|A purse seine is made of a long wall of netting framed with a lead line of equal or longer length than the float line.|
|Purse seiners are the most important and most effective vessels to catch aggregating species near the surface.
|Species EnvironmentFish are into large dense schools near the surface or have been artificially aggregated.Fishing GearA purse seine is made of a long wall of netting framed with floatline and leadline (usually, of equal or longer length than the former) and having purse rings hanging from the lower edge of the gear, through which runs a purse line made from steel wire or rope which allow the pursing of the net. For most of the situation, it is the most efficient gear for catching large and small pelagic species that is shoaling. Compared to on-boat operated purse seining, using a two-boats purse seining method allows, in principle, to use a larger seine.Vessel OverviewThe two seine boats used for this fishing technique could be either two boats with the same general characteristics, power, length, etc. or one main boat operating with an annex.Fishery Production SystemsPossible exploitation forms using bottom pair trawling are: small scale and semi industrial.Fishing EnvironmentMarine coastal and high-sea waters, between 0 and 300 m deep or freshwater.Temperate and tropical countries.Fishing OperationsCompared to on-boat operated purse seining, using a two-boats purse seining method allows, in principle, to use a larger seine and the setting of the net can be made very quickly. Fish shoals can be detected near to the surface by visual observation (fish or seabirds flying over) from a crow's nest in the vessel or it can be searched and detected by using echosounder and sonar. For hauling the net a power block and a crane for brailing sited usually amidships are used.|
|1. Approaching fish schoolThere are two boats, each carrying half of net with centre lying between them. When a school of fish is sighted, the seiners approach it from up wind and at a given signal the safety line and net are released, and the boats pay out the net on divergent courses.|
|2. Setting the netBoats separate and surround school, each paying out net including float line, lead line and purse line. The two vessels come together and attach the safety line again after completing the set.|
|3. PursingBow to bow, each vessel proceeds to winch in its purse line. Once the net is closed, the wings are hauled in by using power blocks.|
|4. Pursing completedMechanical hauling in of the net is continued until the catch is assembled at the central bunt level. Then is ready for brailing. A skiff may assist the operation, but it is not always necessary.|
IssuesDiscard Compared to most of the other fishing techniques, purse seining in general, is not harmful to natural resources or environment. Some potential negative impact may result, in certain cases, from the fact that the fishing is not very selective (in terms of both species and sizes of fish): when there is important bycatch of non-targeted species or many small fish.
|5. BrailingBrailing of the fish from the bunt aboard one, or both, of the vessels using a brailer or with fish pump. It is worth noting that it is always important to start the brailing as soon as possible, in particular; when there is a large quantity of fish concentrated in the bunt, it is particularly important to start the brailing quickly before the fish die, sink and may break the net.|