Longliners are fishing vessels that use a long line with baited hooks attached at intervals to catch fish. This method allows fishermen to target various species, including tuna, swordfish, and cod. Longlining can be done in deep or shallow waters, depending on the target fish. The longline itself can stretch for miles, making it an efficient way to catch large quantities of fish. However, this technique can also unintentionally catch non-target species, known as bycatch, which raises concerns about its impact on marine ecosystems and the sustainability of fish populations.