Trammel-net

              Trammel-nets are commonly operated to catch shrimps.  The netting for trammel-nets is in most cases made of nylon multifilament; the yarn size for the inner net is 210 d/2 whereas for the outer net it is 210 d/4.  There are some local variations in the construction of gear; the size of mesh for the inner net is usually 4 cm, but for the outer net it ranges from 14 to 26 cm.   The hanging ratio of inner net does not vary much; it is about 0.46-0.48 on the float lines, and 0.55-0.57 on the sinker line.  There is, however, a considerable difference in hanging ratios of the outer net: we came across nets with a high hanging ration such as 0.79, and others with a low hanging ratio of only 0.37

              Fishing operation is carried out in either day or night-time, the net is shot across the tide, and allowed to drift by the tide for one hour before hauling.  The water depth of fishing grounds is between 5 and 20 meters.  (Trammel-net for cuttlefish is set along the coast for 12 hour in the day-time).