School of Animal, Plant and Environmental Sciences
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Item Using genetics to prioritise headwater stream fish populations of the Marico barb, Enteromius motebensis Steindachner 1894, for conservation action.(AOSIS OpenJournals Publishing AOSIS (Pty) Ltd, 2017-02) van der Walt, K.-A.; Swartz, E.R.; Woodford, D.J.; Weyl, O.South Africa has a relatively large number of threatened freshwater fish species and limited resources to implement conservation programs. Enteromius motebensis was regionally prioritised for action because of its conservation status and flagship status in a nationally important aquatic ecosystem. Genetic diversity of E. motebensis in headwater refugia of the Groot Marico River Catchment was assessed to determine if genetic diversity is important for conservation planning for this species. The results of the genetic analysis indicate that some prioritisation was possible, with two populations showing evidence of recent isolation. Conservation implications: We recommend that at least three populations be prioritised for conservation action to ensure maintenance of most of the remaining genetic diversity of the species.Item Optimising invasive fish management in the context of invasive species legislation in South Africa(National Botanical Institute/AOSIS, 2017) Woodford, D.J.; Jordaan, M.S.; Kimberg, P.K.; Zengeya, T.; Weyl, O.L.F; Ivey, P.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.Item Evaluating invasion risk for freshwater fishes in South Africa(National Botanical Institute/AOSIS, 2017-03) Marr, S.M.; Ellender, B.R.; Woodford, D.J.; Alexander, M.E.; Wasserman, R.J.; Ivey, P.; Zengeya, T.; Weyl, O.L.F.South Africa, as a signatory of the Convention on Biological Diversity, has an obligation to identify, prioritise and manage invasive species and their introduction pathways. However, this requires knowledge of the introduction pathways, factors influencing establishment success, invasive potential, current distributions and ecological impacts. Objectives: To evaluate the Fish Invasiveness Screening Kit (FISK) to predict the invasion risk posed by fish species proposed for introduction into South Africa. Method: FISK assessments were compiled for species whose invasion status in South Africa was known. A Receiver operating characteristic (ROC) analysis was conducted to calibrate the FISK for South Africa. The calibrated FISK was used to evaluate the risk that three species recently proposed for importation for aquaculture could become invasive in South Africa. Results: A FISK score of 14 was identified as the threshold to delineate between species that could become invasive in South Africa and those that are unlikely to become invasive. Of the three species evaluated, Silurus glanis had a high risk of becoming invasive in South Africa, Lates calcarifer was likely to be invasive and Oncorhynchus tshawytscha was unlikely to be invasive in South Africa. Conclusion: FISK was demonstrated to be a useful risk assessment tool to evaluate the invasion risk posed by species proposed for use in aquaculture. For the large number of fish imported for the pet trade, a rapid screening assessment to flag potentially high risk species was recommended prior to a full FISK assessment for flagged species.Item Ethical considerations for field research on fishes(AOSIS OpenJournals Publishing AOSIS (Pty) Ltd., 2016-12) Bennett, R.H.; Ellender, B.R.; Miya, T.; Pattrick, P.; Wasserman, R.J.; Woodford, D.J.; Weyl, O.L.F.; Makinen, T.Collection of data from animals for research purposes can negatively impact target or by-catch species if suitable animal ethics practices are not followed. This study aimed to assess the ethical requirements of peer-reviewed scientific journals that publish primary literature on fishes, and review the ethical considerations and animal care guidelines of national and international documents on the ethical treatment of animals for research, to provide an overview of the general ethical considerations for field research on fishes. A review of 250 peer-reviewed, ISI-rated journals publishing primary research on fishes revealed that nearly half (46%) had no mention of ethics, treatment of animals or ethical requirements for publication in their author guidelines or publication policies. However, 18% of the journals reviewed identify a specific set of ethical guidelines to be followed before publishing research involving animals. Ethical considerations for investigators undertaking field research on fishes, common to most animal care policies, legislation and guiding documents, include adhering to relevant legislation, minimising sample sizes, reducing or mitigating pain and distress, employing the most appropriate and least invasive techniques and accurately reporting methods and findings. This information will provide potential investigators with a useful starting point for designing and conducting ethical field research. Application of ethical best practices in field sampling studies will improve the welfare of study animals and the conservation of rare and endangered species. Conservation implications: This article provides a list of ethical considerations for designing and conducting field research on fishes. By reviewing sampling techniques and processes that are frequently used in field research on fishes and by highlighting the potential negative impacts of these sampling techniques, this article is intended to assist researchers in planning field research to minimise impacts on fish populations. It is envisaged that this review will be a useful resource for journal editorial committees intending to introduce ethical requirements for publication and for researchers, managers, conservation practitioners and research organisations when designing field studies on fishes, applying for ethical clearance and developing institutional ethical guidelines.