Milkfish grow out culture

1. MILKFISH TECHNOLOGY
Chanos chanos (Forsskal, 1775 )

2. Members:
Arellano, anthea mae
Aficionado, arianwen
Botea, riza mae
Abejero, dea
Etang, eden
Espina, trisha rose
Muchuelas, may

3. Milkfish farming in Indonesia, Taiwan Province of China and the Philippines
started about 4-6 centuries ago. Culture methods in a variety of enclosures
are constantly being improved upon. Since the 1970s, large investments
have been made in the Philippines (as well as in Taiwan Province of China,
Indonesia and Hawaii) in terms of infrastructure, research, credit and training
in support to the milkfish industry. For example, the Southeast Asian
Fisheries Development Center (SEAFDEC) Aquaculture Department (AQD)
was established in Iloilo, Philippines in 1973 with a special remit to find
solutions for milkfish aquaculture problems. Government agencies and
fisheries institutions were also involved in a national effort to intensify milkfish
farming from the mid 1970s until now. In this work, research and
development on farming systems, breeding and fry production technologies
was carried out. There was no attempt at genetic improvement but fry
translocation and trade occurred between Indonesia, Taiwan Province of
China and the Philippines and geographic variations and heterogeneity were
documented. More recently, unconfirmed reports indicate that milkfish are
now being cultured to fingerling or juvenile size in the South Pacific Islands
and in Singapore as tuna bait.
HISTORICALBACKGROUND

4. Milkfish (Chanos chanos) is the only species in the Family Chanidae. Its distribution is
restricted to either low latitude tropics or the subtropical northern hemisphere along
continental shelves and around islands, where temperatures are greater than 20 °C
(Red Sea and South Africa to Hawaii and the Marquesas, north to Japan and south to
Victoria, Australia; and in the Eastern Pacific from San Pedro, California to the
Galapagos).
Adults occur in small to large schools near the coasts or around islands. They are well
developed, migratory, large (up to 1.5 m and 20 kg), and mature sexually in 5 years.
Milkfish only spawn in fully saline waters. The activity is most often correlated with the
new or full moon phases, takes place mostly in the night and, in most regions, has one
or two seasonal peaks. In the natural environment, spawning takes place near coral
reefs during the warm months of the year, and populations near the equator spawn
year-round. Juveniles and adults eat a wide variety of relatively soft and small food
items, from microbial mats to detritus, epiphytes and zooplankton.
HABITAT AND BIOLOGY

5. Milkfish can reach a maximum size of 180 cm SL (male/unsexed)
and 124 cm SL (female). The maximum recorded weight and age
is 14.0 kg and 15 years respectively. Resilience is low, with a
minimum population doubling time of 4.5 - 14 years. Its fisheries
importance is highly commercial, especially in aquaculture, and it
is also used in game fish as bait. It is especially valued as a food
fish in Southeast Asia.
Milkfish is a heterosexual fish; hermaphrodism has not been reported.
In natural spawning stocks the sex ratio is almost equal, with a slightly
higher amount of females. The determination of sex is very difficult,
because there are no easily identifiable morphological differences
between males and females; however, the pheromone PGF2a
(prostaglandin) has been found to be an effective way to identify mature
male milkfish.

6. ONGROWINGTECHNIQUES
Milkfish may be on grown in ponds, pens or cages.

7. Culture of milkfish in ponds may be in shallow or deep water systems.
Shallow water culture is practiced mainly in Indonesia and the Philippines. Milkfish are
traditionally cultured in shallow Brackish water ponds in which the growth of benthic
algae is encouraged through inorganic or organic fertilization. Milkfish will survive on
benthic algae alone only if the productivity of the algae exceeds the grazing rate of the
fish; otherwise, supplemental commercial feeds are applied. The 'lab-lab' culture
system in the Philippines is equivalent to shallow water culture in Taiwan Province of
China. 'Lab-lab' is the term used in this country for the algal mat (and all micro-
organisms associated with it) in the ongrowing ponds.
POND CULTURE
Brackish water ponds in the Philippines were mostly excavated from 'nipa' and mangrove
areas. Shallow water pond design generally consists of several nursery and production ponds
with a typical area of 2 000 m² for nursery ponds and 4 ha for production (ongrowing) ponds.
Typically, ponds have a depth of 30-40 cm and are provided with independent water supplies.

8. The average yield of a typical integrated nursery, transition and shallow grow-out system that
produces 3 crops a year is 800 kg/ha. Modified modular pond designs consisting of a series of
grow-out compartments with a maximum of eight crops a year have been shown to increase
yield to a high as 2 000 kg/ha.
Deep water culture was developed in the mid 1970s in response to the decline of
profitability of shallow water culture, and the limited and increasing value of land and
manpower resources. Deep-water ponds provide a more stable environment and extend
the grow-out period into the winter season. Most deep-water milkfish ponds have been
created by converting either shallow water ponds or freshwater ponds, with a depth of
2-3 m. Production from these systems has sharply increased in Taiwan Province of China,
having expanded from 23 percent of the total production in 1981 to 75 percent in 1990.
Most milkfish ponds in the Philippines and Indonesia are of the extensive and semi-
intensive type, with large shallow pond units, tidal water exchange, natural food,
minimal use of fertilizer alternating with commercial feeds and other inputs, and low to
medium stocking rates (50 000-100 000/ha). The Taiwanese method of production, on
the other hand, employs intensive stocking densities (150 000-200 000/ha). Few
diseases or infestations have been recorded so far in milkfish grow-out farming in these
Asian countries.

9. This system was introduced in the Philippines in 1979 in the Laguna
Lake. At that time, the lake had a very high primary productivity, which
met the nutritional needs of milkfish. Because of the low rate of input
and the high rate of return, the pen culture area increased sharply
from 1973 to 1983, and exceeded more than 50 percent of the total
lake surface, which is 90 000 ha. As the primary production of the lake
could not meet this sudden expansion of aquaculture, and feeding
became necessary to meet the nutritional requirements of the
cultured fish, the pen culture practices developed in lakes were later
introduced into inter-tidal areas in the Philippines along coves and
river estuaries as well. Pen operators stock fingerlings at 30 000-
35 000/ha and provide supplemental commercial diets. However,
disease spreads among culture pens and causes mass mortality.
Government regulations are now being considered to maintain
sustainable yields from this type of farming.

10. PEN

11. Fish cages are smaller and more restricted enclosures
that can be staked in shallow waters or set-up in deep
water with appropriate floats and anchors. Cage
farming of milkfish is commonly carried out in marine
waters along coastal bays. Stocking rates (in the
Philippines) are quite high, from 5 up to 30/m³.

13. In the past, traditional feeding practices for milkfish grow-out
production have consisted of natural food ('lab-lab') or a combination of
phytoplankton and macroalgae (Enteromorpha intestinales, Cladophora
spp. or Chaetomorpha linnum) encouraged by fertilization. In the 1980s
however, special commercial feeds for milkfish were developed and
became almost exclusively used. As cage and pen culture technology
proliferated in the 1990s, both in marine and inland waters, extruded
milkfish feeds were further developed into floating and semi-floating
forms, while sinking forms were used for pond and tank-based grow-
out. Feed supplies are now manufactured commercially in the form of
starters, growers and finishers, which are administered according to the
production stage of the milkfish.

14. HARVESTING TECHNIQUES
Milkfish are normally harvested at sizes of 20-40 cm (about 250-500 g). There
are three known methods used for harvesting milkfish:
Partial harvest. Selective harvest of uniformly grown milkfish from grow-out
facilities (i.e. cages, pens, ponds, tanks) using seine or gillnets, retaining the
undersize fish and harvesting only the commercial sized stocks, with an
average body weight of 250 g or larger.
Total harvest. Complete harvest in one crop period from grow-out facilities (i.e.
total draining of ponds by gravity or pump, hauling of the entire net cage
structure, seining or the use of gillnets in pens). The harvest size at this stage
may vary from 250-500 g.
Forced harvest. Emergency harvesting, regardless of fish size or grow-out
stage, which is carried out during 'fish kills' due to oxygen depletions that are
attributed to algal blooms, red tide occurrence, pollution or other environmental
causes.

15. HANDLING AND PROCESSING
200-400 g milkfish are harvested and marketed mostly fresh or chilled, whole or deboned, frozen,
or processed (e.g. fresh frozen deboned, fresh frozen deboned descaled, and smoked fish
deboned). In general, all marketed milkfish are produced in farms, only a few being caught from
natural waters. In some countries (e.g. the Philippines) fishing for adult milkfish is officially banned
in order to protect the natural broodstocks.
There are two known post-harvest processing techniques for milkfish, which are the traditional
(i.e. drying, fermentation and smoking) or non-traditional methods (i.e. bottling, canning and
freezing) and value-added products such as 'surimi' and deboned products as practiced in Taiwan
Province of China and in the Philippines.
Regulations and standard protocols for manufacturing milkfish products exist for both domestic
consumption and export, as follows:Good Manufacturing Practices (GMPs). Plant construction.
Personnel hygiene and sanitation.
Standard Sanitary Operating Procedures (SSOPs).
HACCP compliance.

16. PRODUCT COSTS
Milkfish farming is a centuries-old industry in Indonesia, Taiwan Province of China and the
Philippines. It has been slow to modernize and now faces challenges from competing
aquaculture species and current economic realities. The domestic market is large and the export
market has globally expanded. Milkfish price and personal income affect the amount of milkfish
consumed in the countries of origin. Studies conducted in Taiwan Province of China and the
Philippines concluded that price and income had a negative and positive elasticity coefficient,
respectively.
The following are the major determining factors affecting the cost of production in milkfish:
Type of culture system: costs are lowest in systems dependent only on natural food; costs
increase as artificial feed is introduced; costs are highest in systems dependent totally on
commercial feeds.
Increasing production: with milkfish production steadily increasing and culture practices
becoming more intense, a big surplus of this commodity is foreseen in the near future.
Cost of feed: feeds account for 60 to 80 percent of the total production cost.
Low farm-gate prices: on average, the farm-gate price for milkfish is only about USD 2.00/kg in
the Philippines. As the supply of milkfish is expected to increase way above demand, fish
farmers cannot demand a higher farm-gate price even though they may be spending heavily to
cover production costs.
Lack of post-harvest facilities for value-adding and processing.

17. DISEASE
AGENT TYPE SYNDROME MEASURES
Nematode
infestation
Capillariasp.
Parasitic
nematode
Emaciated, although shows good appetite in
early stage, then weakens, becomes listless,
loses appetite & colour pattern darkens; fin &
tail rot and skin patches/sores; faeces white &
stringy/slimy; scrapes belly against bottom or
may start to tremble; larval stage of parasite
located in muscle tissue & can be seen
through skin, appearing either coiled up or
rod-like
Administer
trichlorfon (with
caution for small
fish); niclosamide,
levamisole or
mebendazole
mixed in feed
Anchor
worm
disease
Lernaea
cyprinacea
Parasitic
copepod
Parasite visible on skin, head embedded deep
in the tissues of the host; haemorrhages and
open wounds at site of infection; weight loss;
respiratory difficulties; sluggishness; red
areas; ulcers; scale loss; fin damage;
scraping and sometimes hanging vertically or
belly up; parasite length 5 to 22 mm
KMnO4 bath or
0.8-1.1% NaCl
(KMnO4 may be
lethal to small fish
at dosages
required to
killLernaea)
Trichodinos
is
Trichodinas
p.
Protozoan
parasite
Slime covers skin like fog, fins clamped and
denuded of tissue
250 ml/litre
formalin bath for
15 min

18. Scolex infestation
Scolex
pleuronectis
Helminth parasite
Infestation
occurs commonly
in the intestine
None stated
Cryptobia
Infestation
Cryptobiasp. Protozoan parasite
Dark coloration;
increased mucus
build-up; occasional
appearance of skin
lesions followed by
scale loss; difficult
or rapid breathing;
reduced appetite
and weight loss;
secondary bacterial
infections in
advanced stage
leading to pale
and/or red skin
patches and skin &
fin rot
Treat with
formaldehyde (250
ml/litre) or
10mg/litre
malachite green;
place infected fish
in freshwater bath
or treat with
effective
antibacterial agents
Loss of appetite;
lethargic
Dip infected fish in
freshwater (makes
transparent

19. PRODUCTION STATISTICS
Global annual aquaculture production of milkfish has increased every year
since 1997; by 2005 it had risen to nearly 595 000 tonnes, with a value of
almost USD 616 million. The most important producers at this time were the
Philippines (289 000 tonnes), Indonesia (254 000 tonnes) and Taiwan
Province of China (50 000 tonnes).
Global aquaculture production of Chanos chanos
(FAO Fishery Statistic)

20. MARKET AND TRADE
Producers of milkfish do not usually sell fish directly to consumers, but supply them through
cooperatives, brokers, dealers, collectors or wholesalers, and retailers. In general, the majority
of fish products are sold in auction markets through dealers, brokers, wholesalers or
cooperatives to smaller dealers, and then retailers.
Increasingly, more of the milkfish harvest is processed into value-added forms: smoked, dried,
marinated (brined, sweetened), fermented with rice, and canned or bottled in various styles
(salmon style, sardine style, Spanish style, smoked in oil, etc.). Some companies in the
Philippines now produce frozen prime cuts of milkfish bellies and backs, and even of heads and
tails. Milkfish is exported in different product forms: quick-frozen, dried, canned, smoked or
marinated.
The Philippines recorded an export of over 17 040 kg of milkfish products to the EU in 2002,
valued at USD 58 000. While Taiwan Province of China concentrates on processed and value-
added products for export to the USA, Indonesia has strengthened its export of hatchery-reared
seedstock to the rest of the Asia-Pacific region for tuna bait and for grow-out.

21. STATUS AND TRENDS
Successful induced spawning and larval rearing of milkfish were first accomplished at
SEAFDEC/AQD in 1976-1978. The first generation cycle of milkfish in captivity was
completed at AQD when the offspring of a wild female induced to spawn in 1978 in turn
spawned in 1983. Since then, milkfish have matured and spawned in floating cages, ponds,
and concrete tanks in the Philippines, Taiwan Province of China, Hawaii, and Indonesia.
Since the successful completion of larval rearing technology in 1984, fry production has
increased significantly, which has not only provided milkfish farmers in Taiwan Province of
China with ample supply but also opened an export market to neighbouring countries.
To date no substantial technical and scientific research has been documented from major
milkfish producing countries other than the policy and management related research being
conducted by the WorldFish Center, the SEAFDEC Aquaculture Department and the Bureau
of Agricultural Research and BFAR of the Philippine Department of Agriculture.
Research and Development

22. Taiwan Province of China, however, has recently developed an improved strain of
milkfish through selective breeding process resulting in a golden coloured F1 pioneered
by a private farmer; this would accordingly command a better price than the original
silvery coloured strain, once introduced in the market.
Development perspectives
The development of more efficient culture systems has resulted in higher milkfish production,
which continues to increase.
Diversification of aquaculture in Taiwan Province of China, however, has paved the way for
prioritizing other high valued commercial marine species of fish, which has affected the growth
of the milkfish industry.

23. Based on current trends, production in the Philippines (which has expanded its traditional
land-based milkfish farming from Brackish water fishponds to marine cages in coastal
communities through the establishments of mariculture parks) is expected to rise from
289 000 tonnes in 2005 to 369 000 tonnes in 2010. Assuming that the population of the
Philippines reached 84 million by the year 2005, at per capita milkfish consumption of 2.5
kg/yr the total milkfish requirement would reach 210 000 tonnes. With the actual milkfish
production recorded as of 289 000 tonnes in 2005, there would have been an estimated
supply surplus of 79 000 tonnes.In Indonesia backyard hatchery production of milkfish
seeds has become a rural industry at the village level. The majority of these hatcheries have
further shifted to fry production of high-value species of marine finfish.

24. Market perspectives
Marketing of milkfish products contribute a lot to the sustainability of the industry in the major
milkfish producing countries - Indonesia with its seed production exports, Taiwan Province of
China with value-added milkfish products and the Philippines with whole fresh and processed
products both for domestic and export markets.
The General Agreement on Tariffs and Trade GATT/WTO impositions of trade restrictions and the
EU/US bio-safety and quality control standards are considerably affecting the producing
countries and are foreseen to be an added burden among production costs.
Although HACCP from farm to product processing are now strictly observed (for both domestic
and export markets) in the major producing countries, farmers and processors view this as
another trade barrier that has been set by the importing industrialized countries.

25. Main issues
Producers and consumers have benefited from new technology; however, broodstock technology
is still unreliable and fry supply is not fully controlled.
Milkfish will remain a traditional foodfish in the Philippines, Indonesia and Taiwan Province of
China; however, the younger generation tends to avoid eating milkfish because of their bony
flesh; thus new markets will be difficult to create.
High land values and the relatively low value of milkfish mean that farmers will have to introduce
new technology to increase unit productivity.
Milkfish aquaculture will no longer rely only on natural productivity; the use of formulated feed
will become the norm.
More hatcheries, especially in Indonesia and Taiwan Province of China, are expected to come on-
stream. This, and improved spawning technology, is expected to decrease fry costs.
New product forms need to be developed, advertised and marketed.
As mass production of milkfish fry in hatcheries expands, more fingerlings will become available
for the baitfish industry.
Further research and development on the marketing and processing of milkfish is desirable.
The main issues in milkfish farming can be
summarized as follows:

26. RESPONSIBLE AQUACULURE
PRACTICES
Due to global market demand, major milkfish producing countries have recently been
promoting management practices that address food quality and safety issues. At the farm
level for example, the Philippines complies with the minimum aquaculture HACCP
requirements, from hatchery production to harvest, before milkfish products are processed
for export. Taiwan Province of China has introduced product eco-labelling in order to
export quality branded processed milkfish products, while Indonesia ensures the quality of
milkfish fry when exporting to neighbouring Asian countries and accompanies them with
health certificates. Traceability in the use of antibiotics and unregulated drugs is already
strictly imposed in these countries.

27. REFERENES
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Aquaculture, 99:235-248.
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Philippines. ICLARM Technical Report, 58. 38 pp.
Anonymous. 1997. What is multi-species backyard hatchery technology? Newsletter of the Gondol Research Station for Coastal Fisheries, Central
Research Institute of Fisheries, 3:1-8.
Bagarinao, T.U. 1991. Biology of milkfish (Chanos chanos Forsskal). Aquaculture Department Southeast Asian Fisheries Development Center,
Tigbauan, Iloilo, Philippines. 94 pp.
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Baliao, D.D., de los Santos, M.A. and Franco, N.M. 1999. The modular method: milkfish pond culture. Aquaculture Extension Manual No. 25.
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Chang, S.L., Su, M.S. and Liao, I.C. 1993. Milkfish fry production in Taiwan. Tungkang Marine Laboratory Conference Proceedings, 3:157-171.
Corre, V.L. Jr., Janeo, R.L., Dureza, V.A. and Edra, R.B. 2001. Milkfish broodstock management and fry production in tanks. Philippine Council for
Aquatic and Marine Research and Development, Los Baños, Laguna and University of the Philippines in the Visayas, Miag-ao, Iloilo, Philippines.
38 pp.
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the art. The Oceanic Institute. Makapuu Point, Waimanalo, Hawaii 96795, USA. 284 pp.
Israel, D. C. 2000. The milkfish broodstock-hatchery research and development program and industry: a policy study. Philippine Institute for
Development Studies. Makati City, Philippines. 63 pp.
Kumagai, S., Bagarinao, T. and Unggui, A. 1980. A study on the milkfish fry fishing gears in Panay Island, Philippines. SEAFDEC Technical Report,
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Lee, C-S. 1995. Aquaculture of milkfish. Tungkang Marine Laboratory Aquaculture Series, 1:57-83.
Lopez, N.A., Vicaldo, Ma. V. and Fadriquela, J. 1986. The Philippine National Bangus Breeding Program. In: J.L. Maclean, L.B. Dizon & L.V. Hosillos
(eds.), Proceedings of the First Asian Fisheries Forum, 13-15 May 1986, pp. 76-78. Asian Fisheries Society, Manila, Philippines.
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Villaluz, A.C., Villaver, W.R. and Salde, R.J. 1982. Milkfish fry and fingerling industry of the Philippines: methods and practices. SEAFDEC Technical
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Report, 9 (2nd Edition). 81 pp.
BIBLIOGRAPHY