1. Marine Research Institute, Department of Biological Sciences, University of Cape Town, Rondebosch, South Africa
2. Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch, South Africa
3. Western Cape Nature Conservation Board, Scientific Services, Hermanus, South Africa
4. School of Statistics and Actuarial Science, University of Witswatersrand, Johannesburg, South Africa
5. Branch: Oceans and Coasts, Department of Environmental Affairs, Cape Town, South Africa