In a very recent study done at Camps Bay, the presence of herbicide chemical compounds found in seawater, beach sand and marine organisms, indicate the extent of chemical pollution in the local marine ecosystem. The study, undertaken by Cecilia Ojemaye and Leslie Petrik from the Environmental & Nano Sciences Group at UWC, aimed to establish whether raw sewage containing selected persistent chemicals that are released through the marine outfall would be sufficiently diluted by the ocean to prevent impact on the near-shore marine environment of the suburb Camps Bay.
Samples of seawater, sediment, sea-weed, and selected marine organisms present in the near shore environment, such as limpets, mussels, and sea urchins, were analysed for five indicator herbicides, namely atrazine, alachlor, simazine, metolachlor, and butachlor. These chemicals were chosen as they were part of the 2017 CSIR report on the marine outfalls.
Herbicides are a type of pesticide designed to kill or control specific types of pests such as weeds and other problematic plant species. There is a massive range of toxicities associated with pesticides, and herbicides in particular, as few are nontoxic or not harmful to mammals.
This study proved that the herbicides enter the environment of Camps Bay primarily through urban resident’s raw sewage discharged through the marine sewage outfall since there was no storm water runoff in this urban setting during the severe drought of 2015–2018.
This study indicated the extensive use of these herbicides for cosmetic and ornamental purposes in gardening, or for weed control in an urban setting. Many people know very little about the impact of these chemical compounds on the environment, and specifically the indirect impact on the ocean environment. It is clear that consumers and municipalities need to be educated about their inadvertent use and safe disposal of these gardening chemicals. Many of the herbicides found are banned in other countries, but still in use in suburban environments in South Africa. Urgent action is required to educate the public about the associated environmental and human risks of their choices.