Hyacinth overruns Lake Victoria, entangles lives

November 13, 1994|By Alan Zarembo | Alan Zarembo,Special to The Sun

GGABA, Uganda -- When green stalks started sprouting in Lake Victoria a few years back, workers in this fishing village paid little attention.

Entrepreneurs sold the water hyacinth's purple flowers on streets in Kampala. Some hotels hung them in the lobbies. And the floating plant kept multiplying.

It now strands fishermen miles from shore while their catches rot, prevents ships from docking and clogs water-treatment plant pumps. Shaggy green carpets hundreds of feet wide drift on the lake, sometimes hiding the surface for miles.

Water hyacinth is common in other parts of the world, including Florida. But nowhere else does it threaten water so life-sustaining as Lake Victoria -- the source of the Nile, the second-largest lake in the world, the ecological and economic hub of East Africa.

"The lake is our life. It's where we feed from and how we move from place to place," says a Ugandan entomologist, James Ogwang.

He is studying hyacinth-munching beetles imported from West Africa's Benin. The insects would probably only slow the weed's growth in Uganda, where it multiplies so fast that every week there are at least four more acres to destroy.

That growth rate hasn't stopped shoreline industries from trying. Port Bell hired 42 workers at $2 a day each to clear the weeds away from its docks and burn them on the shore. They often can't keep up.

Incoming ships plow through the hyacinth blanket, packing it against the dock so densely the workers walk on it.

For three days, a ship can wait 15 feet from the dock to unload tanker cars of fuel in exchange for rail cars of coffee, Uganda's biggest export. Barefoot workers hack apart the green block with machetes.

"The ships have to wait. There's no other way," says a port officer, Paul Nechi. "It's like a cement floor."

Port officials say they haven't calculated the losses from shipping delays or the price of fixing ship engines whose propellers suck up the weed. The Owens Falls dam, which generates most of the country's power, is experiencing similar problems in its turbines.

Boats that transport island dwellers back and forth to the mainland have been trapped. The sailing club has shut down.

Water taxi operators carry passengers to their boats piggyback-style. Hyacinth is an ideal habitat for snails that carry bilharzia, a parasite that can burrow into people through their feet.

In nearby Entebbe, a water-treatment plant worker strips down to his underwear four times a day to climb into a water tank. Wading waist-deep, he pulls hyacinth roots out of the water intake pipes.

The weed clogged the system's main pump in September, making the pressure too weak to send treated water into the city. Customers went to the treatment plant to collect it in plastic jugs.

Fishermen say fish swim under the hyacinth to hide from their nets. If the weed continues its spread, researchers say, it will devastate fish populations by robbing the water of oxygen.

"We are talking of a big disaster looming," says Dick Nyeko, a senior officer in the fisheries ministry. At least a half-million Ugandans work as fish wholesalers, retailers, processors and boat builders, and millions of people rely on fish as their main protein source.

James Mugabe, a 38-year-old fisherman, says he lost his canoe when wind-propelled weeds swept it off the shore. So now he cleans fish at the market for about $2 a day, a fifteenth of what he once made on the water.

"That's just for surviving," he says. "Your family can go weeks eating only beans."

The hyacinth covers an estimated 6,000 acres of Ugandan fishing bays. The weed rugs can move rapidly, breaking into pieces and rejoining, stranding boats for days.

Some researchers believe removing the weed accelerates its spread by shaking loose buds and seeds, which can survive 30 years buried in mud.

The Ugandan government wants to destroy the weed with the beetles Mr. Ogwang breeds in a lab outside Kampala. Last year 1,000 beetles were released in hyacinth-infested Lake Kyoga, in central Uganda, but results of the trial won't be in for several months.

International politics and money shortages have delayed releases in Lake Victoria. Kenya and Tanzania -- the other countries bordering the lake -- want reassurance that the beetles won't attack crops. The weed's most rapid expansion is happening in Ugandan waters because currents tend to sweep the weed north.

Chemical control and mechanical removal are not popular options.

The effects of spraying herbicides on the lake are unknown. And even the fastest harvesting machines would face an endless task.

How the weed, thought to be native to the Amazon, spread to Africa is a mystery. Researchers are convinced it attacked Lake Victoria from Rwanda, down the Kagera River.

Clumps of hyacinth pour out of the river's mouth, following the same path as the hundreds of Rwandan bodies that tumbled into the lake earlier this year. The corpses scared many Ugandans into temporarily giving up fish.

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