The project is based on the Systematic Conservation Planning (SCP) concept. This is the process of deciding where, when and how to allocate limited biodiversity conservation resources to minimize the loss of biodiversity, ecosystem services and other valuable aspects of the natural environment. The process has been particularly influential in South Africa, including in the marine environment, and has helped shape South Africa’s conservation planning and environmental policy (Driver et al. 2005). However, before the current project, the SCP process had not been applied in the marine environments of the other two member countries of the Benguela Current Commission (BCC), Namibia and Angola. Therefore this project largely focused on the Angolan and Namibian portions of the planning domain, where we attempted to replicate the existing conservation planning analyses undertaken in the South African portion of the planning domain as efficiently as possible within the constraints of key data limitations. The existing information for South Africa is also reported in order to have a single coherent spatial planning product for the entire Benguela Current Large Marine Ecosystem (BCLME). The SCP concept emphasises the need to conserve a representative sample of ecosystems and their species (the principle of representation). It also considers the ecological processes that allow persistence of biodiversity features over time (the principle of persistence). It sets quantitative biodiversity and protection targets that express how much of each biodiversity feature should be maintained in a natural or near-natural state, or included within Protected Areas. These principles of SCP are reflected in the headline indicators of the conservation assessments, namely the Ecosystem Threat Status and Ecosystem Protection Level, and in the process of identifying spatial priorities for conservation actions.