Title: The effects of the colours of mainline and different snood attachments on the catching efficiency of longline

Longline is widely used in the world and it is believed to be an environmentally friendly method, relative to some other gears. The catching efficiency of longline may be affected by several technical, biological and environmental factors. To find out how mainline materials (multifilament with tar and multifilament green) and various kinds of snood attachment systems (using swivel and without swivel) affect the catching efficiency of longline, an experiment was carried out in Icelandic waters from December 2005 to February 2006. This experiment showed that longlines where branch lines are attached to the mainline using knots, give higher catch rates (higher than 35%) than longlines which have branch lines attached to the mainline using a swivel. And the same time it has been shown that longlines, which have a multifilament mainline with tar, can take more catch (24%) than longlines where the mainline consists of multifilament with green colour.