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Surrounding nets
Surrounding nets

ISSCFG code: 01
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Overview Surrounding nets are large netting walls set for surrounding aggregated fish both from the sides and from underneath, thus preventing them from escaping by diving downwards. Apart from a few exceptions, these are surface nets. The netting wall is framed by lines: a floatline on top and leadline at the bottom.Handling Equipment According to the type of surrounding nets gear, specific equipment may be required, the main requirement being some facility for manoeuvreing large to very large net.Vessel OverviewVessels using surrounding nets can be included in the size range going from <12 to >45 meters length. Fish OperationThey catch the fish by surrounding them both from the sides and from underneath, thus preventing the target species from escaping by diving downwards. Target SpeciesSurrounding nets are the most important and most effective gears to catch aggregated pelagic species both large (tuna and tuna-like species) and small ones (for small pelagic fish, midwater trawling in a good alternative in many cases).Water Area OverviewAll over the world.Gear Environment Apart from a few exceptions, surrounding nets are surface nets which can, in principle, be used everywhere, in both marine and inland areas (as long as there is enough space for the operation of a large net). The only limitation could be in too shallow waters where the water depth is less than the height of the surrounding net during the fishing operations making a risk of damage to the fishing gear.ImpactsSpecies Incidental capture of dolphins by tuna purse seiners is regarded as an irresponsible fishing practice. Special techniques have been developed to reduce bycatch of dolphins; the Medina panel and "back down" operation, which ensure that encircled dolphins are released alive. The increasingly used practice of encircling floating objects, including man-made FADs increases the capture of small sized and immature aggregating around such devices.
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