The only legal fishing method for halibut is longline gear. Longline fishing is also often used for harvesting black cod and cod, but never for pollock or sole. Longline fishing vessels are usually independently run by owner-operators. Some longliners are small boats, less than 50 feet in length, but most are somewhat larger.
Longline gear is composed of groundline, buoy lines, and gangions, which are short pieces of line with hooks on the end. Longlines are set along the seabed, with baited hooks every few yards. Longline hooks are retrieved one at a time. The fishermen can unhook other species of fish and return them alive to the sea without bringing them on board. In this way, longlining is considered a style of fishing with very little bycatch.