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Removals from the Pacific halibut resource
Pacific halibut are removed from the resource by various sectors that operate within the IPHC Convention area including commercial (which includes directed catch as well as directed discard mortality), recreational, and personal use (subsistence). Additional mortality occurs in the form of non-directed commercial discard mortality (bycatch) in commercial fisheries targeting other species that are not allowed to retain Pacific halibut. Over the last half century, Pacific halibut removals from all sources have ranged annually from 15,517 to 45,309 metric tons (34.2 to 99.9 million pounds), with an average of 30,113 mt (66.4 million pounds). Total removals in 2022 were 18,284 mt (40.3 million pounds), 6% up from 2021 (17,314 mt or 38.2 million pounds), but 39% below the 50-year average. In 2022, an estimated 11,857 mt (26.1 million pounds) were landed from commercial fisheries (including landings from the Fishery-Independent Setline Survey [FISS]), 2,994 mt (6.6 million pounds) from recreational fisheries, 2,998 mt (6.6 million pounds) from directed and non-directed commercial discard mortality, and 435 mt (1.0 million pounds) from subsistence.
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Detailed information for the different sources of removals accounted for in the stock assessment, click on the button below. | |
Updating Pacific halibut maturity estimates | |
Maturity is a key biological input that directly affects the annual reproductive output estimated in stock assessment. Maturity is currently determined based on visual (i.e. macroscopic) assessments of the whole ovary in the field during the fishery-independent setline survey (FISS). In order to obtain more accurate estimates of maturity, the IPHC Secretariat is undertaking studies to revise maturity schedules of female Pacific halibut coastwide through microscopic (i.e. histological) characterization of maturity.
In 2022, ovarian samples were collected during the FISS in all IPHC biological regions, and were brought back to IPHC HQ in Seattle, WA. These samples have been prepared for histological analysis and are currently being examined and classified for maturity according to histological criteria recently developed by the IPHC Secretariat. The criteria are a result of a large study completed in 2022 that described the temporal progression of female ovarian developmental stages throughout an entire annual reproductive cycle.
The goal of this work is to determine the proportion of Pacific halibut females that are mature at a given length or age for each IPHC biological region using histological data. These updated maturity schedules will be included in the annual Pacific halibut stock assessment. In addition, the current visual criteria used to determine female maturity in the field will be revised by comparing with more accurate microscopic criteria.
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Preparations for the 2023 fishery independent setline survey (FISS) are underway
As in previous years, the 2023 annual fishery-independent setline survey (FISS) will take place during the summer months off the coast of north America in the IPHC Convention area.
Following a multi-year expansion in the 2010s to areas and depths not normally surveyed, IPHC scientists identified 1,890 stations that could help inform on distribution and Pacific halibut biology. Each year, the goal is to sample a subset of these, and in 2023 the design includes 958 of those stations. The map above shows the stations in gold that are planned for this year.
The Setline Survey Specialist (Field) vessel staff has been selected and includes 16 new and returning samplers. Training will take place at IPHC Headquarters in May. They will be joined in the field by headquarters Secretariat at various times during the summer.
Vessel selection is in progress and the FISS is ultimately expected to be completed by 8-10 vessels. As a way to offset the cost of the survey and accomplish the goal of long-term revenue neutrality, the Pacific halibut caught are sold in ports coastwide. Those interested in potentially purchasing one or more of the FISS landings need to fill out an Interested Buyer Form.
The interested buyer form, data from past FISS years, and other information are available by clicking on the button below.
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IPHC Data Highlight
Seeing as the 2023 commercial Pacific halibut season is now underway and commercial catch is hitting the docks, it is a good time to remind everyone of our Pacific Halibut Fishery Limits (FCEY) Report page (previously called the Landings page). There you can find a detailed breakdown of Pacific halibut mortality in tonnes and pounds (net weight) compared to set fishery limits. Each IPHC Regulatory Area is broken down further by different fishery types, if warranted. This table is updated on the 1st and 15th of every month.
Also available, as shown in the image below, is a Year-to-Date Directed Commercial Pacific Halibut Landings (AK, BC, WA, OR, CA) visualization. Hyper-linked at the top of the FCEY Report page, this visualization presents an interactive line chart comparing the percentage of the fishery limit obtained by week of the year. In addition, the graph shows prior seasons, allowing for a direct comparison of landing rates between years.
|  | To access the table and visualizations, follow the link below. | |
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Ask an IPHC Scientist
Q. Recently, IPHC began genetically determining commercial fishery sex ratios, data that were previously lacking in the stock assessment. How has this changed your approach to the stock assessment and perspective of the stock?
- The introduction of direct sex-ratio at age information from the commercial fishery addressed the largest uncertainty we had at that time and resulted in a modest change in both the estimates of stock size as well as the estimates of fishing intensity. We have now integrated this sampling into our monitoring program and have data from 2017-2021 which continues to provide an increasing amount of information for the stock assessment and has allowed us to better model other population dynamics processes such as natural mortality.
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Q. What is the status of the IPHC using the information collected in the ports over the years from snap gear boats?
- We still review and report catch rates for both snap and fixed gear in the commercial fishery each year and evaluate whether the trends are consistent with each other and with those from the fishery-independent setline survey (FISS). This is particularly important information in years when we are lacking FISS data in one or more IPHC Regulatory Area(s). We now have three calibration studies comparing catch rates of the two gears on the FISS and are accepting bids for both gear types for routine survey work, albeit with a preference for fixed gear while we are still refining our understanding of the differences in catch rates over time and across areas for the two gears.
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Q. The IPHC is almost 100 years old and a lot of data have been collected over the years. Are there any new uses for old data?
- The IPHC's historical data sets are an incredible resource for current and future analyses, providing us with context that is unavailable for most fisheries. Since the early 2010s, a number of projects have included incorporating historical data into the stock assessment process such as: 1) Re-analyzing commercial gear-standardization experiments from the 1970s, 2) Re-ageing commercial samples all the way back to the 1920s to compare ageing vs. size-at-age, and 3) incorporating logbook data back to 1907 and biological data back to 1935.
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