Untreated sewage is putting Cape Town’s endangered penguins at risk. The city is pleading poverty
Nicole McCain -- News24



Untreated sewage is putting Cape Town’s endangered penguins at risk.

Untreated sewage is putting Cape Town’s endangered penguins at risk. David Silverman/Getty Images


  • Chemicals in Cape Town’s coastal waters could be affecting the breeding of endangered
  • Research showed that contaminants around penguin colonies could be affecting egg
    shells and chicks.
  • Scientists have shared findings that show various medications and other chemicals are
    contaminating Cape Town’s coastal waters.


Coastal waters contaminated with sewage could affect endangered penguin colonies around
Cape Town.

At a recent briefing to unpack the impact of sewage and wastewater release in coastal areas
around Cape Town, scientists said the ocean was absorbing the medications and pesticides
humans use – and that it could lead to drug-resistant bacteria and contaminated food.
But we aren’t the only ones affected by contaminated water. Research by the University of
Pretoria’s Stephanie Dreyer pointed out that chemicals in coastal waters could impact efforts to
increase local penguin numbers.

The body of research, presented by Emeritus Professor Leslie Petrik from the Department of
Chemistry at the University of the Western Cape, stated that the coastline from Green Point to
Rooi Els was contaminated by chemicals from “inadequately treated sewage”.

Untreated sewage through marine outfalls

Petrik added that discharging untreated sewage through the three marine outfalls at Green
Point, Camps Bay and Hout Bay had added to the extensive chemical pollution of seawater,
sediments, and marine biota.

Contamination was also found around Robben Island and deep in False Bay.

The City of Cape Town is permitted to release screened sewage into the ocean at Green Point,
Hout Bay and Camps Bay via pipes about 1.7km, 1.2km and 1km out to sea, and about 32m, 35m
and 28m deep, respectively. The wastewater passes through screens, but contaminants such as
chemicals or pharmaceuticals are not removed.

The City has commissioned seven specialist studies over the past six years and a report by an
expert panel on the marine outfalls. The studies, and 200 marine toxicity tests, did not find any
toxicity due to the wastewater discharge.

The City previously told News24 that marine outfalls were not the only source of contaminants in
the marine environment and that the challenge of removing contaminants from wastewater was
global. There is no technology available that can remove contaminants to scale cost-effectively
and efficiently, the City said.

The researchers showed that the chemicals in our coastal waters could affect the sperm of
animals, such as penguins. Even at very low levels of exposure, the chemicals could cause
sperm to swim more slowly and become incapable of fertilising an egg.

“This would impact on the survival of these species, and even human sperm was found to be
highly susceptible to being incapacitated by exposure to these chemicals,” Petrik added.

The research focused on penguin colonies at Robben Island, Boulders Beach and Stoney Point.
Samples showed that there were “endocrine-disrupting or toxic” chemicals that are commonly
found in sewage or untreated wastewater. These chemicals included pain-relief medication,
antibiotics, anti-convulsant and anti-depressant medication, as well as antiretroviral drugs.

Contaminated with chemicals

Penguin carcasses and eggs sampled from Boulders Beach and Robben Island colonies were
“contaminated with numerous chemicals”, the research showed.

The researchers said the chemicals were most likely entering the water due to “inadequate
sewage treatment”.

While there is no measurement of the direct effects yet, the compounds could weaken egg
shells and cause deformities in offspring that impact chick viability. Penguins could also
experience changes to their endocrine and immune systems.

Penguins already face a number of stressors, the researchers said, and “cleaning up the
chemical contamination by proper treatment of sewage to remove these chemicals will be one
factor that can reduce stress on them”.

Southern African Foundation for the Conservation of Coastal Birds (Sanccob) researcher Albert
Snyman, who worked with the research team, said that the sample size at Robben Island was
too small to allow for an accurate result. However, the samples from Stony Point and Simon’s
Town match with results found in previous studies in those areas and are more accurate.

“This research adds great value in illustrating the current state and health of our oceans. It does
add an extra concern for our seabirds as they already face numerous threats, including lack of
prey, climate change, pollution (oil spills), predation, as well as disease,” he said.

He added:
Now, adding another threat can place even more strain on the African
penguin and other seabirds found breeding along our coastline.

Snyman added the research highlighted the importance that seabirds, like penguins, play as
ecosystem health indicators.

Contaminants in coastal waters around breeding colonies can have “a severe impact on the
health and performance of our seabirds”, Snyman said.

He added that many of the bacteria found could be antibiotic resistant, making it even more
difficult for Sanccob to treat wounded birds, hand rear chicks or care for sick birds if they have
been exposed to drug-resistant bacteria out in the wild or oceans.

Snyman added that one of the greatest concerns was the impact the contaminants could have
on breeding.

“Contaminants in the ocean can possibly have an effect on the fertility of breeding birds (causing
lower fertility or infertile birds). Possible lower fertility in penguins or seabirds can have a drastic
impact on breeding success, and seeing how few birds are currently breeding in the wild, this
could potentially place even more strain on successful breeding,” he said.

SANParks, which manages some of the penguin colonies, had not responded at the time of

Original source: https://www.news24.com/news24/southafrica/news/untreated-sewage-is-putting-cape-towns-endangered-penguins-at-risk-the-city-is-pleading-poverty-20230403