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Chakona A, Jordaan MS, Raimondo DC, Bills RI, Skelton PH, van der Colff D. Diversity, distribution and extinction risk of native freshwater fishes of South Africa. JOURNAL OF FISH BIOLOGY 2022; 100:1044-1061. [PMID: 35170047 DOI: 10.1111/jfb.15011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/08/2021] [Accepted: 02/13/2022] [Indexed: 06/14/2023]
Abstract
Extinction risk for 101 valid species and 18 unique genetic lineages of native freshwater fishes of South Africa was assessed in 2016 following the IUCN Red List criteria. An additional five species (three new species that were described and two species that were revalidated subsequent to the 2016 assessments) were assessed in the present study. A synthesis of the outcome of the assessments of the 106 valid species and 18 genetic lineages indicates that 45 (36%) of South Africa's freshwater fish taxa are threatened (7 Critically Endangered, 25 Endangered, 13 Vulnerable). Of the remaining taxa, 17 (14%) are listed as Near Threatened, 57 (46%) are Least Concern and five (4%) are Data Deficient. More than 60% of the endemic taxa are threatened. The Cape Fold Ecoregion has the highest proportion of threatened taxa (67%) due to the existence of a unique assemblage of narrow-range endemic species. Galaxias and Pseudobarbus have the highest number of highly threatened taxa as most of the species and lineages in these genera are classified as either CR or EN. Major threats to the native freshwater fishes of the country are invasive fish species, deterioration of water quality, impoundments and excessive water abstraction, land use changes and modification of riverine habitats. Immediate conservation efforts should focus on securing remnant populations of highly threatened taxa and preventing deterioration in threat status, because recovery is rare. Accurate delimitation of species boundaries, mapping their distribution ranges, improved knowledge of pressures and long-term monitoring of population trends need to be prioritised to generate credible data for the 2026 IUCN threat status assessments and designation of important fish areas as part of the National Freshwater Ecosystem Priority Areas (NFEPA) initiative.
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Affiliation(s)
- Albert Chakona
- NRF-South African Institute for Aquatic Biodiversity (NRF-SAIAB), Makhanda (Grahamstown), South Africa
- Department of Ichthyology and Fisheries Science, Rhodes University, Makhanda (Grahamstown), South Africa
| | - Martine S Jordaan
- NRF-South African Institute for Aquatic Biodiversity (NRF-SAIAB), Makhanda (Grahamstown), South Africa
- CapeNature Biodiversity Capabilities Unit, Stellenbosch
- Center of Excellence for Invasion Biology, CapeNature Biodiversity Capabilities Unit, Stellenbosch
| | - Domitilla C Raimondo
- South African National Biodiversity Institute Threatened Species Program, Kirstenbosch National Botanical Gardens, Cape Town
| | - Roger I Bills
- NRF-South African Institute for Aquatic Biodiversity (NRF-SAIAB), Makhanda (Grahamstown), South Africa
| | - Paul H Skelton
- NRF-South African Institute for Aquatic Biodiversity (NRF-SAIAB), Makhanda (Grahamstown), South Africa
| | - Dewidine van der Colff
- Center of Excellence for Invasion Biology, CapeNature Biodiversity Capabilities Unit, Stellenbosch
- South African National Biodiversity Institute Threatened Species Program, Kirstenbosch National Botanical Gardens, Cape Town
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Novoa A, Shackleton R, Canavan S, Cybèle C, Davies SJ, Dehnen-Schmutz K, Fried J, Gaertner M, Geerts S, Griffiths CL, Kaplan H, Kumschick S, Le Maitre DC, Measey GJ, Nunes AL, Richardson DM, Robinson TB, Touza J, Wilson JRU. A framework for engaging stakeholders on the management of alien species. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 205:286-297. [PMID: 29024897 DOI: 10.1016/j.jenvman.2017.09.059] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 09/20/2017] [Accepted: 09/21/2017] [Indexed: 05/28/2023]
Abstract
Alien species can have major ecological and socioeconomic impacts in their novel ranges and so effective management actions are needed. However, management can be contentious and create conflicts, especially when stakeholders who benefit from alien species are different from those who incur costs. Such conflicts of interests mean that management strategies can often not be implemented. There is, therefore, increasing interest in engaging stakeholders affected by alien species or by their management. Through a facilitated workshop and consultation process including academics and managers working on a variety of organisms and in different areas (urban and rural) and ecosystems (terrestrial and aquatic), we developed a framework for engaging stakeholders in the management of alien species. The proposed framework for stakeholder engagement consists of 12 steps: (1) identify stakeholders; (2) select key stakeholders for engagement; (3) explore key stakeholders' perceptions and develop initial aims for management; (4) engage key stakeholders in the development of a draft management strategy; (5) re-explore key stakeholders' perceptions and revise the aims of the strategy; (6) co-design general aims, management objectives and time frames with key stakeholders; (7) co-design a management strategy; (8) facilitate stakeholders' ownership of the strategy and adapt as required; and (9) implement the strategy and monitor management actions to evaluate the need for additional or future actions. In case additional management is needed after these actions take place, some extra steps should be taken: (10) identify any new stakeholders, benefits, and costs; (11) monitor engagement; and (12) revise management strategy. Overall, we believe that our framework provides an effective approach to minimize the impact of conflicts created by alien species management.
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Affiliation(s)
- Ana Novoa
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa; South African National Biodiversity Institute, Kirstenbosch Research Centre, Claremont, South Africa; Institute of Botany, Department of Invasion Ecology, The Czech Academy of Sciences, CZ-252 43, Průhonice, Czech Republic.
| | - Ross Shackleton
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - Susan Canavan
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa; South African National Biodiversity Institute, Kirstenbosch Research Centre, Claremont, South Africa
| | - Cathleen Cybèle
- CIRAD, UMR PVBMT, Saint-Pierre, La Réunion, France; Université de la Réunion, UMR PVBMT, F-97410, Saint-Pierre, La Réunion, France
| | - Sarah J Davies
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - Katharina Dehnen-Schmutz
- Centre for Agroecology, Water and Resilience, Coventry University, Ryton Gardens, Wolston Lane, Coventry, CV8 3LG, UK
| | - Jana Fried
- Centre for Agroecology, Water and Resilience, Coventry University, Ryton Gardens, Wolston Lane, Coventry, CV8 3LG, UK
| | - Mirijam Gaertner
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa; Nürtingen-Geislingen University of Applied Sciences (HFWU), Nürtingen, Germany
| | - Sjirk Geerts
- Department Conservation and Marine Science, Cape Peninsula University of Technology, P.O. Box 652, Cape Town, 8000, South Africa
| | - Charles L Griffiths
- Marine Research (MA-RE) Institute, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa; Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa
| | - Haylee Kaplan
- South African National Biodiversity Institute, Kirstenbosch Research Centre, Claremont, South Africa
| | - Sabrina Kumschick
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa; South African National Biodiversity Institute, Kirstenbosch Research Centre, Claremont, South Africa
| | - David C Le Maitre
- Council for Industrial and Scientific Research, P.O. Box 320, Stellenbosch, 7599, South Africa
| | - G John Measey
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - Ana L Nunes
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa; South African National Biodiversity Institute, Kirstenbosch Research Centre, Claremont, South Africa; South African Institute for Aquatic Biodiversity, Grahamstown, South Africa
| | - David M Richardson
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - Tamara B Robinson
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - Julia Touza
- Environment Department, Wentworth Way, University of York, Heslington, York, YO10 5NG, UK
| | - John R U Wilson
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa; South African National Biodiversity Institute, Kirstenbosch Research Centre, Claremont, South Africa
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Whitfield AK, Weerts SP, Weyl OLF. A review of the influence of biogeography, riverine linkages, and marine connectivity on fish assemblages in evolving lagoons and lakes of coastal southern Africa. Ecol Evol 2017; 7:7382-7398. [PMID: 28944024 PMCID: PMC5606896 DOI: 10.1002/ece3.3266] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 06/06/2017] [Accepted: 06/25/2017] [Indexed: 11/10/2022] Open
Abstract
The Holocene evolution of eight South African coastal lakes and lagoons is examined and related to changes in fish composition over that period. Historical and current connectivity with riverine and marine environments are the primary determinants of present‐day fish assemblages in these systems. A small and remarkably consistent group of relict estuarine species have persisted in these coastal lakes and lagoons. The loss or reduction of connectivity with the sea has impacted on the diversity of marine fishes in all eight study systems, with no marine fishes occurring in those water bodies where connectivity has been completely broken (e.g. Sibaya, Groenvlei). In systems that have retained tenuous linkages with the sea (e.g., Verlorenvlei, Wilderness lakes), elements of the marine fish assemblage have persisted, especially the presence of facultative catadromous species. Freshwater fish diversity in coastal lakes and lagoons is a function of historical and present biogeography and salinity. From a freshwater biogeography perspective, the inflowing rivers of the four temperate systems reviewed here contain three or fewer native freshwater fishes, while the subtropical lakes that are fed by river systems contain up to 40 freshwater fish species. Thus, the significantly higher fish species diversity in subtropical versus temperate coastal lakes and lagoons comes as no surprise. Fish species diversity has been increased further in some systems (e.g., Groenvlei) by alien fish introductions. However, the impacts of fish introductions and translocations have not been studied in the coastal lakes and lagoons of South Africa. In these closed systems, it is probable that predation impacts on small estuarine fishes are significant. The recent alien fish introductions is an example of the growing threats to these systems during the Anthropocene, a period when human activities have had significant negative impacts and show potential to match the changes recorded during the entire Holocene.
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Affiliation(s)
- Alan K Whitfield
- South African Institute for Aquatic Biodiversity (SAIAB) Grahamstown South Africa
| | - Steven P Weerts
- Council for Scientific and Industrial Research (CSIR) Durban South Africa
| | - Olaf L F Weyl
- South African Institute for Aquatic Biodiversity (SAIAB) Grahamstown South Africa
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