Longline fishing Information & Longline fishing Links at HealthHaven.com

External images
	Pelagic longline
	Demersal longline

Longline fishing is a commercial fishing technique. It uses a long line, called the main line, with baited hooks attached at intervals by means of branch lines called "snoods". A snood is a short length of line, attached to the main line using a clip or swivel, with the hook at the other end. Longlines are classified mainly by where they are placed in the water column. This can be at the surface or at the bottom. Lines can also be set by means of an anchor, or left to drift. Hundreds or even thousands of baited hooks can hang from a single line. Longliners commonly target swordfish, tuna, halibut, sablefish and many other species.^[1]

In some unstable fisheries, such as the Patagonian toothfish, fishermen may be limited to as few as 25 hooks per line. In contrast, commercial longliners in certain robust fisheries of the Bering Sea and North Pacific generally run over 2,500 hand-baited hooks on a single series of connected lines many miles in length.^[2]

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, occasionally set gear on the sea floor at depths exceeding 1,100 metres (3,600 ft) using relatively simple equipment. Longlines with traps attached rather than hooks can be used for crab fishing in deep waters.

Longline fishing is prone to the incidental catching and killing of seabirds and sea turtles. Otherwise, compared to other fishing techniques such as bottom trawling, longline fishing is less destructive to bottom habitats. It generally has good species selectivity and low fuel consumption.^[3]

[edit] Incidental catch

Main article: Bycatch

Seabirds with longline fishing vessel

Black-browed Albatross hooked on a long-line

Longline fishing is controversial in some areas because of bycatch, fish caught while seeking another species or immature juveniles of the target species. Seabirds can be particularly vulnerable during the setting of the line.

Methods to mitigate incidental mortality have succeeded in some fisheries. Mitigation techniques include the use of weights to ensure the lines sink quickly, the deployment of streamer lines to scare birds away, setting lines only at night in low light (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 modification does not eliminate by-catch. In March 2006, Hawaii longline swordfish fishing was closed due to excessive loggerhead sea turtle by-catch after open only a few months, despite using modified circle hooks which attempt to reduce by-catch.

Of the 21 albatross species recognised by IUCN on their Red List, 19 are threatened, and the other two are near threatened.^[4] The IUCN lists two species as critically endangered: the Amsterdam Albatross and the Chatham Albatross. One of the main threats is commercial longline fishing,^[5] because albatrosses and other seabirds which readily feed on offal are attracted to the set bait, become hooked on the lines and drown. An estimated 100,000 albatross per year are killed in this fashion. Pirate fisheries exacerbate the problem.

[edit] Footnotes

^ European Union: Identifying Maltese fishing grounds
^ Rice J, Cooper J, Medley P and Hough A (2006) South Georgia Patagonian Toothfish Longline Fishery Moody Marine.
^ Valdemarsen, John W Incidental catch of seabirds in longline fisheries Fishery Technology Service
^ IUCN, 2004. Red List: Albatross Species. Retrieved July 27, 2007.
^ Brothers NP. 1991. "Albatross mortality and associated bait loss in the Japanese longline fishery in the southern ocean." Biological Conservation 55: 255–268.

[edit] References

Brothers, N P; Cooper, J and Lokkeborg S (1999) The Incidental catch of seabirds by longline fisheries. Rome, FAO Fisheries Circular No 937.

Long lining, New Zealand Seafood Industry Council
Johnson, Douglas H; Shaffer, Terry L and Gould, Patrick J (1990) Incidental Catch of Marine Birds in the North Pacific High Seas Driftnet Fisheries U.S. Geological Survey.
Valdemarsen, John W Incidental catch of seabirds in longline fisheries UN Atlas of the Oceans: Fishery Technology Service.

[0] European Union: Identifying Maltese fishing grounds

[1] Rice J, Cooper J, Medley P and Hough A (2006) South Georgia Patagonian Toothfish Longline Fishery Moody Marine.

[2] Valdemarsen, John W Incidental catch of seabirds in longline fisheries Fishery Technology Service

[3] IUCN, 2004. Red List: Albatross Species. Retrieved July 27, 2007.

[4] Brothers NP. 1991. "Albatross mortality and associated bait loss in the Japanese longline fishery in the southern ocean." Biological Conservation 55: 255–268.

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