From Wikipedia, the free encyclopedia
- For other meanings of "longline", see longline.
Longline fishing is a commercial fishing technique that uses hundreds or even thousands of baited hooks hanging from a single line. Swordfish, tuna, halibut, sablefish,Patagonian toothfish and countless other species are commonly targeted by longliners. In some unstable fisheries, such as that of Patagonian toothfish, fishermen may be limited to as few as 25 hooks per line. In contrast, large commercial longliners in certain robust fisheries of the Bering Sea and North Pacific generally run over 2500 hand-baited hooks on a single series of connected lines many miles in length.
Longlines can be set to hang near the surface (pelagic longline) to catch fish such as tuna and swordfish or along the sea floor (demersal longline) for groundfish such as halibut or cod. Longliners fishing for sablefish, also referred to as black cod, will occasionally set gear on the sea floor at depths exceeding 600 fathoms using relatively simple equipment. Longlines with traps attached rather than hooks can be used for crab fishing in deep waters.
[edit] Bycatch
Longline fishing is controversial in some areas because of by-catch. Methods to mitigate such incidental mortality have been developed and successfully implemented in some fisheries. These include the use of weights to ensure the lines sink quickly, the deployment of streamer lines to scare birds away from the baited hooks as they are deployed, setting lines only at night with ship lighting kept low (to avoid attracting birds), limiting fishing seasons to the southern winter (when most seabirds are not feeding young), and not discharging offal while setting lines. However, gear modifications do not eliminate by-catch of many species and the controversy continues. In March 2006, the Hawaii longline swordfish fishing season was closed due to excessive loggerhead sea turtle by-catch after being open only a few months, despite using modified circle hooks which attempt to reduce by-catch.
[edit] External links
External images
