Longlines

Description:

Longlining is a non-selective, passive fishing gear, comprised of four basic elements: (1) mainline, (2) snood (branch lines), (3) hook and (4) bait. The mainline is the primary support, extending from the fishing vessel. Branching out from the mainline, the snoods support baited hooks. The length of individual longlines can vary from 15km to over 100km and can have as many as 2000 hooks for each mainline. As the mainline is deployed from the stern of vessels, known as “setting the mainline”, the hooks are baited. The gear drifts near or below the surface for a set period of time, averaging several hours, and can be identified by floating buoys and lights attached to the mainline. In small boats, the mainline is manually retrieved, often by a handcrank. On larger commercial outfits, mechanical retrieval quickens the process. In some groundfish fisheries, the longline is weighted and sunk to rest on the sea floor, known as deep water longlining.

Bycatch Threat:

The bait on the hooked longlines attracts more than just the target species; seabirds, sea turtles, sharks and marine mammals consider the bait as an easy meal. Unfortunately, these animals can subsequently be injured, or, worse, die after being caught on the hook or entangled in the gear. When the mainline is set, birds, like Albatrosses and Petrels, will attack the bait and in the process can get snared by the hook and subsequently drowned as the lines submerge.  Death by longlines is one of the primary causes in the world wide decline of sea birds. Sea turtles may suffer internal damages from the hook, which may be exacerbated with removal. Marine mammals may ingest the hook or become entangled in lines.

Target Species:

Highly migratory species and groundfish, including: tuna, sharks, Patagonia Toothfish, swordfish, halibut

Geographical Range:

Global

Bycatch Species:

Sea turtles, sea birds, sea lions, fur seals, toothed whales, sharks