Longlining is a commercial fishing method that uses hooks and line. It’s used to catch groundfish, an overall name to describe fish that spend most of their lives near the ocean bottom. This includes halibut, sablefish, rockfish and dogfish.

Long lines – from one to three miles long - are laid along the ocean bottom. At intervals along this length, shorter lines, about 3 feet long are attached with a baited hook at the end.  One longline may have XX baited hooks. Each end of the longline is weighted to sink it to the ocean floor and marked with a buoy on the surface for retrieving the line.  Fishermen leave the longline underwater – called soaking – for several hours or overnight before reeling the line back into the boat and harvesting the hooked fish.

Diagram of a longline deployed.

Until the late 1980’s longline fisheries were known as a derby-style fishery. Fisheries officials opened a certain portion of the coast for a set length of time – as short as two weeks to harvest the year’s quota. Longline vessels then crowded together for the best areas and crews scrambled to fish as much gear as they could to maximize their catch before the fishery closed. Vessels fished regardless of weather, and prices were often low because markets were flooded at the close of the fishery. In the late 1980’s, management of the halibut and sablefish fisheries changed to a quota system, where the annual quota is divided among license holders and each may fish at almost any time of the year until his quota is met.

Hooks baited with squid are set on the longline.

Vessels targeting sablefish tend to be small (78% less than 18 m; 21% between 18-38 m in length) and usually fish two or three sets of gear concurrently, alternating between sets (i.e., hauling in the gear, deploying the gear and then moving on to the next set).  It is estimated that these vessels fished 48.2 million hooks in 1996.  Each set of the longline gear averaged 9 km in length with circle hooks spaced at approximately 1.2 m intervals.

The amount of harvested fish per year is about the same, but the intensity of the fishing effort is now spread out over the year. This has probably led to the increased interactions with sperm whales.