Quiero saber acerca de...

khammond on DSKJM1Z7X2PROD with RULES

Federal Register / Vol. 86, No. 44 / Tuesday, March 9, 2021 / Rules and Regulations models, comprised of two long timeseries models, and two short time-series models incorporating data from 1996 to the present. Each time-series length used data series that are divided either by four geographical regions or aggregated into coastwide summaries.
These models incorporate data from the 2020 IPHC Fishery Independent Setline Survey FISS, the 2020 commercial halibut fishery, the most recent NMFS
trawl survey, sex-specific recreational age composition data from Area 3A, weight-at-age and male/female sex ratio estimates by region in the directed commercial fisheries and in the FISS, commercial fishery logbook information, and age distribution information for bycatch, sport, and sublegal discard removals.
As has been the case since 2012, the results of the ensemble models are integrated and incorporate uncertainty in natural mortality rates, environmental effects on recruitment, and other structural and parameter categories. The data and assessment models used by the IPHC are reviewed by the IPHCs Scientific Review Board comprised of non-IPHC scientists who provide an independent scientific review of the stock assessment data and models and provide recommendations to IPHC staff and to the Commissioners.
The Scientific Review Board did not identify any substantive errors in the data or methods used in the 2021 stock assessment. NMFS believes the IPHCs data and assessments models constitute best available science on the status of the Pacific halibut resource.
The IPHCs data, including the FISS, indicate that the Pacific halibut stock declined continuously from the late 1990s to around 2012, largely as a result of decreasing size at a given age sizeat-age, higher harvest rates in early 2000s, as well as somewhat weaker recruitment strengths than those observed during the 1980s. Results from the 2020 stock assessment incorporate data from an expansion of the FISS
throughout the survey range over the 20112019 period. Among other things, improvements in the setline spatial coverage have helped gain a greater understanding of the degree of spatial and temporal Pacific halibut density, and has helped reduce the uncertainty in the weight per unit effort WPUE and number per unit effort NPUE indices.
Overall, the biomass of spawning females is estimated to have increased gradually to 2016, then decreased to approximately 192,000,000 lb 87,243.96 mt at the beginning of 2021.
This level is currently estimated to be 33 percent with a 95% credible interval of 22% to 52% of unfished levels. This
VerDate Sep<11>2014

16:19 Mar 08, 2021

Jkt 253001

estimate reflects updated calculations recommended during stock assessment external review and review by the Scientific Review Board, as well as developments in the IPHC Management Strategy Evaluation.
The IPHCs current interim management procedure strives to maintain the total mortality of halibut across its range from all sources based on a reference level of fishing intensity so that the Spawning Potential Ratio SPR is equal to 43 percent. The reference fishing intensity of F43
percent SPR seeks to allow a level of fishing intensity that is expected to result in approximately 43 percent of the spawning stock biomass per recruit compared to an unfished stock i.e., no fishing mortality. Lower values indicate higher fishing intensity. The 2020 stock assessment and estimates of fishing intensity were enhanced by newly available data on the male/female sex ratio for the 2019 commercial fishery landings. Combined with similar data collected from the 2017 and 2018
commercial fisheries, the refined and quantified information on the sex ratio affected the treatment of the stock assessment data for the directed commercial fishery in the stock assessment models; it did not change the treatment or sex ratio estimates of mortalities associated with the recreational, subsistence, or nondirected halibut fisheries. Additional information on the status of the halibut resource under these catch limit alternatives is provided in the Analysis see ADDRESSES.
The IPHC harvest decision table Table 3 in: Summary of the Data, Stock Assessment, and Harvest Decision Table for the Pacific Halibut Stock at the End of 2020; IPHC2021AM09708
provides a comparison of the relative risk of a decrease in stock biomass, status, or fishery metrics, for a range of alternative harvest levels for 2021. The harvest decision table employs two metrics of fishing mortality: 1 The Total Constant Exploitation Yield TCEY, which includes harvests and incidental wastage from directed commercial fisheries, plus mortality estimates from sport, subsistence, personal use, and estimates of nondirected discard mortality of halibut over 26 inches; and, 2 Total Mortality, which includes all the above sources of mortality, plus estimates of non-directed discard mortality of halibut less than 26
inches U26. Although U26 halibut mortality is factored into the stock assessment and harvest strategy calculations, there is currently no reliable tool for describing the annual
PO 00000

Frm 00035

Fmt 4700

Sfmt 4700

13477

distribution of halibut under 26 inches across the entire coastwide area.
For 2021, the IPHC adopted a TCEY
totaling 39,000,000 lb 17,690.10 mt coastwide. This corresponds to a fishing intensity of approximately F43 percent, which is similar to the projected fishing intensity of approximately F42 percent used by the IPHC to establish the 2020
TCEY. The 2021 TCEY is 2,400,000 lb 1,088.62 mt greater than the TCEY
adopted in 2020.
The IPHC noted this management approach represents a relatively conservative level of harvest that considers the inherent uncertainties in the stock assessment models. The IPHC
notes that under a broad range of catch limits, including highly restrictive catch limits, the halibut stock is likely to experience a continued decrease in spawning stock biomass given the best available scientific information. In making its recommendation, the IPHC
considered likely stock status, and uncertainties in the status of the stock as well as the significant social and economic impacts of catch limits among areas.
At a 39,000,000 lb TCEY, the IPHC
estimates that the spawning stock biomass will likely decrease over the period from 2022 to 2024 relative to 2021. Specifically, the IPHC estimates there is a 65 percent probability that the spawning stock biomass will decrease in 2022 relative to 2021, and that there is a 39 percent probability that the decrease in 2022 will be at least 5
percent of the 2021 spawning stock biomass. The factors that the IPHC
considered in making their TCEY
recommendations are described in the 2021 Annual Meeting Report IPHC
2021AM097_R and the key recommendations are briefly summarized here.
This final rule does not establish the combined commercial and recreational catch limit for Area 2B British Columbia, which is subject to rulemaking by the Canada and British Columbia governments. However, the IPHCs recommendation for the Area 2B
catch limit is directly related to the current and future U.S. catch limits established by this final rule and is therefore discussed herein. The IPHC
recommended a 2021 TCEY of 7,000,000
lb 3,175.15 mt for Area 2B, which equates to 19.1 percent of the total coastwide TCEY. The IPHC made this recommendation after considering recent historic harvests in Area 2B, the distribution of the TCEY in Area 2B as estimated from the FISS under the current interim management procedure, and other factors described in the 2021

E:FRFM09MRR1.SGM

09MRR1