WATER hyacinth blocks along the uMsundusi and uMngeni Rivers continue to be a problem for the organisers of the Dusi Canoe Marathon, as the rapidly multiplying water plant has reared its head at various points along the route in the build up to the race that starts at Camps Drift on Thursday 13 February.
Having to deal with the unruly invader species is a problem that occurs this time every year, with the bountiful rains of November and December coupled with the searing heat of late January and February meaning the pesky plant can as much as double in area in just 10 to 14 days.
The plant’s mobility is another issue that plagues the Dusi Umgeni Conservation Trust’s (DUCT) efforts to control the aquatic weed as it is easily blown across an expanse of water by the wind, making it difficult to contain and kill off small pockets of the troublesome plant before they drift elsewhere.
DUCT’s field manager, Bart Fokkens, has been dealing with the hyacinth issue for years now and is aware of the problems that it causes for KZN’s river systems.
“The rains in November washed a lot of it down stream which caused an even bigger problem for us and then, with this recent heat, the amount of hyacinth, particularly at the headwaters of Inanda Dam, has just exploded,” said Fokkens.
However Fokkens feels there could be more done to prevent the spread of the hyacinth during this period.
“We did a lot of spraying on the lower uMngeni at the end of last year but the uMngeni Municipality were supposed to do some spraying in December, which did not happen, and this led to a pretty rapid growth of the plant,” he explained.
In order to curb the expansion of the hyacinth, Fokkens and his team have come up with a plan to cordon off the weed in a specific area in order to prevent the wind from spreading it as well as preventing integration between dead and living pockets of the weed.
“We have a plan that we have used before – although on a much smaller scale – where we have a rope that is about 1000 metres and we are using it to cordon off the hyacinth so that we can spray it and keep it together. In the past we have had problems with dead and live hyacinth mixing which makes spraying more difficult so we have taken on the plan to cordon it all against one bank so we can control it in one place,” added Fokkens.
Wind is often seen as a problem when it comes to hyacinth because of the plant’s mobility however Fokkens has decided that they will be able to use the wind to their advantage in cordoning off the plant despite the hyacinth having the potential to prove to be stern resistance against the kilometre long rope.
“This is a huge operation with us having to use vehicles on either bank to block the hyacinth off and this rope will take some serious strain with a 500 metre by 200 metre hyacinth field pressing against it,” said Fokkens.
He said he is confident that it will clear up the area below the sand mining causeway on Inanda Dam, but the difficult part comes in the area above that causeway because the water is too shallow to get there in a boat – so they have to battle to spray it.
The Dusi Canoe Marathon 2014 starts in Pietermaritzburg on Thursday 13 February and ends in Durban on Saturday 15 February.
