The site consists of the delta and most of the flood-plain of the Zambezi river (including the Marromeu Reserve), as well as the adjoining hunting concessions (coutadas 10, 11 and 12). The habitats present include open water (fresh and estuarine), sandbanks, isolated pools, marshland, grassland and Acacia savanna in the delta and flood-plain, extensive lowland forest and deciduous woodland in the hunting concessions, and Brachystegia woodland on the western fringes of the site. The sparse human population is involved in fishing and agriculture on a small scale.
See Box and Table 3 for key species. The site supports a breeding population of Grus carunculatus. The latest available count is of c.70 breeding pairs, but breeding numbers are likely to fluctuate. More than 2,000 birds have been present on occasion. Many waterbirds occur, and concentrations of Anastomus lamelligerus have been observed to exceed the 1% threshold of 1,000 birds. Circaetus fasciolatus and Sheppardia gunningi are forest residents. This is the only IBA site in Mozambique where the latter species is known to occur. Two species typical of the Afrotropical Highlands biome occur, as do two of the Zambezian biome. Current knowledge of the wetland habitats is based on aerial surveys, and investigation on the ground is likely to discover other threatened or restricted-range species.
Non-bird biodiversity: Among larger mammals, Loxodonta africana (EN) occurs (30–40 animals). Significant populations of threatened amphibians, fish and other aquatic fauna are likely but as yet unknown.
Pressure/threats to key biodiversity
The site includes three hunting concessions and the Marromeu Reserve, within which hunting is controlled and agriculture is minimal. The inaccessibility of much of the site contributes to its protection. The natural flooding regime of the Zambezi river has been severely disrupted by the construction of the Kariba and Cahorra Bassa dams upriver. A study supported by the International Crane Foundation is presently under way to assess the effects of the impoundments and to propose a controlled flooding regime which would be consistent with the preservation of biodiversity in the delta. If access by road is improved, protection of Grus carunculatus from hunting will become a major concern. Extensive commercial logging of natural forests has occurred immediately to the south of the site, and the potential encroachment of this activity into the site is of concern. A well developed infrastructure for tourism exists within the hunting concessions.