Fact sheet: Halibut

The face of a halibut
Pacific halibut

The fish

Pacific halibut (Hippoglossus stenolepis) are large flatfish found on the continental shelf from California to the Bering Sea. Halibut have flat, diamond-shaped bodies, can weigh up to 500 pounds, and can grow to eight feet long. The oldest halibut on record, both male and female, is 55 years old.  The stock status of these fish is tracked by the International Pacific Halibut Commission (IPHC), which reports on the status every year at its annual meeting, and provides detailed life history information on their webpage.


Female halibut mature at around 12 years, while males mature at around 8 years. Adult fish tend to remain in the same area year after year, except for their migration to spawning grounds. Adult halibut will migrate long distances from shallow summer feeding grounds to deeper winter spawning grounds. The number of eggs they lay depends on the female’s size. A 50-pound female can produce about 500,000 eggs, while a female over 250 pounds can produce four million eggs. The eggs float freely and drift in deep ocean currents and are fertilized externally. The eggs hatch 12-15 days after fertilization, and the larvae drift to shallow waters on the continental shelf. Larvae begin life in an upright position with eyes on both sides of their head. When they are about an inch long, the left eye migrates over the snout to the right side of the head, and the color of the left side fades. When the young fish are about six months old, they settle to the sea floor, where the protective coloring on their “eyed” side effectively camouflages them.  


Larval halibut feed on zooplankton, while juvenile and adults prey on cod, pollock, sablefish, rockfish, turbot, sculpins, other flatfish, sand lance, herring, octopus, crabs, clams, and occasionally smaller halibut. Adult halibut are sometimes eaten by marine mammals and sharks, but are rarely preyed upon by other fish.

The Management Context

DateHalibut management action
JanuaryInternational Pacific Halibut Commission sets the total allowable catch.
September Council meetingCouncil solicits proposed changes to the Catch Sharing Plan.
Between Sept. & Nov.  meetingsCouncil takes comments on proposed changes to Catch Sharing Plan.
November meetingCouncil makes final recommendations for changes.
Halibut management schedule

Halibut have been fished for hundreds of years by native Americans on the west coast of the U.S. The U.S. commercial fishery started in 1888, when halibut were first landed in Tacoma, Washington.

Because halibut can be kept for long periods of time without spoiling, they soon became a popular target for commercial harvesters. In the 1890s, a fleet of sailing vessels with two-man dories fished for halibut from the west coast. Large steam-powered vessels soon entered the industry, and by the 1910s it became clear that halibut stocks were suffering from overfishing. In 1923 the U.S. and Canada signed a convention on halibut, creating what was eventually called the International Pacific Halibut Commission. In 1924 the Commission implemented a three-month winter closure – the first management action to affect halibut. The convention was revised several times over the years to allow the Commission to meet new conditions in the fishery. The most recent change occurred in the Protocol of 1979, which allowed each government to establish more restrictive regulations. Canada implemented a limited entry system at that time and an individual vessel quota system in 1991.  In the U.S., Alaska implemented an individual fishing quota system in 1995, similar to the individual vessel quota program in Canada except that shares were issued to individuals instead of vessels. Also in 1995, non-tribal commercial fishers in Oregon, Washington, and California had to make a choice: participate in the sport charter industry for halibut, the commercial directed fishery, or the halibut incidental fishery in the salmon troll fishery.

Each year the IPHC conducts a stock assessment to estimate the abundance and trends of the Pacific halibut stock using commercial fishery data and scientific surveys. The Commission utilizes a decision table to report the results of the annual stock assessment, effectively separating the science from policy.  The decision table, prepared annually by IPHC staff, presents the Commissioners with a range of coastwide harvest levels, each with accompanying estimates of potential risk in terms of stock and fishery trend and status metrics.  The Commissioners consider the coastwide assessment, and the current harvest policy in determining the final catch targets for each year.  

Total catch is set by the IPHC, and the Council then allocates that total among Area 2A fisheries (treaty Indian, commercial non-tribal, and recreational). For more information on how IPHC sets halibut catch limits, see the IPHC document “How are Halibut Catch Limits Determined?” To learn more on how harvest is divided off the west coast (Area 2A), see the Halibut Catch Sharing Plan described below and found under ‘Key Documents’.

The Fishery and Gear

The commercial halibut fishery on the West Coast was pioneered by fishers of Norwegian ancestry, many of whom had fished halibut in Norway. Many Nova Scotians and Newfoundlanders have also participated in the West Coast halibut fishery.

Halibut are one of the most valuable fish species in the northern Pacific. Pacific halibut fishing is an important part of several tribal cultures, and many tribal members participate in commercial, ceremonial and subsistence fisheries. Longlining is the main commercial gear used to target halibut, although there is some allowance for incidental catch in the commercial salmon troll and the primary sablefish fisheries. Vessel, trip and landing limits are all used to manage halibut harvest in non-tribal commercial fisheries.

Halibut is also a very popular target for sport fishers in Washington, Oregon, and California.  Because halibut fishing is so popular, managers use closed seasons, bag limits, and possession limits to extend the halibut sport season as long as possible.

In 1995, the U.S. prohibited directed non-tribal commercial fishing north of Pt. Chehalis, Washington in order to allow the tribes to harvest their allocation of halibut.

Halibut Catch Sharing Plan

The Halibut Catch-Sharing Plan is a framework that dictates how the IPHC and NMFS will divide the total allowable catch (TAC) for Oregon, Washington, and California halibut fisheries (Area 2A). The total TAC is set each January by the IPHC, who also endorses the Catch Sharing Plan allocations set by the Council. Allocations between some recreational areas are subject to inseason and other changes. For a description of how the halibut harvest is shared, see the halibut catch sharing plan under “key documents” on this page.

Each year the Council solicits proposed changes to the Catch Sharing Plan for its September meeting and takes comments on proposed changes between its September and November meetings. The Council then makes final recommendations for changes at its November meeting. The proposed changes are described in the Council Newsletter and in the annual September decision document. If you would like to propose a change or comment on proposed changes, you can submit comments by mail, fax, or email, marked to the attention of Robin Ehlke, Pacific halibut staff officer.


For more information on halibut management, please contact Robin Ehlke.