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The West Indian Ocean region is an extensive area consisting of two large marine ecosystems (LME): the Somali Current LME and the Agulhas Current LME. The Somali Current, a Western Boundary Current, runs along the northeastern coast of Africa and consists of the continental shelf adjacent to Yemen, Somalia, Kenya, and Tanzania. The ecosystem is moderately productive due to the annual reversal in the direction of flow between the summer and winter seasons. This reversal affects the nutrient-rich upwelling that occurs during the northerly summer flow.

The Agulhas Current LME encompasses the continental shelf south of the Somali current and includes the area around the Seychelles, the Comoros Islands, Madagascar, Mauritius, Mozambique, and South Africa. The Agulhas Current flows southwest along the coast and continues west past South Africa where it joins the Benguela Current.

The West Indian Ocean region contains a great deal of biodiversity because of the large variety of coastal, island, and marine habitats. These habitats include coral reefs, mangroves, sea grass beds, estuaries, lagoons, flood plains, freshwater marshes, saltwater marshes and beaches, many of which are important breeding grounds and nurseries. These habitats are also home to a variety of endemic and remarkable species. For example, the only viable population of East African dugong is found in the Bazaruto Archipelago in Mozambique. The coelacanth, a fish once thought to be extinct and can be traced back 400 million years, is found in the deep water off of the Comoro Islands. Many other species inhabit the region including whales, dolphins, jellyfish, sponges, sea turtles, and endemic fish such as the Zanzibar and African butterfly fish.

Fishing in the West Indian Ocean, especially within the island countries, is dominated by artisanal fishing, with sardines, mackerel, crustaceans and mollusks being the most fished. Commercial catches are dominated by tuna and crustaceans in the Agulhas Current LME, and herrings, sardines, anchovies and pelagic shrimp in the Somali Current LME. The fishing industry and its related industries are especially economically important because they provide jobs for thousands of people. Other activities of note taking place in the region include a busy crude oil shipping route, aquaculture, oil and gas exploration, and tourism.

The West Indian Ocean region includes several mainland and island countries, therefore the issues and threats affecting marine resources are widespread and numerous. Unsustainable and destructive fishing practices, exploitation by foreign fishing fleets, pollution, mining, dredging, oil and gas exploration, mariculture and salt production, development and increased population along coastal regions, increased tourism, and climate change are threatening the entire region to varying extents. The impacts of these threats are equally extensive: severely reduced fish stocks, increased mortality of non-target species, coral bleaching, and habitat destruction of seagrass beds, estuaries, mangroves, and coral reefs. Climate change is also a concern for low lying islands and coastal areas because of the potential for sea level rise. These threats reduce and endanger marine species, can change the existing dynamics of the ecosystem, and can have a severe impact on the livelihoods of local human populations.

As with all large marine ecosystems that encompass many countries, managing these threats is difficult due to transboundary resources and differences in governments and management systems. Some countries have little or no support for marine resource management, while others, such as the Seychelles, South Africa, Kenya, Tanzania and Madagascar, have been able to establish marine protected areas or are attempting to improve current management practices. Many organizations are working to improve scientific knowledge and understanding of the marine resources, develop regional cooperation between countries, promote sustainable practices, and protect the substantial biodiversity of the Western Indian Ocean region.

Page 2 | West Indian - Somali & Agulhas Currents: Conservation in Action