Mozambique A flourishing prawn farming industry
by Dr Gianluigi Negroni, ALVEO Scarl, Italy
Industrial fishing in Mozambique is mainly operated through joint ventures between the government and foreign companies, primarily from Japan and Spain. The main commercial species in Mozambique are lobster, crabs, gamba (deep-water prawns), shallow water prawns, crayfish and squid. Lobsters, shallow water prawns and gamba are the main exported species.
The prawn fishing industry, based primarily in Beira, Quelimane and Maputo is mainly export-oriented and represents an important source of income for the country from other countries.
Large-scale shrimp production comes from two major commercial companies, Pescamar and Efripel, who have just recently began a joint co-operation themselves. Their catch is frozen directly on-board their fishing vessels, before being exported to Asia and the European Union.
Small-scale and artisanal fisheries in Mozambique play a significant role in contributing towards the national economy. This sector provides employment, income and a source of sustainable and responsibly-sourced protein to the majority of coastal communities.
Artisanal fisheries in Mozambique consist of individuals or small groups of fishermen working relatively independently. They make use of either wind or hand-propelled fishing boats. They use beach seines, gillnets and long lines to catch fish.
In general, marine artisanal activities take place along the entire coastline. They are especially prominent in the provinces of Nampula, Zambezia, Safala, Inhambane and Maputo.
Of the many varieties of shallow-water prawns that inhabit the waters of Mozambique, the banana shrimp (Fenneropenaeus merguiensis) are the most abundantly farmed. It is estimated that the banana shrimp makes up as much a 60 percent of shallow-water prawn catches. Other key species include the Red-legged banana prawn (Fenneropenaeus indicus) and the Speckled shrimp (Metapenaeus monoceros).
Other less prominent but still farmed species of shallow-water prawns include the kuruma shrimp (M. japonicus), Western king prawn (Melicertus latisulcatus), Giant tiger prawn (Penaeus monodon), and the Green tiger prawn (P. semisulcatus).
Many deep-water prawns are also farmed in Mozambique, including the Knife shrimp (Haliporoides triarthrus), Giant red shrimp (Aristaemorpha foliacae), Blue and red shrimp (Aristeus antennatus), Scarlet shrimp (Plesiopenaeus edwardsianus) and Scythe shrimp (Penaeopsis balssi).
Several studies have highlighted the variations in the catch of shallow-water shrimp at the Sofala Bank in central Mozambique. Monthly, seasonal and year-to-year fluctuations are common occurrences when fishing in the Zambezi River.
analyses show that the catch rate is directly related to river runoff. Annual prawn abundance may be predicted based following the wet season river runoff. During years with a well defined dry season and a late onset of the wet season, there appears to be a shift in the size distribution towards larger prawns being more abundant.
Certain local regulations may be used to enhance prawn production along the Zambezi River, by ensuring well-planned water releases.
In fact, although the construction of dams up river may have little effect on the average runoff from rivers, it may still alter the seasonal variations in the runoff pattern.
Studies suggest that many shrimp species present in the Mozambican waters prefer sandy substrata, whilst others choose areas rich in submerged macrophytes. Some shrimp appear to favour muddy mangrove channels, although some may also require marginal or floating vegetation to act as nurseries.
In contrast, species such as the Peregrine shrimp (Metapenaeus stebbingi) seem to prefer quiet areas with minimal wave action, while Speckled shrimp prefer more widespread areas and are able to cope with very low salinities.
Managers of coastal systems should, therefore, attempt to maintain a diversity of biotopes within larger systems because, even if postlarvae do enter an estuary, juvenile populations will not develop if their specific habitat has been destroyed and several mangrove areas are under threat in Mozambique. This is especially true in Maputo Bay, Limpopo delta and Sofala bank which see a great deal of shrimp farming taking place.
One big challenge facing the shrimp farming industry in Mozambique is meeting demand.
Non-prawn bycatch is far greater than the target catch of shrimp and, as a result, the majority of what is caught is discarded.
Because of high rates of bycatch and the range of species caught (including large pelagic species and sharks, predominantly in the shallow-water trawls), ecosystem cascade effects are likely.
Due to the intensive use of fishing waters and resources, management measures are being put in place to secure sustainability of shrimp, both now and in the future. Economic models have been established to ensure proper and efficient management of fisheries, with these regulations updated every year by the Instituto de Investigacao Pesqueira (IIP).