Citizen Research Highlights: Blue Flag Beach is not a Reliable Eco-Label to Protect Bathers in Cape Town

Abstract

Background: Every day over 50 million liters of raw sewage are pumped into the Atlantic Ocean at several marine outfalls around the Cape Peninsula. They are in proximity to Blue Flag beaches and marine coastal nature reserves. This wastewater disposal poses severe health risks to citizens and recreational bathers. Moreover, sea food is contaminated by germs, pharmaceuticals, chemicals and other toxic substances. Caused by the wastewater pollution the marine ecosystem is under threat and deteriorating. Furthermore, Cape Town experiences recurrent droughts and the wastewater disposal puts additional strain to fresh water resources.

Study design: The Blue Flag beach criteria were applied as a framework. A citizen research approach was used. Seawater was analysed daily over two months during high tide at Blue Flag beaches in Cape Town during Blue Flag season. Wind directions were recorded, photo documentation performed, and drone flights were conducted. Wastewater related diseases were reported by an online questionnaire.

Results: The water at Blue Flag beaches in Cape Town is contaminated by E. coli. The drone flights showed that the sewage plume is shifted by wind directions, tides and currents towards the coast and Blue Flag beaches. Skin rashes, ear infections, stomach cramps, diarrhea as well as vomiting were reported by recreational bathers.

Conclusions: The dissemination of sewage and other pollutants are influenced by wind directions and currents. The present sewage disposal into the sea poses a risk to the health of recreational bathers and sea food consumers. The International Blue Flag beach label promotes beaches as major tourist attractions but is not a reliable label indicating the cleanliness of water. Tertiary wastewater treatment plants are mandatory for coastal cities to protect the marine environment and recreational bathers. The appropriate recycling of wastewater is required to combat recurrent droughts to mitigate the climate crisis.