Potential application of baited remote underwater video to survey abundance of west coast rock lobster Jasus lalandii |
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| Authors: | L A Roberson C G Attwood H Winker A C Cockroft D L Van Zyl |
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| Affiliation: | 1. Department of Biological Sciences, Marine Research Institute, University of Cape Town, Rondebosch, South Africa;2. Kirstenbosch Research Centre, South African National Biodiversity Institute, Claremont, South Africa;3. Department of Statistical Sciences, Centre for 4. Statistics in Ecology, Environment and Conservation (SEEC), University of Cape Town, Rondebosch, South Africa;5. Branch Fisheries, Department of Agriculture, Forestry and Fisheries, Rogge Bay, South Africa |
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| Abstract: | The first assessment of the baited remote underwater video system (BRUVs) for monitoring rock lobster Jasus lalandii (Milne‐Edwards) in South Africa was compared to annual ring net and trap survey data. Count data from 58 BRUVs, 36 ring net and 95 trap samples were fitted with generalised additive models using depth, habitat, time and spatial gradient as independent variables. A power analysis was used to determine the number of samples needed per annum to detect a 5 and 10% increase and decrease in population size. The BRUVs outperformed the nets and traps in terms of sampling effort and were better at detecting changes in abundance of lobster than abundance of three fish species. Considering factors such as cost, analysis time, additional data and environmental impact, traps are the most feasible method in deeper waters but BRUVs could replace nets and traps in depths less than 60 m, low‐density areas and marine reserves. |
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| Keywords: | abundance surveys BRUVs fisheries monitoring lobster traps power analysis ring nets |
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