Longline fishing

Longline fishing is a commercial fishing technique that uses a long line, called the main line, with baited hooks attached at intervals by means of branch lines called gangions. It is used to catch a variety of fish species, including tuna, swordfish, and halibut.

Technique

Preparing lines for salmon longlining

The longline fishing method involves setting a main line that can be several kilometers long. The main line is supported by floats and is anchored at both ends. Branch lines with baited hooks are attached to the main line at regular intervals. The line is left to drift or is anchored in place, depending on the target species and fishing conditions.

Setting the Line

A longline radiobuoy

Gangions used in salmon longlining

The process of setting the line involves deploying the main line and attaching the gangions with baited hooks. This is often done from the stern of a fishing vessel. The line is set in the water and allowed to drift or is anchored to the seabed.

Setting a buoy to mark the end of a salmon longline

Retrieving the Line

After a set period, the line is retrieved, and the catch is hauled aboard. The retrieval process involves winding the main line back onto the vessel and removing the fish from the hooks.

Target Species

Longline fishing is used to target a variety of species, including:

• Tuna
• Swordfish
• Halibut
• Cod
• Mackerel

Environmental Impact

Seabirds following a longliner

Longline fishing can have significant environmental impacts, particularly on non-target species such as seabirds, sharks, and sea turtles. Seabirds, such as albatrosses, are particularly vulnerable to being caught on the hooks as they dive for bait.

An albatross caught on a longline hook

Bycatch

Bycatch is a major concern in longline fishing. Efforts to reduce bycatch include using bird-scaring lines, setting lines at night, and using weighted hooks to sink the bait more quickly.

Equipment

The equipment used in longline fishing includes the main line, gangions, hooks, floats, and buoys. Radiobuoys are often used to track the position of the line.

Related Pages

• Fishing techniques
• Sustainable fishing
• Bycatch
• Seabird conservation