DOI: https://doi.org/10.3354/esr01465
copiedWhite sharks under threats in South Africa: a call for precautionary management action
- Enrico Gennari
- Neil Hammerschlag
- Chris Fallows
- Monique Fallows
- Sara Andreotti
- Wilfred Chivell
- Michael Rutzen
- Bruce Noble
- Ronelle Friend
- Lloyd Edwards
ABSTRACT:
South Africa was the first country to protect white sharks: an important decision taken despite limited data on population status, but guided by a precautionary approach in recognition of the species’ ecological and economic value. Unfortunately, several lines of evidence suggest an ongoing population reduction, including declines in sightings from aggregation sites in the last decade, especially of large mature individuals, low genetic diversity and low effective population size. Simulation modelling indicated that current levels of white shark removals by South Africa’s lethal shark control program are alone unsustainable and sufficient to drive population decline. This has led to growing calls for further conservation actions. Nevertheless, a recent study has claimed that this population has remained stable since 1991 and likely redistributed eastward due to predatory effects of orcas. On this basis, no additional conservation management action has yet been taken. Here, we synthesize several lines of historical and newly acquired information to argue that this white shark population is more likely in decline. While predator–prey dynamics are natural phenomena, anthropogenic threats (i.e. the lethal shark control program and demersal shark fishery) are subject to management. We recognize that management must balance public safety, community livelihoods, and conservation goals. However, consistent with the country’s history of applying a precautionary approach and its commitments to existing national and international frameworks, we urge the South African government to reduce anthropogenic sources of white shark mortality, to conserve this population and its attendant ecosystem services that South Africans depends upon.
KEYWORDS
Enrico Gennari (Corresponding Author)
- Oceans Research Institute, PO box 1767, Mossel Bay 6500, South Africa
- Department of Ichthyology and Fisheries Science, Rhodes University, Makhanda 6140, South Africa
- South African Institute for Aquatic Biodiversity, Private Bag 1015, Makhanda 6140, South Africa
Neil Hammerschlag (Co-author)
- Shark Research Foundation Inc., Boutiliers Point, Nova Scotia B3Z 0M9, Canada
Chris Fallows (Co-author)
- Apex Shark Expeditions, Wharf St, Simon’s Town, Cape Town 7975, South Africa
Monique Fallows (Co-author)
- Apex Shark Expeditions, Wharf St, Simon’s Town, Cape Town 7975, South Africa
Sara Andreotti (Co-author)
- Evolutionary Genomics Group, Department of Botany and Zoology, Stellenbosch University, Stellenbosch 7600, South Africa
- Shark Conservation and Research Trust, 16 Dawn Crescent, De Wijnlanden Estate, Stellenbosch 7602, South Africa
Wilfred Chivell (Co-author)
- Dyer Island Conservation Trust, 5 Geelbek St, Van Dyks Bay 7220, South Africa
Michael Rutzen (Co-author)
- Shark Conservation and Research Trust, 16 Dawn Crescent, De Wijnlanden Estate, Stellenbosch 7602, South Africa
Bruce Noble (Co-author)
- Oceans Research Institute, PO box 1767, Mossel Bay 6500, South Africa
Ronelle Friend (Co-author)
- Algoa Bay Conservation, 180 Pleasant Avenue, Theescombe, Gqeberha 7001, South Africa
Lloyd Edwards (Co-author)
- Raggy charters, 3 Albatross Crescent, Seaview, Gqeberha 6070, South Africa
Handling Editor:
Helene Marsh, Townsville, Queensland, Australia
Reviewers:
D. McPhee, R. Elliott
