Freshwater fish are the most threatened species group in South Africa – more threatened than plants, birds or mammals. Just like other tributaries of the Doring River, the Biedouw was once a paradise for endemic fish species. But over the years these rivers have been overrun by alien fish and now the five endemic species that once swam the length of the Biedouw are relegated to just 900 m of “safe” habitat above a small waterfall in the gorge that keeps alien fish out. Among these endemics is the endangered Clanwilliam Sandfish – South Africa’s most threatened migratory freshwater fish species.

Restoring the upper Biedouw River
The Saving Sandfish Project, which launched in 2019, has rescued over 35 000 young Sandfish and is rebuilding the declining Sandfish population in the lower Biedouw River. But to secure the future of this species in the Biedouw River, the whole ecosystem needs to be restored. The Biedouw River Restoration Project, a collaboration between the Freshwater Research Centre, CapeNature and the Fynbos Fish Trust, works with local landowners and up-skilled community members to restore and reclaim critical river habitat for fish species and in so doing, “rewild” the Biedouw River.
Invasive fish eradication
The plan is simple: remove alien fish (spotted bass and bluegill sunfish) from 9 km of river and allow indigenous fish to repopulate by swimming downstream into newly cleared, alien fish-free waters. But the river is heavily bushed in by poplars, reeds and blue gums so the first step of the project has been to clear this vegetation to make the river more accessible.

Vegetation clearing
Clearing riparian vegetation to open up the river channel has been the job of Fynbos Fish Trust’s Riaan van der Walt and his experienced and energetic team from Langkloof – Lionel, Keenan, Malin, and Denzil. Some of this work involves trimming indigenous plants to expose the river, but a big component of the project has also been to clear all invasive vegetation along the 9-km restoration zone. This involves manually chopping and ring-barking woody invasive plant species like black wattle, blue gum and poplar.
While clearing poplars by hand is tough but doable, the project team identified that a 2.5 km section of dense reed beds was going to be impossible to clear and that a controlled burn would be necessary.
After obtaining permission from West Coast District Municipality Fire & Rescue Services and consent from the affected landowners, the date was set – the 3rd of April. The “Agter Pakhuis” community was notified via WhatsApp so that huge clouds of smoke drifting from the valley would not cause for alarm.
The 3rd of April was a hot, still day – perfect for a burn. The veld was dry and sparse after a long, dry summer and so the risk of a runaway fire was low. Present on the day of the were dedicated teams from Bushmans Kloof, CapeNature, FRC, Fynbos Fish Trust as well as personnel from Mertenhof, Welbedacht and Biedouw farms. As a precautionary measure there were two “bakkie sakkies” on standby thanks to Bushmans Kloof and CapeNature.
The burn started at 9 am and burned until approximately 4 pm, and while the flames and the smoke looked impressive and dramatic, the fire remained under control the entire day. A back burn was used to prevent the fire from travelling further down the valley. Once the main fire had burned its course, teams were deployed to extinguish any flare ups.

A successful burn completed
We are pleased to report that the burn was a complete success: it achieved the goal of opening up the previously impenetrable reed beds, it did not burn beyond the desired area and no property was harmed or lost in the process. Thanks to this burn and the work of Riaan and his team, the vegetation clearing phase of this project is now complete. We would like to thank the landowners, Barry Lubbe, Sarel van der Merwe, Joubert van der Merwe, and Bertus van der Merwe, as well as our project partners, Bushmans Kloof and CapeNature for their support and collaboration – without which we would not have been able to complete the critical first step of this ambitious conservation project. To the broader Biedouw Valley and Agter Pakhuis community – thank you for your support and trust. We will be keeping you all informed on the progress of the Biedouw River Restoration Project as it unfolds.
Next steps
Invasive bass and bluegill will be eradicated from 9km of the Biedouw River in summer 2025, to restore critical riverine habitat for 5 species of native freshwater fish, including the endangered Clanwilliam sandfish.

Partners and support
This work is funded by Fondation Segré through IUCN Save Our Species, The Mohamed Bin Zayed Species Conservation Fund, the Federation of Southern African Flyfishers (FOSAF), Mount Ceder, Bushmans Kloof, the Ford Wildlife Foundation and Alu-Cab. CapeNature and the Fynbos Fish Trust are partners on the project.