harvest, and customers arrive on the
appointed day. In Zomba District, 96% of
commercially oriented fish farmers sell
their fish on site. Tbis obviates the needs
for specialized marketing strategies, the
role offish traders, and processing, thereby
side stepping potential constraints caused
by infrastructural deficiencies.
Prices of cash sales are tempered by
reciprocity and urban demand. Although
there is a close-to-current-market price
that fish farmers could seek, many sales to
friends and relatives are "socially priced"
at a lower rate. Nevertheless, farmers are
mostly able to obtain close to current
market prices (Mills 1989).
Protective legislation. Aquaculture
developments in developing countries are
commonly unprotected by formal
legislation, and customary law does not
usually apply to the practice. On the
contrary, legislation governing water
abstraction, river pollution, public health,
fish handling, and water or coastal and
lakeshore rights all hinder the
development ofaquaculture, especially by
small-scale farmers. Thus one impact of
aquaculture development, as in Southern
Malawi, is a widely perceived need to
formalize the processes for securing sites
and water, and obtainingvarious licenses
and obtaininglegal protection against theft
and the like. Legislation is also required to
protect the water rights of fish farmers
against upstream pollution and damage to
watersheds. Insurance against accidental
loss is also required by small-scale
operators, particularly to mitigate
perceived risk that retards dissemination
of aquaculture.
IMPACTS ON COMMUNITY WELFARE
Public health. There is little evidence
that the development of small-scale
aquaculture anywhere has had an adverse
impact on public health, by spreading
disease. Regardless ofthis, however, publichealth measures must be planned as an
integral part of aquaculture development,
since if the development of aquaculture is
perceived locally to be responsible for
increasing morbidity rates of
schistosomiasis and other debilitating
diseases, the innovation will be critically
evaluated by adopters and nonadopters
with respect to the trade-off between
nutritional and economic benefits
compared with health implications.
Aquaculture development has the potential
to increase hazards to human health,
primarily from waterborne diseases
(especially schistosomiasis, malaria and
guinea worm) and fish parasites.
Schistosomiasis is perhaps the most
prevalent debilitating disease, with an
incidence of 70-90%.Conclusions
Aquaculture development in
developing countries has had a chequered
history, at best. This is particularly true of
Africa, but also, to a lesser extent, of Asia.
In large part, failures have stemmed from
social, cultural and economic causes, and,
in particular, from the lack of appreciation
among policymakers and planners that
aquaculture is just one dimension of a
much larger human ecological system.
Above all, aquaculture must be seen in
context. In particular, but not exclusively,
it must be planned for and assessed in the
context of (1) national development policy
and goals and existing levels of national
development and the constraints that these
impose on sustainability; (2) its
socioeconomic and other relationships to
alternative sources of both animal and
vegetable protein; (3) the physical and
biological environments into which its
introduction is proposed; (4) the
socioeconomic environment into which its
introduction is proposed; and (5) its
capacity for integration with existing or
potential resource use practices, especially