124 Kitojo Wetengere and Aubrey Harris
ponds/cages were too close to human activities (like fish landing sites) making
them prone to trespassing and issues such as defecation and waste dumping in
the pond (ibid.). Accessibility to most sites in Rufiji, Mafia and Kilwa
(RUMAKI) was extremely difficult due to deep mud, piercing mangrove prop
roots and mosquitoes (ibid.). These necessitated proper protective gear to
ensure a conducive working environment.
Quantity and Quality of Fingerlings
A major challenge facing aquaculture development in Tanzania today is
that of the availability of a regular supply of quality fingerlings (Wetengere,
2009a). It is a chronic problem with several important dimensions: quantity,
quality, cost of producing fingerlings and means of distributing fingerlings to
the farmers (FAO, 2000). The main source of fingerlings for most marine
species is collection from the wild (Wetengere and Madalla, 2011; Mmochi,
2011; Bueno, 2011). Fingerlings are collected by farmers, fishermen or local
collectors. The dependence on wild collection constrains the development and
sustainability of aquaculture: Firstly, it is difficult to collect the amount for the
correct stocking rate of the pond/cage especially for bigger ponds/cages. Most
ponds/cages seen during the field work in Zanzibar were understocked or not
stocked at all. This is possibly also because farmers were unable to pay for a
large number of fingerlings at a time. Secondly, occurrence of wild fingerlings
is seasonal and location specific. There are generally two peak seasons for
fingerlings coinciding with long and short rainy seasons. In Zanzibar, studies
indicate peak abundance from February to May and October to November
(Dubi et al., 2004) with significant periods when fingerlings are not readily
available. This compels the farmers to a culture period coinciding with the
abundant supply of fingerlings. Lunar cycles also influence the occurrence of
fingerlings in the coastal waters. For instance, milkfish spawn in the wild
during the first and last quarter moon, so fry are abundant in coastal waters
during full and new moons. Fingerling catches increase when the wind
direction is towards the shore. They are normally caught in sandy shores,
estuaries and mangrove areas. Thirdly, the fingerlings are not all of the same
size which impacts on growth and harvest. Moreover, a number of other
fingerlings species are also caught some of which are carnivorous and predate
on milkfish resulting in large losses (Mmochi, 2011). Finally, collection from
the wild does not guarantee the quality of the fingerlings.