peoples and for environmental
conservation, may not suffice for the needs
of all who will depend upon the food
production sector. Urbanization is
proceeding rapidly and affordable produce
will have to be available to maintain the
social fabric of developing-country cities.
This will probably require the development
of some large-scale aquaculture enterprises
(run by estates and corporations) to
increase fish supply and lower prices.
Bimbao and Smith (1988) reviewed
the economics of tilapia production in the
Philippines and found that the purchasing
power ofthe average Filipino had declined
by about 30% from 1983-85 (due mainly to
high inflation) and that tilapia, like most
fish, was becoming beyond the purchasing
power of the majority of low-income
consumers; this in a country where rice
and fish form the staple diet. This
illustrates the difficulty in fostering
development that will provide a balance
between benefits to low-income producers
andlow-income consumers. Tilapiaretails
at about US$3.00/kg in Metro Manila
markets. Bimbao and Ahrned (1990) found
that an expansion of tilapia supply of up to
40% would not depress prices significantly.
Thereafter, prices would fall with further
increases in supply but wouId still be
attractive to producers. The situation is
probably very different elsewhere; for
example, concurrent tilapia prices in
Bangkok were only about US$O.GO/kg.
Opportunities for and needs of rural
producers and consumers, upban fringe
producers and consumers and city dweller
consumers must all be considered.
Therefore all kinds of aquaculture, small-
to large-scale and extensive to intensive,
including enhanced fisheries, can make
sense in developing-country aquaculture
development, depending upon the needs
of different sections of the community.
It is also most important to view
aquaculture development as only one of
several options for meeting livelihood and
nutritional needs. One must avoid the
naive assumption that aquaculture 'must'
be able to fill the fish supply or proteingap.
Fish is only one protein source. Expansion
of fish supply through aquaculture must
be weighed against the pros and cons of
increased supply of vegetable and other
animal proteins.Experience Gained in
Developed Countries
In the pursuit of environmentally
compatible aquaculture development for
developing countries, experience gained
in developed countries is useful. However,
this must be applied with a realistic
appreciation of developing-country needs
and constraints. Environmental
conservation and human needs must be
balanced. Where pristine habitats are
disappearing there should be all possible
efforts to conserve their remnants but
developingcountries need realistic policies
and legislation to suit their circumstances.
The contrast between Philippine coastal
waters and Scandinavian fiords is an
example. The former support the needs of
millions of people, have virtually no
pristine habitats andhave suffered massive
loss of, and damage to, coral reef and
mangrove ecosystems. The latter include
many pristine and near-pristine habitats
and support very low human populations.
Clearly, achievable environmental targets
are different for these two contrasting
locations.
This also applies to aquaculture
development in inland waters. Costa-
Pierce and Roem (1990) studied waste
production and efficiency offeedutilization
in cage culture in a tropical eutrophic
reservoir (Saguling, near Bandung, West
Java, Indonesia) in which 1,300 cage units
produced2,550 t ofcommon carp (Cyprinus
carpio)in1988. The percentage loss offeed
nutrients in Saguling was low (C, 5.4%; N,
3.5%; P, undetectable) and the