Original Research

Optimising invasive fish management in the context of invasive species legislation in South Africa

Darragh J. Woodford, Phillip Ivey, Martine S. Jordaan, Peter K. Kimberg, Tsungai Zengeya, Olaf L.F. Weyl
Bothalia | Vol 47, No 2 | a2138 | DOI: https://doi.org/10.4102/abc.v47i2.2138 | © 2017 Darragh J. Woodford, Phillip Ivey, Martine S. Jordaan, Peter K. Kimberg, Tsungai Zengeya, Olaf L.F. Weyl | This work is licensed under CC Attribution 4.0
Submitted: 29 July 2016 | Published: 31 March 2017

About the author(s)

Darragh J. Woodford, Centre for Invasion Biology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand; South African Institute for Aquatic Biodiversity (SAIAB), Grahamstown, South Africa
Phillip Ivey, South African National Biodiversity Institute, Cussonia, Pretoria, South Africa
Martine S. Jordaan, South African Institute for Aquatic Biodiversity (SAIAB), Grahamstown; Cape Nature Scientific Services CapeNature Scientific Services, Stellenbosch, South Africa
Peter K. Kimberg, The Biodiversity Company (TBC), Johannesburg, South Africa
Tsungai Zengeya, South African National Biodiversity Institute, Cussonia, Pretoria,, South Africa
Olaf L.F. Weyl, South African Institute for Aquatic Biodiversity (SAIAB), Grahamstown; Centre for Invasion Biology, SAIAB, Grahamstown, South Africa


Background: South Africa hosts a large number of non-native freshwater fishes that were introduced for various industries. Many of these species are now listed under the National Environmental Management: Biodiversity Act (NEM:BA) Alien and Invasive Species (A&IS) lists and regulations, though the practical options available to conservation agencies to effectively manage these fishes vary greatly among species and regions.
Objectives & methods: We assessed the history and status of national legislation pertaining to invasive freshwater fishes, and the practical implications of the legislation for managing different species with contrasting distributions, impacts and utilisation value.
Results: The smallmouth bass, despite being a potential conflict-generating species, is fairly straightforward to manage based on current legislation. Two species of trout, which remain absent from the NEM:BA A&IS lists because of ongoing consultation with stakeholders, continue to be managed in regions like the Western Cape province using existing provincial legislation. To maximise the limited capacity for management within conservation agencies, we proposed a decision-support tool that prioritises invasive fish populations that represent high environmental risk and low potential for conflict with stakeholders. Using three case studies, we demonstrated how the tool can be used to set management goals of ‘eradicate’, ‘manage against impacts and further spread’ and ‘continue to monitor population’ as the most pragmatic solutions given the state of an invasion, its socio-economic impact and the capacity of the responsible agency to act.
Conclusion: By choosing a pragmatic management strategy, conservation agencies can maximise the effective deployment of limited resources, while minimising avoidable conflicts with stakeholders.


National legislation; conflict species; decision support framework; management approach


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Crossref Citations

1. The ghost of introduction past: Spatial and temporal variability in the genetic diversity of invasive smallmouth bass
Genevieve Diedericks, Romina Henriques, Sophie von der Heyden, Olaf L. F. Weyl, Cang Hui
Evolutionary Applications  vol: 11  issue: 9  first page: 1609  year: 2018  
doi: 10.1111/eva.12652