Use of wild fish and other aquatic organisms as feed in aquaculture in the Asia-Pacific 111
province, China, the pond area has decreased from 3 300 ha in the mid-1990s to the
current 650 ha (however, production intensity and efficacy have increased).
Species commonly cultured as food for mandarin fish include Chinese mud carp
(Cirrhinus chinensis), silver carp (Hypophthalmichthys molitrix), bighead carp (H.
nobilis) and black carp (Mylopharyngodon piceus), all cultured and popular foodfishes.
In general, mandarin fish culture goes hand in hand with the culture of its foodfish
species, either in cages or ponds, often adjacent to the culture site of the mandarin
fish. The live fish are fed at a size ranging from about 2 cm to a maximum of 8–10 cm,
depending on the size of the mandarin fish stock (Figure 21). Fish are fed every fourth
to fifth day, and the amount of live feed presented is determined by the farmer based on
the response of the mandarin fish to the feed, the more aggressive the feeding, the more
feed provided. During a culture cycle of 4.5 to 5.5 months, the average yield obtained
in pond culture of mandarin fish ranges from 7 500 to 10 500 kg per ha, and the average
conversion efficiency is 4. Even though mandarin fish culture demands more space, it
remains significantly more profitable than culturing the filter-feeding Chinese carps,
based on pond fertilization only, because the market price of Chinese carps is only
about CNY12 to 15 per kg at the best of times. A simple cost-benefit analysis (Table
19) indicates that economic gains from mandarin fish culture are, as might be expected,
sensitive to market price. Mandarin fish culture typically requires three times the space
(pond and or cage) than the culture of its live food (carps). However, because of the
very low market price of carps, the total gains from their culture up to market size are
less attractive than the highly demanding but highly profitable culture of mandarin fish.
By contrast the risks associated with mandarin fish culture (a form of monoculture),
particularly potential mortality from disease, are far greater than for the culture of
carps, and more often than not the average farmer is unwilling to take this risk.
- USE OF FISH IN FEEDS IN ASIA-PACIFIC AQUACULTURE: AN OVERALL
ANALYSIS
Fish are used, directly (e.g. as fishmeal) or indirectly (as animal food) in significant
quantity in the aquaculture sector in the Asia-Pacific region. This usage falls into three
categories that are summarized in Table 20. Overall, fishmeal accounts for the highest
usage, and in this regard, Asia-Pacific aquaculture uses the greatest proportion of
global fishmeal production.
Tacon, Hasan and Subasinghe (2006) estimated that in 2003, global aquaculture used
2.94 million tonnes of fishmeal (53.2 percent of global fishmeal production), which was
considered to be equivalent to the consumption of from 14.95 to 18.69 million tonnes
of trash fish/low-value fish, primarily pelagics. These authors also reckoned that nearly
5 million tonnes of such fish were used directly as a feed source for cultured stocks,
thereby totalling a consumption of 20–25 million tonnes, primarily for the production
of 30 million tonnes of farmed finfish and crustaceans.
In the Asia-Pacific region, an estimated 9.8 million tonnes of the total capture fishery
of 40 million tonnes (approximately 25 percent) are used directly (e.g. as fishmeal) or
TABLE 19
A cost-benefit analysis of mandarin fish culture on a farm in Hang Lang Township, Zongshan Prefecture,
Guangdong province, China
Parameter Unit price (CNY) Stocking density (no.) Harvest (kg) Value (CNY) Profit (CNY)
Mandarin fish seed (5 cm) 5 15 000 – 75 000 –
Harvest (ave. 700 g; 80% survival) 40/kg – 4 800 192 000 117 000
60/kg 4 800 288 000 213 000
The cost of feed is CNY/kg totalling CNY201 600 (US$1=CNY7.85).^ In mandarin fish culture, mud carp fingerlings are commonly used
as a live feed.
Source: Personal observations