FAO/FIIT Fishing Gear Type Fact-Sheet Surrounding nets updated : 10-mai-2001 ISSCFG Classification : > Category : Surrounding nets   Lampara nets   Purse seines   Ring nets Profile General Description: 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: afloatline on top andleadline at the bottom. Specific 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. Fishing Vessels using this gear: Vessels using surrounding nets can be included in the size range going from<12 to >45 meters length. Fishing Operations: They catch the fish by surrounding them both from the sides and from underneath, thus preventing the target species from escaping by diving downwards. Features Target Species: Surrounding 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). Areas: all The Gear and its Environment: Deployment Area: 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. Impact on Aquatic Species: Incidental capture of dolphins by tuna purse seiners is regarded as an irresponsible fishing practice. Special techniques have been developed to reduce bycatch ofdolphins; theMedina panel and "back down" operation, which ensure that encircled dolphins are released alive. The increasingly used practice of encircling floating objects, including man-madeFADs increases the capture of small sized and immature aggregating around such devices.