countries ofthe region, produces primarily
cheap food fish (e.g., cyprinids and tilapias)
affordable for the poorer segments of the
population. More expensive commodities
(e.g., carnivorous fish species) are produced
mainly in the developed or newly
industrialized countries of the region.
Culture techniques in Asian inland
aguaculture are characterized by simple,
low input pond culture methods. Cage and
pen culture in inland waters, although
introduced in most countries of the region,
seldom reaches commercially important
proportions. However, in certain areas of
Cambodia, Indonesia, Nepal, the
Philippines, Thailand and Vietnam
commercial freshwater cage or pen culture
has demonstrated both economical and
social feasibility. At the same time, these
more intensive systems have the inherent
threat of overloading the carryingcapacity
of the environment, as happened in the
well-documented case of Laguna de Bay in
the Philippines (Pullin 1981, this vol. p. 1).
Raceway and tank culture are not really
typical for Asia; few examples are found
even in the developed and newly
industrialized countries of the region.
Typical freshwater culture systems in
the region are the extensive or semi-
intensive polycultural systems with some
fertilization and supplementary feeding.
Suitable fish species (Chinese and Indian
major carps and tilapias) for such systems
were introduced in the 1960s and 1970s to
practically every country of the region (De
Silva 1989).
Freshwater aguaculture is generally
a small-scale activity in Asia. Most of the
ponds are operated by small farmers as
part of their simple, rice-based farming
systems. Thus, there are few problems
with their environmental compatibility.
Their competition for natural resources
(land, water) or external inputs (manure,
fertilizer, feed) remains also limited.
Governments in many developing
countries of the region, concerned about
rice self-sufficiency, were afraid of
converting too big a portion ofricefields to
fishponds. Some of these countries even
imposed bans on such conversions in the
rapid growth phase of inland aquaculture.
Later, however, these fears abated as it
was proven that small farmers are unlikely
to convert too high a portion of their
ricefields to fishponds in order to maintain
their simple but well balanced farming
systems.
An interesting phenomenon was
witnessedin several countries ofthe region
where inland aquaculture was introduced
only recently (e.g., in Bhutan, Laos, and
Nepal). Although a significant portion of
fishponds were constructed by converting
ricefields, rice output of the affected
communities increased rather than
decreased. The explanationis that because
of the introduction of aquaculture (which
produces a high-value crop compared to
rice) farmers had to improve on their
traditional water and farm management
practices. This, in turn, raised their rice
yields.Coastal Aquaculture
Coastal aquaculture in Asia received
much less attention than freshwater fish
culturein the past. Recently, however, the
rapidgrowth of shrimp culture has focused
attention on coastal areas and new
perceptions have appeared which regard
coastal aquaculture as a new, socially
contradictory and environmentally
incompatible phenomenon. A closer look
at the history and status of Asian coastal
aquaculture contradicts these vi.ews. Data
given in Table 4 show that, in 1990 as much
as 51.5% of the total production of the
region came from coastal aquaculture. This
ratio has decreased rather than increased
in the past 15 years; coastal aquaculture
produced 63.3% of the regional total in
1975.
Coastal aquaculture dominates the
scene in Australia, Japan, both Koreas,