3.) Computation for stock requirement = width x length x usable depth x stocking rate4.) Computation for daily feed requirement = Total # of stock x ABW x FR x SR SD – stocking density FR – feeding rate ABW – average body weight SR – survival rate

MAINTENANCE

• Inspect regularly for net breakage to ensure the safety of the stocks• Clean the net regularly by shaking it vigorously or by brushing• Tow the cage structure at a sheltered area during the occurrence of bad weather

HARVESTING – stocks are ready for harvest after 4 months culture period

Partial harvest – use seine, gill net or cast net and select only the bigger fishes. Total harvest – Roll a bamboo, starting from one end going to another end to concentrate the fish on the other side of the net.

Milkfish locally known as bangus is the national fish of the Phililppines. It is one of the major aquaculture finfish species raised in the country contributing more than 50% of the total national brackishwater pond production annually.

According to BAS (2008 - 2009), the country’s per capita consumption for milkfish is 4.16 kilograms representing more than 10% of our total fresh fish consumption of 38 kgs per year. The ever – increasing population of the country and the corresponding demand for finfish as source of protein has resulted in the adoption of different fish culture technologies. One of these technologies is fish cage farming.

There is therefore a need to sustain our milkfish production to meet the demand of our growing population. Milkfish production in brackishwater pond is limited by the capacity and biomass of its environment. The culture of fish in cages is considered as one of the most productive aquaculture methods which is now widely used in many countries. Among the popularly cultured species are milkfish, grouper, sea bass, saline tilapia, siganids, and caranx species.

Site suitability requirement for the culture of milkfish in marine cages:

1. Sheltered coastal waters that are unpolluted.2. Free from flood and protected from strong winds, big waves and current.3. Coves, bays, inlets or estuarine provided that the minimum water depth is at least 2 meters

during lowest tide water level experienced in the locality.4. Salinity is between 10 – 30 ppt, usually prevalent during summer months.5. Temperature is between 26 – 30 °C, water pH is 7.5 to 8.5 and dissolved oxygen level is

greater than 3 ppm. 6. Free from any government restriction, legal impediment and security problems.7. Easy access for inputs and market outlet.

PROCEDURE

1. Cage Frame• Cut all the threads at the end of the pipe before joining thru welding all the parts• Cut 16 pieces at 16 inches long for horizontal braces, 16 pieces at 0.5 meter long for

vertical braces• Cut 36 pieces at 4 inches long using flat bar 1/4 x 2 inches and drill 2 holes, 3/8

diameter on both ends• Assemble all parts by welding

2. Grow-out Cage Net (P.E. net 17K)• Measure 13.33 meters and cut 2 pcs• Join the bottom net mesh to mesh • Measure and cut 41.32 meters for the side net• Start joining on one end all around until reaching the starting point• Join the edges at the starting point to enclose the cage net• Rig all the meshes of the upper edge using #8 PE rope as reeving line• Measure the exact width and length of the cage net and staple using PE twine 400/6

at 3 inches interval

• Provide eye splice on the four corners of the net for attachment to the cage frame.

3. Formation of Hapa • Assemble first the bottom portion• Measure and cut 20 meters and follow the procedure for the grow-out net

4. Installation of the cage structure

• Install the cage structure with the shortest side facing the NE or SW monsoons• Secure the cage structure with sand bag or iron anchor• Install the net cage by tying into the peripheral net hanger at 2 meters interval• Install the hapa inside the grow-out cage net• Tie and install tom weight inside the grow-out net at 2 meters interval• Install the cover net after stocking

STOCKING

1. Stock 30 – 40 day old milkfish fingerlings in hapa with an average weight of 3 – 5 grams.2. Acclimatize fish at site salinity and temperature upon arrival.3. Allow the plastic bags to float inside the hapa for 20 to 30 minutes before finally releasing

the fish.4. Open the plastic bag and allow the fish to go out voluntarily.5. Sample at random to determine the initial weight and feed ration required.6. Release the fish to the grow-out cage after 45 days at 30 - 50 pieces per cubic meter.7. Remove and clean the hapa and keep for future use.8. Install the feed guard around the grow-out net.

FEEDING GUIDE

Culture Period Feed Type Feeding Rate Time

1 to 30 days Starter crumble 10-15% of body weight

6 AM / 9 AM / 12 noon / 6 PM

31 to 60 days Crumble / Juvenile 8-10% of BW same61 to 90 days Juvenile 5-8 % of BW same

91 to 120 days Adult 2-3 % BW 6 AM / 10 AM / 2 PM / 6PM

Sample the stock every month to adjust feeding rate and feed requirement

Sample computation for amount of feed to be given daily Daily Feed Ration (DFR):

1.) compute for average body weight (ABW)ABW = total weight of samples taken = 1800 grams = 90 grams No. of samples taken 20 pieces

2.) compute for DFRDFR = total # os stocks x SR x ABW x FR = 4,050 x 90% x 90g x 9% = 29,524.5 g or 29.5 kilos of feeds daily

Cost and Return Analysis1 unit 5.4 m x 10 m x 2.5 m

DEVELOPMENT COST

Cage FrameItem Quantity Unit Price (Php) Total Cost

GI Pipe 11/4 x 20 sched. 40 (pcs.) 12 1,000.00 12,000.00 GI Pipe 1 x 20 sched. 40 (pcs.) 11 700.00 7,700.00 Welding Rod 10 80.00 800.00 Epoxy Primer (gal) 1 700.00 700.00 Lacquer thinner (gal) 1 200.00 200.00 Paint Brush (pcs) 2 80.00 160.00 Plastic Drum (pcs) 8 1,000.00 8,000.00 Hacksaw blade(pcs.) 3 70.00 210.00 Marine Epoxy (pint) 1 350.00 350.00 Labor Cost (15% of the Material Cost) 4,518.00

Sub Total 34,638.00 Yearly Depreciation (5 years) 6,927.60

Depreciation Cost per cycle 3,463.80

Cage NetItem Quantity Unit Price (Php) Total Cost

PE net 400/6, 17k (roll) 1 7,000.00 7,000.00 PE rope # 18 (roll) 1 1,000.00 1,000.00 PE rope # 8 (roll) 1 400.00 400.00 PE rope # 6 (roll) 2 300.00 600.00 PE twine 400/6 (spool) 4 200.00 800.00 DD net#14 (mts) 35 60.00 2,100.00 DD net #22 (mts) 70 60.00 4,200.00 Netting needle (pcs.) 10 30.00 300.00 Labor Cost (15% of the Material Cost) 2,460.00

Sub Total 18,860.00 Yearly Depreciation (2 years) 9,340.00

Depreciation Cost per cycle 4,715.00

OPERATING EXPENSE (per cycle)

Item Quantity Unit Price (Php) Total CostBangus fingerlings 3-5 inches 3,800 2.50 9,500.00 Feeds(bags) starter crumble 12 750.00 9,000.00 juvenile 24 720.00 17,280.00 adult 17 720.00 12,240.00

53Salary of Caretaker 4,000.00

Marketig Expenses (5% of Gross Sales) 4,037.50 Sub-Total 56,057.50

CALCULATION OF BENEFITS

Production ( @ 85% Survival rate, 4 pcs/kg) 808.00Gross (Farm gate price of P100/kg) 80,750.00Less:Depreciation Cost 8,178.80 Operating Expenses 56,057.50Total Expenses/ cycle 64,236.30Net Income 16,513.70ROI 26%

PLAN OF CAGE FRAMECollapsible 5.4m x 10m x 2.5m G.I. Fish Cage