Longline is consisting of many short lines, each baited with a hook, suspended vertically from a main line that is dragged horizontally through the water.
Longlines can carry thousands of hooks and stretch as long as 40 miles. This method is generally associated with moderate to high bycatch, depending on how many hooks and where and when the lines are set. They are set for tuna fishes, and other fishes like swordfish, sharks, turtles, and seabirds.
List of books: Longline