Stocks of Pacific halibut are at historically low numbers, and are growing more slowly. Last year’s harvest was the lowest on record in over 120 years, according to data from fishery managers.
The International Pacific Halibut Commission, or IPHC, has been managing harvest of the giant flatfish for over 100 years. The Halibut Commission was created so the United States and Canada can cooperatively manage a common resource according to the group's website.
Although there are eight separate regulatory areas, Pacific halibut are managed as a single stock that extends from Northern California to the Aleutian Islands and Bering Sea. According to the Halibut Commission’s website their objectives are to develop Pacific halibut to levels that will, “permit the optimum yield from the fishery and to maintain the stocks at those levels.”
The abundance levels for halibut are as low as they have ever been during the century of management by the Halibut Commission. The 2024 harvest of 9,317 tons was the lowest since the 8,106 tons harvested in 1901.
According to the Halibut Commission’s 2024 assessment, since the late 1990s the Pacific halibut stock has been on a long slow decline. This decline is not just the result of fewer young fish, also called recruits; it’s also the result of fish growing slower. A twelve-year-old halibut today weighs about half as much as a twelve-year-old halibut did in the 1980s according to the Halibut Commission's data.
Smaller fish also affects another important measure of stock health - smaller fish equals smaller spawning biomass. The spawning biomass, which is a measure of the fish mature enough to reproduce, dropped to 145 million pounds in 2024; the lowest it has been since the 1970s. It then bounced up a bit at the start of this year to 149 million pounds.
But the possible range of actual spawning biomass, across the vast expanse of halibut habitat, could be anywhere from 97 million pounds to 216 million.
The Halibut Commission has established a relative spawning biomass of 30% as a level of concern for the fishery, and if that number drops to 20%, directed fishing would be halted. The relative spawning biomass at the beginning of 2024 was estimated to be 38%.
Scientists estimate there is a 30% chance that the stock is already below the Halibut Commission’s thirty percent threshold of concern, and an 11% chance that the stock is already under 20% of spawning biomass. Latest estimates of spawning biomass were reduced after catcher vessel logbooks showed a worse than expected catch rate for the fleet.
