aquafarm news • seabass culture
A U S T R A L I A 
Seabass , popular ly known as 
barramundi in Australia, are highly 
valued foodfish throughout its 
range. Research work on seabass 
culture began in the mid-1980s to 
develop commercial and recrea-
tional fisheries. 
There are three different meth-
ods used for growing barramundi 
in Australia. The first is brackish-
water or freshwater pond culture. 
Usually, the fish are maintained in 
cages in ponds because of the dif-
ficulties in stock management and 
harvesting. Cage culture in estua-
rine waters is considered when 
large-scale production is envis-
aged. However, relatively few 
companies are using this technique 
primarily because of the difficul-
ties in obtaining government ap-
proval to establish fish farms in 
public waters and, to a lesser extent, biofouling and preda-
tion. The third method is intensive production in an indoor, 
controlled-environment building, using underground water 
(pathogen-free) and a high level of recirculation through a 
biological filter. Using this method, year-round production 
is possible and environmental concern associated with the 
release of nutrients to open waterways is avoided. 
In Barramundi Waters, Australia's largest producer of 
cultured seabass, the fish are grown in floating cages in fresh-
water ponds. Fingerlings (15 cm) are stocked in 2 × 2 ×1.5 
m or 10 × 5 × 1.5 m net cages at 100 kg per m 2 . Barramundi 
are fed by hand to satiation twice a day, every morning and 
evening. Floating pellets is generally given to minimize 
wastage and monitor the feeding activity of the fish. In 
other farms however, seabass are "reluctant" to feed at the 
surface when water clarity is high, hence sinking pellets are 
used. Fish are graded every two months during the 8-month 
rearing period. The high turbidity in ponds minimizes foul-
ing of mesh nets. Good aeration is maintained in the ponds 
using aerators and paddlewheels. Regular monitoring of 
water quality is undertaken and whenever necessary, wa-
ter is exchanged. As quoted from the owner Chris Phillips, 
"the barra are tough and don't need large water exchange." 
Harvesting and processing of the fish takes place at 
Barramundi Waters twice a week. Dip nets are used to 
catch the fish in cages while escapees from the cages are 
gillnetted from the ponds. Draining of the ponds is done 
once a year to make sure that no larger fish are present 
before the next crop is stocked. Harvested plate-size 
seabass (350-600 g) are killed by slitting the throat and 
letting the fish bleed in an ice brine. After gilling and gut-
ting they are packed with ice in polystyrene boxes and air-
freighted to the marketplace. The late 1995 selling price 
of gilled and gutted fish is US$12.50 per kg and that of 
gut-in fish is US$10-10.50 per kg. With increasing do-
mestic demand of larger barramundi (2-3 kg) at an esti-
mated price of US$5-6 per kg for fish fillet, the seabass 
industry in Australia seems to have a bright future. 
REFERENCES
Barlow C, Williams K and Rimmer M. 1996. Sea bass culture in 
Australia. Infofish International (2):26-33. 
O'Sullivan D. 1996. Leading barramundi farmer to double 
production this season. Austasia Aquaculture 9(6): 39-43. 
M A L A Y S I A 
Seabass are the most predominant fish cultured in cages in 
Malaysia. Although ponds are used, the bulk of seabass 
production comes from floating netcages because these are 
easy to construct, investment cost is low, farm manage-
ment is easy and cages are versatile. 
Most of the floating cage farms in Malaysia consist of 
wooden platforms supported by floats made of steel drums, 
fiberglass-coated styrofoam or plastic containers. The net-
cages themselves are usually made of polyethylene net-
ting, the mesh size of which varies according to the size of 
Seabass grow-out and marketing: lessons from 
Australia, Malaysia, and Thailand 
By R Buendia 
27Volume XIX No. 4 October 1997SEAFDEC Asian Aquaculture
aquafarm news • seabass culture
the fish stocked. The common size of individual net cages 
used is 3 x 3 x 2 m. The cages are anchored to the seabed 
by means of concrete blocks, wooden pegs driven into the 
seabed, or by long metal or wooden poles. 
Seabass are usually grown in calm and protected bays 
and lagoons where water current does not exceed 0.5 m 
per sec. A tidal range of around 1-2 m allows sufficient 
water exchange through the cages to wash away the feces 
and uneaten food and ensures an adequate supply of dis-
solved oxygen. The dissolved oxygen content of the water 
at the chosen location should not be less than 3 ppm. Clear 
water is an advantage as the nets will not be easily clogged 
by fouling organisms and silt particles. Seabass can grow 
well in 10-30 ppt salinity range. The depth of the water 
should be such that at no time are the cages touching the 
sea bottom. 
Fingerlings of 2-3 inches in size are initially stocked 
at 15-23 per m 3 . As seabass grow, they are periodically 
graded and transferred to larger mesh size cages with stock-
ing density reduced to 10-12 per m 3 . Trashfish are given 
once a day. The nets are cleared regularly of fouling or-
ganisms such as barnacles and seaweeds to ensure a clear 
flow of water through the cages. Seabass usually attains 
marketable size (500-600 g) in about 6-8 months with a 
survival rate of 60-80%. 
Most of the seabass produced is consumed domesti-
cally, with high demand in seafood restaurants and five-
star hotels. Home consumption is very limited. The ideal 
market size ranges between 600-700 g apiece. Ex-farm 
price of live seabass in 1994 is RM 15 apiece. In a restau-
rant, the price of live fish (later cooked) may range be-
tween RM 28-30 apiece. 
The market for fresh or chilled seabass in Malaysia is 
comparatively smaller. The September 1997 wholesale 
price of chilled fish is RM 11-14 per kg (see also preceding 
article). Fresh or chilled seabass is normally sold through 
supermarkets and wet markets with prices ranging between 
RM 17-18 per kg. 
Despite the high domestic demand, Malaysia also ex-
ports live seabass to neighboring Singapore as the market 
offers a better price. Live fish are transported by truck or 
by boat from the northern states of peninsular Malaysia to 
Singapore. 
REFERENCES
Singh T. 1991. Malaysia enjoys the seabass boom. Infofish 
International (2):45-48. 
Ferdouse F. 1995. Cultured sea bass - market. Infofish International 
(2): 20-22. 
T H A I L A N D
Commercial-scale farming of seabass was made possible 
by research on artificial propagation by the Thai Depart-
ment of Fisheries in mid-1970s. Seabass then became one 
of the most widely cultured and marketed fish in Thailand. 
Seabass are reared in 5 x 5 x 2 m floating cages in coastal 
waters or stationary cages in shallow bays. Stocking of 25 
cm fish varies from 12 to 300 per m3 depending on water 
quality and the environmental conditions of the culture site. 
More fish are stocked in floating cages than in stationary 
cages because they are usually in sites with deeper water, 
smaller fluctuation of salinity, more rapid circulation and 
further away from sources of pollution. 
Fresh and clean sardines and other marine trashfish are 
the main feed of seabass. Trashfish are chopped to fit the 
mouth of seabass. Seabass are fed to satiation twice a day, 
in the morning and afternoon. Food conversion rates range 
from 4 :1 to 10:1. Normal growth and survival rates are 1 
kg per yr and 80-95%, respectively. 
The cages are checked once or twice a month to ensure 
that these are not damaged and to monitor fish number and 
health. Cleaning or changing of the cages is done every 
month. Cover nets are used to prevent fish from jumping 
out, especially when the sea is rough, and to prevent preda-
tion. 
Seabass are reared for 5 to 20 months until the market-
able size of 700-900 g and 2,000-3,000 g are reached. How-
ever, 700-900 g fish is preferred by the local market. 
Thailand is a major consumer of cultured seabass. Do-
mestic production is sufficient to cater to increasing demand. 
Thailand also exports seabass particularly to Malaysia when 
there is shortage of the fish in the Malaysian market. 
REFERENCES
Tookwinas S. 1990. Review of grow-out techniques under tropical 
conditions: experience of Thailand on seabass (Lates calcarifer) 
and grouper (Epinephelus malabaricus). In: Advances in Tropical 
Aquaculture. Workshop at Tahiti, French Polynesia, Feb 20 - Mar 
4, 1989. AQUACOP. IFREMER. Actes de Colloque 9. pp.737-
750. 
Ferdouse F. 1995. Cultured sea bass - market. Infofish International 
(2):20-22. 
28 SEAFDEC Asian Aquaculture Vol XIX No. 4 October 1997