Saturday, June 2, 2012

Mixed benefit as water hyacinth invades Lake Victoria by Philip Alambo

Ugandan fishermen pushing their boat stuck in water hyacinth at Lake Victoria SOURCE: INTERNET

The infestation of Lake Victoria with water hyacinth dates back to 1984, when it was first spotted in River Kagera, which empties its water into the Lake.

Since then, water hyacinth has been synonymous with the lake. Like the Kagera River, the lake is today chocked with Hyacinth, which poses risk to local inhabitants by harboring  crocodiles along its shores.

cientifically referred to as Eichoirnia Crassippes, water hyacinth multiplies to cover more than 50 hectares of a water body within two weeks. This rapid growth is enhanced by massive disposal of industrial and sewages waste in the lake.

 “Nutrients from industrial wastes, both treated and untreated, dumped into Lake Victoria is conducive for the growth of water Hyacinth.” Peter Kamau, an environmentalist from COSMER-LAV which monitors the groeth from Kisumu said.

He says discharging of effluent into the fresh water body is to be faulted for the uncontrolled growth of the exotic weed that has now invaded the lake.

The negative impact of the weed started to be felt in the early 90s by fishermen who largely dependent on the lake for their livelihood. They say their standard of living with others around the lake basin have been drastically affected which can be attributed to high number of school dropouts increased owing to difficulties in raising funds necessary for early childhood education.

“Water Hyacinth hindered the free movements of boats. As a result, our daily catch gradually declined”, recalls Joakim Otieno, a fisherman living at Dunga Beach in Kisumu.

“The weeds caused disruption to boat riding business. What awaited the investors was the inevitable expectation of financial instability on their part” he adds

No one talks about water hyacinth without making mention of its infamies. However, recent studies indicate that the floating vegetation has come to the rescue of the endangered native fish species. To this end, the indigenous hide beneath Water Hyacinth to escape the snares of Nile Perch which feed on them.

“Since Water Hyacinth heavily consumes oxygen in the lake, Nile Perch cannot survive underneath it, to the safety of the smaller fish, which can withstand a less oxygenated environment. Water Hyacinth thus harbors the smaller fish from their predators”, remarks Peter Kamau.
“In early 60s,” he adds, “Lake Victoria was inhabited by over 560 species of indigenous fish. Forty years on, only 162 have been left.”

For Kamau and other observers, the introduction of Nile Perch and overfishing are to blame for the extinction of these fish species. Water Hyacinth is thus instrumental in saving the remaining endangered fish population.

A number of organizations, notably OSIENALA (Friends of Lake Victoria) and National Environmental Management Authority (NEMA) have come to the fore in attempting to regulate the growth of water hyacinth so that it does not pose an obstruction to the main economic activity of residents of the lake region.

OSIENALA strongly recommends the reduction in disposal of industrial effluent into the fresh water body, given that nutrients sustain the growth and multiplication of the weeds. Reading from the same script, Mr. Omollo, an environmental science lecturer, Maseno University, suggests that a buffer be created along the shores of the lake where industrial wastes are discharged into the water body.

“On the buffers”, he adds,” hippo grass should be grown to utilize the nutrients supportive of the growth of water hyacinth. That way, the speedy growth of the unwanted plantation will have been regulated.”

The World Bank, in collaboration with Europe in 1988 set up a $9.3 million project, geared towards mopping up the dreaded Water Hyacinth. In the program, local stakeholders such as Lake Victoria Environmental Management Authority (LVEMP) were furnished with funds necessary for eradication of the plants.

Beetles were introduced into the lake, feeding over 12,000 hectares of water covered with the floating weeds.

Nevertheless, the beetles were unable to phase out the weeds. These fruitless attempts have thus been met with sharp criticisms emanating from scientists and politicians, terming them as an exercise in futility. Scholars and researchers therefore have a task of finding ways of redressing this phenomenom

No comments:

Post a Comment