The City of Cape Town warned people not to catch and eat tilapia and carp fish from Zeekoevlei as samples taken from the water containing levels of mercury was not safe for human consumption.
The City wants to advise the public not to eat fish caught from Zeekoevlei, and the Groot and Little Lotus rivers until further notice.
Some people visit the Zeekoevlei, located within the False Bay Nature Reserve, to catch fish. Although for most angling is a hobby, some fish are removed for consumption, and as such, the City strongly advises residents not to eat the fish.
The City also advised when buying fish from sellers, to avoid tilapia and carp, unless the seller can prove the source.
Sidney Jacobs, chairperson of the Friends of Zeekoevlei and Rondevlei (FOZR), said people fish at Zeekoevlei on a daily basis. “Despite the warnings from the City, being advised by local residents, being removed or chased away by the City Rangers, some people fish and even sell them to consumers, knowing that they are contaminated.”
Mr Jacobs said FOZR and most local residents care about people’s health, “we monitor all the time and report it to our local rangers for enforcement continuously.”
In the meantime, the City plans to install signage at Zeekoevlei to inform the public accordingly, inform visitors as they enter the False Bay Nature Reserve, and to also hand out pamphlets to visitors and residents in neighbouring areas.
In July last year the City appointed independent consultants to develop a rehabilitation plan for Zeekoevlei.
A specialist fish study formed part of the brief, and entailed a survey of the fish populations in the vlei; an assessment of the levels of trace metals such as lead, zinc, and mercury in the fish; and potential risks associated with human consumption.
The specialist fish study was undertaken in April this year, covering the common carp and Mozambique tilapia, both invasive alien fish that constitute the far majority of the fish population in the Zeekoevlei.
The City has been informed that tissue samples from some of the carp and tilapia which were analysed revealed lead and mercury levels exceeding the permissible levels for safe human consumption.
The source of these elements is as yet undetermined. Water Pollution Control has been activated to investigate and trace possible sources of pollution, however, it is unlikely that the mercury and lead have emanated from any sewage infrastructure.
As such, the City wants to discourage residents from eating fish from the Zeekoevlei and Lotus rivers.
The high levels of lead and mercury are attributed to the presence of pollutants in the vlei which emanate from the catchment.
Mr Jacobs said although this is the first time that “we have recorded these high levels of mercury and lead as this has not been tested before”. “However, we urge people to refrain from fishing so that there are no health risks to any one. We also urge those selling to unsuspecting people to stop and put people’s lives first and not money. Report those who fish illegally so that it stops.”
Mr Jacobs said on Saturday (June 25) they had a community litter clean-up and removed over 30 bags of litter from the shores of the vlei, where the dirt eventually landed in the rivers and into the vlei. “We urge people to stop that as it kills our environment.”
The City said they are busy undertaking interventions to improve catchment management and to prevent effluent from entering the rivers and stormwater systems, and eventually, the vlei.
Future interventions include dredging to lower the nutrient load and remove polluted sediment which will assist to improve the overall health of the vlei, and fish population.