Scattered clumps of a smallish green bulbous plant (hyacinth) appeared on the sides of the Leidam during the latter part of February this year. It was initially seen as just an innocuous weed which, like some of the previous forms of algae/moss that had appeared on the water from time to time, would work itself out of the system and not require any specific attention.

During the latter half of March, a very small section of the dam was sprayed with Round-up to see if it would have any effect on the weed. Although some of the weed showed signs of dying off, the extent of the weed on the dam was such that the spraying of small sections of the dam at that early stage was considered ineffectual.

By the end of April, the gravity of the situation was brought to the attention of the Montagu Eco Club by Piet van Zyl of Vrojilikehid, and it became abundantly clear that an immediate process would have to be commenced to rid the Leidam of the identified ‘Salvina molesta’ better known as Kariba weed/Water fern.

Upon the identification of the weed/hyacinth and the knowledge of the devastating effect that it has had and still continues to have in especially Central Africa, with the world renowned Kariba Dam being most severely affected, immediate ‘remedial action’ was set in motion.

The Chairperson of the Montagu Leiwater Gebruikersvereniging, Richard Knipe, very kindly undertook the total spraying of the weed with Round-up (all the young trees and shrubs were covered in bubble wrap to protect them) The effect was almost instantaneous with large sections of the weed turning brown within a few days.

By the beginning of June large areas of the weed were dead and a program was then set in place to remove the decaying weed from the water by hand and later, using a boat kindly lent to the workers by Antonette Kotze of the Montagu Caravan Park.

To date, over 36 cubic metres of Kariba weed have been removed from the dam. A regular patrol of the dam will be conducted and any signs of the recurrence of the weed will receive immediate attention.

The photographs below reflect the situation at the Leidam during the period April – June 2010.

Compiled by the Montagu Eco Club
023-6142311
mmvz/22.06 2010