Summer05Aquanews9

Marketing studies and trials will be conducted at the major tourist hotels and restaurants in Zanzibar town. Training in handling and sanitation will also be provided to assure product quality and safety leading to improved consumer acceptability.
Other initiatives are underway to complement the biological and market studies. One is to derive more productive use from the pearl oysters which are simply being consumed at a small size rather than being used to produce pearls. Menai Bay exhibits a relatively high rate of pearl oyster spat settlement which is a real asset as many pearl farms have to rely on hatchery production in areas where spat settlement is sporadic. The spat settling naturally on the plot stakes will be collected, grown to grafting size, then used to cultivate mabe pearls. Mabe pearls are half-spherical pearls formed when a plastic half-dome is glued to the inside of the shells and subsequently covered with nacre. These pearls can be sold to the local tourist market and the remaining shell used to produce handicrafts.
Updates will appear in Aquanews as the work progresses.

plots are delineated by borders of wood stakes or stones and are located on the tidal flat so that they are only exposed during spring tides when the tides are at the maximum low. The stones and stakes serve to signal ownership of the plot, but also provide substrate for settlement of juvenile bivalves (spat). As women collect shellfish for sale from the tidal flats, any mollusk ranging in size from 1 cm to just under market size is placed in the plot for grow-out. Labor requirements are low, so the cultured shellfish survive well with minimal attention. During neap tides when the plots are inaccessible, the women work in other activities. The activity is highly compatible with seaweed farming as it occurs in the same areas and the plots can be tended as the same times women go to the shore to cultivate their seaweed farms.
The trials were run for one year to determine growth and survival rates, and to collect basic economic data. Women generally gather juvenile bivalves of several types for sale or to culture in their enclosures: Black-lip pearl oysters (Pinctada margaritifera); Mangrove oysters (Isognomon isognomon); mussels (Modiolus auriculatus); pen shells (Atrina vexilum); and cockles (Anadara antiquata). The year long monitoring indicated that most species reached market size in seven to eight months. Some mortality occurred, particularly in the larger animals, which may have been due to water temperatures, crowding, or predation by birds or crabs. It is also postulated that the shellfish aggregations may contribute to improved spawning conditions as most of these species are gregarious spawners, and the entire structure provides additional substrate for spat settlement.
Most shellfish collectors work only during the 10 days or so per month that the intertidal flats are accessible during low tide periods. Most can collect 100-200 shellfish per day during this period. The meats from all species are generally pooled and sold in batches of 150 g.

(Figure 3). A kilo of mixed shellfish meats costs Tshs 1,000 in the village to TS2,000 per kg in Zanzibar town. 1 USD is about 1,100 Tshs. The culture trials have been a financial success for women, adding another revenue stream to their incomes. Women who cultivate shellfish and grow seaweed made about $35/month as compared to $10/month for women who only gather and sell shellfish.
The current effort will continue in a two-pronged approach to improving production and revenues for the women. First, previous research has indicated that stocking densities could be increased well above the current 100/m² average density. Stocking and harvesting need to be scheduled more rigorously and adhered to. Increasing plot size or replicating the number of plots may also be possible. In general, there is still a great deal to do in terms of improving the production technology and transferring basic bivalve technology to coastal communities.
The SUCCESS project aims to complement the on-going shellfish research by working to improving income generation through providing assistance that will enable the women to sell more shellfish at higher prices, targeting tourist hotels and establishment of low-tech seafood kiosks to be run by the women at popular tourist sites, many of which are quite close to the culture sites.