Fish as feed inputs for aquaculture: practices, sustainability and implications

110 Fish as feed inputs for aquaculture – Practices, sustainability and implications

Sugiyama, Staples and Funge-Smith (2004) estimated that in China, 3 615 000 tonnes

and in the Philippines 144 638 tonnes of trash fish/low-value fish were used as feed

for cultured stocks. Edwards, Le and Allan (2004) estimated that in Viet Nam 323 440

tonnes were used in aquaculture, the bulk of them being used in the preparation of

farm-made feeds for pangasiid culture in the Mekong Delta.

The above estimates, as well as that of the present analysis, are significantly lower

than those of Allan (2004), who estimated that the global usage of trash fish/low-value

fish as a direct feed source in aquaculture was 5 million tonnes per year. Assuming

that the Asia-Pacific region accounts for 80 percent of the global trash fish/low-value

fish usage in aquaculture, it is believed that the current estimates are closer to reality,

as these are based on observed production levels and farm surveys. Importantly, the

predictions for the future indicate a significant reduction in trash fish/low-value fish

use in aquaculture in the Asia-Pacific.

6. USE OF LIVE FISH AS FEED IN
   ASIAN AQUACULTURE
   Instances of live cultured fish being
   raised for the sole purpose of feeding
   to another, generally much higher-
   valued cultured species are uncommon.
   There is one such example known
   from Asia, that of the mandarin fish
   (Siniperca chuatsi). There are also less
   significant instances where low-value
   fish such as small-sized tilapias have
   been used as food for culturing higher-
   valued species. In addition, there is
   the farming of species such as milkfish
   (Chanos chanos) to fingerling size for
   use as live bait for tuna fishing.
   The mandarin fish, a percichthyid,
   is one of the most highly valued freshwater species cultured in Asia. Mandarin fish
   culture is almost totally confined to a few provinces of China, such as Guangdong and
   Hubei. This top carnivore cannot be weaned onto dry or moist feed and thus has to
   be fed on live fish only, unlike the closely
   related Murray cod (Maccullochella peelii
   peelii), a large Australian iconic freshwater
   fish. In spite of this limitation, it is cultured
   extensively in reservoirs (in cages) and
   in ponds, and the total production from
   aquaculture has grown from 37 000
   tonnes to almost 170 000 tons over the last
   ten year period (1995–2004) (Figure 20).
   With the increase in production, there had
   been a decline in the farmgate price, which
   dropped from about CNY80 to 120 per
   kg (US$1=CNY7.85) in the early 1990s
   to the current price of CNY35 to 60. This
   decrease in farmgate price, as well as other
   development demands has resulted in the
   reduction of the area used for mandarin
   fish culture. For example, in Hang Lang
   Township, Zongshan Prefecture, Guangdong

FIGURE 20

Changes in Mandarin fish production in China and the

estimated live fish feed needed based on two conversion

efficiencies

37

58

68

83 89

99

116

130

150

169

30

50

70

90

110

130

150

170

100

200

300

400

500

600

700

800

900

1 000

1 100

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004

F eed in p u ts (th o u san d to n n es) Production (thousand tonnes)

Years

Feed 4:1 Feed 6:1 Actual production

Source: FAO (2006a)

FIGURE 21

Mandarin fish from a culture pond at Hang Lang

Township, Zongshan Prefecture, Guangdong Province,

China with its live fish feed, mud carp. Prey fish are

introduced into the mandarin fish grow-out ponds, on

average, every fifth day