Fish processing, the principal industrial activity, is carried out in Nouadhibou. By far the largest fish processor is Mauritanian Fish Industries (IMAPEC), a Spanish company in which the Mauritanian government acquired a 51% share in 1980. IMAPEC has facilities for salting, drying, canning, and freezing fish, and for producing fish flour; virtually all of its output is exported. Overfishing is a problem, however, as is mismanagement of the fishing sector and the lack of an effective governmental fisheries policy. The government is modernizing the fisheries sector, through port extension and the development of warehouses. Other small industries in 2002 included chemical and plastic plants, food and beverages, metal products, building materials, and cookie factories.
The first desalination plant in Africa was completed at Nouakchott in January 1969, with a capacity of 3,000 cu m (106,000 cu ft) a day. A rolling mill at Nouadhibou, built in 1977, produced small quantities of iron rods and steel. A petroleum refinery in Nouadhibou, with an annual capacity of 1 million tons, opened in 1982, shut down in 1983, and resumed operation in 1987 with help from Algeria. In 1995, the refinery produced 2 million barrels (about 270,000 tons) of refined petroleum products. Algeria also helped revitalize a sugar refining plant. Similarly, Kuwaiti and Jordanian interests reopened the steel mill after a shutdown. Each of these operations represents a drain on state revenues, and the government has shifted policy toward the promotion of less ambitious industrial development.
The government has signed exploration contracts with the Canadian Rex Diamond Mining Corporation, the American BHP Minerals and Bab-Co, the French La Source, and the Australian Ashton West Africa Property Limited in order to find gold, oil, phosphate, aluminum, and copper in Mauritania. Although the country has no known hydrocarbon reserves, exploration is ongoing. Mauritania is one of four countries in West Africa with an operating oil refinery.