Central and Eastern Africa: IRIN Briefing on Water Hyacinth, 12/17/97

Central and Eastern Africa: IRIN Briefing on Water Hyacinth, 12/17/97

U N I T E D N A T I O N S Department of Humanitarian Affairs Integrated Regional Information Network for Central and Eastern Africa

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IRIN Briefing on Water Hyacinth 17 December 97

IRIN provides this background briefing for the benefit of the humanitarian community. It is intended as an outline of the problems related to water hyacinth, based on varied and reliable sources, but does not claim to be a comprehensive review of the situation.


Already battered by man-made crises, the central and eastern region of Africa is now in the grip of an environmental disaster. The fast-spreading water hyacinth is encroaching on some of the region's major inland waterways, threatening communities living on their shores. Tanzania, Uganda and Kenya, as the countries most affected by the floating weed, are taking steps to try and eradicate it, but have come under criticism for not taking the problem seriously enough.

Water hyacinth (Eichhornia crassipes), which originates from South America, was believed to have been brought to the region by Belgian colonialists as ornamental pond plants. With no natural predator it quickly multiplied - in the right conditions, the plants can double every five to 15 days. In the late 1980s, it began its stealthy voyage, invading the Kagera river in Rwanda, from where it fed into a number of lakes along the way such as Kyoga and George in Uganda and the huge expanse of Lake Victoria. Its hold on regional waterways has intensified this decade.


Lake Victoria today is on the verge of "ecological collapse", observers say, and scientists say the vast inland sea is dying. With a surface area of 68,800 sq km and a catchment area of 184,000 sq km, it is the second largest body of freshwater in the world. Respectively Kenya, Tanzania and Uganda control six, 49 and 45 percent of the lake which supports 25 million people or one third of the combined population of the three countries. The lake basin is a vital source of food, energy, drinking and irrigation water. Environmental protection is therefore essential to support the main economic activity of subsistence fishing. The lake has already seen its ecosystem undergo alarming fundamental changes over the last few decades, not least the introduction of Nile perch in the 1950s to boost fisheries. The voracious fish soon gobbled up much of the existing cichlid fish species, vital to the lake's survival. With the disappearance of over half the cichlid species, a huge layer of deoxygenated water was created in which nothing could survive. The subsequent appearance of water hyacinth is tipping the already precarious ecological balance of Lake Victoria, particularly in Uganda. Surveillance satellites show an estimated one percent of the lake has already succumbed to the killer plant.

The purple-flowering plant, ranging from a few inches to as much as three feet in height, usually floats in large masses but may also be rooted in mud, slowly choking the life of the waterway, clogging up vital structures such as dams and imprisoning boats. The merciless hyacinths, ideal nesting sites for bilharzia-causing snails, malarial mosquitoes and snakes, form a dense mat blocking the sunlight from organisms in the water below.


Driving along the Lake Victoria shoreline, it is difficult to see where the land stops and the lake begins. The main Kenyan lake port of Kisumu is completely blocked by the plant which extends as far as the eye can see. Even large vessels have been ensnared by its leaves and port activity is at a standstill. Rail goods are stranded at the port, unable to be loaded onto boats. A WFP food consignment destined for Rwanda has been held up for over a week. One cargo ship from Mwanza in Tanzania, forcing its way through the green carpet, came to a grinding halt as its engines overheated. According to Kenyan press reports, the rampant weed has resulted in hundreds of fishermen and transporters losing their jobs. Kenya's fisheries department, which lends support to projects to clean up the lake, says Kenya's portion of the lake at Winam Gulf, while small, is the most productive because it has several inward-flowing rivers. The Kenya Railways Corporation, which manages Kisumu port, has lost millions of shillings worth of business and has urged the government to declare a national disaster to encourage removal of the water hyacinth.

Further south, the effect of the weed in towns such as Homa Bay and Kendu Bay has completely disrupted small fishing communities. Local fishermen say no-one is interested in their plight. "A government official brought someone to have a look," one fisherman from Homa Bay told IRIN during a recent visit. "They started removing the plant, but when it started growing faster than they could take it away they just left it alone. No-one has been since." The surrounding land is dry and cannot support agriculture, so many local people are totally dependent on fishing and fishing-related activities for their livelihoods. The cost of their business has escalated. Unable to anchor at weed-choked landing sites, they have to land where they can, often tens of kilometres away from their homes. They then have to take public transport home.

The Kenya fisheries department says entire communities are on the move, searching for weed-free areas in which to fish. They in turn are overburdening the communities on which they descend, which do not have the infrasctructure to support a mass influx of people. "It's just like a refugee crisis", one official said. Three weeks ago, Homa Bay was completely colonised by the water hyacinth. A change in wind direction blew most of it away towards Kisumu, but fishermen are all too aware the respite is temporary. Kenyan press reports said that local people had even paid a "magician" to dispel the weed. And even though fishermen can now go out to fish without their nets becoming entangled or their boats marooned, their catches are pitiful. "We used to catch hundreds of fish, now we come back with just three or four, sometimes 10, big fish and 20 to 40 smaller fish," they say. The fisheries department estimates that fish landings, which dropped by 10 percent last year, will tumble even further this year by some 20 percent. People are angry, believing they have been left to tackle a problem that is too great for them to cope with alone. The story is repeated throughout the three east African countries where lakeside communities are facing economic ruin as fish catches dwindle.


A project set up by the three nations seeks in part to control the aquatic menace. The Lake Victoria Environmental Management Project (LVEMP), established in 1994, says the lake itself is not the source of its problems, which are due rather to human activity. It pinpoints two main hypotheses: the introduction of Nile perch which altered the food web structure and nutrients from adjoining catchment areas which are causing eutrophication or an over-abundance of water organisms. The project, aimed at rehabilitating the lake's ecosystem with the involvement of local communities, acknowledges there are difficulties. A study of community needs undertaken in Tanzania, for example, concluded one of the major setbacks was the "general lack" of community participation in management programmes. A project report stresses that for tackling the water hyacinth problem in particular, it is essential for local people to understand and assist in the biological control efforts LVEMP is conducting. The report warns that the current cost of controlling water hyacinth infestation - estimated at up to US $10 million per year - will shoot up still further if the problem is allowed to spread. The LVEMP received a boost from the World Bank last month which pledged US $77 million to assist the programme, specifically for research purposes on fisheries, water quality, management of the wetlands and the environment.

One of the problems in tackling the weed, is a divergence of views among the experts and disagreement between the governments involved. Scientists point out that as governments and donors come to realise the extent of the problem there is still much confusion about what needs to be done. The International Institute of Biological Control (IIBC) in Kenya says chemical, mechanical and biological controls all have positive and negative aspects. Uganda, fearful for the impact on its hydroelectric production, favours chemical treatment but experts believe this should only be used to treat priority areas. If Uganda goes ahead with the use of chemicals, reports say the European Union has threatened to ban fish imports from the country, where water hyacinth has laid siege to over 7,000 hectares of the lake. And while some scientists argue that mechanical control is the only long-term solution, others doubt its practicality on the scale required. IIBC says harvesting machines to scoop up the hyacinth are expensive pieces of equipment with a dubious record for sustainable control, but easy to deliver as part of a development assistance package. Some organisations, such as the Kenya Agricultural Research Institute (KARI), are trying to develop biological control which has successfully been implemented in other parts of the world affected by water hyacinth, such as Australia. KARI for example is breeding weevils which burrow down into the plant and kill it. Ugandan scientists have reported successful results after the introduction of Central American weevils in the much smaller Lake Kyoga. Biological control with weevils will take a long time to take effect even in favourable conditions. But some scientists reject this form of treatment for Lake Victoria anyway because of the scale involved. Billions of weevils would be required, and their rate of multiplication is very slow compared to that of the weed. The notion of floating booms or fixed barriers has been mooted for protecting key sites, such as ports and the Owen Falls Power Station in Uganda.

However help may be in sight. An article in Kenya's 'Economic Review' weekly noted Nairobi University's botany department had made a possible breakthrough in the fight against the hyacinth. The method involves collecting fungus from diseased hyacinth leaves and using it to kill the healthy plants. The university's Professor R.K.Mibey, who says the method has been successfully used in the USA, claims the most potent fungi have already been isolated. The scheme which involves spraying the leaves with the fungus is reportedly environmentally-friendly. Mibey told the weekly he hoped for funding from interested parties, but was afraid "vested interests" might spoil his chances.


There are some positive uses for the destructive weed, although they cannot be considered large-scale control measures. According to a report in 'Nature Watch' - a publication of the East African Wildlife Society - inmates at the maximum security Luzira prison in Kampala have been producing high quality furniture, bags and rope from the water hyacinth. Prison work-teams collect the weed, whose roots and leaves are discarded and the stem split and left to dry in the sun. The fibre is then soaked in preservative and braided into ropes which are then woven into furniture or bags. Rotting water hyacinths also produce methane gas for cooking.

The 'EastAfrican' weekly, meanwhile, noted the three East African states, in conjunction with research institutes, NGOs and environmentalists, had held numerous meetings on the issue since 1990, but it asked the question why was it taking so long to "add more vigour" to the campaign. The article warned against politicising the issue as the three countries sought to look after their own interests rather than working together to tackle the hyacinth menace. As a step towards better cooperation, Kenya, Uganda and Tanzania have now agreed to coordinate their fisheries regulations. Lake Victoria is suffering because the gravity of the situation was assessed too late. While experts and governments squabble over funds and methods, the weed threatens to swamp all vital waterways and freshwater facilities in the region.

Nairobi, 17 December 1997 [ENDS]

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Date: Wed, 17 Dec 1997 13:24:26 -0300 (GMT+3) From: UN IRIN - Central and Eastern Africa <> ubject: Central and Eastern Africa: IRIN Briefing on Water Hyacinth 97.12.17 Message-ID: <>

Editor: Dr. Ali B. Ali-Dinar, Ph.D

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