Keys to Successful Milkfish Farming Ra Province, Fiji Islands

Mark Rowel Napulan

Aquaculture Consultant

kram_lewor501@yahoo.com

February 21, 2012

Knowing Milkfish Biology

Milkfish Farming Situation in the Philippines

Stocking Procedures

Review of Pond Dynamics

Farm Management

Geographic Distribution

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Broodstock • Mature at 5-7years old

• 65-80cm most fertile (Angeles, 1971)

• 4-8Kgs body weight (Angeles, 1971)

• Female Max Length: 124 cm

• Male Max. Length: 180

• Produce 100,000-400,000 pcs of fry per kilogram of body weight

Egg Hatching

• Egg division begins an hour after and hatching occurs 35-36 hours after spawning

• Milkfish eggs (1.1-1.2 mm in diameter)

• In the wild, eggs are probably released in deeper oceanic waters and in the outer reef region

• Salinity 29-34ppt

• Temp 26-32 degree celsius

Larvae Facts

• Started at 3.5mm

• Catch on shore at 10-17mm length

• Active swimmers proved by migration onshore and where they can be caught by fine-mesh nets operated along sandy beaches and mangrove area

• Relatively passive as carried by water currents during tide and wind direction

On the Fry Behaviour

• Fry appear inshore in great

numbers

• Distribute mainly in surface

• Fry are carried by water movements

• Fry enter coastal wetlands

• Fry are attracted by light

• Fry are caught by filtering and

driving

On the Fry Collection

• Fry appear most 10-30com in the surface

• Abundant in mouth of rivers , swamp

outlets and sandy beaches

• Notable coinciding with semi-lunar rhythm

▫ New Moon and Full Moon

• 1-3 hours before high tide is the peak catch

• Should be present in the area otherwise no

fry will be catch at all

Why Fry Dozer?

Designed by John Eric Basco

Photo taken by John Eric Basco

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Commercial pellet, mass of planktons and zooplanktons, larvae

Start feeding 80 hours after hatching

Copepod, Diatoms , Cyanobacteria Artificial diet, Artemia, Rotifer-chlorella

cyanobacteria, diatoms, and detritus, Filamentous green algae, Invertebrates (small crustaceans and worms.) Artificial feed.

Place Estimated area Gear type *Estimated

catch/person/day (4

hours/day)

Nasese 1 km area beach Fry barrier net, skimming net,

fry bulldozer and push net

500 to 1,000 fry

Bau/Gau beach 4 km river mouth and

beaches

Fry bulldozer and push net 500 to 1,000 fry

Kototonga Village,

Sigatoka

2 km beach/cove Fry barrier net, push net and

fry bulldozer

500 to 1,000 fry

Sigatoka River 4 km river mouth (both sides)

Tidal set net, fry barrier net

and push net

2,000 to 5,000 fry

Raviravi area, Ba fronting three floodgates Fry barrier net and push net 2,000 to 5,000 fry

Nabila village, Momi

bay 1 sq. km mangrove area

Skimming net and fry barrier

net

200 to 500 fry

Tavua bay 0.5 km beach

Skimming net and pushing

net 200 to 500 fry

Navua/Deuba 2 km beach/river mouth

Fry barrier net, push net and

tidal set net

500 to 1,000 fry

Tokotoko Beach

fronting floodgate 1 km beach and mangrove

area

Fry bulldozer, push net and

fry barrier net

500 to 1,000 fry

Nakalou Village,

Dreketi 500 m sandy beach

Push net and fry bulldozer 500 to 1,000 fry

Lekutu Village 1 km sandy beach Push net and fry bulldozer 500 to 1,000 fry

Biological Nature of Milkfish Filter feeders

Benthic feeders

Daytime feeders

Euryhaline

Phytophagous but carnivorous

Resistant to diseases and not cannibalistic

Exhibit compensatory growth

Artificial Breeding vs Wild Caught

Successfully bred in the hatchery

Mature after 5-10years old in captivity

Spawn spontaneously in concrete tanks or cages

Survival quality and grow rate is comparable with wild fry

Milkfish Farming Situation In The

Philippines

6.6% Increase in 2011

Cage Culture

-Stocking Density ranges from 20-30 per cu.m.

-Production per 600cu.m cage ranges from 2,400kgs-3,600kgs

-40-60tons per hectare

Fishery Issues Degradation of quality fingerling stocks due to inbreeding.

• Insufficient supply of quality bangus fry in far flung areas.

• High cost of farm inputs

• Lack of manpower to effectively transfer technology to the municipal level.

• Marketing layers which stand between producer and consumer; and

• Lost opportunities to participate in global market for value-added products

Issues and Trends

Climate Change

Mass Fish Kill/ Eutrophication

Mismanagement (Overstocking)

Weak Import Demand

Failure Imposition of Fishery Programs

800 tons Fish Kill in Taal Lake June 2011

Caused by: Upwelling Overstocking Lowering Dissolved Oxygen Eutrophication

• Acclimitization • Temperature shock • Salinity shock Acclimatization

• If equal or less than 5ppt salinity diff can stock in awhile

• If more than 5ppt gradually add up pond water until desired parameter is attained. Takes 30mins to 1hour.

Time Span

• Compute target density in nursery pond or HAPA

• Partially submerged the plastic then allow the fry to swim out

Proper Release

STEPS ON PROPER STOCKING

Steps in Acclimatization Process

• Open the fry plastic bags

• Let the bags float

• Add water gradually using hand/sprinkler

• Check salinity and temperature

• If salinity in the plastic bags is equal to that of the receiving pond submerged the plastic bags and allow fry to swim out

Milkfish Farming Basic

Regular monitoring and take action promptly

Establish good ecosystem And animal welfare

Predator Elimination & Proper Acclimatization

Determine the system

Management

Pond/Water preparation

Fry Collection & Stocking

Site Selection

Farm Management

Pond Preparation

Always Remember the Term “Carrying Capacity”

Sun Drying Plowing

Poisoning of

Unwanted

Animals Fertilization

PROCESS

mati.n@cpf.co.th

OXIDIZE SOIL.

HELPS IN THE EVAPORATION OF HYDROGEN

SULFIDE AND OTHER TOXIC GASES.

AERATES THE SOIL PARTICLES AND FAVORS

AEROBIC ORGANIC MATTER DECOMPOSITION

AND MINERALIZATION.

ENSURES KILLING OF FISH AND PREDATORS

Review on Pond Dynamics: Daytime High Dissolved Oxygen High pH High Temp.

Algae

Waste Milkfish

Bacteria

Oxygen

Carbon Dioxide

Review on Pond Dynamics: Night time

Low Dissolved Oxygen Low pH Low Temp.

Algae

Bacteria

Milk fish

Waste

Carbon Dioxide

Oxygen Aerator

Wind

Pumps/Water exchnge

When rain comes…

Low Dissolved Oxygen Low pH Low Temp.

Salinity= 0 ppt

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Salinity= 25ppt

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When rain comes…

Lowering Salinity: Low Dissolved Oxygen: Low pH: Lowering Temp.: Algae Die-off:

Salinity= 0 ppt

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Top Drain Change water.Pump if possible Apply hydrated lime if necessary Reduce feed Fertilize again. Change water.

Feeding Management

Summary Of Known Requirements Of the Milkfish Chanos Chanos Forsskal

Source: SEAFDEC AQD 1994)

Nutrient Requirement

Protein 40% for Fry 30-40% for Juveniles

44% Protein:energy Essential Amino Acid %

Arginine 5.2 Histidine 2

Ileucine 4 Leucine 5.1

Lysine 4 Methionine + Cystine 2.5(cys, 0.8) Phenylalanine + Tyrosine 4.2(tyr, 1.0)

Threonine 4.5 Tryptophan 0.6

Valine 3.6 Lipid 7-10%

Essential Fatty Acids 1-1.5% n-3 PUFA Carbohydrates 25%

Digestible Energy 2500-3500Kcal/kg

Knowing the number of stock inside the pond matters!

What is Feed Rate? Example:

Stock: 10,000

Fry ABW (Ave Body Weight): 2gms

Feed rate: 4%

Feed/Day: ? Kgs

Computation:

Biomass: 10,000 x 2gms = 20Kgs

1,000

Feed/day= Biomass x Feedrate

= 2okgs x 4%

= 0.8kgs = 800gms

Remember Fry Can Consume Benthic Algae at 60% of Body Weight:

Feed/day= 20Kgs x 60%

= 12kgs of “Lablab”

Juvenile can consume 25 % of body weight

How to feed in the HAPA?

Feeding by satiation

Monitor fry closely when feeding

Normally 5-% feed by body weight

Protein 24%

Check predators always

Feeding Method

Feeding by Satiation

Milkfish Satiation last for 2-3hours

Digestion 5hours

Suggested Feeding Time 7am, 11am, 3pm

Demand Feeder: Pond

Demand Feeder: Cage

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Designed By: Leo Plasus

Nursery Feeder

mati.n@cpf.co.th

Photo Courtesy of Leo Plasus

Adaptable or not?

Proper Culture Techniques…

“Any cultured specie will grow faster and survive more if the animal feels that they are taking care of properly”

Maintaining Optimum Water Parameters

Keep the Records

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Maintaining Enough Food Source:The Main Priority

Fish/Shrimp Stocking Density

Natural Food Organism

Exogenous or Artificial Feeding

………………EXTENSIVE

….……….SEMI-INTENSIVE

.………....INTENSIVE

Water Replenishment

• Reduce sedimentation

• Water dilution

• Waste reduction

• 30% volume 4times every spring tide

Fertilization

• Replenish nutrients

• Application rate:

-Combination of

5 g./m2 16-20-00 and

1.5 g./m2 46-00-00 or 30 g/m2 of chicken manure

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Gradual water

increase

• Tendency to float

Scoop if floating/die-

off

May result to

overgrazing

• Supplement

feeding using rice

bran, dried fish

meal or bread

crumbs

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A. Read Transparency Everyday

Ideal Reading:

20-30cm

1) Lag phase

2) Exponential phase : Mass

3) Retardation phase : Harvest

4) Stationary phase

5) Death phase Age of culture

Biom

ass

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B. Replenish water before die-off.

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C. Fertilize again using organic fertilizer

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Manure Average Composition (%)

Moisture N P2O5 K20

Dairy

Cattle

85 0.5 0.2 0.5

Beef

Cattle

85 0.7 0.5 0.5

Poultry

(Chicken

Manure)

72 1.2 1.3 0.6

Swine 82 0.5 0.3 0.4

Sheep 77 1.4 1.4 1.2

Fertilizer constituents in fresh manure of selected farm animals. (Morrison,1961).

Prefer Obtain From Broiler Farms

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Ingredients 24% Protein

31% Protein

Fishmeal 10.8 16.1 Soybean Meal 23.8 35.7 Cassava leaf meal 13 13 Rice bran 27.9 17.4 Rice hull 15.5 8.4 Cod liver oil 2 2.2 Soybean oil 2 2.2 Breadflour 5 5 Proximate Analysis (Dry Matter Basis) 24 30.5 Crude Protein 11.4 11.2 Crude Fat 43.5 39.9 Nitrigen-free Extract 43.5 39.9 Crude Fiber 11.2 9.1 Ash 9.9 9.3 Metabolizable Energy (kcal/kg) 3,726 3,824

Feed with abw 5gms at 7,000sq.m

Found that protein quantity relative to growth does not vary instead with the amount of feed given

Suggest to feed 24% protein at 4% body weight

Rice Straw Compost

Feed: 24% protein

RSC: protein 7.4%, organic matter 37%, ash 64%

Tested

100%feed-0% RSC

50%feed-50%RSC

75%feed-25%RSC

25%feed-75%RSC Did not grow well

Recovery Rate:

83.9-98.2%

Other Alternatives Dried Fishmeal

Trash fish

Bread crumbs

Rice bran

Rice hull

Cassava meal

Copra meal

Other Things to Remember

Prevent Predator Entry

Tarpon (Megalops

cyprinoides)

Ten-pounder (Elops

machnata)

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Photo courtesy of John Eric Basco

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Check Fish Health

Weigh to get Average Body Weight

Correct Feed Estimation

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Pond Parameters are

Dynamic

Troubleshooting must be

Prompt

Changing of Water

Preferably night-time

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Total Drainage

Swimming against the current

Gill netting

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Handpicking method

after total drain

Result to Poor Quality

Mud Smell and taste

proliferates

Lower market value

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The same method

employ in sea

capture

Mark around napes

Lower market value

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Current method

Letting fish swim

near the gate then

scooped and seined

Quality retains

Less damaged

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