Tourists used to flock to South Africa's Hartbeespoort Dam for the region's beautiful scenery and fun water activities. Invasive green liquid hyacinth vegetation has turned the formerly clear water into a nightmare for boaters, and the tourists who come to see it now have something else to worry about.
With Hartbeespoort on the horizon, it's no surprise that pollution from Johannesburg and Pretoria has contributed to a rise in the number of Harties in the region. This includes sewage, industrial chemicals, heavy metals, and rubbish floating down rivers.
"In South Africa, we are faced with severely polluted waters," said Professor Julie Coetzee, who oversees the aquatic weeds program at Rhodes University's Centre for Organic Control and has researched water hyacinths for more than 20 years.
The weed's severe impact on communities' livelihoods makes it a major worry, and the nutrients in the pollutants function as cross fertilizers for the weed.
Recreational boat company owner Dion Mostert, 53, is about to lay off 25 employees since business has ground to a halt due to the carpet of liquid hyacinths.
"Nowhere are the boats going to go. That has an impact on temporary positions, such as those held by tourists, in our city "Mostert noted as he pointed to his high-end fishing vessel. There was this character named "Alba," and she got lost in the underbrush.
Even while he insists on using pesticides, he recognizes that they will only be a short-term solution to the weed problem.
But, scientists and residents of the area have come up with an innovative solution to the invasion: they have released a beetle named Megamelus scutellaris into the area to feast on the liquid hyacinth.
Both the plants and the small insects that feed on the plants' phloem are native to the Amazon basin in South America, and each year thousands of them are set free.
Insects murder the weed by eating the tissue responsible for transporting the nutrients produced during photosynthesis from the leaves to the remainder of the plant.
Coetzee noted that the water hyacinth coverage on the dam had been reduced to less than 5 percent due to the insect army. There have been periods when the weed has covered at least half of it.
Grootvaly Blesbokspruit wetland sanctuary, southeast of Harties, was previously home to more than a hundred species of birds that attracted a lot of tourists. Environmentalist Patrick Ganda, 41, mass rears the bugs there.
But now, only two or three species of birds remain since they can't get to the fish and numerous vegetation in the wetland's water because of the plants that cover the water.
Scientists warn that the insects have so far been reasonably successful in managing their location, but that more has to be done to handle their shifts, which authorities may tackle by strengthening restrictions on waste water management.
"We are merely treating the symptom of a much greater problem," explains Kelby English, a biologist at Rhodes University.