After review of a staff discussion paper, the Council drafted a suite of alternatives to establish abundance-based halibut prohibited species catch (PSC) limits for the BSAI groundfish fisheries, for preliminary analysis. The discussion paper synthesized staff work on ABM control rules and their relative performance compared to Council objectives, using the Council’s draft suite of October 2017 elements and options to develop “strawman ABMs” (example ABM alternatives) based on various combinations of trawl and setline survey indices of halibut abundance. The paper also evaluated how different control rules function, the relative features of different control rules, and tradeoffs among control rules with respect to setting PSC limits for BSAI groundfish fisheries (by gear type), through a preliminary analysis of the example ABMs using both historical data and hypothetical scenarios illustrating contrasting halibut abundance trends. After extensive discussion of the relative features of control rules and specific elements and options, the Council drafted a suite of five alternatives for preliminary analysis by the interagency staff workgroup:
Alternative 1: Status quo (current fixed PSC limits and allocations)
Alternative 2: Index PSC by gear type. Index trawl PSC to EBS trawl survey biomass. Index longline PSC to IPHC setline survey in 4ABCDE biomass.
Alternatives 3 and 4: Index PSC by gear type. Index trawl gear PSC and fixed gear PSC to both EBS trawl survey biomass (primary index for trawl, secondary index for longline) and IPHC setline survey in 4ABCDE biomass (primary index for longline, secondary index for trawl). Alternatives 2 and 3 differ in the methodology by which the PSC is adjusted to the secondary index.
Alternative 5: Index fixed gear PSC to both EBS trawl survey biomass and IPHC setline survey in 4ABCDE biomass using a look-up table which combines information from both surveys in establishing a PSC limit.
Each of these alternatives contains elements and options for establishing the responsiveness of the PSC limit to changes in abundance, and the starting point, ceiling and floors for the PSC limit. The Council requested that staff also evaluate a series of items including the time series for the indices used, the relative values selected for ‘high, medium, and low’ stock status in Alternatives 3 and 4, analysis of a range of fixed PSC limits to contrast with PSC limits indexed to abundance, and use of a 3-5 year rolling average on PSC limits. The complete motion is available here. The Council acknowledged that the development of alternatives for this action will be an iterative process, and that it is likely that alternatives will be adjusted further at the next review of the analysis.
One such iterative adjustment could be the inclusion of a performance standard to directly address the O26 component of the bycatch, and implications for the directed halibut fishery in the Bering Sea. The Council did not include this provision in the alternative set at this time, but requested a discussion paper that would bring forward data on relative O26:U26 proportions of halibut bycatch by weight, numbers, and gear type, as well as discussion of potential anomalies and bias in the data due both to sampling changes by the Observer Program in recent years as well as differences in sampling resulting from the practices of deck-sorting and use of halibut excluders. The paper should also develop some options for performance standards that are consistent with potential data limitations and have the ability to achieve the objectives of the overall action.
The Council has requested that the SSC review a report from the workgroup in June which outlines the methodological approach for the analysis. This would include the approach to analyze the biological and economic impacts of the current range of alternatives, given the complexity of the range of elements and options. Should O26 data be available in time for consideration by the workgroup, the discussion paper on O26 bycatch by sector, and proposed performance standard options, will also be available for the June meeting.
The Council received a scoping report from NMFS, as it has been determined that preparation of an Environmental Impact Statement (EIS) may be required for this action because abundance-based halibut PSC limits may have effects on target and bycatch species and their users that are uncertain or unknown and may result in significant impacts on the human environment not previously analyzed. This report summarizes the comments received during the December 12, 2017, to February 16, 2018, scoping period for the BSAI Halibut Abundance-Based PSC EIS. The purpose of this report is to inform the Council and the public of the results of scoping and to assist in the development of the range of alternatives for analysis in the draft EIS.
Staff contact is Diana Stram.