JP le Roux, Aquatic Conservationist, Source to Sea Programme
World Fish Migration Day (WFMD) is a one-day global celebration to create awareness around the importance of open rivers and migratory fish and in 2018 it was celebrated on 21 April, with the theme of Connecting fish, rivers and people.
This day is significant because many fish need to migrate to reproduce, feed and complete their life cycles. Migratory fish make up a crucial link in the food chain and play an important role in healthy and productive river systems. They are also an important source of food and livelihoods for many people. Unfortunately, many migratory fish species face threats such as dams, weirs and sluices, which disrupt the natural flow of rivers and prevent their migration.
The EWT’s Source to Sea Programme took part in a special event in Groot Marico to mark this day, organised by Iggdrasil Scientific Services. The event was focused on barriers to fish migration, both natural and manmade. They travelled around Marico looking at barriers that limit the movement of the endemic Marico Barb as well as the impact of Largemouth Bass on indigenous fish communities. They found that in some cases the barriers limit the dispersal of invasive fish, which in turn limits their effect on the endemic fish population. One of the biggest threats to the Marico Barb was identified as the introduction of invasive fish in the upper part of the catchment, which will need an education and outreach programme to be mitigated.
Thanks to Elizabeth Wakeman Henderson Charitable Foundation for their support of this work.