An evaluation of methods for alien fish removals in headwater streams: Lessons from South Africa

Jeremy Shelton

Publication Date:

Headwater streams are critical habitats for conserving freshwater biodiversity, but invasions by non‚Äźnative predatory fish can compromise the value of otherwise-pristine headwater habitats as sanctuaries for native species within largely transformed riverscapes. In certain situations, the removal of alien fishes can be an effective means for rehabilitating invaded rivers through increasing habitat area and connectivity for threatened and fragmented native species populations. While both developed and developing countries recognize the threat posed by non-native fish, few of the latter have implemented control programmes to manage it. In South Africa, introduced predatory fish have depleted, or eliminated, native fish populations, modified community structure in otherwise pristine headwater streams, and pose a serious future threat to several endemic freshwater species. In response to this situation, recent interventions, including both chemical and mechanical approaches, have been applied to rivers in South Africa with varying success. Here, we review the different options available for removing non-native fish from headwater streams and draw on case studies from South Africa to identify strengths, weaknesses, and criteria for maximising the success of future-such interventions.

Resource Type:
Audio/Video, Conference Presentation, SER2019

Society for Ecological Restoration