ROOIBOS BOOSTS SUSTAINABLE AQUACULTURE

Researchers from Walter Sisulu University have discovered that adding green Rooibos extract to tilapia feed significantly improves fish growth rates and feed efficiency.

Led by Prof Grace Okuthe, senior researcher at Walter Sisulu University, the trial compared commercial fish feed against feed enhanced with either fermented Rooibos (the familiar red variety) or unfermented green Rooibos extract. The results were clear: tilapia fed green Rooibos grew about 2.83% faster and converted feed into body mass 0.9% more efficiently than the control group.

The team believes the effect is linked to Rooibos’ bioactive phenolic compounds, which may make feed more palatable, promote gut health and improve nutrient absorption. The study also found evidence of DNA protection in the fish, suggesting an overall health benefit. Improved feed efficiency means less waste entering the water, a major environmental challenge in fish farming. Reducing nutrient runoff helps prevent algal blooms and protects aquatic ecosystems.

Rooibos is cultivated exclusively in the Western Cape and a commercial-scale demand for green Rooibos extract could create a new market for growers, supporting job creation in harvesting, processing and distribution. It also supports South Africa’s commitment under the Nagoya Protocol, ensuring that benefits flow back to the Khoikhoi and San communities who are the traditional custodians of Rooibos.

The Rooibos–tilapia study demonstrates the potential of South Africa’s natural resources to support sustainable aquaculture and create new economic opportunities for rural communities.

www.sarooibos.co.za