Conserving one of the world’s most threatened migratory fish

Guest Author: Jeremy Shelton

Editor: Patrick Cooney

What is a sandfish?

The Clanwilliam sandfish (Labeo seeberi) is a curious creature.

Just look at the down-turned hoover-like mouth (locally called an ‘onderbek’) specially adapted for grazing algae and detritus (organic material) on the stream bed. Then check out the small rasp-like scales and powerful fleshy fins it uses for swimming great distances during their annual spawning migration.

A healthy adult Clanwilliam sandfish (photo Bruce Paxton)

‘Bottom-feeders’, like sandfish, are vital to river ecosystems. Without them, rivers can quickly become clogged up with sediments that smother vital habitats used by countless aquatic creatures.

Swimming towards extinction

In the early 1990s sandfish were so plentiful in the Olifants-Doring River system of South Africa that locals collected them from the river by hand when they gathered en masse to spawn. They used the fish to make curries, fish cakes, and biltong (similar to meat jerky). However, these recipes have since vanished from the lives of those that live in the valleys once frequented by sandfish. The former mass-migrations now exist only as memories, and in the rock art left behind by the indigenous San people who thrived in the Cederberg thousands of years ago.

Sandfish-like forms depicted on the walls of a cave where the indigenous San people once lived (photo Jeanette Deacon)
The Biedouw River flows from the Cederberg mountains and provides irrigation to rooibos and livestock farms, as well as important spawning grounds for the Clanwilliam sandfish (photo Otto Whitehead)

The Clanwilliam sandfish, endemic to South Africa’s Olifants-Doring River system has become the country’s most threatened migratory freshwater fish. Once widespread throughout the system, its distribution has contracted and fragmented to the point where it has entirely disappeared from the Olifants catchment, and is now only known to spawn in two small tributaries of the Doring; the Oorlogskloof and Biedouw Rivers. What is particularly concerning is that these populations are under pressure from the increasing threat of alien fish, water abstraction, drought, and sedimentation.

The Olifants-Doring River system where sandfish were once abundant (image from Google Earth)
Sarah Fransman from the Biedouw valley remembers a time when the sandfish were still plentiful (photo Otto Whitehead)

Today, sandfish have become so scarce that the scientists studying them are worried that they could go extinct in the next decade unless bold conservation action is taken. In 2013, Dr Bruce Paxton and Alwyn Lubbe (then Endangered Wildlife Trust) led the last comprehensive survey of sandfish in the Doring River and found a mere 45 adult sandfish.

Dr Bruce Paxton surveying sandfish populations in the Doring River catchment (photo Jeremy Shelton)

A conservation plan to save the sandfish from extinction

In response to this dire situation, the Saving Sandfish project  – a collaborative effort led by the Freshwater Research Centre – has initiated a programme to increase sandfish survival. This will be achieved by rescuing young fish from vulnerable habitats in the lower Biedouw River where they are heavily preyed on by invasive north American black bass and bluegill sunfish, and relocating them to safer river habitats and temporary sanctuaries in the valley.

Although solitary for most of the year, adult sandfish move into tributaries like the Biedouw River during spring where they gather to spawn (photo Jeremy Shelton)
Invasive bluegill sunfish being removed from a farm dam to create a sandfish sanctuary (photo Jeremy Shelton)

On-the-ground action

In October, 610 juvenile sandfish were rescued and relocated to the upper Biedouw River, where the river flows year-round, and a small waterfall keeps invasive bass and bluegill out of a 900m indigenous fish refuge. Rigorous scientific monitoring is underway to gauge the success of this conservation intervention and inform future efforts.

Young sandfish being released into a safer habitat in the upper Biedouw River valley (photo Jeremy Shelton)

Next steps

The project aims to rescue a further 5,000 young sandfish between 2020-2021 and, with the help of local land-owners, relocate them to temporary ‘sandfish sanctuaries’ created by removing alien fish from farm dams. This should give them a chance to survive longer and grow to a ‘bass-proof’ size (probably about 20cm), thereby helping to prevent sandfish populations from extinction. When the fish are large enough to avoid predation by alien fish, they will be released back to the Doring River to bolster sandfish populations and hopefully one day spawn themselves!

University of Cape Town masters student Cecilia Cerrilla admires an adult sandfish from the Biedouw River (photo Jeremy Shelton)

Sponsor a sandfish

To support this project, please consider sponsoring a sandfish, or making a custom donation.  All donations will go directly toward rescuing and relocating juvenile sandfish to safe habitats, rehabilitating sandfish habitat to create safe refugia within transformed riverscapes, collecting robust scientific data to monitor the success of these interventions, and communicating the project story and findings to build further support for freshwater biodiversity conservation in South Africa.

Saving Sandfish web series

The Saving Sandfish journey is being chronicled by Fishwater Films founders Dr Jeremy Shelton and Dr Otto Whitehead in the form of a colourful web series called Saving Sandfish. This series takes the viewer on a comical and purposeful journey to remote parts of the Greater Cederberg to find the last spawning populations of sandfish and help prevent their extinction. The series also profiles the passionate people they meet along the way. Check out the episodes below and follow to see new episodes as they roll out.

Partners and funders

This project falls within the FRC’s Cape Critical Rivers (CCR) conservation programme, which includes partners CapeNature, DENC, EWT, Bushmanskloof Reserve, Enjo Nature Farm, Mertenhof Farm, World Fish Migration Foundation, and Gone Outdoor to bring the ambitious project activities to life! Funding from the National Geographic Society, Mohammed Bin Zayed Species Conservation Fund and the Federation of South African Flyfishers is fuelling this work.

Social Media links

Fishwater Films

www.fishwaterfilms.com

Instagram @fishwaterfilms

Dr Jeremy Shelton

www.jeremymarkshelton.com

Instagram @jeremymarkshelton

Dr Otto Whitehead

www.ottowhitehead.com

Instagram @ottowhitehead

About the Guest Author

Jeremy Shelton

Since a child, Jeremy has been drawn to watery environments, fascinated by the wonder of the world beneath the surface. Through his studies in freshwater conservation biology at the University of Cape Town (2000-2013), he felt an increasing need to share the hidden wonders and struggles of freshwater environments with the world, and seeks to achieve this through a blend of science, education and film.

Jeremy believes that “we only care about what we love, and we will only love those things that we come to know” and is especially passionate about sharing his love of rivers with the youth of today – the future custodians of our rivers and wetlands.  “I feel lucky to share this beautiful planet with such an insane diversity of wild and wonderful creatures, but it also troubles me that we have devastated so much of our wondrous world over such a short time. Without our help the natural splendor of this place will disappear for good, and be lost from the lives of our children’s children!”

Since 2014, Jeremy has been working as a freshwater conservation biologist at the Freshwater Research Centre, a non-profit based in Kommetjie (Cape Town, South Africa). In addition to research, Jeremy is spending more and more time communicating science through film and photography, and working on the Centre’s outdoor education programme, “Living Labs”.

Please leave a thought provoking reply. We reserve the right to remove comments deemed inappropriate.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.