FYNBOS FISH | BLOG
Protecting the Fynbos Fish in the Breekkrans RivER
FYNBOS FISH PROJECTS | 8 JUNE 2020
home to five species of Fynbos Fish
The Breekkrans River, which originates in the Cederberg mountains, is home to five species of Fynbos Fish – including the Critically Endangered Doring River redfin. Four of these are ENDEMIC to the Olifants-Doring River (ODR) system , and are therefore found nowhere else in the world.
non-native invasive fish
THESE FYNBOS FISH FACE NUMEROUS THREATS
One of the main threats is predation by non-native invasive fish, in particular three species of Black Bass (Micropterus salmoides, Micropterus dolomieu and Micropterus punctulatus). The Bass were introduced from America in the 1930s for recreational fishing.
Today they have invaded more than 81% of the ODR system.
Despite the impact of the invasive fish on the Olifants-Doring River system, there is hope. And it rests in the pristine Breekkrans River. This river is a perennial tributary to the Olifants-Doring system. The upper catchment falls in a protected area. No water abstraction takes place here. And non-native invasive plants have been removed from the riparian zones.
That’s why the Fynbos Fish Trust is launching an innovative project to remove these non-native fish from sections of the Breekkrans River, and prevent them from reinvading these sections.
Image above: Breekkrans River
Here’s our plan
We’ll construct an alien fish barrier.
The barrier has an 80cm vertical drop, making it impossible for non-native fish (especially bass) downstream to reinvade the stream. It will be constructed with rock filled gabions and steel reinforced concrete. The environmental impact assessment and water licence application has both been approved by the relevant state departments.
Non-native invasive fish are removed by mechanical clearing.
These include gill, fyke and sein nets; hand nets; and spearguns. The eradication team starts at the top of the river, and works downstream. Temporary block nets are placed in the river around 300m apart.
We work with a team employed from the local Wuppertal community
who will receive additional training and employment.
The sites are monitored
working in partnership with the Freshwater Research Centre, and records are kept of all fish caught. Basic habitat assessments and SASS samples are taken regularly.
paper for publication in a scientific journal
We hope to write up the project into a paper for publication in a scientific journal.
The project creates employment for four people for two years.
Image above: Spotted bass in the lower Breekkrans River
CapeNature has already received funding support to construct the alien fish barrier. The project team has applied for additional support, and is hoping the project will be launched soon.
We’ll keep you up to date on the project as it rolls out.