A review of the current legal status and management options for invasive fishes in South Africa

A review of the current legal status and management options for invasive fishes in South Africa
Darragh J. WOODFORD1, Philip Ivey2, Olaf L.F. Weyl3, Martine Jordaan4, Tsungai A. Zengeya5
1University of the Witwatersrand
2Invasive Species Programme, South African National Biodiversity Institute
3South African Institute for Aquatic Biodiversity
4CapeNature
5South African National Biodiversity Institute, Pretoria National Botanical Gardens

South Africa has a long history of non-native fish introductions, and continues to see new introductions as well as range-expansions within its borders. The historical response of government and conservation agencies to this biodiversity threat has been negligible, with few successes. The Alien and Invasive Species (A&IS) Regulations of the National Environmental Management: Biodiversity Act, are meant to set the legal framework under which invasive fishes can be managed in South Africa, although there are several complications to assessing or enforcing compliance with the new legislation.

A chief aspect of invasive fishes is that many were introduced for, and continue to provide, recreational and subsistence fisheries in South Africa. This means that any management action taken under NEM:BA has to take the local socio-economic value of an invasive species into account, particularly as many species are legally entitled to remain within their current distribution under the A&IS regulations. Furthermore, two invasive species, rainbow trout and brown trout, are currently excluded from the AIS lists and are being managed under a separate process involving the mapping of “trout areas”.

In this paper, we discuss the current implications of the A&IS regulations for conservation management, and assess the value of a recently-developed decision support tool for managing invasive fishes. We employ the tool in three case studies to demonstrate how current legislation, the practical limitations for control, and socio-economic impact of a particular invasive fish population can be used to determine a reasonable management goal for that population.