February 6, 2020 — For the first time in its 96 year history, the International Pacific Halibut Commission will be setting catch limits for halibut this week with the knowledge that the commercial fleet’s catch has been around 90 percent female, a notably higher proportion than previously thought.
“The Commission has long known that the directed commercial Pacific halibut fishery catches mostly female, but we’ve had indications over time that perhaps the fishery is able to capture even more females than we see on a set line survey relative to males,” said Ian Stewart, a quantitative scientist for IPHC.
Stewart works to develop the stock assessment for Pacific halibut, which IPHC commissioners use to set catch limits for the U.S. and Canada. Knowing what percentage of the catch is female is an important factor that could influence how the stock is managed and thus, what restrictions and limitations are put on fishermen. New data from the IPHC shows that the sex ratio of the commercial catch ranged from 81 percent female in some regions of the Gulf of Alaska to 97 percent female in some regions in the Bering Sea.
“For conservation purposes we track female spawning biomass. And in order to understand that we need to know not only how many females are out there, but how many we’re catching in a given year,” Stewart said.
Biologists with IPHC use setline surveys fishing the same gear in the same places with the same bait year after year to estimate trends in the population and collection biological information including size, age and sex.