Why Aquaculture Trials Have Not Been Successful in Tanzania? 123such as low production which was attributed to poor growth of aquaculture
produce, human theft, inadequate fingerlings and feeds, lack of aquaculture
knowledge, low price of fish/crab, fish ponds/cages washed away by high tide
and problems associated with group owned fish pond/cages. The farmers’
failure to meet their objectives explained to a large extent why aquaculture had
been operated as a leisure affair and why farmers kept asking for assistance in
cash and/or kind from the project/government. This is also somewhat the
situation seen during the mission in Zanzibar.
Supporting the above, some farmers during the field survey were of the
opinion that cash generation was more pressing and important in the study
area. This implies that if aquaculture is to be adopted and sustained, it has to
generate significant and regular income. To be able to do so, aquaculture has
to operate as a business, which will require intensification. Successful
intensification can result from an increase in quantity and quality of
fingerlings, proper grow-out management, and good marketing.
Location of the Aquaculture Ponds/Cages
Site selection is one of the most important first stages in aquaculture
development (Mmochi, 2011). A good site particularly for milkfish pond
mariculture needs to have good supply of water, be protected from flooding,
waves and strong winds and with clay or clay loam soil for construction of the
dikes. Sites for crab fattening and sea cucumber farming also need to be
selected with care. Wrong site selection can cause problems including theft,
animal predation, unavailability of water supply, flooding, water seepage and
breakage of the dikes by strong waves and winds. The site needs to be
accessible and well-guarded. Most milkfish ponds suffered from water
shortage as spring tide, the main source of water, occurs only twice a month
(Wetengere and Madalla, 2011). The situation was exacerbated by poorly
selected sites where even the spring tide was insufficient to fill in the pond. A
shortage of water resulted in perilously low pond water levels exposing fish to
predatory birds, high water temperatures and increased water salinity (ibid.).
Water quality deteriorated further due to overcrowding of fish in the refuge
trench. This led to poor growth, mortality and poor yields (ibid.).
Most of milkfish ponds, crab fattening cages and sea cucumber farms
were located as far as 5 km away from homesteads (Wetengere and Madalla,
20 11). Such distance caused difficulties in routine management activities and
increased exposure to theft, vandalism and predation. In some areas