Longlines can be used to capture fish in surface waters (pelagic) as well as bottom living species (demersal). Longlining sets a length of line and from this come branch lines carrying baited hooks. Large longlines used offshore can be tens of kilometres long and carry thousands of hooks. Smaller inshore vessels use shorter, lighter lines with roughly less than a thousand hooks.
Seabird bycatch on longline hooks can be reduced by the use of weighted lines, coloured bird-scaring streamers and fishing at night. Hook shape adaptations (such as a circle shape instead of J shaped) have helped to reduce shark and seaturtle bycatch in some fisheries.