Pacific Halibut (Hippoglossus stenolepis)

• Pacific halibut populations are healthy.
• Pacific halibut is managed by a treaty between the U.S. and Canada through recommendations of the International Pacific Halibut Commission.
• Halibut is low in saturated fat and sodium and is a very good source of protein, niacin, phosphorus, and selenium. For more on nutrition, see Nutrition Facts. (USDA)
• Close to 100% of the halibut landed in the U.S. is Pacific halibut. The main sources for Pacific halibut are the U.S. and Canada.

Sustainability Status

Biomass: Coastwide exploitable biomass in 2010 is estimated to be 334 million pounds.
Overfishing: Undefined
Overfished: No
Fishing and habitat: Bottom longline gear is the main commercial gear used to target halibut. The effects of bottom longline gear on habitats are poorly understood but could include disturbance of sediments, benthic structures, and other organisms.
Bycatch:  Seabirds, including short-tailed albatross, blackfooted/Laysan albatross, northern fulmars, and shearwaters. Regulations are in effect that make it mandatory for longline vessels to use seabird avoidance devices. The IPHC is also involved in bird bycatch research and acts as a repository for multi-agency observations on seabird distribution. The commercial fishery switched from J-hooks to circle hooks in 1983, which lowered mortality on sub-legal sized halibut released during commercial fishing. Incidentally-caught groundfish stocks include some that are overfished, such as canary and yelloweye rockfish in Washington and Oregon waters, as well as healthy stocks of Pacific cod, other rockfish, and flatfish. Regulations prohibit commercial Pacific halibut fisheries in specific depths and areas off Washington, Oregon, and California, and conservation areas are closed to all fishing in several areas off the Pacific coast and Bering Sea. The IPHC is conducting joint research with NOAA Fisheries Service, the Pacific States Marine Fish Commission, the North Pacific Research Board, and the halibut industry to evaluate use of electronic monitoring (cameras and GPS) to characterize bycatch in the Alaskan halibut fishery.
Aquaculture: There is no commercial aquaculture of Pacific halibut on the west coast of the United States or Alaska.

Science and Management

Pacific halibut is managed by the United States and Canada through the International Pacific Halibut Commission (IPHC), formed in 1923. The IPHC annually establishes total allowable catch (TAC) levels for halibut that will be caught by recreational and commercial harvesters in the U.S. and Canadian exclusive economic zones (EEZs) and assesses the abundance and potential yield of Pacific halibut using all available data from the commercial fishery and scientific surveys.

Management of the Pacific halibut fishery is based on an agreement between Canada and the U.S. and is given effect in the U.S. by the Northern Pacific Halibut Act of 1982. Per the terms of the Act, the North Pacific Fishery Management Council (NPFMC) recommends regulations to govern the directed halibut fisheries in waters off Alaska, provided that its actions do not conflict with regulations recommended by the IPHC. NPFMC actions must be approved and implemented by the U.S. Secretary of Commerce. In 1995, the NPFMC and NOAA Fisheries Service Alaska Regional Office implemented an individual quota system for Alaska, similar to Canada's (implemented in 1991), for the halibut industry. As a result, the commercial fishing season was extended from only days to 8 months or more, the value of the fishery has increased, bycatch has been reduced, and fewer fishermen have lost their lives.

The U.S. waters off the states of Washington, Oregon, and California are managed as Area 2A. Regulations for Area 2A are established by the Pacific Fishery Management Council (PFMC) and NOAA Fisheries Service Northwest Regional Office. The total allowable catch for halibut in this regulatory area is set by the IPHC, and the PFMC allocates the catch among the following user groups: non-treaty commercial (incidental salmon troll fishery, directed longline halibut fishery, and incidental longline sablefish fishery), sport, and treaty Indian commercial and ceremonial and subsistence. The PFMC describes this halibut catch division each year in the Pacific Halibut Catch Sharing Plan for Area 2A.

Halibut is also a popular target for sport fishermen and an important part of many tribal cultures. Management subareas off Oregon, Washington, and California have catch limits for recreational halibut fishing; closed seasons, daily bag limits, and possession limits are all used to control the fishery. Community harvest permits, ceremonial permits, and educational permits provide for traditional uses within Alaska Native cultures.

Life History and Habitat

Life history, including information on the habitat, growth, feeding, and reproduction of a species, is important because it affects how a fishery is managed. For example, in 2006, evidence of greater migration than previously believed of legal-sized fish from the western Gulf of Alaska to eastern areas led IPHC scientists to question the underlying assumptions of the then-current method of stock assessment. Scientists changed their stock assessment methods to account for this migration and avoid mis-estimation of biomass.

• Geographic range: Coastal waters of the northeast Pacific from northern California to the Gulf of Alaska to the Aleutian Island chain and into the Bering Sea, with a center of abundance around Kodiak Island. About 2% of the exploitable biomass is off Oregon and Washington, about 15% off British Columbia, and the remainder off Alaska.
• Habitat: Juveniles (1 inch and larger) are common in shallow, near-shore waters 6.5 to 164 feet deep in Alaska and British Columbia. Fish move to deeper water as they age, and migrate primarily eastward and southward.
• Life span: Females and males both live to be quite old. The oldest halibut on record (recorded by IPHC) for both males and females was 55 years old.
• Food: Larvae feed on zooplankton (tiny floating animals). Juveniles consume small crustaceans and other benthic organisms. Mature halibut prey on cod, pollock, sablefish, rockfish, turbot, sculpins, other flatfish, sand lance, herring, octopus, crabs, clams, and occasionally smaller halibut.
• Growth rate: Both females and male halibut grow about 4 inches per year until about age 6. Thereafter, females grow faster and reach substantially greater sizes. Growth rates of both sexes have varied greatly over the last century and are inversely dependent on stock size.
• Maximum size: Halibut can weigh over 500 pounds and grow to 9 feet. Males are smaller than females.
• Reaches reproductive maturity: Female halibut mature around 12 years old, while males mature around 8 years old.
• Reproduction: A 50-pound female can produce about 500,000 eggs, while a female over 250 pounds can produce 4 million eggs. While females spawn only once per year, they are believed to release their eggs in a series of batches over several days during the spawning season. Eggs develop at depth and hatch after 12 to 15 days. The larvae slowly float closer to the surface where they remain in the water column for about 6 months until they reach their adult form and settle to the bottom in shallow water.
• Spawning grounds: In deep water (approximately 600 to 1,500 feet) along the continental slope, concentrated at a number of locations in the Bering Sea, Aleutian Islands, Gulf of Alaska, and south to British Columbia.
• Migrations: Most adult fish can be found on the same summer feeding grounds year after year. Adults conduct a long-distance migration from shallow summer feeding grounds to deeper winter spawning grounds. There is growing evidence that a portion of the adult stock continues to migrate from the western areas to those in the east.
• Predators: Halibut are sometimes eaten by marine mammals and sharks but are rarely preyed upon by other fish.
• Commercial or recreational interest: Both
• Distinguishing characteristics: Flat, diamond-shaped bodies

Role in the Ecosystem

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

Additional Information

Market name: Halibut
Vernacular names: Pacific halibut, Alaskan halibut, Common halibut, Whitesided paltus
Atlantic and California halibut are also marketed as Halibut. Some wild and increasing amounts of farmed Atlantic halibut are sold, primarily in U.S. east coast markets.

Biomass

Biomass refers to the amount of Pacific halibut in the ocean. Scientists cannot collect and weigh every single fish to determine biomass, so they use mathematical models to estimate it instead. These biomass estimates can help determine if a stock is being fished too heavily or if it may be able to tolerate more fishing pressure. Managers can then make appropriate changes in the regulations of the fishery.

In general, coastwide exploitable biomass is estimated to have declined by about 35% during 2000-2010. The extent of and reasons behind the declines vary by area. Only biomass estimates from Area 3A (the central Gulf of Alaska) are shown in the graph. About 37% of the stock is in Area 3A, so this area indexes the entire stock quite well. Biomass remains in a healthy state in Area 3A and will likely continue to support removals of the size seen over the past 2 to 3 decades.

Landings

Landings refer to the amount of catch that is brought to land. Catch limits were drastically reduced in the 1970s and remained low for a decade, as evidenced by the lowest points in the graph. In the 1980s, the stock was considered rebuilt and a constant harvest rate policy was set. In the early and mid 1990s, both the Department of Fisheries and Oceans in Canada and the NPFMC in Alaska adopted Individual Quota systems. Landings have been relatively steady since the late 1990s.

Only commercial landings from Area 3A (the central Gulf of Alaska) are shown in the graph. About 37% of the stock is in Area 3A, so this area indexes the entire fishery quite well. Area 3A has been fished for many decades. Landings from Area 3A have been fairly stable for over the past 10 years.

Biomass and Landings

Biomass and landings data can sometimes be used to detect trends in a fishery. They may influence each other, and factors such as changes in management measures, fishing effort, market preferences, or environmental conditions may impact landings and biomass as well.

Data sources:
Biomass and landings from International Pacific Halibut Commission: Assessment of the Pacific halibut stock at the end of 2009

Important Dates

1923 – U.S. and Canada sign convention on halibut, leading to the creation of the International Pacific Halibut Commission (IPHC) to conduct biological studies and recommend management measures
1924 – IPHC implements 3-month closure, the first management action to affect halibut
1932 – IPHC commences quota management
1960s – Distant-water trawl fleets arrive in the northeast Pacific and take a large bycatch of halibut; recruitment is poor, and the stock declines steeply
Early 1970s – Catch limits drastically reduced; remain low for a decade
1976 – Both U.S. and Canada extend their maritime jurisdiction
1977 – Climate change in North Pacific; recruitment is doubled
1980s – Fishery seasons grow progressively shorter, creating a "derby fishery"
1984 – Stock declared rebuilt; a constant harvest rate policy for setting catch limits is adopted
1987 – U.S. prohibits directed non-treaty commercial fishing north of Pt. Chehalis, Washington to allow treaty tribes to harvest their allocation of halibut
1991– An Individual Vessel Quota system is implemented by the Dept. of Fisheries and Oceans for the fishery off British Columbia; eight month season established by IPHC
1995– Individual Fishing Quota Program adopted by the NPFMC for the fishery off Alaska; eight month season established by IPHC
1995– Western Alaska Community Development Quota (CDQ) Program created by NPFMC in 1992 for pollock is extended to halibut
2003 – Regulations implemented to recognize the subsistence use of halibut by Alaska Native Tribes and rural Alaskans
2007 – Rule to reduce sport fishing mortality in the charter vessel sector fishing in IPHC Area 2C (Southeast Alaska) through a maximum size on one halibut retained under the 2-fish bag limit
2009 – U.S. reduces the daily bag limit to one fish for anglers fishing from charter vessels in Area 2C

Notes and Links

General Information:
NOAA Fisheries Service Alaska Fisheries Science Center Fisheries Behavioral Ecology Program Species of Particular Interest - Pacific Halibut

Pacific Fishery Management Council's Background on Halibut

Pacific Fishery Management Council's Halibut Fact Sheet

International Pacific Halibut Commission

NOAA Fisheries Service Sustainability Species Identification for Pacific halibut

NOAA Fisheries Service Halibut Charter Management

NOAA Fisheries Service Individual Fishing Quota (IFQ) Halibut and Sablefish Program

Subsistence Halibut Fishing in Alaska

North Pacific Fishery Management Council - Current Issues in the Halibut Fishery

Stock Assessments:
International Pacific Halibut Commission: Assessment of the Pacific halibut stock at the end of 2009

Page last updated: January 25, 2010