The Agulhas and Somali Current Large Marine Ecosystems (ASCLME) Project and the South West Indian Ocean Fisheries Project (SWIOFP) are part of a multi-project and multi-agency undertaking to institutionalize cooperative and adaptive management of the Agulhas and Somali LMEs. South Africa, Mozambique, Tanzania, Kenya, Comoros, Seychelles, Madagascar and Mauritius are full participants in both Project activities while Somalia has observer status. France is a full participant in the SWIOF Project and an active partner in the ASCLME Project. This Transboundary Diagnostic Analysis (TDA) has been developed jointly by the ASCLME and SWIOF Projects and is the regional synthesis report on the current status of the Agulhas and Somali Current Large Marine Ecosystems. It presents an analysis of the ecosystem status and the threats to the long term sustainability of coastal and marine processes and resources in the region. The relative importance of the immediate and root sources and causes of the problems are assessed with a view to identifying potential preventive and remedial actions. As such, the TDA provides the technical basis for development of a Strategic Action Programme (SAP) for the region. The TDA is based on the outcomes of a four-year process of data collection, regional reviews and assessments, and engagement with stakeholders in the ASCLME countries from community to ministerial level. The input to the Analysis comes from the National Marine Ecosystem Diagnostic Analyses (MEDAs) together with a total of 56 reports and studies resulting from detailed specialist studies undertaken by the projects.