun River site at Kara. He identified a huge population of the notorious water weed.
Ogunseitan confirmed the water weed as the cause of the blockage and advises very quick response from Environmental Protection Agencies in Lagos and Ogun State to prevent a new and totally unknown environmental threat to Agriculture in the Nigerian South West.
Ogunseitan said he identified huge populations of a particular moth and some grasshoppers already feeding voraciously on the water weed and he fears for the local plant population in the area been able to resist the insects, should they be allowed to spread.
Live samples of the unusual grasshoppers feeding on the water weed will be delivered to Scientists at the University of Lagos today.
The notorious aquatic water weed, Eichhornia crassipes came into Nigerian waters from the Republic of Benin, through the Lagos lagoon in 1985. Efforts were made by the federal government back then, to prevent the weed crossing the Lagos lagoon, where salty waters of the Atlantic Ocean killed the weed and kept its spread in check.
The weeds which have been reported to be capable of covering hundreds of kilometres of fresh water surface within days, overan the Yewa and Ologe lagoons in Lagos in the 1980s and crossed into the Mahin Lagoon from where it reached other fresh water bodies in Ogun, Ondo, Edo and other states in south eastern Nigeria and the middle belt.
A lecturer at the University of Lagos (UNILAG), Dr Olusola Shonubi, said hyacinth increases in population as a result of low salinity, adding that it has strong roots that intertwine to form a carpet.
“The water hyacinth normally comes up when the salinity of the water is low; so it is easy to propagate very fast. The root of the hyacinth is fibrous so they lock strongly. In areas of Ondo, fishermen cannot paddle their canoes when there are lots of water hyacinths,” she said.