industries which have expanded into the
coastal areas since the 1970s. Much of the
mangroves converted to shrimp ponds were
already worthless shrublands rather than
high value forests, and would have needed
systematic and expensive reforestation to
become productive forests again. However,
because of the entrenched interests of the
loggingindustry in many countries ofhsia,
the least risky solution is to put the blame
on the end-users of destroyed mangroves,
that is, on shrimp farmers.
The environmental effects of shrimp
culture are discussed in more detail in
Phillips et al. (this vol.).Mollusc Culture
Although.several countries ofEast Asia
have traditions in culturing molluscs,
aquaculture production of this commodity
group is not as widespread in the region as
that of finfishes or crustaceans. The share
of the Asia-Pacific region in the global
production of cultured molluscs was 55%
in1975 and by 1990 it reached 74%. Several
of the major producers of other aquaculture
commodities (e.g., Bangladesh, Indonesia,
Pakistan and Vietnam) do not report
mollusc culture at all. This list of countries
indicate cultural problems with the
acceptance of molluscs. The growth of
mollusc culture in the region was relatively
slow until 1983 after which it accelerated
to over 11% per year (Fig. 5). However, the
share of molluscs in the total aquaculture
output of the region has not changed since
1975; in 1990 it was 17% (Table 3).
Details of cultured mollusc production
are given in Table 13. Major producers in
1988 in terms oftotal volume were China,
Japan and the Republic of Korea, followed
by Thailand and Taiwan. The comparison
of countries is again more accurate on the
basis of their production per length of
coastline (Table 14). In 1990, China
produced over 60 t.km-l of cultured
molluscs; the next three (Taiwan, Thailand,
the Republic of Korea) between 25'hnd 40
t.km-l. These figures show the dominant
role of cooler waters in the present
production pattern and also the potentials
in tropical countries.
As in the rest of the world, freshwater
molluscs play only a minor role in the
region, although interest in freshwaterFig. 5. Gmwth of cultured mollusc production in Asia and the Pacific. Data aggregated before- (Sources: Saenger et al. X983; FA0 1992a).