Use of wild fish and other aquatic organisms as feed in aquaculture in the Asia-Pacific 83metabolism differs among finfish species, particularly with respect to traits such as
“protein sparing” capability. In general, the protein sparing capabilities of cultured
tropical species are not that significant. Therefore, from a feed formulation viewpoint,
the prospect of using this physiological trait to reduce the amount of fishmeal in the
diets of tropical finfish is relatively remote. These traits, together with the generally
poor uptake of research findings by feed manufacturers (De Silva and Davy, 1992; De
Silva and Hasan, 2007), have delayed achieving reduction of fishmeal and fish oil use
in aquaculture.
There are lessons to be learned from Japan, where large-scale mariculture originated
based entirely on using trash fish/low-value fish as the feed source (Watanabe, Davy
and Nose, 1989). The development of formulated feeds took a certain length of time,
a major breakthrough being the development of a soft-dry diet with high palatability
for Japanese amberjack (Seriola quinqueradiata). This breakthrough revolutionized
feed development for marine cage farming and literally removed its dependence on the
direct use of trash fish/low-value fish (Watanabe, Davy and Nose, 1989). Of course,
feed formulations and feed manufacturing technology for finfish have now progressed
much further (Box 4). Currently, much research effort is being expended on feed
formulation for emerging marine cage-farming species in the Asian tropics such as
grouper and cobia (Rimmer, McBride and Williams, 2004).
4 .2 Fishmeal and fish oil production in Asia
Fishmeal and fish oil are world-traded commodities, with the production dominated
by Chile, Iceland, Norway and Peru, all countries that have access to and exploit large
single-species stocks such as the anchovetta, sand eel and Atlantic menhaden. Although
fishmeal and fish oil production has increased over the years and has somewhat
steadied in the last three years, these commodities are often subjected to unpredictable
availability and wide price fluctuations due to the influence of climatic changes such
as the El Niño events (Jackson, 2006). For example, the fishmeal price increased from
approximately US$600 to US$1 600 per tonne from 2003 to January 2006 (INFOFISH,
2006), while the price of a commodity such as soybean meal, for example, remained
almost static over the same period (GLOBEFISH, 2005).
Fishmeal production in Asia is dominated by Thailand, China and Japan (Table 3).
Chinese production has shown a decline since 2000 (Figure 12) and was only 306 000
tonnes in 2004. Globally, only Japan, Thailand, China, Taiwan POC, Indonesia and
Viet Nam are included among the top 16 producers, importers and consumers of
fishmeal (IFFO, 2005). It is noteworthy that, other than Japan and China (which
produced 68 000 and 13 000 tonnes, respectively, in 2004), Asian countries are not
significant fish oil producers.
BOX 4
Research trends in finfish nutrition
Over the years, the most extensive research on finfish nutrition has been the study of
fishmeal replacement in feeds. This research has involved almost all species of cultured
finfish and a wide range of potential ingredients ranging from agricultural by-products
to single-cell proteins to animal industry by-products. Most recently, the use of krill
species (Euphausia spp.) as a potential substitute for fishmeal (Olsen et al., 2006;
Suontama et al., 2007) has received considerable attention. However, it should be noted
that a reduction in krill populations has been observed (Atkinson et al., 2004), possibly
as a result of global warming. Moreover, the use of krill may do little more than shift the
problem of sustainability from finfish stocks to krill.