Survey again shows drop in halibut stocks in Gulf of Alaska
Things aren’t looking good for many Alaska halibut fishermen next year, though official quota limit decisions are still to come.
The 2018 stock status report presented to the International Pacific Halibut Commission at its interim meeting on Nov. 27 shows yet another drop in the biomass of Pacific halibut in the North Pacific — about 7 percent down from the 2017 fishery-independent setline survey.
That doesn’t mean every single region dropped, as it’s an average, but Alaska’s three main areas of effort — 2C, the entirety of Region 3, and Region 4 excluding the western Aleutian Islands — all dropped.
The most significant drop was in Area 2, which stretches from northern California to Southeast, falling 15 percent. Region 3, which stretches across the Gulf of Alaska out to the Alaska Peninsula, fell 7 percent.
Halibut stocks dropped year-over-year from the late 1990s through 2011, when it appears to have stabilized, according to the report.
“That trend is estimated to have been largely a result of decreasing size-at-age, as well as somewhat weaker recruitment strengths than those observed during the 1980s,” the report states.
The spawning female biomass stabilized in 2011, increasing the stock through 2016, with a projected spawning biomass of 190 million pounds at the beginning of 2019. Researchers are linking the fluctuations with favorable ocean conditions in connection with the Pacific Decadal Oscillation, an ocean temperature trend correlated with fisheries regimes.
Historically, conditions were favorable from 1978–2006 and poor from 2007–13, with more positive indications from 2014 through October 2018. However, that’s not the only variable playing into ocean conditions for halibut in the North Pacific.
Sea surface temperatures in the Gulf of Alaska jumped in 2015 and remained anomalously high for several years, earning the warm water mass the nickname “the Blob,” and wreaking widespread havoc on fish stocks and leading to uncertainty for forecasters.
“Many other environmental indicators, current and temperature patterns have been anomalous relative to historical periods and therefore historical patterns of productivity related to the (Pacific Decadal Oscillation) may not be relevant to the most recent few years,” the report states.
Though conditions have been favorable, the cohorts from 2006–10 were smaller than the prior few years, which will affect abundance as time goes on and those age cohorts become a more significant part of the fishery.
The International Pacific Halibut Commission will set its quota limits at its annual meeting in January. Last year, when the stock status led to recommendations for significant cuts to harvest, the commissioners could not come to an agreement and decided to have the U.S. and Canada set their fisheries limits independently, though no higher than the previous year.
The stock status report doesn’t make direct recommendations for fishing limits but projects how fisheries limits will impact the population. For all total constant exploitation yield amounts, or TCEY — all halibut mortality for fish longer than 26 inches, including bycatch and research kills — more than 20 million pounds, the stock is project to decline from 2019–21. At the status quo TCEY of 37.2 million pounds total, there’s a 30 percent chance of a stock decline of at least 5 percent in 2019 that climbs to a 79 percent chance by 2022, according to the report.
Total mortality of Pacific halibut in 2018 was about 38.7 million pounds. The commercial halibut catch, though — about 23.5 million pounds — was actually an all-time low for the last 10 years, according to the report. Bycatch mortality fell to 6.1 million pounds, the lowest since the arrival of foreign fishing fleets in 1962. Mortality from recreational catches was down as well, about 5 percent lower than 2017.
The International Pacific Halibut Commission is scheduled hold its full annual meeting from Jan. 28–Feb. 1 in Victoria, British Columbia.
Elizabeth Earl can be reached at [email protected].