The line is anchored at each end and held off the bottom with floats. This method produces millions of pounds of by-catch, and is also "responsible for death of thousand of seabirds every year including the endangered species the Short-Tailed Albatross"(nmnh.si.edu). The birds circle the boat while the baited line is being let out, and then dive on the bait when in the water becoming hooked.
Trawling- is used to catch the deeper ocean living species like Orange Roughy, Hake, and Squid. These giant nets are towed behind one or two boats depending on the size of the net. They are usually towed for two or three hours at about five M.P.H. "Nets of both bottom and mid-water trawling are held open by two doors, which act as paravanes, or underwater kites"(starfish.govnt.nz). There are many negative effects of bottom trawling the worst however, would be the effect it has on the oceans floor which supports many forms of life and habitats. When the nets are dragged over the floor not only do they capture everything in their path but they also destroy everything in their path. "Trawling of the ocean floor is often compared to clear cutting of forests on land but with one dramatic difference. The area of the ocean floor that is trawled every year is 150 times greater than the area of forest that is clear cut annually"(biology.duke.edu). .
Purse Seine Nets- capture large amounts of pelagic fish (fish that swim in mid to shallow waters) by surrounding the school of fish with a deep curtain of netting which is supported at the surface by floats. Small lead weights at the bottom of the curtain ensure that the netting quickly sinks and is then pursed under the boat by tightening on a wire or purseline, which runs through steel rings attached to the lower edge of the net. When the netting is closed and fish can no longer escape, the seine netting is hauled lengthways using a mechanical power block until the fish are packed tightly in the last remaining section of the net to be hauled in.
