3. Trammel Nets

     Trammel nets are used on small boats with engines of less than 25 Hp or on non-powered boats. The trammel net is operated in small-scale activities, in shallow waters of less than 20 m in depth.

     There are two types of trammel net. They are the shrimp trammel net and the cuttlefish trammel net. The construction is almost the same, they are only different in mesh size and yam diameters of the inner and outer net. The length of the head rope is less than 1,500 m and the height is less than 4.5 m.

     For the shrimp trammel net, the netting is made of nylon multifilament or monofilament. The yam size of the inner net is 110D/2, 210D/6 or PA Mono 0.3mm diameter, whereas that of the outer nets is 210D/4 - 210D/6 or 0.8 mm. The mesh size of the inner net is 44 - 100 mm and that of the outer nets is 300 - 800 mm.

     For the cuttlefish trammel nets, the netting is made of nylon monofilament or multifilament, the yam size of inner net is 0.1 - 0.25 mm in diameter with a mesh size of 75 -100 mm. For outer nets, the yam size is 0.2 - 0.4 mm diameter and the mesh size ranges from 400 to 480 mm.

Net Setting:

     The setting operation of the trammel net is like the bottom gill net, but the trammel net is set in line across the current. According to the target species and the clarity of the water in fishing ground, this work can be done in daytime or at night.

Net Hauling:

     The vessel tows the net at a speed of 1 - 2 kts. Normally, fish are picked out after the net is hauled and put on the deck, then the net is prepared carefully for the next setting.