Abstract: The failure of traditional fisheries management is now widely recognized and ecosystem based approaches are advocated as viable alternatives for future management of marine ecosystems. This requires a holistic cross-sectoral approach integrating biological and socio-economic aspects to achieve the desired social benefits within the limits of sustainable utilization. Although adopted in principle, implementation has been poor due to cross cutting issues and lack of guidance on a way forward. Systematic marine spatial planning is a key managerial tool which can facilitate implementation but requires detailed spatial information which is lacking for most marine systems. This research aimed to overcome these problems and develop a marine spatial plan for Algoa Bay, South Africa through the identification of priority areas for conservation. A monitoring framework for evaluating the effectiveness of future spatial management in achieving ecological and socio-economic objectives was also developed.
Key habitats, biological communities and fisheries activities were identified in Algoa Bay. Controlled angling and diving surveys were conducted to assess reef ichthyofauna, while roving creel, access point and aerial surveys were conducted to evaluate recreational shore and skiboat fisheries as no prior information was available. The Department of Agriculture, Forestry and Fisheries (DAFF) provided research trawl data for the assessment of ichthyofauna communities over trawlable areas, and catch, VMS and observer data for the evaluation of six commercial fisheries sectors active within Algoa Bay. Thirty-six ecological features were identified for inclusion in the MPA network and targets for representation were set based on the overall management objectives. Systematic conservation planning analyses were conducted using MARXAN. Spatial indices of relative recreational and commercial importance were developed and used as a cost layer to prioritise the selection of areas which conflicted least with fisheries activities. The efficiency of different planning scenarios was assessed in terms of area required to meet feature targets, and the displacement of fisheries effort.
In order to achieve the desired conservation targets for the selected ecological features in Algoa Bay 25% of the planning area was required which resulted in an overall displacement of 41% of fisheries effort. The inclusion of the unified recreational and commercial cost layer resulted in least displacement of fisheries effort (14%) of all planning scenarios considered while still achieving all feature targets. A MPA footprint design has previously been proposed for Algoa Bay based on expert knowledge. This design was unable to achieve the targets for seven of the conservation features yet resulted in the displacement of 16% of fisheries effort in Algoa Bay. This highlights the value of using quantitative approaches in the future design of MPA networks and the importance of including spatially explicit fisheries data in such analyses. Protocols for monitoring long-term trends in ecological and socio-economic parameters were developed and integrated into a pressure-state-response framework to facilitate adaptive management.