| Main Components | ||||||||
| Aquatic species | ||||||||
| Target Species Demersal species | ||||||||
| Gear types: Boat seines | ||||||||
Boat seines | ||||||||
| Vessel types: Seiners | ||||||||
Seiners | ||||||||
| Characteristics | ||||||||
Scottish seiningDrawing of Fly dragging (Scottish seining) | ||||||||
Species EnvironmentThis fishing method is especially suitable for the capture of both flatfish and demersal round fish either scattered on or close to the bottom.Fishing GearThe boat seines consists basically of a conical netting body, two relatively long wings and a bag. An important component for the capture efficiency of boat seines is the long ropes extending from the wings, which are used to encircle a large area. As for Danish seining, keeping the rope into close contact with the bottom as long as possible during the hauling is a major advantage and, for this reason, special heavy ropes are normally used. Many Seine nets are very similar in design to Trawl nets. Frequently, however, the wings are longer than on trawl nets.Vessel OverviewIn medium and large sized vessels special rope hauling and coiling machinery is installed on deck. Long ropes (or draglines) is either just coiled on the deck or stored on drums. On modern seiners, hydraulically operated articulated power blocks are used for hauling the seine; on smaller boats, this is done by hand.Fishery Production SystemsSmall scale and semi-industrial.Fishing EnvironmentFly dragging is appropriate for areas where good fishing, "trawlable" bottoms are broken up with patches of hard and rough ones. The catching area depends on the length of the hauling lines and, to a lesser extent, the length of the wings. Fishing depth when using this method ranges from shallow waters less than 50 m to around 500 m in marine waters.Especially in northern regions; not much in use in tropical and sub-tropical regions.Fishing OperationsWhen fish have been detected the vessel steams some distance away, depending on the depth, sea conditions and the concentration of fish. A marker buoy with flag, called a dhan, attached to the free end of the first rope is then dropped over the side. The vessel then steam towards one side of where the fish have been located, paying out rope as it steams. When the vessel has passed the fish it moves across to shoot the seine net. The vessel then heads back to the dan, paying out the other length of ropes. By the time the gear is set, the dan picked up and the end of the first rope retrieved, nearly all the length of rope each side is lying on the seabed, encircling the fish which was originally detected. With the vessel maintaining sufficient way to be just going ahead, (or in cases, after the seiner steamed ahead for some time) both ropes are hauled simultaneously, slowly at first, the ropes herding fish towards the path of the net as they close. When the ropes are about half way closed, as seen from the vessel, hauling speed is increased and the net begins to chase fish just in front of it whilst the ropes continue to herd fish inwards. When the ropes are seen to be nearly closed they are then fast hauled and the net overtakes fish herded into its path. Fast hauling continues until the net is up to the vessel. A minimum of four crew on deck and one in the wheelhouse is necessary if a power block can help bringing the seine on board; at least two more crew members are necessary if the net is brought aboard by hand.
Sainsbury, J.C. 1996 “Commercial fishing methods: an introduction to vessels and gears.” Fishing New Books. 0-85238-217-0. |
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