Tuesday, May 3, 2011

trawl


Trawls


A conical bag-shaped net with two or more wings, pulled by one or two boats for a period, to catch mainly demersal fish or other aquatic animals that live directly on, or stay near the seabed. The trawl is subdivided into three major types: bottom trawl, pair trawl and beam trawl.

Trawls in Brunei Darussalam can be classified into 1 type.

1. Pukat tunda (demersal bottom trawl)
The demersal bottom trawl in Brunei Darussalam has two different types, one for catching fish and another for catching shrimp. The main difference is the design and the mesh sizes of the netting used. The fish trawl is about 30 m footrope length and 26 m head-a-rope length. The cod-end of the net has a mesh size set to a minimum of 51 mm of square mesh. The fish trawl net has a higher vertical opening as compared to the shrimp trawl net. Both types are operated with trawl wooden or steel doors to maintain its horizontal spread. The trawling speed ranges from about 3 to 3.5 knots. The trawl fishing boats are propelled with marine diesel engines with capacities ranging from 180 to 500 hp. The fishing boats are also equipped with mechanical drums as shown in figure 10 to facilitate the shooting and hauling of the net. The boat is also equipped with electronic instruments for navigation and for searching for suitable fishing grounds.

Gill nets

Gill nets

1.Andang jarang (bottom set gill net)
The gear is made from monofilament or nylon (PA) material with mesh size ranging from 51 to 76 mm. The gear is also fitted with floats and sinkers to stay vertical at the bottom of the river or sea. It is usually operated by one or two fishers on board an outboard motor boat along the coastal areas The soaking time is from six to eight hours. The catch usually consists of pony fish, hard-tail scads, croakers, etc.

Portable traps

Bubu (Fish pot/trap)
     This gear is usually made of chicken wire mesh and set up near coral reefs in the open sea (see Figure 23). The usual size for pots is 1.8 m x 0.9 m x 0.9 m; and it has a mouth to trap entering fish. Fishermen visit their pots once a week. The catch is usually composed of snappers, groupers, etc. Other versions of pots used in the rivers or streams are usually made of woven bamboo with the mouth facing the oncoming flow of water. The pot opening or mouth is made of a non-return valve shaped like a cone with a big outer opening and smaller inner end to keep the entrap fish from escaping.

Bubu fishing

source :http://www.youtube.com/watch?v=4DvBSEuL3Zg&feature=related


Bu bu fishing in the Island Philippines is good investment,

In our Place Marcelo Mabini Bohol before  illegal fishing is very rampant in our place the result years come there no fish to be catch now a days because of the bantay Dagat and the help of the fisheries teaching how to catch fish legally that small one will preserve.and only the market size allowed to be catch. So Bubu fishing or Bubu Cages karon profitable na

Then here is your investment
40 ka bubu
1.net plastic i set cost php 15,000
2.nylon                              1,000
3. labor                             3,000
4.stick                               3,000                                                        
5.others                             2000
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                                  P        24000 

expected investment return

40 bubu fishing at 1 fish per day =40 isda times 30 days =1200 fish
assuming 10 fish per kilo = 120 kilos
assuming  50 per kilo so 120 times 50=Phjp 6,000 /month