Environment and aquaculture in developing countries

with proper stocking, they can produce
significant amounts of fish without
endangering their other functions.
Similarly, in Vietnam -and Laos,
aquaculture is successfully practiced in
the millions of bomb craters which dot the
war-torn landscape using the same
(primarily photosynthesis-dependent)fish
culture method. These methods do not
compete for land, water, fertilizer and feed
with crop or livestock production, blend
well with their environment and produce
the cheapestfishnext to those from capture
fisheries.
Culture of carnivorous fish, although
it produces only 7% of the regional finfish
production, cannot be neglected because it
has a significant economic and environ-
mental impact. Countries of the region
can be classified into three groups in this
regard: Australia, Japan, New Zealand
and Singapore produce almost exclusively
carnivorous species; Hong Kong, the Re-
public of Korea, Malaysia, Taiwan and
Thailand produce significant amounts of
carnivores (over 25% but below 60% of
their total finfish production); while car-
nivorousfish productionis insignificant in
the rest oftheregion(Tab1e 8). It is obvious
that the production of the more expensive
carnivorous finfish species is closely re-
lated to the prosperity of the country. Also,
the total volume of cultured carnivores
produced in a country is not necessarily
consumed there. ~i~h-value
export products play an im-
portant role in the foreign
exchange earning of the
Southeast Asian countries in
which aquaculture is more
developed.
While in other regions of
the world, salmonid species
and catfish dominate the
production of carnivores,
Asia and the Pacific present

are only 11% ofthe total and catfish species

represent 14%. The biggest contributor is

the yellowtail (Seriola quinquerudiata),

with a 33% share of the total carnivorous

fish production; eels amount to 19%; and

various species of seabreams make up

10%. The "other" category comprises

marine fish species too, of which the most

important are the sea perch (Lutes

calcarifer), called "seabass" in Asia and

"barramundi7'inAustralia, and the bastard

halibut or Japanese flounder (Paralichthys

olivaceusl.

Despite the rapid growth in the

production of some minor groups of

cultured carnivores (e.g., salmon, groupers,

flatfishes), development of carnivorous fish

production from 1984 to 1990 has been

slow (7% per year). The reason is the

overwhelming dominance of Japan, where

the required volume from one or another

species is limited and market niches get

saturated rather rapidly.

About 60% of the carnivorous fish in

the region are cultured in marine cages

(yellowtail, seabreams, salmons, seabass,

groupers, snappers) and 40% in intensive

ponds (eels, trouts, catfishes). Originally

all these species were fed with so-called

trashfish (by-catch of trawling) or, in

Japan, with low-value marine fish (like

sardines, anchovies, sand lances,

mackerels). Producers in Japan, however,

have shifted to formulated feeds, which

Table 10. Cultured carnivorous iish by species groups in 1990.

(Source: FA0 1992a).

Asia-Pacific Reat of World

Species groups (xlo3 t) (%) (~10~ t) (%)

Yellowtails 169.1 33.1 0.3 0.0

Eels 96.1 18.8 8.0 1.1

Catfishes 70.4 13.8 169.7 24.0

Seabreams 63.0 10.4 5.1 0.7

Balmone 27.3 6.4 266.1 36.2

Tmub 27.2 6.3 266.3 37.6

Othere 67.2 13.2 2.9 0.4

a different and more diverse
picture (Table 10). Salmonids

510.3 100.0 708.4 100.0