Cape Town - The Milnerton Central Residents Association (MCRA) has reiterated its call for the severely polluted Milnerton lagoon to be declared an environmental disaster after the second fish die-off it experienced this year as a result of worsening sewage spills and overall ecosystem collapse.
The residents and groups in the area said the lagoon stank so badly, it discouraged people from taking part in recreational activities, including at the beach.
They believed the City’s upgrades and interventions were being implemented too late and by the time they are completed, the lagoon’s ecosystem would have collapsed.
MCRA member Caroline Marx said, “It has been almost impossible for fish or other aquatic life like crabs or sand prawns to survive in the lagoon since April 2021.
“The fish that are dying are ocean fish that swim into the estuary to breed but cannot survive. The MCRA is disappointed at the lack of progress in resolving the root causes of the ecosystem collapse, including ongoing poor quality effluent from the Potsdam Wastewater Treatment Works for four years, and raw sewage spills.”
Marx said the collapse of the ecosystem was an environmental disaster. However, the City was of the opinion that it would not assist in any way to declare it one.
The MCRA would be investigating further to see if doing so would shorten procurement processes or free up additional funding to fast track solutions to the ongoing lagoon pollution.
The City has named numerous projects to increase the quality of the ecosystem at the lagoon and the Diep River estuary, including upgrades to Potsdam and the possibility of a low-flow vegetated channel east of the existing channel in the estuary to mitigate the quality of discharge.
City spokesperson Priya Reddy said: “A multi-pronged, collaborative approach between stakeholders, including the City, different spheres of government and the public is required to address the chronic pollution in the Milnerton lagoon.”
Marx added that reduced contact with the lagoon had severely impacted the community’s normal enjoyment of the beautiful scenic estuary that was part of a nature reserve and historically rich in bird and aquatic life.
Resident Darren Silke said: “Often when we come to the beach we have this waft of sewage smell following us.
“We don’t live here on Woodbridge Island, we stay a bit further away but even there you sometimes get a whiff of the sewage smell. You even get the sewage smell while driving on Otto du Plessis Drive.”
Silke said he would not put his feet in the water at the beach, never mind actually swim there because of the high levels of sewage and visible discolouration.
Resident Harold Goldstuck added, “It’s a stench hole, nobody comes here anymore.”
Organisation Undoing Tax Abuse (Outa) member Ferrial Adam said, “We support the MCRA’s call to the City to declare the state of the lagoon an environmental disaster or emergency as the ecosystem has totally collapsed.”
UWC professor Leslie Petrik, an expert in the field of chemistry, environmental remediation, water treatment and beneficiation of industrial wastes, said: “If visible species such as fish die off, one can be sure that the smaller living species have died as well unless they are exceptionally tolerant to the toxins and lack of oxygen in the water.
“The whole ecosystem has collapsed in the lagoon.”
Reddy explained that the recent fish die-off was most likely as a result of loss of oxygen levels in the water which occurs when nutrient loading from pollution in the river or estuary creates rapid algal/bacterial growth, which then depletes oxygen levels in the water causing the fish die off.
Petrik added that as long as inadequately treated effluents were discharged, the damage would continue and current effluent discharge guidelines were far too lax to hold the City accountable to prevent ecological harm.
kristin.engel@inl.co.za