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Wednesday, October 4, 2017

How to Catch Tilapia Using Gil Net ("Tabal")


How to Catch Tilapia Using Gill Net ("Tabal")
 

I mentioned in one of my blogs (pls. click this) the presence of tilapia in our brackish water ponds, where we grow bangus as our primary crop. It’s as if they sprout from everywhere. Actually they start as tilapia eggs (that survived pest eradication). Or they come from our adjacent tilapia ponds through unseen holes in the perimeter net or dikes.
 

Considered as staple fish, tilapia are not exactly bad. They’re not predators but are considered competitors with bangus for feeds, pond space, and dissolved oxygen.

In my farm, we do allot two ponds exclusively for growing tilapia where they are allowed to breed and grow to market size.

From experience, we see quite a number of tilapias emerge in our bangus grow out ponds where they grow and breed. They then consume bangus feeds too. This is why we installed our bangus feeder devices (pls. click this and see this video), to keep tilapia out of the bangus feeder area.

Since tilapia command a decent enough market price (even enjoy unusually high price during certain months or weeks), we also include them in our harvest plans and schedules and sell them either alone or together with our bangus and vannameis.

Methods Used to Catch Tilapia
 

How do we typically catch tilapia then?

1. First is through the usual seine (“kalokor”) net, used during a typical harvest. (Pls. click this and go to the section on How to Harvest Bangus, Steps 6 to 9 on use of "kalokor"). The “kalokor” net catches everything in its path and the workers sort them out later.

2. By fishing rod – when we want to cook or grill a few pieces of fresh tilapia for lunch or dinner. I ask one of my pond persons to catch them using a crude bamboo rod with nylon line and hook using earthworm as bait.

3. By cage trap (“nasa”) - tilapias are lured into the cage (lowered into the pond bottom) using some sort of bait, then the cage is hauled out of the pond. The cage may or may not be provided with a pull string. We don’t use this device in our farm, but it's popular elsewhere. Because it can be used surreptitiously even during daytime, the cage trap ("nasa") is the preferred tool of the unscrupulous.

4. By gill net (“tabal”) - the net (with rubber floaters on top and lead sinkers at the bottom) is set up along the sides of the pond and with a few also placed across. The tilapia is trapped when it hits the fine strands of the net. The fish head is lodged in one of the holes, catching it by the gills - fish can’t dislodge itself moving forward or backward.

Catching Tilapia by Gill Nets
 

Catching tilapia by gill net is indeed an efficient and much cheaper way compared to using seine (“kalokor”) nets that employ several workers and entail higher costs.

Even only one worker can do it (i.e. nets are placed by him and the fish caught are removed by him). Further, we can also ask the same worker to sell the catch by himself at the Dagupan fish center. 


A worker untangling a trapped tilapia from the net and about to put it into a plastic drum with the other tilapia

Raising the gill net to check it out and finding 2 pieces of tilapia

Quantity of harvest can be easily increased. How? Simply install as many as 8 or 9 around the ponds and a few across. If you don’t have them, just rent the desired number of nets.
 

Gillnets ("tabal") placed all around the pond (see the line with the rubber floaters)

For transport, the worker can even ride a cheap public utility vehicle (jeepney) to Dagupan when, say, only 10 to 15 kilos are caught. Else, you can hire a driver to transport larger quantities of catch using a converted tricycle for cargo (“garong”) to the fish center. The "garong" can easily accommodate a couple of drums of tilapia.

Another advantage of using gill nets - you can project outright the average size of the catch. For example the use of the #5 nets (i.e., size of mesh hole) gives an average of 5 to 6 pieces per kilo. Use of #5.5 nets yields 7-8 pieces per kilo. Use of both could yield an average of around 7 pieces per kilo. As the number gets higher, the smaller the mesh hole, and the smaller the size of fish caught.

Reminder: To be on the safe side, just avoid making gill nets with a mesh size of less than 3 cm (between two opposite knots of a mesh). By law (R.A. 8550, Section 89), use of fine mesh nets is prohibited. The law applies to all fishing areas, including fishponds, public or private.

 
As a guide, a half drum full of tilapia (see last photo of this blog post), but without water, is expected to accommodate 75 to 80 kilos of tilapia catch. This is an important tip for pond owners and operators, who may decide to delegate the selling to his staff. He’d know for sure that the actual weight at the fish center would be very close to 75 to 80 kilos. Besides, the fish center would issue a receipt containing the details of weight in kilos, selling price per kilo, total sales and deductions.

To be sure though, it’s always best to get the actual weight before the catch is transported to the fish center. Make sure to have a large weighing scale in your farm. Besides, pond workers will not fill up the half drum to its brim, when hauling tilapia to the transport vehicle (usually a "garong"). They'll allow space for water and some empty space.

Reasons for Taking Out Tilapia
 

Why take out tilapia from the ponds?

a. To decongest the tilapia ponds. Remember that unlike bangus, tilapias can breed and multiply.

b. To generate working capital to cover the cost of harvesting as well as cost of tilapia feeds.

c. To reduce the number of competitor fish in a bangus grow-out pond, thus allowing more space for the bangus to grow, increasing the dissolved oxygen presence in the pond (preventing “tangok” or condition of dissolved oxygen-starved fish swimming at the pond surface), and improving the feeding efficiency of the bangus, the primary crop.

d. To take advantage of high tilapia prices during certain months and weeks.

How to Make a Gill Net ("Tabal")
 

1. Buy the following materials from Dagupan or Lingayen fish supplies stores:

a. Net (with a width measured as 100 mesh holes (“mata”)). This particular width is good for making 3 gillnets. Length is 100 meters.

  
A newly purchased tabal net, 100 meters, 100 holes

b. Lead sinkers – will need around a kilo per gill net.

c. Rubber floaters – will need around a hundred pieces per gill net.



Four pieces of lead sinkers, a piece of rubber floater

d. Cord to be attached on top and bottom of a gill net. Should be #4.
 

e. Thread – one spool, should be #1. The thread is used to attach each lead sinker and rubber floater to the cord and net.



A roll of cord and a spool of thread

Materials bought to make a gill net shown together (clockwise from top left) - net (white), roll of cord (green), spool of thread, 3 pieces of rubber floaters, 4 pieces of lead sinkers (left below)

2. You'll also need some basic tools - scissors, wooden spool, and plastic threading needle.

An improvised wooden (plywood) spool on which to roll up the cord
 
A plastic threading needle

3. Unpack the cord from its original wrapper then wind the entire length onto the plywood spool.

Transferring the entire cord length to the wooden spool
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Entire cord rewound onto a wooden spool. This will make handling of the cord easier.

4. Unwind the net using a basin so it can be spread.

Unwinding the net

5. Cut the net into three pieces, each measuring 32 or 33 mesh holes each. You may cut the net on the ground, or decide to hang the entire net from end to end and cut a third of the net’s width at a time.

Note: Some gill net ("tabal") makers prefer to insert a top cord first before dividing the net into 3 (Step 6).
 

Cutting the net at the 33rd hole all the way across the length to make one gill net

A cut net which can be made into one gill net. Only the cords, floaters and sinkers need to be attached.

6. Insert the cord into the holes of the net at the top and bottom along the net’s entire length.
 

Inserting green cord into the blue shaded hole at top of net

Using the plastic threading needle to make job easier. The needle is inserted into the blue holes.

7. Attach another cord of same length on top of the inserted cord (top part). No need to insert.

8. Attach one rubber floater at a time at the top of the net (that is, between the two top cords). Use a plastic needle and thread to sew the floater in place.
 

Close up view of the first rubber floater (black) inserted between two top cords

9. Place the second floater 22 holes away. Using the plastic needle and thread, sew the second floater in place. Repeat until you cover the entire length of the net.
 

A second rubber floater (yellow)

5 floaters already sewn in place on top of the net in between the 2 top cords

10. Attach another cord of the same length as the inserted cord (at the bottom part).
 

Two cords at bottom of net being tied together at one end

11. Attach one lead sinker at a time at the bottom of the net (that is, between the two bottom cords). Use the plastic needle and thread to sew the sinker in place.
 

First lead sinker being attached at the bottom end of the net

First lead sinker being sewn in place using needle and thread


12. Place the second sinker on the fourth hole from end of the first sinker, that is, first and second sinkers are separated by 3 holes. Using the plastic needle and thread, sew the second sinker in place. Repeat until you've attached sinkers along the entire bottom length of the net. As rough guide, you'll need about a kilo of sinkers per gill net.
 


A second sinker being inserted after 3 holes

The second sinker being sewn in place

Note: Other tabal makers allow a slightly longer distance between sinkers, to make it less heavier. This also means using less number of lead sinkers per gill net.

Below is a completed gill net ready for use in taking out marketable-sized tilapia (photo to follow soon).


To test its effectiveness, we tried using our new gill net (size 5) and we got 10.5 kilos of tilapias (59 pieces, or around 5.6 pieces per kilo), after just an hour or two. Not bad at all for one tabal.

We also tried renting 8 more tabals (comes with two workers) and caught 650 pieces of tilapia. Under this arrangement, they get 20 to 25% of the net sales proceeds (as payment for the net rental, labor of two workers, and service to sell the catch at the fish center).


Two workers come with rental of gill net. See them checking out the nets

Tilapia caught using tabal nets (in a drum and tub) ready to be brought to the fish center on board a "garong".

For a complete list of Fish Pond Buddy blog posts on fish farm-related topics, please click the Index page.



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