aquaculture systems are beyond doubt.
Especially harmful are those pond systems
which are constructed in mangrove areas
and alter irreversibly the original rich
ecosystem. Another significant difference
lies in the nature of competition for the
available resources. Ininland areas, there
may be some competition between
aquaculture and crop production for land
and water, usually within an integrated
farm unit. In coastal aquaculture, the
competition is usually between the
traditional users of hitherto open-access
resources and those who are encroaching
on and expropriating these. This is because
traditional users of coastal wetlands do
not have property rights over these lands,
which legally belong to the state in most
countries of Asia. Moreover, small-scale
fishers and other users of coastal resources
(charcoal burners, gatherers, etc.) usually
belong to the poorest segment of the
population; they are easily outcompeted
by "outsiders"in acquiringlegal ownership
over coastal lands and transforming them
to shrimplfish farms (Bailey 1988; Bailey
and Skladany 1988).
It is also important to realize that the
aspiration of coastal aquaculture is usually
not to produce more food for local
consumption. Coastal communitiesusually
have a reasonable supply of cheap
captured/collected seafood with which no
cultured product can compete in price. In
coastal areas, the dominant function of
aquaculture is income generation, the
production of cash crops sold in distant
markets (often for export). This is as
legitimate an ambition as cheap food fish
production in inland areas. The real
problem is that coastal communities are
seldom direct beneficiaries of such
aquaculture development. Benefits of
shrimp culture development, for instance,
trickle down to coastal fishing communities
only by generating some additional
employment and by enhancing the overall
rural development of hitherto neglected,
impoverished coastal areas. However, in
countries with high population densities,
coastal aquaculture can open up a new
frontier without putting more pressure on
the limited land resources. This is the
reason why China has turned towards this
type of aquaculture and has given its
development high priority over the past
decade. It is also important to realize that
out of the broad range of coastal
aquaculture systems only the pond culture
of marine fish and shrimp is
environmentally incompatible and socially
controversial. These systems do not
produce more than13% of the total coastal
aquaculture productionvolume (0.9 million
t out of the 6.6 million t in 1990).Finfish Culture
As already demonstrated, finfish
species form the biggest commodity group
in the aquaculture production of the Asia-
Pacific region (54% of 'the total in 1990),
and the most important one in the nutrition
of the poor of the region's developing
countries. Out of the 7 million t of cultured
fish produced in 1990 as much as 6.1
million tor 87% were freshwater fish; the
proportion of diadromous species was 9%,
that of marine fish only 4%. These values
are characteristic for the region. In the
rest of the world, the shares of both
freshwater and marine fish are lower (61 %
and 2%) respectively), at the same time
diadromous fish (primarily salmonids)
have a much higher share (38%).
Production of finfish shows a
significant and steady growth in the region
(Fig. 2).Between1975 and1990, the annual
average growth rate was 8.7% per year,
the developing countries of the region
having a slightly higher rate of growth
(9.0% per year). Information on the species
composition of finfish culture was rather
scanty before 1984 (when the regular data
collection work ofFAO started). However,
the improvement of the database now
makes possible a more detailed analysis.