3. Searching Purse Seine

     According to the structure and size of the net, the searching purse seines may be classified into two groups: searching purse seine for catching small pelagic fish and for catching tuna.

      The fishing method of' this gear is different from the luring purse seine. The difference is that this method does not need lights to attract fish, so it can be carried out both by day or night and relies on the fishermen's experience of visually finding the fish schools or using a fish finding sonar. Normally, the length and setting speed of' the searching purse seine are greater than those of the luring purse seine with a view to catching the whole school while they are swimming.

    The fishing technology consists of both setting and hauling processes carried out similarly to those of the luring purse seine.

    The target species are scad, mackerel and tuna, etc.

3.1. Small Fish Purse Seine Using the Searching Method

     For the searching method, the purse seiners must have powerful engines, of a size suitable for operating in the offshore fishing grounds. The boats often use engines of more than 60 up to 450 Hp.

    The sizes of the nets are 450-700 m long and 50-90 m deep. Mesh sizes are the same as for the luring method.

    Fishing operations are conducted during the day or at nighttime. Fishermen seek the fish schools by a simple visual search.

3.2. Tuna Purse Seine

     Tuna are one of the species that move at high speed so the purse seines for catching them often have a length of 500-1200 m and a depth of 70-120 m. The mesh size is about 30-35 mm in the bunt and 40-60 mm in other parts.

     At present, there are many new types of equipment used including: radar, GPS, fish finders, winches and power-blocks that are useful during fishing operations.