Long-lining is one of the most fuel-efficient catching methods. This method is used to capture both demersal and pelagic fishes including swordfish and tuna. It involves setting out a length of line, possibly as much as 50-100 km long, to which short lengths of line, or snoods, carrying baited hooks are attached at intervals. The lines may be set vertically in the water column, or horizontally along the bottom. The size of fish and the species caught is determined by hook size and the type of bait used.
Although a selective method of catching fish, long-lining poses one of the greatest threats to seabirds. Species such as albatross, petrels, shearwaters and fulmars scavenge on baited hooks, get hooked, are dragged underwater and drowned.The problem occurs whilst the baited hooks are on or near the surface i.e. before the hook sinks. Commonly the bait used is squid, the principal prey of many seabird species. Most globally threatened species, including the majestic wandering albatross, live in the Southern Ocean. A range of practical measures have been developed to help prevent seabirds being hooked and drowned on longlines. These include bird-scaring streamers that flap and scare birds away, setting lines at night when most albatross do not feed and weighting the line so it sinks quickly, bird scaring water cannons and setting the line nearer the water surface rather than over the side of the boat,thus minimising the lenght of time the bait is visible/available. Any of these measures will contribute to reducing seabird by-catch. Ask your supplier if the longline caught fish you buy has been caught using "seabird-friendly" methods. For more information on ‘seabird-friendly’ fishing see www.birdlife.net.