FEATUREPeces endémicos amenazados en la región florística de Cabo en Sudáfrica: un nuevo comienzo en el Río Rondegat RESUMEN: en muchos ríos a lo largo del mundo, las comunidades ícticas nativas se ven amenazadas por peces foráneos. En la región florística de Cabo, en Sudáfrica, la depredación ejercida por peces foráneos ha impactado severamente las poblaciones nativas de peces y más de 17 especies endémicas de peces están amenazadas. Con el fin de preservar la fauna íctica endémica, se le dio prioridad a la remoción de especies foráneas en las áreas de conservación en esta región. En febrero de 2012, la primera erradicación de peces no nativos mediante el uso de rotenona, se dio lugar en el Río Rondegat, un pequeño cuerpo de agua que ha sido invadido por la lobina boca chica (Micropterus dolomieu). El tratamiento fue exitoso y culminó después de un proceso de diez años facilitado por la colaboración de las autoridades de conservación de Sudáfrica (CapeNature), el Instituto Sudafricano de Biodiversidad Acuática y el subcomité de Manejo de Químicos de La Sociedad Americana de Pesquerías. Se anticipa que el incremento casi instantáneo de la biodiversidad tras la remoción efectiva de peces foráneos invite a tomar nuevos esfuerzos para restaurar más poblaciones de peces endémicos en Sudáfrica. ABSTRACT: Nonnative fishes threaten native fish communities in many rivers of the world. In South Africa's Cape Floristic Region, predation by nonnative fishes has severely impactednative fish populations and more than half of the 17 endemic fish species are endangered. To preserve the unique endemic fish fauna, removal of nonnative fish from conservation areas is a priority in this region. In February 2012, South Africa's first nonnative fish eradication using rotenone took place in the Rondegat River, a small headwater stream that had been invaded by Smallmouth Bass (Micropterus dolomieu). The successful treatment culminated from a decade-long process that was facilitated through collaboration among a South African nature conservation authority (CapeNature), the South African Institute for Aquatic Biodiversity, and the American Fisheries Society Fish Management Chemicals Subcommittee. The successful removal of alien fish and almost instantaneous increase in biodiversity is anticipated to encourage more endemic fish restorations in South Africa.

The Anthropocene Epoch is characterized by novel and increasingly complex dependencies between the environment and human civilization, with many challenges of biodiversity management emerging as wicked problems. Problems arising from the management of biological invasions can be either tame (with simple or obvious solutions) or wicked, where difficulty in appropriately defining the problem can make complete solutions impossible to find. We review four case studies that reflect the main goals in the management of biological invasions -prevention, eradication, and impact reduction -assessing the drivers and extent of wickedness in each. We find that a disconnect between the perception and reality of how wicked a problem is can profoundly influence the likelihood of successful management. For example, managing species introductions can be wicked, but shifting from species-focused to vector-focused risk management can greatly reduce the complexity, making it a tame problem. The scope and scale of the overall management goal will also dictate the wickedness of the problem and the achievability of management solutions (cf. eradication and ecosystem restoration). Finally, managing species that have both positive and negative impacts requires engagement with all stakeholders and scenario-based planning. Effective management of invasions requires either recognizing unavoidable wickedness, or circumventing it by seeking alternative management perspectives.

Background: This paper reviewed the benefits and negative impacts of alien species that are currently listed in the Alien and Invasive Species Regulations of the National Environmental Management: Biodiversity Act (Act no 10 of 2004) and certain alien species that are not yet listed in the regulations for which conflicts of interest complicate management. Objectives: Specifically, it identified conflict-generating species, evaluated the causes and driving forces of these conflicts and assessed how the conflicts have affected management. Method: A simple scoring system was used to classify the alien species according to their relative degree of benefits and negative impacts. Conflict-generating species were then identified and further evaluated using an integrated cognitive hierarchy theory and risk perception framework to identify the value systems (intrinsic and economic) and risk perceptions associated with each conflict. Results: A total of 552 alien species were assessed. Most of the species were classified as inconsequential (55%) or destructive (29%). Beneficial (10%) and conflict-generating (6%) species made a minor contribution. The majority (46%) of the conflict cases were associated with more than one value system or both values and risk perception. The other conflicts cases were based on intrinsic (40%) and utilitarian (14%) value systems. Conclusions: Conflicts based on value and risk perceptions are inherently difficult to resolve because authorities need to balance the needs of different stakeholders while meeting the mandate of conserving the environment, ecosystem services and human well-being. This paper uses the identified conflict-generating species to highlight the challenges and trade-offs of managing invasive species in South Africa.

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