By Walter Marwizi

MASVINGO- AN out-of-control aquatic weed fed by raw sewer dramatically clogged old Shakashe River bridge, blocking traffic for over two weeks.

The unusual development highlighted the threat posed by the exotic pest plant which is choking life out of Shakashe River, threatening biodiversity. ln May last year, dead fish and other amphibians were found floating in the river, sparking an outcry from unimpressed environmentalists.

Studies show that water hyacinth reduces biodiversity by crowding out native plants at the water’s surface and below. It also degrades water quality by blocking the air-water interface and greatly reducing oxygen levels in the water, eliminating underwater animals such as fish, frogs and crabs.

Why Shakashe matters

Shakashe river is a tributary that feeds into Lake Mutirikwi, Zimbabwe’s second largest in-land lake, which is the major source of drinking water for Masvingo City. The lake also provides irrigation water for the vast sugar and citrus estates of the Lowveld where thousands are employed by the giant sugar producer, Tongaat Hullets in Chiredzi and Triangle. Fishermen and villagers in the drought prone region also derive their livelihood from the water reservoir which boasts of 21 species of fish and is a tourism drawcard.

Despite this importance, authorities have not taken any action to destroy the invasive plant lurking in the lake’s tributary. Over the past few months the weed has grown from a tiny speck visible above water to a dense, impenetrable green mat which clogged the river which is below Caravan Park.

ZimTracker has documented the unfolding disaster since October last year, culminating in the dramatic lower Shakashe bridge blockade by the notorious weed. We are not publishing the pictures showing the current situation at the POLLUTED bridge to protect some readers who may find rotting hyacinth, which resembles dried sewage, offensive.