Fishing methods explained: Longlining

13th December 2017

The methods of fishing vary greatly depending on the species of fish that is being targeted and the type of water being fished. Over a series of articles we take a look at some of the more common methods of both commercial and recreational fishing.

What is longline fishing?

Longline fishing is a technique used by commercial fishermen in which a long line (or main line) is baited with multiple hooks. Each hook is attached at intervals by shorter branch lines called gangions (or snoods).

Hand-baited these lines are then cast out to sea and, depending on the target species, anchored to the sea floor (demersal longlining) or left to drift (pelagic longlining).

Demersal longline fishing is effective in catching ground fish such as sable, cod or halibut whereas it is more common to catch swordfish or tuna with pelagic longlining.

The lines of commercial vessels can run for several miles and as such radio beacons, along with marker buoys, are used to help the crew to locate the lines they have laid. The buoys are also used to fix the depth at which the lines are floated to vary the species of fish being targeted as is the choice of bait. Some commercial fishermen also use luminescent sticks attached to the lead lines both to make the bait more attractive but also to lure smaller fish upon which the target species prey.

Commercial lines vary in their size and length with small Pacific operators using as few as 25 hooks per line but most commercial boats utilising several thousand hooks across many miles of line.

Launched in 2013 the Alaskan super-fishing vessel, Northern Leader, has the capacity for the crew to bait up to 76,800 hooks per day!

A history of longlining

Longlining, as we know it today, purports to have originated from Japan as long ago as the mid-19th century. There are reports that a fisherman known as Fujii used gear in the Izu region of Japan during the Kaei Era (1848-1853) and that locals of the Bôsô area were also using similar techniques. However there is also evidence that locals of a fishing village near Tokyo Bay were using this form of gear as early as the 1750’s.

It wasn’t until the early quarter of the 20th century that this technique began to migrate when a Japanese fisherman called Imose introduced longlining to Hawaii in 1917. Following the increase in mobility in the fishing industry the technique began to crop up in European waters with instances occurring in the Mediterranean in the 1920’s and in the US by the mid-1940’s off the coast of New England.

Each region took the basic technique and adapted it slightly to suit the environment in which they were fishing, the vessels they were using and the species of fish they were targeting. A form of longlining using synthetic line to float just below the surface was developed in the 1960’s in Norway to target porbeagle shark. Around the same time, Cuban fishermen were using similar methods to fish at night for swordfish.

Further advances in the mobility and range of fishing fleets further expanded the adoption of the technique of longlining and, by the 1970’s, had become the principle method of commercial harvesting of fish.

Long lining and sustainability

Due to the fact that baiting on long lines occurs at well-spaced intervals the technique is regarded as a habitat friendly and conservative method of fishing when compared to other systems. Of course, as with rod and reel fishing, there is no certainty about the species of fish which will be caught as a result of baiting but commercial fishermen are strictly regulated in their reporting of catches with US operators required to carry independent observers to ensure accurate reporting.

The method of longlining is considered far more preferable to trawling as a means by which to protect the habitat of the ocean floor. According to research undertaken by scientists, longlining , when compared to trawling has ‘little impact on vulnerable marine ecosystems’.

Headlines in the public domain exploit these positive findings and the demand by consumers for line-caught fish over other methods has seen a huge global increase in the adoption of longlining.

Longlining for beginners

Although a widely adopted method for wholesale commercial fishing, longlining can be adapted to suit amateur or small-scale fishing and is quite easy and cheap to set-up.

Using a single length of main line attached to two buoy lines and weighted to suit the depth of sea in which you are fishing you can attach as many baited hooks as suits your aims providing they are spaced at regular intervals. With one end of the line attached to a flag/buoy you simply clip on each pre-baited hook and slowly lower each one over the side of your boat until you reach the end of your line. Repeat the same process as for the beginning of your main line and attach with a weight to a final marker buoy. Use local bait such as squid, hermit crabs, mussels, cockles or worms and be sure to check with the local Sea Fisheries Officer on local regulations and byelaws before you start.

It’s advised to set your lines about half an hour before low-tide and to return about an hour and half before the next low-tide to retrieve your line.

For all your longline fishing supplies be sure to head over to our classifieds where you can find suppliers of suitable gear and bait to suit all your long lining needs.


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