The Bight of Sofala/Swamp Coast is a marine ecoregion along the eastern coast of Africa, characterized by extensive

mangrove A mangrove is a shrub or tree that grows in coastal saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evolution in several ...

swamps and coastal wetlands. It extends along the coast of

Mozambique Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Mala ...

, from

Angoche Angoche is a district, city and municipality located in Nampula Province in north-eastern Mozambique. The district has limits in the North with Mogincual District, in the South with Larde District, to the east with the Indian Ocean and to the wes ...

(16°14' S) to the Bazaruto Archipelago (21°14’ S). It adjoins the East African coral coast ecoregion to the north, and the Delagoa ecoregion to the south.

Geography

The Bight of Sofala, also known as Sofala Bay, is a large indentation on the African coast. The continental shelf is wide in the region, reaching up to 140 km near Beira, in contrast with the narrower continental shelves to the north and south. The concave coastline and shallow seas create high-amplitude

tide Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can ...

s. The Mozambique Current runs generally southward along the coast, and eddy currents form in coastal indentations like the Sofala Bight.

Habitat types

24 rivers empty into the ocean in this region, which supports extensive

mangroves A mangrove is a shrub or tree that grows in coastal saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evolution in several ...

, coastal swamps, and tidal estuaries. The

Zambezi The Zambezi River (also spelled Zambeze and Zambesi) is the fourth-longest river in Africa, the longest east-flowing river in Africa and the largest flowing into the Indian Ocean from Africa. Its drainage basin covers , slightly less than hal ...

, Pungwe, and Save rivers form large

river delta A river delta is a landform shaped like a triangle, created by deposition of sediment that is carried by a river and enters slower-moving or stagnant water. This occurs where a river enters an ocean, sea, estuary, lake, reservoir, or (more ra ...

s, and numerous smaller rivers support coastal estuaries, mangroves, and estuaries. The waters are

turbid Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. Fluids can ...

with fine river sediments. Salinity of coastal waters varies seasonally as river discharge rises and falls, from 20 ppt in the rainy season to 34 ppt in the dry season.

Fauna

The extensive mangrove forests and coastal wetlands are important habitat for

waterbird A water bird, alternatively waterbird or aquatic bird, is a bird that lives on or around water. In some definitions, the term ''water bird'' is especially applied to birds in freshwater ecosystems, although others make no distinction from seab ...

s, with over 73 species present. The turbid waters of the region, along with occasional cold-water

upwelling Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted surface water. The nut ...

, limits the growth of corals in the region.

Human use

The Sofala Bank is an productive fishery, particularly for

Indian prawn The Indian prawn (''Fenneropenaeus indicus'', formerly ''Penaeus indicus''), is one of the major commercial prawn species of the world. It is found in the Indo-West Pacific from eastern and south-eastern Africa, through India, Malaysia and Indone ...

s ''(Fenneropenaeus indicus)''. Large dams on the Zambezi –

Kariba Dam The Kariba Dam is a double curvature concrete arch dam in the Kariba Gorge of the Zambezi river basin between Zambia and Zimbabwe. The dam stands tall and long. The dam forms Lake Kariba, which extends for and holds of water. Construction ...

, completed in 1959, and

Cahora Bassa The Cahora Bassa lake—in the Portuguese colonial era (until 1974) known as Cabora Bassa, from Nyungwe ''Kahoura-Bassa'', meaning "finish the job"—is Africa's fourth-largest artificial lake, situated in the Tete Province in Mozambique. In Afr ...

, completed in 1975 – have altered freshwater, sediment, and nutrient flows into the Zambezi Delta and Sofala Bight. Large seasonal floods have been reduced, and sediments and nutrients formerly carried to the sea by floodwaters are now trapped behind dams. The productivity of the Sofala Bight prawn harvest decreased continually from the 1970s through the 1990s, from 90kg per hour in 1977 to 30kg per hour by the early 2000s. The productivity continued to decrease from 2000 to 2014, and the region also saw a decline the total harvest of prawns and other food fish during the same period.Penn, James & Sousa, Lizette. (2018). Assessment of the shallow water shrimp fishery of Sofala Bank, Mozambique 2014".

Protected areas

Marine protected areas include: * Marromeu National Reserve and other game reserves (''coutadas'') in the

delta *

Primeiras and Segundas Islands Environmental Protected Area The Primeiras and Segundas Archipelago is a chain of 10 sparsely inhabited barrier islands and two coral reef complexes situated in the Indian Ocean off the coast of Mozambique and near the coastal city of Angoche. The islands lie in two groups alon ...

extends into the northern portion of the ecoregion.

References

{{coord missing, Mozambique Continental shelves Ecoregions of Mozambique Bays of Mozambique Marine ecoregions Western Indo-Pacific