Management Track Assessments Fall 2022

1.  2022 MANAGEMENT TRACK PEER REVIEW PANEL REPORT

Appendix A.  Summary of Assessment Oversight Panel Meetings for September 2022 Management Track Stock Assessments

The NRCC Assessment Oversight Panel (AOP) met to review the operational stock assessment plans for ocean pout, Atlantic wolffish, Georges Bank winter flounder, Gulf of Maine winter flounder, Cape Cod/Gulf of Maine yellowtail flounder, Southern New England/Mid-Atlantic yellowtail flounder, northern and southern monkfish, Georges Bank haddock, Gulf of Maine haddock, Atlantic halibut, witch flounder, white hake and pollock stocks on May 23–24, 2022. The AOP also met on August 3, 2022 to review the assessment plan for American Plaice, which underwent a Research Track peer review in July 2022. Four assessments were recommended for Level 1 Reviews (Direct Delivery) and these assessments will undergo an internal review before being delivered to the appropriate management body. The assessments for stocks/species recommended for Level 2 and 3 peer reviews will be reviewed during a meeting September 19–23, 2022.

The AOP consisted of:

Russell W. Brown, Ph. D.⁵⁵ Northeast Fisheries Science Center, Woods Hole, Massachusetts. (5/23, 5/24, 8/3)  (chair), Gary Nelson, Ph. D.⁶⁶ Atlantic States Marine Fisheries Commission, Massachusetts Division of Marine Fisheries. (5/23, 5/24, 8/3), Lisa Kerr, Ph. D.⁷⁷ Chair of the NEFMC Scientific and Statistical Committee, Gulf of Maine Research Institute. (5/23, 5/24, 8/3), Paul Rago, Ph. D.⁸⁸ Chair of the MAFMC Scientific and Statistical Committee, NOAA Fisheries (retired). (5/24, 8/3)   and  Michael Wilberg, Ph. D.⁹⁹ Vice-chair of the MAFMC Scientific and Statistical Committee, University of Maryland. (5/23).

Meeting Details:

These meetings were guided by the NRCC approved stock assessment guidance documents. Three background documents were provided to the Panel: (1) an updated prospectus for each stock; (2) an overview summary of all the salient data and model information for each stock; and (3) the NRCC Guidance memo on the Operational Assessments. Prior to the meeting, each assessment lead prepared a proposal for their Management Track Assessment. The proposal reflected the research track or most recent assessment results, the peer review panel Summary Report results and any initial investigations conducted for the management track assessment.

At the meeting, each assessment lead gave a presentation on the data to be used, model specifications (if applicable), evaluation of model performance, the process for updating the Biological Reference Points, the basis for catch projections, and an alternate assessment approach if their analytical assessment was rejected by the peer review panel.

Major Recommendations for Review of Individual Stocks:

In general, the AOP approved the plans presented, but recommended several points of emphasis to the recommended review levels as summarized below. AOP guidelines can be found in the stock assessment process document.

Table 2:  Stocks reviewed at September 2022 Management Track Assessment Stock Assessments meeting

Stock	Lead	Review Level	Rationale and Comments
Ocean Pout	Charles Adams	Level 1 Direct Delivery	Little impact of swept area adjustments on survey indices, low biomass could result in variable survey indices. Concern about the reliability of the discards.
Atlantic Wolffish	Charles Adams	Level 1 Direct Delivery	Little impact of swept area adjustments on survey indices, low biomass could result in variable survey indices; AOP requested that the longline survey indices be presented with the assessment; some concern length frequency data.
Georges Bank Winter Flounder	Alex Hansell	Level 2 Expedited Review	VPA assessment update with little change to the previous assessment, major retrospective pattern in previous assessment.
Gulf of Maine Winter Flounder	Paul Nitschke	Level 2 Expedited Review	Little change proposed to the assessment methods, little impact of the swept area adjustments on the NEFSC survey indices; missing survey in 2020 is problematic and the panel would recommend investigating other averaging approaches.
Atlantic Halibut	Dan Hennen	Level 2 Expedited Review	There was a large increase in the 2020 Canadian catch attributable to increased targeting by their longline fishery. We encourage investigation of the U.S. longline and any Canadian indices of abundance. There is sufficient investigation planned in the assessment methods to warrant a Level 2 review.
Witch Flounder	Susan Wigley	Level 1 Direct Delivery	Witch Flounder currently uses an empirical approach to provide management advice. The NEFSC bottom trawl surveys will be updated to include swept area adjusted abundance and biomass surveys. 2020 survey values missing due to Covid will be treated as missing in the application of the empirical approach.
Monkfish North	Jon Deroba	Level 2 Expedited Review	Revise discard estimation method from simple ratio to combined ratio method to make this consistent with SBRM and other stocks. No longer manually remove some ‘extreme’ discard observations. Make the stat areas that define each management area consistent among landing and discard calculations. Reconsider discard mortality assumption of scallop dredge based on Weissman et al. 2021.
Monkfish South	Jon Deroba	Level 2 Expedited Review	Revise discard estimation method from simple ratio to combined ratio method to make this consistent with SBRM and other stocks. No longer manually remove some “extreme" discard observations. Make the stat areas that define each management area consistent among landing and discard calculations. Reconsider discard mortality assumption of scallop dredge based on Weissman et al. 2021.
Georges Bank Haddock	Liz Brooks	Level 2 Expedited Review	Research Track completed earlier in 2022. Swept area adjustments to survey indices are within the confidence bounds of the survey estimates. Some changes to the projection methodology vs. the VPA based projections done in agepro.
Gulf of Maine Haddock	Charles Perretti	Level 3 Enhanced Review	The analyst plans to follow up on recommendations from the Research Track peer review to include the Bottom Longline Survey as a survey index and to develop a quantitative model that accounts for cohort strength to replace the averaging of Weights-at-Age over recent years in the projection approach.
CCGM Yellowtail Flounder	Larry Alade	Level 1 Direct Delivery	Scheduled for a Research Track assessment in 2024. One of the last remaining VPA. Few changes will be implemented. Missing survey data were evaluated and concerned about the retrospective.
SNEMA Yellowtail Flounder	Chris Legault	Level 2 Expedited Review	Scheduled for a Research Track assessment in 2024. Catch and survey indices are likely to remain very low. The analyst plans to explore fleet selectivity and other aspects to tune the ASAP model and explore cold pool indices relative to current recruitment to determine appropriate years to use projections.
White Hake	Kathy Sosebee	Level 3 Enhanced Review	Update all fishery and survey data through 2021. For 2020 CAA, use pooled Age Length Key as done for half 2 2003 since no survey age data. Potentially add ASMFC shrimp survey (include new age data) and bottom longline surveys either using spring and fall bottom trawl ages or direct ages.
Atlantic Pollock	Brian Linton	Level 3 Enhanced Review	Use new area swept-based NEFSC spring and fall survey indices. Evaluate use of a historical recreational catch series (1970–1980). Use current ASAP base and sensitivity model configurations. Evaluate new assessment starting year of 1981. Evaluate use of a single fishery fleet (commercial + recreational). Update base and sensitivity model BRPs using 2010 SAW 50 SSB/SSB Threshold, F40%SPR and SSB at F40%SPR projection approach.
American Plaice	Larry Alade	Level 2 Expedited Review	A Research Track stock assessment for American Plaice was peer reviewed in July 2022 (less than 3 weeks before the AOP meeting). New sources of data included 2020 and 2021 landings estimated through the Catch Assessment and Monitoring System (CAMS) and discards will be derived using CAMS generated landings and discard ratios generated using recent observer data. Projections will be done internally within WHAM, which will result in internally consistent input data. The alternative approach will be an ASAP type model (without random effects) that can be implemented within the WHAM framework.

Individual Stock Discussion Summaries:

Ocean Pout (AOP Lead: Michael Wilberg)

Recommendation: Level 1 (Direct Delivery)

Ocean pout is assessed using the relative exploitation rate following the accepted assessment in the 2008 GARM, and its most recent status was overfished but overfishing not occurring. The assessment uses the catch divided by the 3-year moving average of the NEFSC Spring Trawl Survey. Catch is prohibited, so all catch is from discards. Projections are not done for this stock, and there is no alternate assessment approach. Recent years discards are estimated using the total CAMS catch and discard ratios from NEFOP. Recreational discards are not included as they are considered negligible. The survey indices had only very minor changes from the swept area adjustments. The stock appears to be at low biomass, which could result in variable survey indices.

The management track assessment will go through 2021. There are no proposed changes to analyses, but two data streams have changes in how they are calculated: the NEFSC Spring Trawl Survey Index and the discarded catch. These changes in processing the data streams are expected to have minor effects, but they could result in larger changes than anticipated. In particular, the lack of NEFOP sampling during part of 2020 has the potential to affect the estimate of discards. The direction and magnitude of that effect would depend on whether the period for which samples are not available is different from the rest of the period over which discards are calculated. Additionally, the 2020 NEFSC Spring Trawl Survey index is not available, and a two-year moving average will be used for the years impacted by that year. Therefore, the AOP recommends a Level 1 (Direct Delivery) review.

Atlantic Wolffish (AOP Lead: Lisa Kerr)

Recommendation: Level 1 (Direct Delivery)

Wolffish is currently assessed using a forward projection model known as scale (Statistical Catch At Length) which tunes to size and age data from trawl survey recruitment and adult indices, total catch, and catch size distributions along with overall growth information. The model was approved by the 2008 Northeast Data Poor Stocks Working Group (NDPSWG) and last updated in 2020. The model features one fishery fleet with one selectivity block and four survey indices (NEFSC spring recruitment, and NEFSC fall and spring and MA DMF adult indices). The most recent stock status was overfished but overfishing is not occurring. In 2010, there was a change to a no possession limit for wolffish, so catch is from discards since that time. The NDPSWG deemed projections unreliable for this stock assessment and they are not conducted.

The management track assessment will update data for this stock through 2021. There are no proposed changes to the model, but two data streams (i.e., NEFSC Trawl Survey and the discarded catch) have changes in how they are calculated and Covid-19 disruptions resulted in missing surveys and reduced observer and port sampling of catch data in 2020. The NEFSC has adopted swept area biomass calculations of indices and the impact of the adjustment to the NEFSC trawl survey data was reported to be minimal for wolffish. The most recent years discards (2020 and 2021) will be estimated based on discard ratios calculated as usual based on observer data and the CAMS derived fleet landings. The missing 2020 surveydata will be treated as missing in the assessment (i.e., not imputed). The Panel expressed concern regarding the sufficiency of length frequency data in 2020 due to reduced observer coverage and how that could impact the assessment. The lead analyst noted that scale MRIP allows for missing length data and there are previous years with missing data. In addition, there is a general deficiency of data for this stock which would make it challenging to do much analytically about this issue. The  interceptAOP suggested that Bottom Longline Survey indices for wolffish be provided along with the assessment. The backup assessment approach is a ‘Plan B’ Loesssmooth of NEFSC spring and fall adult indices. The uncertainty introduced by using ocean pout calibration and integration of newly published sex specific growth parameters were discussed but won’t be addressed in this management track due to time limitations. This management track assessment will update data through 2021 and include a new survey index as additional information for consideration outside of the assessment. The AOP recommended a Level 1 (Direct Delivery) review for wolffish with the opportunity for an update from the analyst on any identified data or model issues at the August AOP meeting.

Georges Bank Winter Flounder (AOP Lead: Gary Nelson)

Recommendation: Level 2 (Expedited Review)

The current assessment method for Georges Bank Winter Flounder is a VPA model that includes age-specific US and Canadian landings and discards, and age-specific trawl indices (NEFSC fall, NEFSC spring and CA DFO spring surveys). The proposed work for the 2022 Management Track assessment includes updating all landings, discards and the survey data, and performing OFL and ABC projections at F_MSY for 2024–2026. The landings and discards will be updated via the CAMS system and the old NEFSC indices will be replaced with new NEFSC area-swept indices.

The AOP discussed the potential impact of the missing survey indices in 2020, data deficiencies with sampling and CAMS system estimates on the assessment. Comparisons between the new and old indices and between the 2019 AA and CAMS landings and discards were not provided, so members were uncomfortable concluding that the changes would have limited impacts on assessment results. In addition, the last VPA had a large retrospective bias and members expressed concern that low samples of data for characterizing catch-at-age could exacerbate the bias. Based on those concerns, the Panel elevated the assessment to a Level 2 (Expedited) review.

Gulf of Maine Winter Flounder (AOP Lead: Gary Nelson)

Recommendation: Level 2 (Expedited Review)

The current assessment method is an index-based approach that uses catch and estimates of 30+cm biomass from three non-overlapping fall trawl surveys (ME/NH, MA DMF, NEFSC). The proposed work for the 2022 Management Track assessment is to update the fall surveys and catch through 2021. The plan proposes to replace the NEFSC standardized trawl index with the new area-swept adjusted index. In addition, catch data will be assembled using the new CAMS automated system.

The AOP discussed three primary issues with the proposed assessment update. The AOP was concerned about the impact that Covid restrictions in 2020 had on sampling activities (e.g., sampling, observer coverage, etc.) from which estimates of landings and discards are made, and they wondered what biases could occur in the estimations. The AOP discussed the impact of the missing survey indices in 2020 on the calculation of catch advice because it is usually computed by using the average of two recent fall surveys; therefore, members worried about potential instability in the updated estimate using only one year (2021). Also, the AOP conferred that, although differences between NEFSC new area-swept index and the old index appear minor, some unanticipated changes in the results could occur. Based on those discussions, the Panel agreed to elevate this assessment to a Level 2 (Expedited) review.

Atlantic Halibut (AOP Lead: Paul Rago)

Recommendation: Level 2 (Expedited Review)

Atlantic halibut catches limits are based on an index method that combines trends in several measures of relative abundance to adjust recent catches on a regular basis. The method is known as the First and Second Derivative (FSD) method because it adjusts catches using a linear combination of the slope and rate of change in slopes of abundance indices. The catch in year t+ 1 is estimated as the product of the adjustment rate and the catch in year t. The abundance indices are the NEFSC fall bottom trawl survey and discard ratios for gillnet and trawl fleets in the Northeast. No biological reference points for Atlantic halibut in the US are available.

Application of the model in 2022 is complicated by a major change in the Canadian fishery in 2020. The total catch used in the original model includes catches in Canada from Stat Area 5. Shackell et al. (2021) reports the ongoing recovery of halibut but the recovery in Canadian waters may be occurring more quickly. Tagging analyses reported in Rago (2018) suggest regular movement of Atlantic halibut between US and Canada.

The sharp increase in landings in Canadian waters and declining indices in the US poses a dilemma for application of the current FSD model. Canada’s increase in landings is driven by results of a DFO assessment that increased the quota. This assessment is likely to have indices that are trending upward in contrast to US indices which appear to be either level or slightly decreasing. Nonetheless, the slightly lower FSD multiplier, when multiplied by the increased total catch, results in a large increase in potential US catch. The appropriateness of this calculation was discussed but not resolvable during the AOP meeting.

The Panel suggested that an investigation of the basis for the increase in Canadian landings would be useful. Comparisons of US index trends with Canadian indices of abundance might also be useful. The assessment lead will also investigate the applicability of the Cooperative Longline survey in the Gulf of Maine in the FSD model. The assessment lead also proposes to modify and align some of the Stat Areas with survey areas but does not plan to redefine stock areas. In view of the potential changes in the model framework and addition of a new index, the Panel recommended a Level 2 (Expedited) review for Atlantic halibut.

Witch Flounder (AOP Lead: Russell Brown)

Recommendation: Level 1 (Direct Delivery)

Witch Flounder currently uses an empirical approach to provide management advice. It is a unit stock, so is less dependent on CAMS approaches to allocate catch to separate stock areas. The NEFSC bottom trawl surveys will be updated to include swept area adjusted abundance and biomass surveys. 2020 survey values missing due to Covid will be treated as missing in the application of the empirical approach. It was noted that the age structure of the population continues to be truncated and the analyst will include supplement data in the data portal that is not directly used in the empirical analysis. The panel concluded that a Level 1 (Direct Delivery) review was warranted.

Northern and Southern Monkfish (AOP Lead: Gary Nelson)

Recommendation: Level 2 (Expedited Review)

The current assessment method for the northern and southern Monkfish stocks is the index-based method known as ‘PlanBsmooth’ that uses fishery landings and discards, and NEFSC fall, spring and summer survey indices. The proposed work for the 2022 Management Track assessment includes updating all landings, discards and the survey data through 2021 (the spring survey will be updated through 2022). The landings will be updated via the CAMS system and a new method for estimating discards will be examined. Also, the old NEFSC indices will be replaced with new NEFSC area-swept indices and methods for dealing with the missing 2020 survey values will be explored. Additionally, the discard mortality assumption of Monkfish in scallop dredges will be re-examined, how extreme discard observations are handled will be changed, and adjustments to statistical areas that define the managements will be made consistent.

The main discussion of the AOP pertained to the proposed exploration of imputing missing survey values. One member wondered what the potential outcome would be and suggested that including an additional year further back in time might help with stability of resulting catch advice. The analyst responded that, based on earlier simulations examining biases in the ‘PlanBsmooth’ method, catch advice should be fairly robust with a missing year, but he will try the suggested method. The AOP panel agreed that a Level 2 (Expedited) review is appropriate for the proposed changes.

Georges Bank Haddock (AOP Lead: Russell Brown)

Recommendation: Level 2 (Expedited Review)

A Research Track Assessment for Haddock was completed earlier in 2022. The assessment will be updated through 2021 and utilize a WHAM state space model to develop estimates of recruitment, biomass, and fishery mortality. In the Research Track, the working group and analyst demonstrated extensive bridge building from VPA to ASAP, and from ASAP to WHAM (Research Track TOR#4). The panel was concerned that this is one of the first implementations of WHAM, uncertainty about the change in the scale of the catch advice, and about reduced sampling in recent years. On this basis, the panel recommended a Level 2 (Expedited) review for this stock.

Gulf of Maine Haddock (AOP Lead: Russell Brown)

Recommendation: Level 3 (Enhanced Review)

A Research Track Assessment for Haddock was completed earlier in 2022. The assessment will be updated through 2021 and utilize an ASAP model to develop estimates of recruitment, biomass, and fishery mortality. The analyst plans to follow up on recommendations from the Research Track peer review to include the Bottom Longline Survey as a survey index and to develop a quantitative model that accounts for cohort strength to replace the averaging of Weights-at-Age over recent years in the projection approach. Based on these proposed changes to the assessment methodology the AOP concurred with the analyst recommendation that the management track update should receive a Level 3 (Enhanced) review.

Cape Cod/Gulf of Maine Yellowtail Flounder (AOP Lead: Lisa Kerr)

Recommendation: Level 1 (Direct Delivery)

Cape Cod/Gulf of Maine (CCGM) yellowtail flounder is assessed using a VPA that was approved in 2008 at GARM III and was last updated in 2019. The model includes a single fishery fleet and fall and spring time series from three fishery independent surveys (NEFSC, MA DMF, and ME/NH trawl surveys). This assessment has retrospective issues and adjustments were made to the model results. The most recent stock status is not overfished and overfishing is not occurring.

Two data streams (i.e., NEFSC trawl survey and landings) have changes in how they are calculated and Covid-19 disruptions resulted in missing surveys and reduced observer and port sampling of catch data in 2020. The NEFSC has adopted swept area biomass calculations of indices and the impact of the adjustment to the NEFSC trawl survey data is minimal for CCGM yellowtail flounder. The transition from AA tables to CAMS is not anticipated to have a significant impact based on a 2019 data comparison. The missing survey data will be treated as missing in the assessment (i.e., not imputed). An initial analysis of the impact of missing survey data on the performance of the VPA suggests the impact will be minimal.

This management track assessment will update all fishery and survey data through 2021 and use the current VPA model configuration with no changes. Projections will be calculated and BRPs will be updated using the prescribed approach without changes. The analyst will perform a comparison of population size between the cooperative research twin trawl catchability study and the VPA model estimates. The alternative assessment is an empirical approach which applies catchability estimates from the twin trawl study to expand survey catch/tow to absolute biomass from Bigelow Spring and Fall survey estimates. There are no major changes to the assessment model or the types of data incorporated in the model. The analyses of impacts of changes in data streams and missing data suggest that these will have minimal impact. The AOP recommended a Level 1 (Direct Delivery) review for CCGM yellowtail flounder with the opportunity for an update on any identified data or model issues at the August AOP meeting. The last management track assessment cited concerns about the uncertainty and retrospective patterns in this stock assessment. This is one of the last remaining assessments that applies the VPA approach and it is scheduled for a Research Track Stock Assessment in 2024. Major changes will be addressed at that time with a likely change in model type.

Southern New England/Mid-Atlantic Yellowtail Flounder (AOP Lead: Paul Rago)

Recommendation: Level 2 (Expedited Review)

The current assessment model for SNEMA yellowtail is based on an ASAP model, accepted in 2012 at SAW 54 and last updated in 2019. The model features an age dependent M, single fleet fishery, and three fishery independent surveys. Six selectivity blocks are used to model the stock from 1973 to 2018. The most recent selectivity block began in 2002. The stock is severely depleted, at about 10% of the 1/2 B_MSY level, but overfishing is not occurring. Recruitment has been low and both reference points and projections are based on R estimates from 1990 onward.

The pandemic resulted in loss of both spring and fall bottom trawl surveys in 2020 and reductions in observer coverage. Funding issues reduced port sampling efforts. There are no recreational landings. Bottom trawl estimates will now use swept area per tow measurements to improve accuracy. Slight changes in overall means have been observed, but the variances of estimates tend to be large, overwhelming potential differences in scale. There does not seem to be any significant trend towards higher or lower values given adjustments for swept area. Landings estimates by stat area, previously based on the AA method, are expected to change only slightly as a result of the new CAMS approach. The new estimates of landings will not have any effects on estimates of discards but might be important in some instances in the future. Discard estimates are scaled by multiplying discard:kept ratios by total landings, which will change when CAMS rather than AA based estimates are used. The lead analyst has proposed to re-examine the selectivity blocks and other settings to improve model performance. The potential effects of swept area-adjusted survey indices will also be examined. Several recent publications in the literature have illustrated the utility of state-space models to estimate effects of environmental factors on stock dynamics. In particular, increases of the cold pool index (i.e., warmer) in the mid-Atlantic are associated with lower recruitment. These results cannot be directly included in the current model but they may be used to refine the range of years used to define ‘recent’ recruitment. Such a change, if justifiable, would alter both the biological reference points and abundance projections.

Given the potential effects of changes in selectivity blocks and the consideration of state space model results to inform the current assessment, the AOP recommended a Level 2 (Expedited) review for SNEMA yellowtail.

White Hake (AOP Lead: Lisa Kerr)

Recommendation: Level 3 (Enhanced Review)

White Hake is currently assessed using the ASAP model which was accepted in 2013 at SAW 56 and was last updated in 2019. The model extends back to 1963 and includes one fishery fleet with two selectivity blocks and two trawl survey indices (NEFSC fall and spring). Catch at age information is not well characterized for this stock due to possible misidentification of species in the commercial and observer data, particularly in early years, low sampling of commercial landings in some years, and sparse discard length data. Pooled age length keys (ALK) have been used during periods with deficient age data. The current status is overfished and overfishing is not occurring. This assessment has retrospective issues and adjustments were made to the model results.

Two data streams (i.e., NEFSC Trawl Survey and landings) have changes in how they are calculated and Covid-19 disruptions resulted in missing surveys and reduced observer and port sampling of catch data in 2020. The NEFSC has adopted swept area biomass calculations of indices and the impact of the adjustment to the NEFSC trawl survey data will be reported for white hake. The impact of the transition from AA tables to CAMS for white hake will be documented based on a 2019 data comparison. The missing survey data will be treated as missing in the assessment (i.e., not imputed) and a pooled ALK will be used for 2020 CAA for commercial landings.

The management track assessment will update all fishery and survey data through 2021. In addition, two new indices will be considered in the management track, the ASMFC shrimp survey and the Bottom Longline Survey. The current ASAP model configuration will be used with the additional indices. The analyst will explore the model sensitivity to use of pooled ALK. The biological reference points will be updated using approach prescribed through SAW 56 and projections will be performed assuming catch in 2022 is equal to the PDT provided 2022 landings. The alternative assessment plan is Loess smoothing of both NEFSC surveys indices to infer future catch increase. Age information as an important source of uncertainty for this stock. Ageing was completed for white hake from the shrimp survey, however, there is still a need for observer ages and from the bottom longline survey.

This management track assessment will involve substantial changes, including the potential addition of a new survey index. The AOP agreed with the analyst’s suggestion of a Level 3 (Enhanced) review for this stock.

Pollock (AOP Lead: Paul Rago)

Recommendation: Level 3 (Enhanced Review)

Pollock is currently assessed with an ASAP model that relies on dome shaped selectivity patterns for both the fishery and surveys. To ensure model convergence, the selectivity of oldest fish is fixed. The double dome model creates a “cryptic" biomass that cannot be estimated by survey data or captured by the commercial fishery.

Assessment scientists, managers, and even some harvesters have expressed concerns about the validity of the base (i.e., double-domed) model. An alternative model, which includes the same data but assumes a flat-top selectivity for survey indices, is used for comparison. Estimates of exploitable biomass from the base model compare favorably to the estimates from the sensitivity model (with a flat-top selectivity pattern for the survey).

The change from AA to CAMS appears to have little effect (0.1% increase) for 2019 comparison. Similarly, the use of a variable area per tow estimator appears to have little effect on the annual mean abundance estimates.

Commercial and recreational fisheries are modeled separately using data from 1970 to present. However, recreational catch before the start of the MRFSS program is assumed to be zero. To eliminate this inconsistency, a revised starting year of 1981 is proposed. The assessment lead also suggested pooling of recreational and commercial landings. This would eliminate the need to specify two selectivity patterns for these fleets. However, there may be some conflating of selectivity patterns because recreational catcheshistorically occurred inshore and on smaller fish (so called harbor pollock). The joint effects of changing the starting year, combining the recreational and commercial catches into a single fleet, and inherent instability of the base model are likely to require significant exploration of alternative model runs. After consideration of the number of changes, and their potential interactive effects, the Panel concurred with the lead scientist’s recommendation for a Level 3 (Enhanced) review.

American Plaice (AOP Lead: Russell Brown)

Recommendation: Level 2 (Expedited Review)

The Research Track stock assessment for American Plaice was peer reviewed in July 2022 (less than 3 weeks before the AOP meeting). A state space WHAM model informed by data through 2019 was tabled by the Management Track and accepted by the CIE peer review panel. New sources of data included 2020 and 2021 landings estimated through the Catch Assessment and Monitoring System (CAMS) and discards will be derived using CAMS generated landings and discard ratios generated using recent observer data. Model diagnostics for the assessment through 2019 were well behaved and the retrospective pattern was relatively insignificant (no retrospective adjustments are anticipated). Projections will be done internally within WHAM, which will result in internally consistent input data. The alternative approach will be an ASAP type model (without random effects) that can be implemented within the WHAM framework. As a result of these proposed changes, the AOP concurred that this assessment should receive a Level 2 (Expedited) review.

AOP Meeting Conclusions:

The AOP met on May 23–24, 2022 to review the stock assessment plans for 14 stocks and on August 3, 2022 for one stock scheduled for the September 2022 Management Track cycle. The panel concluded that Level 1 reviews (Direct Delivery) were warranted for ocean pout, Atlantic wolffish, witch flounder, and Cape Cod/Gulf of Maine yellowtail flounder; Level 2 reviews (Expedited Review) for Georges Bank winter flounder, Gulf of Maine winter flounder, Atlantic halibut, northern and southern monkfish, Georges Bank haddock, Southern New England/Mid-Atlantic yellowtail flounder and American Plaice; and Level 3 reviews (Enhanced Review) for Gulf of Maine haddock, white hake, and pollock. The Level 2 and 3 reviews will occur during the September 2022 Management Track Peer Review scheduled for September 19–22, 2022. Changes in the required review level would be triggered by a Northeast Fisheries Science Center request to increase the review level for a given stock. The AOP could concur to increase the review level via email or request to reconvene the AOP panel to have further discussions with the stock assessment lead. Any need to reconvene the panel would be a publicly announced meeting and any subsequent changes to the review level would be publicized to assessment partners and stakeholders.

Appendix A.1.  Meeting participants

Panel, May 2022:

• Lisa Kerr  –   AOP  ( NEFMC   SSC )
• Gary Nelson  –   AOP  ( ASMFC )
• Mike Wilberg and Paul Rago  –   AOP  ( MAFMC   SSC )
• Russ Brown  –   AOP  Chair ( NEFSC )
• Michele Traver  –   NEFSC  Assessment Process Lead

Attendees and Presenters, May 2022:

• Alex Dunn  –   NEFSC
• Alex Hansell  –   NEFSC
• Andrew Jones  –   NEFSC
• Angela Forristall  –   NEFMC
• Benjamin Levy  –   NEFSC
• Brian Linton  –   NEFSC
• Cate O’Keefe  –  Fishery Applications Consultant
• Charles Adams  –   NEFSC
• Charles Perretti  –   NEFSC
• Chris Kellogg  –   NEFMC
• Chris Legault  –   NEFSC
• Christopher Maguire  –  Nature Conservancy
• Daniel Hennen  –   NEFSC
• Gareth Lawson  –  Conservation Law Foundation
• Jamie Cournane  –   NEFMC
• Janice Plante  –   NEFMC
• Jean-Jacques Maguire  –   NEFMC   SSC
• Jennifer Couture  –   NEFMC
• John Pappalardo  –   NEFMC  member, Cape Cod Commercial Fishermen’s Alliance
• Jon Deroba  –   NEFSC
• Julie Nieland  –   NEFSC
• Katherine Sosebee  –   NEFSC
• Kelley Whitmore  –   MA DMF
• Kiersten Curti  –   NEFSC
• Larry Alade  –   NEFSC
• Libby Etrie  –   NEFMC  member, Northeast Sector Service Network, Inc.
• Liz Brooks  –   NEFSC
• Liz Sullivan  –   GARFO
• Maggie Raymond  –  Associated Fisheries of Maine
• Melissa Sanderson  –  Cape Cod Commercial Fishermen’s Alliance
• Paul Nitschke  –   NEFSC
• Peter Melanson  –  Protech AIS
• Rachel Feeney  –   NEFMC
• Rebecca Peters  –   ME DMR
• Rick Bellavance  –   NEFMC  Vice Chair,  RI  Party and Charter Boat Association
• Robin Frede  –   NEFMC
• Spencer Talmage  –   GARFO
• Steve Cadrin  –   SMAST
• Susan Wigley  –   NEFSC
• Tara Dolan  –   MA DMF
• Thomas Nies  –   NEFMC  Executive Director
• Tracey Bauer  –   ASMFC

Appendix B.  Management Track Stock Assessment Terms of Reference

1. 1.
   Estimate catch from all sources including landings and discards.
2. 2.
   Evaluate indices used in the assessment (e.g., indices of relative or absolute abundance, recruitment, state surveys, age-length data, etc.).
3. 3.
   Estimate annual fishing mortality, recruitment and stock biomass (both total and spawning stock) as possible (depending on the assessment method) for the time series using the approved assessment method and estimate their uncertainty. Include retrospective analyses if possible (both historical and within-model) to allow a comparison with previous assessment results and projections, and to examine model fit.

   1. a.
      Include bridge runs to sequentially document each change from the previously accepted model to the updated model proposed for this peer review.
   2. b.
      Prepare a backup assessment approach that would serve as an alternative for providing scientific advice to management if the analytical assessment were to not pass review.
4. 4.
   Re-estimate or update the  BRPs as defined by the management track level and recommend stock status. Also, provide qualitative descriptions of stock status based on simple indicators/metrics (e.g., age- and size-structure, temporal trends in population size or recruitment indices, etc.).
5. 5.
   Conduct short-term stock projections when appropriate.
6. 6.
   Respond to any review panel comments or  SSC  concerns from the most recent prior research or management track assessment.

Note: Major changes from the previous stock assessment require pre-approval by the Assessment Oversight Panel.

Appendix C.  September 2022 Management Track Peer Review meeting attendees.

Panel, September 2022:

• Richard Merrick  –  Chair
• Matt Cieri  –  Panel
• Cate O’Keefe  –  Panel
• Yan Jiao  –  Panel
• Russ Brown  –   NEFSC  
• Michele Traver  –   NEFSC

Attendees and Presenters, September 2022:

• Alan d’Entremont– Scotia Harvest Inc.,  TMGC  Canadian co-chair
• Alex Dunn  –   NEFSC
• Alex Hansell  –   NEFSC
• Angela Forristall  –   NEFMC
• Bill Devoe  –   ME DMR
• Brian Linton  –   NEFSC
• Carl Wilson  –   ME DMR
• Charles Adams  –   NEFSC
• Charles Perretti  –   NEFSC
• Chris Kellogg  –   NEFMC
• Chris Legault  –   NEFSC
• Dan Hennen  –   NEFSC
• Dave McElroy  –   NEFSC
• Dave Richardson  –   NEFSC
• Gareth Lawson  –  Conservation Law Foundation
• Gary Nelson  –   MA DMF
• Jackie O’Dell  –  Northeast Fisheries Coalition
• Jamie Cournane  –   NEFMC
• Jason Didden  –   MAFMC
• Jennifer Couture  –   NEFMC
• Jon Deroba  –   NEFSC
• Jonathon Peros  –   NEFMC
• Joseph Powers  –   NOAA  (retired)
• Julie Nieland  –   NEFSC
• Kathy Sosebee  –   NEFSC
• Kelly Whitmore  –   MA DMF
• Kiersten Curti  –   NEFSC
• Kris Vascotto  –  Atlantic Groundfish Council, Executive Director
• Larry Alade  –   NEFSC
• Libby Etrie  –  Northeast Sector Service Network, Inc.
• Liz Brooks  –   NEFSC
• Liz Sullivan  –   GARFO
• Melanie Griffin  –   MA DMF
• Mark Terceiro  –   NEFSC
• Paul Nitschke  –   NEFSC
• Rachel Feeney  –   NEFMC
• Rebecca Peters  –   ME DMR
• Rick Bellavance  –   RI  Party and Charter Boat Association
• Robin Frede  –   NEFMC  
• Spencer Talmage  –   GARFO
• Steve Cadrin  –   SMAST
• Susan Wigley  –   NEFSC
• Tara Dolan  –   MA DMF
• Tara Trinko Lake  –   NEFSC
• Tom Miller  –   NEFSC
• Tom Nies  –   NEFMC , Executive Director
• Tracey Bauer  –   NCDMF
• Xavier Mouy  –   NEFSC
• Yanjun Wang  –   DFO

Aerial view of NMFS  building and surrounds, Woods Hole Laboratory, MA; photo © WHOI

Appendix D.  Realized AgendaforSeptember2022 ManagementTrack peer review

Time	Activity	Lead
Monday, September 19, 2022
9:00–9:15am	Welcome/Logistics/Conduct of Meeting	Michele Traver, Russ Brown, Richard Merrick, Chair
9:15–10:00am	Input Data Changes Discussion/Questions	Russ Brown, Review Panel
10:00–11:00am	GOM Winter flounder Discussion/Questions	Paul Nitschke, Review Panel
11:00–11:15am	— Break —
11:15–12:15pm	George Bank winter flounder Discussion/Questions	Alex Hansell, Review Panel
12:15–12:30pm	Discussion/Summary	Review Panel
12:30–12:45pm	Public Comment	Public
12:45–1:45pm	— Lunch —
1:45–2:45pm	Atlantic halibut Discussion/Questions	Dan Hennen, Review Panel
2:45–3:45pm	Georges Bank haddock Discussion/Questions	Liz Brooks, Review Panel
3:45–4:00pm	— Break —
4:00–4:15pm	Discussion/Summary	Review Panel
4:15–4:30pm	Public Comment	Public
4:30pm	— Adjourn —
Tuesday, September 20, 2022
9:00–9:05am	Welcome/Logistics	Michele Traver, Richard Merrick, Chair
9:05–10:30am	White hake	Kathy Sosebee
10:30–10:45am	— Break —
10:45–12:00am	White hake cont. Discussion/Questions	Kathy Sosebee, Review Panel
12:00–12:15pm	Discussion/Summary	Review Panel
12:15–12:30pm	Public Comment	Public
12:30–1:30pm	— Lunch —
1:30–3:30pm	Monkfish (North and South) Discussion/Questions	Jon Deroba, Review Panel
3:30–3:45pm	— Break —
3:45–4:45pm	Southern New England/Mid-Atlantic yellowtail flounder Discussion/Questions	Chris Legault
4:45–5:00pm	Discussion/Summary	Review Panel
5:00–5:15pm	Public Comment	Public
5:15pm	— Adjourn —
Wednesday, September 21
9:00–9:05am	Welcome/Logistics	Michele Traver, Richard Merrick, Chair
9:05–10:30am	Gulf of Maine haddock	Charles Perretti
10:30–10:45am	— Break —
10:45–12:00pm	Gulf of Maine haddock cont. Discussion/Questions	Charles Perretti, Review Panel
12:00–12:15pm	Discussion/Summary	Review Panel
12:15–12:30pm	Public Comment	Public
12:30–1:30pm	— Lunch —
1:30–3:30pm	Pollock	Brian Linton
3:30–3:45pm	— Break —
3:45–4:45pm	Pollock cont. Discussion/Questions	Brian Linton
4:45–5:00pm	Discussion/Summary	Review Panel
5:00–5:15pm	Public Comment	Public
5:15pm	— Adjourn —
Thursday, September 22
9:30–11:00am	American plaice Discussion/Questions	Larry Alade
11:00–11:15am	Discussion/Summary	Review Panel
11:15–11:30am	Public Comment	Public
11:30–12:00am	Key Points/Follow ups	Review Panel
12:00–1:00pm	— Lunch —
1:00–5:00pm	Report Writing	Review Panel

2.  ATLANTIC WOLFFISH

State of Stock: Based on this updated assessment, the Atlantic wolffish (Anarhichas lupus) stock is overfished and overfishing is not occurring (Figures 1–2). Retrospective adjustments were not made to the model results. Spawning stock biomass (SSB) in 2021 was estimated to be 690 (mt) which is 46% of the biomass target (SSB_{MSY proxy} = 1,509; Figure 1). The 2021 fully selected fishing mortality was estimated to be 0.004 which is 2% of the overfishing threshold proxy (F_{MSY proxy}= 0.192; Figure 2).

Special Comments: 

• •
  What are the most important sources of uncertainty in this stock assessment? Explain, and describe qualitatively how they affect the assessment results (such as estimates of biomass,  F, recruitment, and population projections).

  The primary sources of uncertainty are the use of the ocean pout calibration coefficient (Atlantic wolffish coefficients are unknown), and the change to a no possession limit in May 2010. The ocean pout calibration coefficient (4.575) is one of the largest for any species (Miller et al. 2010), and results in lower biomass estimates. The change to a no possession limit places greater importance on discard mortality. Additionally, it is unclear whether the lack of a recruitment index since 2005 is due to an actual decrease in recruitment, or a change in catchability resulting from the increase in liner mesh size associated with the switch to the Bigelow. Other sources of uncertainty were identified in previous Atlantic wolffish assessments (NDPSWG 2009, NEFSC 2012): the surveys may have reached the limit of wolffish detectability due to the decline in abundance; and the lack of commercial length information results in model estimation difficulties for fishery selectivity.

• •
  Does this assessment model have a retrospective pattern? If so, is the pattern minor, or major? (A major retrospective pattern occurs when the adjusted  SSB  or  F_Full  lies outside of the approximate joint confidence region for  SSB  and  F_Full).

  This assessment has retrospective patterns with Mohn’s ρ= 0.18 for SSB and −0.10 for F. However, confidence intervals are not available because MCMC is not fully developed for the scale model.

• •
  Based on this stock assessment, are population projections well determined or uncertain? If this stock is in a rebuilding plan, how do the projections compare to the rebuilding schedule?

  Due to the uncertainties in the assessment, the Northeast Data Poor Stocks Working Group (NDPSWG 2009) concluded that stock projections would be unreliable and should not be conducted. Catch advice is derived as OFL=F_MSY×B_Terminal using the terminal year exploitable biomass.

• •
  Describe any changes that were made to the current stock assessment, beyond incorporating additional years of data and the effect these changes had on the assessment and stock status.

  The time series of Bigelow indices was recalculated using station-specific swept areas. Supplemental Figure 26 (seeSASINF ) was presented to the Assessment Oversight Panel (AOP) on May 23, 2022; the AOP agreed that the differences were minor.The data source for commercial landings changed to the Catch Accounting and Monitoring System (CAMS) beginning in 2020. However, given the no possession limit, the AOP agreed that this is not an issue.

• •
  If the stock status has changed a lot since the previous assessment, explain why this occurred.

  Stock status has not changed since the previous assessment.

• •
  Provide qualitative statements describing the condition of the stock that relate to stock status.

  Catch has been limited almost exclusively to discards since the implementation of the no possession rule in May 2010. No age-1 recruits have been caught in the NEFSC spring survey since 2005.

• •
  Indicate what data or studies are currently lacking and which would be needed most to improve this stock assessment in the future.

  Several research needs were identified by the Peer Review Panel in the 2015 assessment (NEFSC 2015): potential use of a likelihood profile to apply the criterion for a retrospective adjustment; further studies on growth parameters; a tagging study to provide information on stock structure and movement; and a study of post-capture nest site fidelity.

• •
  Are there other important issues?

  All 2020 surveys were treated as missing in the scale model. However, it should be noted that the scale model treats survey indices with zero catch as missing as well. For example, the NEFSC spring adult index had zero catch in 2004–2006, 2008 and 2011; thus, these years are treated as missing by the scale model.Recruitment at the end of the time series increases toward the initial recruitment estimate (Table 3; Figure 3) because there is no information in the model to inform these estimates. There is no indication in the data that recruitment has increased recently.Approximate 90% log-normal confidence intervals are not shown in Figures 1–3 because MCMC is not fully developed for the scale model.Discards estimates assume an 8% mortality rate based on Grant and Hiscock (2014). This results in very low removals under the no possession rule. Future model updates should see a population response from these low removals. However, if no change is observed in the data inputs (e.g., increased survey indices) then the diagnostics may worsen.Bottom long-line survey indices, which are not currently used in the scale model, are shown in supplemental Figure 27 (seeSASINF ) for informational purposes.

Wolffish at floor of aquarium tank. Photo credit: Woods Hole Aquarium

Anarhichas lupus, Atlantic wolffish.

Figure 1: Trends in spawning stock biomass of Atlantic wolffish between 1968 and 2021 from the current (solid line) and previous (dashed line) assessment and the corresponding  SSB_Threshold  ( 1/2 SSB_{MSY proxy} ; horizontal dashed line) as well as  SSB_Target  ( SSB_{MSY proxy}; horizontal dotted line) based on the 2022 assessment. Biomass was not adjusted for a retrospective pattern.

Figure 2: Trends in the fully selected fishing mortality ( F_Full ) of Atlantic wolffish between 1968 and 2021 from the current (solid line) and previous (dashed line) assessment and the corresponding  F_Threshold  ( F_{MSY proxy}= 0.192 ; horizontal dashed line) based on the 2022 assessment.  F_Full  was not adjusted for a retrospective pattern

Figure 3: Trends in age-1 recruits (millions) of Atlantic wolffish between 1968 and 2021 from the current (solid line) and previous (dashed line) assessment.

Figure 4: Total catch of Atlantic wolffish between 1968 and 2021 by fleet (commercial and recreational) and disposition (landings and discards). Note that a no possession limit was put in place in May 2010.

Figure 5: Indices of biomass for Atlantic wolffish between 1968 and 2021 for the Northeast Fisheries Science Center ( NEFSC) spring and fall bottom trawl surveys, and the Massachusetts Division of Marine Fisheries ( MADMF ) spring bottom trawl survey. The approximate 90%  log-normal  confidence intervals are shown.

3.  GULF OF MAINE WINTER FLOUNDER

State of Stock: Based on this updated assessment, the Gulf of Maine winter flounder (Pseudopleu- ronectes americanus) stock biomass status is unknown and overfishing is not occurring (Figures 6–7). Retrospective adjustments were not made to the model results. Biomass (30+cm mt) in 2021 was estimated to be 5,093 mt (Figure 6). The 2021 30+cm exploitation rate was estimated to be 0.033 which is 14% of the overfishing exploitation threshold proxy (E_{MSY proxy}= 0.23; Figure 7).

Projections: Projections are not possible with area-swept based assessments. Catch advice was based on 75% of E_40%(75%E_{MSY proxy}) using the terminal year fall area-swept estimate assuming q= 0.81 on the wing spread which was updated using the average efficiency from 2009–2021 from the sweep experiment (Miller et al., 2017). Updated 2021 fall 30+cm area-swept biomass (5,093 mt) implies an OFL of 1,171 mt based on the E_{MSY proxy} and a catch of 879 mt for 75% of the E_{MSY proxy}. Catch advice (OFLs and ABCs) from the 2020 Management Track assessment was based on the average of the last two years of the fall surveys to make better use of the available new information and to help stabilize the catch advice. Alternatively, since the 2020 surveys are not available due to Covid, using the average of updated 2021 and 2022 spring and 2021 fall 30+cm area-swept biomass (4,660 mt) implies an OFL of 1,072 mt based on the E_{MSY proxy} and a catch of 804 mt for 75% of the E_{MSY proxy}.

Special Comments: 

• •
  What are the most important sources of uncertainty in this stock assessment? Explain, and describe qualitatively how they affect the assessment results (such as estimates of biomass,  F, recruitment, and population projections).

  The largest source of uncertainty with the direct estimates of stock biomass from survey area-swept estimates originates from the survey gear catchability (q). Biomass and exploitation rate estimates are sensitive to the survey q assumption. However this 2022 update does incorporate the use of a re-estimated q through an average estimate of efficiency from 2009–2021 fall and 2009–2022 spring (q= 0.81 fall and q= 0.70 spring) from the sweep study for the NEFSC survey. This updated q assumption (0.81) results in a lower estimate of 30+cm  biomass (5,093 mt) relative to the 2020 estimate q= 0.71 assumption (5,783 mt) from the updated fall surveys. Another major source of uncertainty with this method is that biomass based reference points cannot be determined and overfished status is unknown.

• •
  Does this assessment model have a retrospective pattern? If so, is the pattern minor, or major? (A major retrospective pattern occurs when the adjusted  SSB  or  F_Full  lies outside of the approximate joint confidence region for  SSB  and  F_Full.)

   The model used to determine status of this stock does not allow estimation of a retrospective pattern. An analytical stock assessment model does not exist for Gulf of Maine winter flounder. An analytical model was no longer used for stock status determination at SARC 52 (2011) due to concerns with a strong retrospective pattern. Models have difficulty with the apparent lack of a relationship between a large decrease in the catch with little change in the indices and age and/or size structure over time.

• •
  Based on this stock assessment, are population projections well determined or uncertain? If this stock is in a rebuilding plan, how do the projections compare to the rebuilding schedule?

  Population projections for Gulf of Maine winter flounder do not exist for area-swept assessments and stock biomass status is unknown. This stock was never declared as overfished. Catch advice from area-swept estimates tend to vary with inter-annual variability in the surveys. Consideration was given to using multiple surveys (fall 2021 and spring 2021–2022) to stabilize the biomass estimates and catch advice since 2020 surveys are not available due to Covid.

• •
  Describe any changes that were made to the current stock assessment, beyond incorporating additional years of data and the effect these changes had on the assessment and stock status.

  The assumption on q changed from 0.71 to 0.81 for the fall and from 0.62 to 0.70 for the spring using information from the updated average qs from the NEFSC survey (Miller et al., 2017) and incorporation of new survey data were made to this Gulf of Maine winter flounder Management Track assessment. The 2020 and 2021 commercial catch estimates are based on CAMS in this assessment. However, changes in total removals will not directly affect the estimated biomass or catch advice and total removals still remain far below the overfishing definition. In addition there were some minor changes to the survey indices due to tow based area-swept adjustments.

• •
  If the stock status has changed a lot since the previous assessment, explain why this occurred.

  The overfishing status of Gulf of Maine winter flounder has not changed.

• •
  Provide qualitative statements describing the condition of the stock that relate to stock status.

  The Gulf of Maine winter flounder has relatively flat survey indices with little change in the size structure over time. There have been large declines in the commercial and recreational removals since the 1980s. This large decline over the time series does not appear to have resulted in a response in the stock’s size structure within the catch and surveys nor has it resulted in a change in the survey indices of abundance. However, there have been increases in the fall 2021 and the spring 2021 and 2022 area swept biomass estimates. If increasing biomass trends continue then perhaps this is the beginning of a response to time series lows in exploitation rates.

• •
  Indicate what data or studies are currently lacking and which would be needed most to improve this stock assessment in the future.

  Direct area-swept assessments could be improved with additional studies on state survey gear efficiency. Quantifying the degree of herding between the doors and escapement under the footrope and/or above the headrope for state surveys is needed to improve the area-swept biomass estimates. Studies quantifying winter flounder abundance and distribution among habitat types and within estuaries could improve the biomass estimate.

• •
  Are there other important issues?

  The general lack of a response in survey indices and age/size structure are the primary sources of concern with catches remaining far below the overfishing level. Recent increases in the biomass could perhaps be the being of a response to removals being at record lows over the last three years (2019–2021). If recent increases in biomass is a response to the low catches then continuation of keeping catches near recent levels should result in further increases in biomass.

Pseudopleuronectes americanus, Winter Flounder.

Figure 6: Trends in 30 + cm  area-swept biomass of Gulf of Maine winter flounder between 2009 and 2021 from the current assessment based on the fall ( ME/NH ,  MADMF ,  NEFSC) surveys.

Figure 7: Trends in the exploitation rates ( E_Full) of Gulf of Maine winter flounder between 2009 and 2021 from the current assessment based on the fall ( ME/NH ,  MADMF ,  NEFSC ) surveys and the corresponding  F_Threshold  ( E_{MSY proxy}= 0.23; horizontal dashed line).

Figure 8: Total catch of Gulf of Maine winter flounder between 2009 and 2021 by fleet (commercial and recreational) and disposition (landings and discards). A 15% mortality rate is assumed on recreational discards and a 50% mortality rate on commercial discards.

Figure 9: Indices of biomass for the Gulf of Maine winter flounder between 1978 and 2022 for the Northeast Fisheries Science Center ( NEFSC), Massachusetts Division of Marine Fisheries ( MADMF), and the Maine New Hampshire ( ME/NH ) spring and fall bottom trawl (strata 1–3) surveys.  NEFSC  indices are calculated with gear and vessel conversion factors where appropriate. The approximate 90%  log-normal  confidence intervals are shown.

4.  GEORGES BANK WINTER FLOUNDER

State of Stock: Based on this updated assessment, the Georges Bank Winter Flounder (Pseudopleu- ronectes americanus) stock is not overfished and overfishing is not occurring (Figures 10–11). Retrospective adjustments were made to the model results. Spawning stock biomass (SSB) in 2021 was estimated to be 7159 mt. The 2021 fully selected fishing mortality (F) was estimated to be 0.0485. However, the 2021 point estimate of SSB and F, when adjusted for retrospective error (59% for SSB and −36% for F), are outside the 90% confidence intervals of the unadjusted 2021 point estimates. Therefore, the values used in the stock status determination were the retrospective-adjusted values of F₂₀₂₁= 0.076 which is 16% of the overfishing threshold (F_{MSY proxy}= 0.452; Figure 11), and SSB₂₀₂₁= 4,503 mt which is 60% of the biomass target (SSB_{MSY proxy}= 7,503 with a threshold of 50% of SSB_{MSY proxy}; Figure 10).

Projections: Short-term projections of biomass were derived by sampling from a cumulative distribution function of recruitment estimates (1982–2020 Y_c) from the final run of the adapt VPA model. The annual fishery selectivity, maturity ogive (a 3-year moving window), and mean weights-at-age used in the projection are the most recent five-year averages (2017–2021). An SSB retrospective adjustment factor of 0.629 was applied in the projections.

Special Comments: 

• •
  What are the most important sources of uncertainty in this stock assessment? Explain, and describe qualitatively how they affect the assessment results (such as estimates of biomass,  F, recruitment, and population projections).

  The largest source of uncertainty is probably the estimate of natural mortality, which is based on longevity (max. age = 20). Natural mortality is not well studied in Georges Bank Winter Flounder and is assumed to be constant over time. Natural mortality affects the scale of the biomass and fishing mortality estimates.

  VPA assumes catch is known without error, which in the case of Georges Bank Winter Flounder is certainly not true. Discards from the Canadian bottom trawl fleet were not provided by DFO and the precision of the Canadian scallop dredge discard estimates are uncertain. In addition, there are no length or age composition data for the Canadian landings or discards of GB winter flounder. The lack of age data for the Canadian spring survey catches requires the use of the US spring survey A/L keys for several disparate data streams, including the Canadian scallop discards, US otter trawl and scallop discards, despite selectivity differences. Various other gaps in catch data at age or length have been filled using decisions based on expert opinion and are difficult, if not impossible, to reproduce. Different decisions produce different model inputs and result in differentoutcomes. The direction and magnitude of the bias associated with filling gaps using expert opinion is unknown, but likely common in VPA assessments.

  Another potentially important uncertainty is the lack of 2020 NEFSC fall and spring surveys. For 2022, DFO survey estimates were not available due to the use of a new survey vessel and an absence of a calibration factor.

• •
  Does this assessment model have a retrospective pattern? If so, is the pattern minor, or major? (A major retrospective pattern occurs when the adjusted  SSB  or  F_Full  lies outside of the 90% confidence intervals for  SSB  and  F_Full.)

   The 7-year Mohn’s ρ, relative to SSB, was 0.57 in the 2020 assessment and was 0.59 in 2021. The 7-year Mohn’s ρ, relative to F, was −0.34 in the 2020 assessment and was −0.36 in 2021. There was a major retrospective pattern for this assessment because the ρ-adjusted estimates of 2021 SSB (SSB_ρ= 4,503) and 2021 F (F_ρ= 0.076) were outside the 90% confidence limits for SSB (6,871–11,642) and F (0.03–0.049). A retrospective adjustment was made for both the determination of stock status and for projections. The retrospective adjustment changed the 2021 SSB from 7,159 to 4,503 and the 2021 F_Full from 0.0485 to 0.076.

• •
  Based on this stock assessment, are population projections well determined or uncertain? If this stock is in a rebuilding plan, how do the projections compare to the rebuilding schedule?

  Population projections for Georges Bank Winter Flounder are uncertain because confidence bounds for projected biomass estimates from the previous assessment did not capture the terminal estimate of biomass from this one. This stock was required to be rebuilt by 2017, but this did not occur. The stock is in a revised rebuilding plan, based on fishing at 70% of F_{MSY proxy}, with rebuilding by 2029.

• •
  Describe any changes that were made to the current stock assessment, beyond incorporating additional years of data and the affect these changes had on the assessment and stock status.

   Changes made to the Georges Bank Winter Flounder assessment included updating the most recent 5-year averages (2017–2021) of fishery selectivity-, proportion mature-, stock weights-, catch weights-, and spawning stock weights-at-age.

  US spring and fall indices were revised from 2009 to 2022 to account for tow-specific area swept; revised indices were similar to previous relative abundance estimates. The new US commercial fishery data processing system (Catch Accounting and Monitoring System [CAMS]) was used to produce US landings estimates for 2020 and 2021. In 2021, age samples were not available for US landings so the A/L key from the 2020 landings were used to produce estimates for 2021. The Covid epidemic caused the cancelation of the 2020 NEFSC spring and fall surveys. DFO survey results were not available for 2022 because of a change in vessel. The missing NEFSC surveys appear to have had a minor effect; however, the absence of the DFO survey most likely increased SSB estimates. The DFO survey results will be available once a calibration study occurs (see GBFLWupdate2022Extras.pdf available atSASINF for discussion of sensitivity testing on this and other potential issues).

• •
  If the stock status has changed a lot since the previous assessment, explain why this occurred.

  The stock status of Georges Bank Winter Flounder has changed from ‘overfished and overfishing is not occurring’ to ‘not overfished and overfishing is not occurring’.

• •
  Provide qualitative statements describing the condition of the stock that relate to stock status.

   The ‘Plan B’ assessment results (available atSASINF ) indicate that biomass has increased since 2019. There are indications of improvement in stock condition. Catch weight-at-age has been increasing for the last few years and there are indications of a better than average recruitment class in 2020 in the CA spring survey.

• •
  Indicate what data or studies are currently lacking and which would be needed most to improve this stock assessment in the future.

  The Georges Bank Winter Flounder assessment could be improved with a shift to a model that incorporates statistical fits to commercial length and age composition and deprecates the requirement that catch be known without error.

• •
  Are there other important issues?

  2020 commercial data, in addition to survey data, was likely affected by the Covid-19 outbreak. Commercial vessels may have carried fewer observers and fished fewer days. The lack of consistency in commercial data may reduce the precision and accuracy of the Georges Bank Winter Flounder assessment in the near term.

Pseudopleuronectes americanus, Winter Flounder.

Displaying a Winter flounder catch.

Figure 10: Trends in spawning stock biomass ( mt ) of Georges Bank Winter Flounder between 1982 and 2021 from the current (solid line) and previous (dashed line) assessments and the corresponding  SSB_Threshold( 1/2 SSB_{MSY proxy} ; horizontal dashed line) as well as  SSB_Target  ( SSB_{MSY proxy} ; horizontal dotted line) based on the 2022 assessment. Biomass was adjusted for a retrospective pattern and the adjustment is shown in red. The  90%  normal confidence interval is shown for 2021.

Figure 11: Trends in fully selected fishing mortality ( F_Full ) of Georges Bank Winter Flounder between 1982 and 2021 from the current (solid line) and previous (dashed line) assessments and the corresponding  F_Threshold( F_{MSY proxy}= 0.452; horizontal dashed line) as well as ( F_Target= 75%  of  F_{MSY proxy} ; horizontal dotted line).  F_Full  was adjusted for a retrospective pattern and the adjustment is shown in red. The  90%  normal confidence interval is shown for 2021.

Figure 12: Trends in Recruits (age-1) ( 000s) of Georges Bank Winter Flounder between 1982 and 2021 from the current (solid line) and previous (dashed line) assessments.

Figure 13: Total catches ( mt) of Georges Bank Winter Flounder between 1982 and 2022 by country and disposition (landings and discards).

Figure 14: Indices of abundance for the Georges Bank Winter Flounder for the Northeast Fisheries Science Center ( NEFSC ) spring (1968–2021) and fall (1963–2021) bottom trawl surveys and the Canadian  DFO  spring survey (1987–2021). The  90%  normal confidence interval is shown.

5.  GEORGES BANK HADDOCK

State of Stock: Based on this updated assessment, the Georges Bank haddock (Melanogrammus aeglefinus) stock is not overfished, and overfishing is not occurring (Figures 15–16). Retrospective adjustments were not made to the model results. Spawning stock biomass (SSB) in 2021 was estimated to be 79,513 mt which is 66% of the biomass target (SSB_{MSY proxy}= 120,580; Figure 15). The 2021 average fishing mortality on ages 5–7 was estimated to be 0.137 which is 55% of the overfishing threshold proxy (F_{MSY proxy}= 0.25; Figure 16). The F_{MSY proxy} is expressed as the average F on ages 5–7.

Projections: Short term projections were conducted in WHAM, which propagates uncertainty in the processes of recruitment and transitions between numbers at age. For projection specifications, the Plan Development Team supplied an estimate of total catch for 2022, and fishing mortality was set equal to F_40%SPR for 2023–2025. Annual fishery selectivity and maturity were fixed at a recent 2-year average (2020–2021 values), following analyses and decisions made at the 2021 research track. Weights at age for catch and SSB that were predicted from a Gaussian Markov Random Field (GMRF) model, rather than a recent 2-year average, were preferred by the peer reviewers for this Management Track, and were used in the projections summarized in this report. Retrospective adjustments were not applied. The Overfished threshold is 60,290 mt, and the stock is not projected to drop below this value in 2025.

Special Comments: 

• •
  What are the most important sources of uncertainty in this stock assessment? Explain, and describe qualitatively how they affect the assessment results (such as estimates of biomass,  F, recruitment, and population projections).

  Sources of uncertainty include dynamics in the plus group, the magnitude of the 2020 and 2021 year classes, and future assumptions about weights and selectivity at age. The 2013 year class, the largest ever observed for this stock, accounts for 20% of the population abundance in 2021 (at age-8), and is in the plus group for all of the projections. It’s contribution to catch (in biomass) in the projections is 35% in 2022, and diminishes to 17% in 2025. However, negative annual deviations have been estimated in the plus group in recent years, and it is uncertain if this will persist in projections. Catches in 2023–2025 are reliant on the 2020 year class, which constitutes 33%–41% of the 2023–2025 catch (in biomass). The 2022 year class is not part of the model input, but initial observations in the survey suggest that it may be close to the time series average; additional observations in future surveys are needed to confirm this. Projections from the research track assessment (with data through 2019) aligned well with estimates from the current assessment model (updated with data through 2021), in spite of the projected selectivities being consistently less than the model estimated selectivities from the current assessment. The accuracy of projected weights varied based on the year and year class, with some being very accurate and others over- or underestimated. A sensitivity projection was made using weights estimated from a Gaussian Markov random field (GMRF, methodology in Nielsen, manuscript in preparation), and the review panel recommended using these for projections instead of the 2-year average weights at age. These GMRF weights at age predicted a slightly greater increase in weights at age in later years of projections (with large uncertainty bounds), and consequently produced larger estimates of catch and SSB in 2022–2025 compared to projections using a two year average for weights at age. Long range accuracy for projecting weights and selectivity is not expected, given the many factors that influence those processes.

• •
  Does this assessment model have a retrospective pattern? If so, is the pattern minor, or major? (A major retrospective pattern occurs when the adjusted  SSB  or  F̅_5:7  lies outside of the approximate joint confidence region for  SSB  and  F̅_5:7).

   The 7-year Mohn’s ρ, relative to SSB, was 0.70 in the 2019 assessment and was 0.26 in 2021. The 7-year Mohn’s ρ, relative to F, was −0.44 in the 2019 assessment and was −0.27 in 2021. There was a minor retrospective pattern for this assessment because the ρ-adjusted estimates of 2021 SSB (SSB_ρ= 79,513) and 2021 F (F_ρ= 0.137) were inside the estimated 95% confidence regions around SSB (46,084–137,174) and F (0.073–0.259). No retrospective adjustment was made for either the determination of stock status or for projections of catch in 2023.

• •
  Based on this stock assessment, are population projections well determined or uncertain? If this stock is in a rebuilding plan, how do the projections compare to the rebuilding schedule?

  As noted in the first bullet, population projections for Georges Bank haddock are uncertain due to future values of selectivity and weights at age, dynamics of the plus group, and magnitude of incoming 2020 and 2021 year classes. This stock is not in a rebuilding plan.

• •
  Describe any changes that were made to the current stock assessment, beyond incorporating additional years of data and the affect these changes had on the assessment and stock status.

   No changes, other than the incorporation of new data, were made to the Georges Bank haddock assessment for this update. NEFSC indices from 2009–2021 were calculated using tow-specific swept area.

• •
  If the stock status has changed a lot since the previous assessment, explain why this occurred.

  The stock status of Georges Bank haddock has not changed.

• •
  Provide qualitative statements describing the condition of the stock that relate to stock status.

  The Georges Bank haddock shows a broad age structure, and broad spatial distribution. This stock has produced several exceptionally strong year classes in the last 20 years, leading to record high SSB in the last decade. As the strong year classes age out of the population, abundance has returned to levels last observed in the early 2000s, which could potentially lead to an increase in weights at age as growth is released from density-dependent pressures. Catches in recent years have been well below the total quota (US+Canada), but projected catch levels will be substantially less than recent quotas due to declining abundance and the combined effect of re-estimated Canadian weights at age and a re-estimated length-based calibration for the NEFSC Albatross : H.B. Bigelow vessels.

• •
  Indicate what data or studies are currently lacking and which would be needed most to improve this stock assessment in the future.

   The research track assessment in 2021 for Georges Bank haddock strongly recommended studies to collect data to re-estimate gutted to whole weight conversion factors, as well as measuring individual fish weight in addition to the length and otolith sampling performed on commercially landed fish.

• •
  Are there other important issues?

  The Georges Bank haddock assessment estimates that the haddock stock has declined to levels last observed in the early 2000s. Projections at F_40%SPR using GMRF weights at age predict a slight increase in SSB in 2023 but then a decline in 2024–2025. Projections at F_40%SPR using a 2-year average for weights-at-age predicted a steady decline in SSB, with the stock on the cusp of overfished in 2024, and overfished in 2025. Future stock status is very dependent on assumed weights at age. Surges in stock abundance and quotas are driven by strong year classes, creating a boom and bust cycle. The current assessment shows the stock leaving the boom phase and heading in the bust direction. If initial estimates of the 2020 and 2021 year classes are at or above the time series average, this may slow the current decline.

Melanogrammus aeglefinus, Haddock.

Haddock swimming over rocky bottom.

Figure 15: Trends in spawning stock biomass of Georges Bank haddock between 1931 and 2021 from the current (solid line) and previous (dashed line) 2019 assessment and the corresponding  SSB_Threshold( 1/2 SSB_{MSY proxy} ; horizontal dashed line) as well as  SSB_Target  ( SSB_{MSY proxy} ; horizontal dotted line) based on the 2021 assessment. The  95%  confidence intervals are shown.

Figure 16: Trends in the average fishing mortality ( F̅_5:7 ) of Georges Bank haddock between 1931 and 2021 from the current (solid line) and previous (dashed line) assessment and corresponding  F_Threshold  ( F_{MSY proxy}= 0.25 ; horizontal dashed line) based on the 2021 assessment.  F̅_5:7  was adjusted for a retrospective pattern and the adjustment is shown in red. The  95%  confidence intervals are shown.

Figure 17: Trends in Recruits (age-1) ( 000s ) of Georges Bank haddock between 1931 and 2021 from the current (solid line) and previous (dashed line) assessment. The  95%  confidence intervals are shown.

Figure 18: Total catch of Georges Bank haddock between 1931 and 2021 by fleet ( US  Commercial, Canadian, or foreign fleet) and disposition (landings and discards).

Figure 19: Indices of biomass (Mean  kg/tow) for the Georges Bank haddock stock between 1963 and 2021 for the Northeast Fisheries Science Center ( NEFSC ) spring and fall bottom trawl surveys and the  DFO  winter bottom trawl survey. The approximate 95%  log-normal  confidence intervals are shown for  DFO  only. Confidence bounds for the new length-based biomass calibration are not yet available.

6.  GULF OF MAINE HADDOCK

State of Stock: Based on this updated assessment, the stock status for the Gulf of Maine haddock (Melanogrammus aeglefinus) stock is not overfished and overfishing is occurring (Figures 20–21). Retrospective adjustments were not made to the model results (seeSpecial Comments section of this report). Spawning stock biomass (SSB) in 2021 was estimated to be 16,528 (mt) which is 270% of the biomass target (SSB_{MSY proxy} = 6,123; Figure 20). The 2021 fully selected fishing mortality was estimated to be 0.375 which is 111% of the overfishing threshold proxy (F_{MSY proxy}=F_40%SPR= 0.338; Figure 21).

Projections: Short term projections of median total fishery yield and spawning stock biomass for Gulf of Maine haddock were conducted based on a harvest scenario of fishing at the F_{MSY proxy} between 2023 and 2025. Catch in 2022 has been estimated at 3,912 mt. Recruitment was sampled from a cumulative distribution function of model estimated age-1 recruitment from 1977–2019. The age-1 estimate in 2022 was generated from the geometric mean of the 1977–2021 recruitment series. The annual fishery selectivity in the projections was the terminal selectivity from the assessment model. The time-invariantmaturity ogive, and the projected mean weights-at-age were used in the projections. Retrospective adjustments were not applied in the projections.

Special Comments: 

• •
  What are the most important sources of uncertainty in this stock assessment? Explain, and describe qualitatively how they affect the assessment results (such as estimates of biomass,  F, recruitment, and population projections).

   The main source of uncertainty in this assessment is the faster than expected rate of decline in biomass that has occurred since the last update. Although the last update projected a decline in biomass, the realized decline has been faster than anticipated, and this has resulted in a substantial increase in F which is now above the overfishing threshold.

• •
  Does this assessment model have a retrospective pattern? If so, is the pattern minor, or major? (A major retrospective pattern occurs when the adjusted  SSB  or  F_Full  lie outside of the approximate joint confidence region for  SSB  and  F_Full).

   This assessment exhibits a retrospective pattern, however the 7-year Mohn’s ρ-adjusted values of SSB and F fall within the 90% confidence interval of their estimates, therefore the pattern is considered minor, and no retrospective adjustment is required.

• •
  Based on this stock assessment, are population projections well determined or uncertain? If this stock is in a rebuilding plan, how do the projections compare to the rebuilding schedule?

  Population projections for Gulf of Maine haddock in the previous update correctly identified that the population would decline, however the rate of decline has been faster than projected. As a result, the projected 2021 SSB from the last assessment is above the upper confidence bound of the 2021 SSB estimated in the current assessment. The over-projection of SSB was magnified by a change in direction of the retrospective pattern and over-projected weights-at-age, the latter of which has been addressed in this update using a new weight-at-age projection model. The projected F for 2022 is above the overfishing threshold (Table 15). This stock is not in a rebuilding plan.

• •
  Describe any changes that were made to the current stock assessment beyond incorporating additional years of data, and the effect these changes had on the assessment and stock status.

   The actual tow-swept-area was used when calculating the NEFSC Bottom Trawl indicies of abundance for the R/V Bigelow years (2009+). A comparison of the survey time series with and without this adjustment showed that the impact on the time series is minor. In addition, following the recommendation of the 2021 Research Track Review Panel (CIE, In Prep), an exploratory model run was performed which included the NEFSC Bottom Longline Survey (BLLS). Model diagnostics were generally worse when including the BLLS, particularly the retrospective pattern, and therefore the Base model was chosen as the preferred model. Also following the recommendation of the Research Track Review Panel, a state-space growth model was developed for projecting WAA. In a 20-year retrospective backtest, the growth model outperformed the previous approach of using the terminal two-year average, and therefore it was chosen as the WAA projection method in this update.

• •
  If the stock status has changed a lot since the previous assessment, explain why this occurred.

  Unlike the previous assessment (NEFSC 2022), overfishing is now occurring. See above comments on why this occurred. The stock remains not overfished.

• •
  Provide qualitative statements describing the condition of the stock that relate to stock status.

  The Gulf of Maine haddock stock has experienced several large year classes since 2010, particularly the 2013 year class. The stock has recently declined as these large year classes have aged out. The 2020 year class is currently estimated as the second largest on record, however it is still substantially smaller than the 2013 year class and its estimate is highly uncertain. Future stock status will depend on the strength of this and subsequent year classes.

• •
  Indicate what data or studies are currently lacking and which would be needed most to improve this stock assessment in the future.

  A better understanding of what is driving the retrospective pattern would be helpful.

• •
  Are there other important issues?

  None.

Sorted Haddock in baskets.

Figure 20: Trends in spawning stock biomass ( SSB ) of Gulf of Maine haddock between 1977 and 2021 from the current (solid line) and previous (dashed line) assessment and the corresponding  SSB_Threshold  ( 1/2 SSB_{MSY proxy} ; horizontal dashed line) as well as  SSB_Target  ( SSB_{MSY proxy} ; horizontal dotted line) based on the 2022 assessment. The approximate 90%  log-normal  confidence intervals are shown. The red dot indicates the  ρ -adjusted  SSB  value that would have resulted had a retrospective adjustment been made (see Special Comments  section).

Figure 21: Trends in the fully selected fishing mortality ( F ) of Gulf of Maine haddock between 1977 and 2021 from the current (solid line) and previous (dashed line) assessment and the corresponding  F_Threshold  ( F_{MSY proxy}= 0.338 ; horizontal dashed line) from the 2022 assessment model. The approximate 90%  log-normal  confidence intervals are shown. The red dot indicates the  ρ -adjusted  F  value that would have resulted had a retrospective adjustment been made (see Special Comments  section).

Figure 22: Trends in Recruits (age-1) ( 000s ) of Gulf of Maine haddock between 1977 and 2021 from the current (solid line) and previous (dashed line) assessment. The approximate 90%  log-normal  confidence intervals are shown.

Figure 23: Total catch of Gulf of Maine haddock between 1977 and 2021 by fleet (commercial, recreational, or foreign) and disposition (landings and discards).

Figure 24: Indices of biomass for the Gulf of Maine haddock between 1963 and 2021 for the Northeast Fisheries Science Center ( NEFSC ) spring and fall bottom trawl surveys. The approximate 90%  log-normal  confidence intervals are shown.

7.  ATLANTIC HALIBUT

State of Stock: Based on this updated assessment, Atlantic halibut (Hippoglossus hippoglossus) stock status cannot be determined analytically due to a lack of biological reference points associated with the FSD method. Biomass (SSB) in 2021 was unknown. The 2021 fully selected fishing mortality was unknown.

Projections: Short term projections are not possible using the FSD approach. The FSD approach is based on applying a multiplier to the catch from the previous year and cannot be projected beyond the catch time series. The catch multiplier for 2021 resulting from the FSD model is 0.87 and the estimatedcatch for 2021 is 185 mt, which results in catch advice of 160 mt for 2022. The FSD model is explained in (Rago, 2018) and additional information is available in a document called ‘AtlanticHalibutMTextras.pdf’, both are available atSASINF .

Special Comments: 

• •
  What are the most important sources of uncertainty in this stock assessment? Explain, and describe qualitatively how they affect the assessment results (such as estimates of biomass,  F, recruitment, and population projections).

   The assessment model (FSD) used for Atlantic halibut is a ‘Plan B’ assessment method. It uses recent trends in 3 abundance indices as well as recent changes in those trends to adjust the previous year’s catch. For example, if the abundance indices are increasing, the catch will be adjusted up. If that increasing trend in abundance is increasing in magnitude over time, the adjustment to catch will be commensurately higher. The FSD method was rigorously tested in simulation (Rago, 2018) and should perform well for Atlantic halibut in the US. Sources of uncertainty in the FSD method include process error related to potential changes in stock productivity over time, the choice of relative weights for the control parameters used in the model and the lag in information inherent in using change in trend as one of the control parameters, which requires dropping one data point from the regression fit to generate a comparison. Other sources of uncertainty include the observation error in the abundance indices. The FSD method also relies on the assumption that abundance can be described with linear dynamics, but that assumption should be relatively unimportant if the stock abundance is well below it’s theoretical carrying capacity.

• •
  Does this assessment model have a retrospective pattern? If so, is the pattern minor, or major?

  The FSD model does not support retrospective analysis.

• •
  Based on this stock assessment, are population projections well determined or uncertain?

  The FSD model provides catch advice in the year following the terminal year of the input data. It is not intended to to project further ahead than one year. It is possible however to assume that catch in the year following the terminal year will equal the catch advice from the FSD model and that the population abundance indices will continue to follow the same trend and that the change in trend will be identical to the previous five years of data. These assumptions allow for a projection any number of years into the future. The relative quality of these projections degrades as the indices of abundance depart from the behavior of the most recent data available to the model.

• •
  Describe any changes that were made to the current stock assessment, beyond incorporating additional years of data and the affect these changes had on the assessment and stock status.

   The loss of a survey data point in 2020 (Covid) resulted in the need to interpolate one survey index observation. The survey index value used in 2020 was equal to the average of the 2019 and 2021 values.Catch efficiency studies and data are not used for the Atlantic halibut assessment because not enough Atlantic halibut are caught to provide a comparison between the gear types and produce estimate of catchability.

• •
  If the stock status has changed a lot since the previous assessment, explain why this occurred.

   Stock status cannot be determined and remains unchanged. The stock is likely depleted relative to its virgin biomass based on estimates of historical landings, which were much higher than current landings. Rago in his 2018 report argued that overfishing was unlikely because the catch multiplier estimated in the FSD model had been greater than one for several years. The catch multiplier has now been less than one for four years, which would be consistent with recent overfishing. There is however, no way to determine stock status without reference points.

• •
  Indicate what data or studies are currently lacking and which would be needed most to improve this stock assessment in the future.

   The Atlantic halibut assessment could be improved with more precise fishery independent indices of abundance, additional age and length composition data, and a better understanding of stock structure. These would allow for alternative assessment methods, and potential development of a more sophisticated stock assessment model.

• •
  Are there other important issues?

   Canadian catch in 2020 and 2021 in area 5Z (eastern Georges Bank) was 4 times higher than it has been in at least the last 20 years (seeSASINF ). Because this area is included in the calculation of catch in the FSD model, the recommended catch output (catch advice) for 2021 and 2022 is at or above status quo (circa 2017–2019). This result is counter to expectation given that the catch multiplier for each year since 2017 indicates a reduction in recommended catch is warranted (Table 16). Managers should be aware of this issue when recommending catch levels for Atlantic halibut.

Hippoglossus hippoglossus, Atlantic Halibut.

Halibut on deck of fishing vessel.

Figure 25: The catch multiplier resulting from the  FSD  model for Atlantic halibut between 2006 and 2022 from the current (solid line) assessment. A dashed line at 1 is added for reference.

Figure 26: The catch advice resulting from multiplying catch and the catch multiplier from the  FSD  model for Atlantic halibut between 2006 and 2022 from the current assessment.

Figure 27: Total catch of Atlantic halibut between 2006 and 2022 by disposition (landings and discards).

Figure 28: Indices of biomass for the Atlantic halibut between 2002 and 2021 for the Northeast Fisheries Science Center ( NEFSC ) fall bottom trawl survey and 2 discard ratio estimators. Discard mortality is assumed to be 0.76 for trawl gear and 0.3 for gillnet gear. The 2020  NEFSC  fall bottom trawl value was interpolated as the mean of the 2019 and 2021 values. The 90% lognormal confidence intervals are shown.

8.  WHITE HAKE

State of Stock: Based on this updated assessment, the white hake (Urophycis tenuis) stock is not overfished and overfishing is not occurring (Figures 29–30). Retrospective adjustments were made to the model results. Spawning stock biomass (SSB) in 2021 was estimated to be 19,497 mt which is 69% of the biomass target (SSB_{MSY proxy} = 28,191; Figure 29). The 2021 fully selected fishing mortality was estimated to be 0.104 which is 65% of the overfishing threshold proxy (F_{MSY proxy}= 0.1605; Figure 30).

Projections: Short term projections of catch and SSB were derived by sampling from a cumulative distribution function of recruitment estimates from ASAP from 1995–2019. The mean weights-at-age used in the projection are the 2017–2019+2020 averages. The numbers-at-age used to start the projections were adjusted for retrospective bias using age-specific ρ estimates.

Special Comments: 

• •
  What are the most important sources of uncertainty in this stock assessment? Explain, and describe qualitatively how they affect the assessment results (such as estimates of biomass,  F, recruitment, and population projections).

  1. Catch-at-age information is not well characterized due to possible mis-identification of species in the commercial and observer data, particularly in early years, low sampling of commercial landings in some years, and sparse discard length data.2. Since the commercial catch is aged primarily with survey age/length keys, there is considerable augmentation required, mainly for ages 5 and older. The numbers-at-age and mean weights-at-age in the catch for these ages may therefore not be well specified.3. White hake may move seasonally into and out of the defined stock area.4. There are no commercial catch-at-age data prior to 1989 and the catchability of older ages in the surveys is very low. This results in a large uncertainty in starting numbers-at-age.5. Since 2003, dealers have been culling extra-large fish out of the large category. However, there was no market category for landings until June 2014. The length compositions are distinct from fish characterized as large and have been identified since 2011. This may bias the age composition of the landings, particularly in 2014 when 2000 of the 5000 large samples were these extra-large fish.

  6. A pooled age/length key is used for 1963–1981, fall 2003 survey data as well as the second half of the commercial key, and for the 2020 commercial CAA.

• •
  Does this assessment model have a retrospective pattern? If so, is the pattern minor, or major? (A major retrospective pattern occurs when the adjusted  SSB  or  F_Full  lies outside of the approximate joint confidence region for  SSB  and  F_Full  

   The 7-year Mohn’s ρ, relative to SSB, was 0.31 in the 2019 assessment and was 0.21 in 2021. The 7-year Mohn’s ρ, relative to F, was −0.22 in the 2019 assessment and was −0.17 in 2021. There was a major retrospective pattern for this assessment because the ρ-adjusted estimate of 2021 SSB (SSB_ρ= 19,497) was outside the approximate 90% confidence regions around SSB (19,894–26,646). A retrospective adjustment was made for both the determination of stock status and for projections of catch in 2023. The retrospective adjustment changed the 2021 SSB from 23,670 to 19,497 and the 2021 F_Full from 0.09 to 0.104.

• •
  Based on this stock assessment, are population projections well determined or uncertain? If this stock is in a rebuilding plan, how do the projections compare to the rebuilding schedule?

  Population projections for white hake are not well determined and projected biomass from the last assessment was near the edge the confidence bounds of the biomass estimated in the current assessment. The rebuilding deadline for this stock is now 2031 and the stock may rebuild.

• •
  Describe any changes that were made to the current stock assessment, beyond incorporating additional years of data and the affect these changes had on the assessment and stock status. In the 2022 assessment of white hake, the catch efficiency studies and data were not used because studies were not applicable to roundfish.

  Minor changes to the catch-at-age for 2003 and 2015–2018 were made and made little difference to the model. The swept-area adjusted survey values for 2009–2018 were used as well as the bootstrap CVs. This lowered the estimates of SSB over that time period and slightly increased fishing mortality. In addition, one new survey was added to the ASAP model which reduced the retrospective pattern.

• •
  If the stock status has changed a lot since the previous assessment, explain why this occurred.

  Stock status of white hake has changed from overfished to not overfished for at least two reasons. First, the retrospective pattern was reduced. Second, the biomass reference point was also reduced because of a lower mean recruitment.

• •
  Provide qualitative statements describing the condition of the stock that relate to stock status.

   The white hake stock shows no truncation of age structure. Estimates of commercial landings and discards have decreased over time.

• •
  Indicate what data or studies are currently lacking and which would be needed most to improve this stock assessment in the future.

  Age structures collected by the observer program are available and should be aged to augment the survey keys. The additional years of age structures from the ASMFC shrimp survey should also be aged and continue to be collected. There are two bottom longline surveys that should be monitored as the time series gets longer, and the otoliths aged and collected.

• •
  Are there other important issues?

  None.

Brian Gay of Millsboro, Delaware holding the record-setting white hake he caughtin 2019. Photo credit: Maryland Department of Natural Resources.

Urophycis tenuis, White Hake.

Figure 29: Trends in spawning stock biomass of white hake between 1963 and 2021 from the current (solid line) and previous (dashed line) assessment and the corresponding  SSB_Threshold  ( 1/2 SSB_{MSY proxy} ; horizontal dashed line) as well as  SSB_Target  ( SSB_{MSY proxy} ; horizontal dotted line) based on the 2022 assessment. Biomass was adjusted for a retrospective pattern and the adjustment is shown in red. The approximate  90%    log-normal  confidence intervals are shown.

Figure 30: Trends in the fully selected fishing mortality ( F_Full ) of white hake between 1963 and 2021 from the current (solid line) and previous (dashed line) assessment and the corresponding  F_Threshold  ( F_{MSY proxy}= 0.1605; horizontal dashed line). based on the 2022 assessment.The F_Full  was adjusted for a retrospective pattern and the adjustment is shown in red. The approximate  90%    log-normal  confidence intervals are shown.

Figure 31: Trends in Recruits (age-1) ( 000s ) of white hake between 1963 and 2021 from the current (solid line) and previous (dashed line) assessment. The approximate  90%    log-normal  confidence intervals are shown.

Figure 32: Total catch of white hake between 1963 and 2021 by fleet (commercial, recreational, or Canadian) and disposition (landings and discards).

Figure 33: Indices of biomass for white hake between 1963 and 2022 for the Northeast Fisheries Science Center ( NEFSC ) spring and fall bottom trawl surveys and the  ASMFC  shrimp survey. The approximate  90%    log-normal  confidence intervals are shown.

9.  NORTHERN MONKFISH

State of Stock: Based on this Management Track assessment, Northern Monkfish (Lophius ameri- canus) stock status is unknown.

Projections: Short term projections were not conducted due to lack of an analytical assessment. The catch multiplier resulting from the Ismooth approach equaled 0.829.

Special Comments: 

• •
  What are the most important sources of uncertainty in this stock assessment? Explain, and describe qualitatively how they affect the assessment results (such as estimates of biomass,  F, recruitment, and population projections).

  The largest source of uncertainty in this stock assessment is lack of a reliable aging method. Finding a reliable aging method seems unlikely. Monkfish migratory patterns also add uncertainty to the assessment and may complicate interpretation of indices of abundance.

• •
  Does this assessment model have a retrospective pattern? If so, is the pattern minor, or major? (A major retrospective pattern occurs when the adjusted  SSB  or  F_Full  lies outside of the approximate joint confidence region for  SSB  and  F_Full).

  Not applicable.

• •
  Based on this stock assessment, are population projections well determined or uncertain? If this stock is in a rebuilding plan, how do the projections compare to the rebuilding schedule?

  Not applicable.

• •
  Describe any changes that were made to the current stock assessment, beyond incorporating additional years of data and the effect these changes had on the assessment and stock status.

  The assumed discard mortality rate of monkfish caught using scallop dredges was lowered from 100% to 64%. This change was based on a recent tagging study (Weissman et al., 2021).

• •
  If the stock status has changed a lot since the previous assessment, explain why this occurred.

  Not applicable.

• •
  Provide qualitative statements describing the condition of the stock that relate to stock status.

  All indices of abundance reported in the stock assessment, including those not used in the Ismooth approach, showed declines of varying degrees over the past 3–5 years.

• •
  Indicate what data or studies are currently lacking and which would be needed most to improve this stock assessment in the future.

  The assessment could be most improved through development of an aging method, or exploration of a simpler two-stage, analytical assessment model.

• •
  Are there other important issues?

  The effects of climate change on monkfish biology and movement are likely to become increasingly important.

Lophius americanus, monkfish.

Monkfish on the measuring table.

Figure 34: Total catch of Northern Monkfish by fleet (commercial, recreational, or Canadian) and disposition (landings and discards).

Figure 35: Indices of biomass for the Northern Monkfish between 1990 and 2022 for the Northeast Fisheries Science Center ( NEFSC ) spring and fall bottom trawl surveys. The approximate 90%  log-normal  confidence intervals are shown.

10.  SOUTHERN MONKFISH

State of Stock: Based on this Management Track assessment, Southern Monkfish (Lophius ameri- canus) stock status is unknown.

Projections: Short term projections were not conducted due to lack of an analytical assessment. The catch multiplier resulting from the ‘Ismooth’ approach equaled 0.646.

Special Comments: 

• •
  What are the most important sources of uncertainty in this stock assessment? Explain, and describe qualitatively how they affect the assessment results (such as estimates of biomass,  F, recruitment, and population projections).

  The largest source of uncertainty in this stock assessment is lack of a reliable aging method. Finding a reliable aging method seems unlikely. Monkfish migratory patterns also add uncertainty to the assessment and may complicate interpretation of indices of abundance.

• •
  Does this assessment model have a retrospective pattern? If so, is the pattern minor, or major? (A major retrospective pattern occurs when the adjusted  SSB  or  F_Full  lies outside of the approximate joint confidence region for  SSB  and  F_Full).

  Not applicable.

• •
  Based on this stock assessment, are population projections well determined or uncertain? If this stock is in a rebuilding plan, how do the projections compare to the rebuilding schedule?

  Not applicable.

• •
  Describe any changes that were made to the current stock assessment, beyond incorporating additional years of data and the effect these changes had on the assessment and stock status.

  The assumed discard mortality rate of monkfish caught using scallop dredges was lowered from 100% to 64%. This change was based on a recent tagging study (Weissman et al., 2021).

• •
  If the stock status has changed a lot since the previous assessment, explain why this occurred.

  Not applicable.

• •
  Provide qualitative statements describing the condition of the stock that relate to stock status.

  All indices of abundance reported in the stock assessment, including those not used in the ‘Ismooth’ approach, showed declines of varying degrees over the past 3–5 years.

• •
  Indicate what data or studies are currently lacking and which would be needed most to improve this stock assessment in the future.

  The assessment could be most improved through development of an aging method, or exploration of a simpler two-stage, analytical assessment model.

• •
  Are there other important issues?

  The effects of climate change on monkfish biology and movement are likely to become increasingly important.

Lophius americanus, monkfish.

Monkfish at gravelly sea bottom. Photo credit: iStock

Figure 36: Total catch of Southern Monkfish by fleet (commercial, recreational, or Canadian) and disposition (landings and discards).

Figure 37: Indices of biomass for the Southern Monkfish between 1990 and 2022 for the Northeast Fisheries Science Center ( NEFSC ) spring and fall bottom trawl surveys. The approximate 90%  log-normal  confidence intervals are shown.

11.  OCEAN POUT

State of Stock: Based on this updated assessment, the ocean pout (Zoarces americanus) stock is overfished and overfishing is not occurring (Figures 38–39). Retrospective adjustments were not made to the model results. Biomass proxy (B) in 2021 was estimated to be 0.263 (kg/tow) which is 5% of the biomass target (SSB_{MSY proxy}= 4.94; Figure 38). The 2021 fully selected fishing mortality was estimated to be 0.234 which is 31% of the overfishing threshold proxy (F_{MSY proxy}= 0.76; Figure 39).

Special Comments: 

• •
  What are the most important sources of uncertainty in this stock assessment? Explain, and describe qualitatively how they affect the assessment results (such as estimates of biomass,  F, recruitment, and population projections).

   An important source of uncertainty is the stock has not responded to low catch as expected.

• •
  Does this assessment model have a retrospective pattern? If so, is the pattern minor, or major? (A major retrospective pattern occurs when the adjusted  SSB  or  F_Full  lies outside of the approximate joint confidence region for  SSB  and  F_Full).

  The exploitation ratio does not allow estimation of a retrospective pattern.

• •
  Based on this stock assessment, are population projections well determined or uncertain? If this stock is in a rebuilding plan, how do the projections compare to the rebuilding schedule?

  Projections are not available for the exploitation ratio.

• •
  Describe any changes that were made to the current stock assessment, beyond incorporating additional years of data and the effect these changes had on the assessment and stock status.

  The time series of Bigelow indices was recalculated using station-specific swept areas. Supplemental Figure 6 (seeSASINF ) was presented to the Assessment Oversight Panel (AOP) on May 23, 2022; the AOP agreed that the differences were minor.The data source for commercial landings changed to the Catch Accounting and Monitoring System (CAMS) beginning in 2020. However, given the no possession limit, the AOP agreed that this is not an issue.

• •
  If the stock status has changed a lot since the previous assessment, explain why this occurred.

  Stock status has not changed since the previous assessment.

• •
  Provide qualitative statements describing the condition of the stock that relate to stock status.

  Discards comprise most of the catch since the no possession regulation was implemented in May 2010. The NEFSC survey indices remain at near-record low levels; there are few large fish in the population. The ocean pout stock remains in poor condition.

• •
  Indicate what data or studies are currently lacking and which would be needed most to improve this stock assessment in the future.

  The assessment could be improved with studies that explore why this stock is not rebuilding as expected.

• •
  Are there other important issues?

  The 2020 spring NEFSC survey was treated as missing for this assessment. Thus, the moving average was calculated as the mean of the 2021 and 2022 survey indices. It is worth noting that a similar approach is taken at the start of the time series, where the moving average for 1968 is calculated as the mean of the 1968 and 1969 survey indices.The Assessment Oversight Panel (AOP) determined that the 2022 management track assessment for ocean pout would be a Level 1 direct delivery on May 23, 2022. Shortly afterward, while reviewing the report from the October 2020 NEFMC SSC meeting, this statement was noted “The SSC had a thorough discussion about ocean pout, and contemplated stating that the OFL was unknown but decided not to do this. The reference point used for this stock (F_MSY= 0.76) was set several assessment cycles back and, as such, probably needs to be reexamined to determine whether it is still applicable”.The Population Dynamics Branch convened a brainstorming session on July 6, 2022 to address this issue. It was concluded that:- Survey indices for ocean pout remain at, or near, record low levels, and that since the implementation of the no possession limit in May 2010, catch has consisted almost exclusively of discards.- In spite of the no possession limit, stock size has not increased, suggesting that this stock may have entered a depensatory state.- There is no clear alternative to the current reference point proxies, which are based upon survey biomass trends and the exploitation history.- The current reference points should remain in place until more justifiable alternatives can be developed.- More generally, removal of biological reference points (BRPs) is not desirable unless there is a clear justification on why the BRPs are no longer appropriate for stock status determination.

Figure 38: Trends in biomass (kg/tow) of ocean pout between 1968 and 2021 from the current (solid line) and previous (dashed line) assessment and the corresponding  SSB_Threshold  ( 1/2 SSB_{MSY proxy} ; horizontal dashed line) as well as  SSB_Target  ( SSB_{MSY proxy}; horizontal dotted line) based on the 2022 assessment.

Figure 39: Trends in the exploitation ratio of ocean pout between 1968 and 2021 from the current (solid line) and previous (dashed line) assessment and the corresponding  F_Threshold  ( F_{MSY proxy}= 0.76; horizontal dashed line) based on the 2022 assessment.

Figure 40: Total catch of ocean pout between 1968 and 2021 by fleet ( US  and other) and disposition (landings and discards). Note that a no possession limit was put in place in May 2010.

Figure 41: Indices of biomass ( kg/tow) for ocean pout between 1968 and 2022 for the Northeast Fisheries Science Center ( NEFSC ) spring bottom trawl survey. The approximate 90%  log-normal  confidence intervals are shown.

12.  AMERICAN PLAICE

State of Stock: Based on this Management Track assessment, the American plaice (Hippoglossoides platessoides) stock is not overfished and overfishing is not occurring (Figures 42–43). Retrospective adjustment patterns were minor and retrospective adjustments for terminal year estimates were not needed. Spawning stock biomass (SSB) in 2021 was estimated to be 18,809mt, corresponding to 99% of the biomass target (SSB_{MSY proxy}= 19,051; Figure 42). The 2021 fully selected fishing mortality was estimated to be 0.045, corresponding to 11% of the overfishing threshold proxy (F_{MSY proxy}= 0.414; Figure 43).

Projections: Short-term projections were conducted in the WHAM model, which propagates uncertainty in the recruitment and survival processes. For projection specifications, the NEFMC Groundfish Plan Development Team supplied an interim catch estimate for 2022. The annual fishery selectivity, maturity ogive, and mean weights-at-age used in the projections represent the most recent 5-year averages, following the decisions made at the 2022 research track. The stock is projected to remain above the overfished threshold throughout the short-term projection period.

Special Comments: 

• •
  What are the most important sources of uncertainty in this stock assessment? Explain, and describe qualitatively how they affect the assessment results (such as estimates of biomass,  F, recruitment, and population projections).

  The most important source of uncertainty in this assessment is in the commercial landings age samples available for 2020 and 2021. The initial application of the 2020 and 2021 commercial landed age samples resulted in a significant decrease in fish weights-at-age that could not be explained biologically (i.e., cohort shrinkage). Inspection of growth data (i.e., the age-length keys) showed evidence of skewness in the length-at age distribution, particularly in 2021. There is very little confidence that the age samples from the commercial landings for 2020 and 2021 are representative of the landed catch as it may relate to a sampling issue. For the purpose of this assessment, the 2019 age samples were used to characterize the age composition of the commercial landed catch data for both 2020 and 2021. Given the decadal growth pattern in American plaice, this alternative approach to characterizing the age composition for the last two years of landings time series for the assessment is reasonably justified.

• •
  Does this assessment model have a retrospective pattern? If so, is the pattern minor, or major? (A major retrospective pattern occurs when the adjusted  SSB  or  F_Full  lies outside of the approximate joint confidence region for  SSB  and  F_Full).

   The 7-year Mohn’s ρ, relative to SSB, was −0.023 in the 2022 research track assessment and 0.084 in 2021 for the current Management Track assessment. The 7-year Mohn’s ρ, relative to F, was 0.031 in the 2022 research track assessment and −0.065 in 2021 for the current Management Track assessment. The retrospective pattern for this assessment was considered to be minor because the ρ-adjusted estimates of 2021 SSB (SSB_ρ= 17354) and 2021 F (F_ρ= 0.048) were within the approximate 95% confidence intervals around SSB (13,229–26,742) and F (0.029–0.071). Consequently, a retrospective adjustment of spawning stock biomass or fishing mortality in 2021 was not required.

• •
  Based on this stock assessment, are population projections well determined or uncertain? If this stock is in a rebuilding plan, how do the projections compare to the rebuilding schedule?

  Population projections for American plaice are well determined. The stock is not in a rebuilding plan.

• •
  Describe any changes that were made to the current stock assessment, beyond incorporating additional years of data and the effect these changes had on the assessment and stock status.

   The commercial landings changed to the Catch Accounting and Monitoring System (CAMS) beginning in 2020. Supplementary information was presented to the Assessment Oversight Panel (AOP) on August 3^rd, 2022; the AOP concurred that there were no notable differences between the AA tables and CAMS. Additionally, the input data for the research track WHAM model were revised to address two issues. The first was to correct for the appropriate survey timing for spring and fall NEFSC survey indices. Second, the mapping of the weights-at-age matrices to the correct survey index was also revised to match the correct survey. Bridge model runs were conducted and the impacts of these changes on model results were inconsequential.

• •
  If the stock status has changed a lot since the previous assessment, explain why this occurred.

  The stock status of American plaice has not changed since the previous assessment (NEFSC 2022).

• •
  Provide qualitative statements describing the condition of the stock that relate to stock status.

  The NEFSC fall and spring survey indices continue to show large declines in abundance and weight. This partly explains the continued decline in model estimates of SSB since 2019.

• •
  Indicate what data or studies are currently lacking and which would be needed most to improve this stock assessment in the future.

  The peer-review panel from the 2022 research track identified a number of research recommendations, the most important of which is to explore the availability of observer age samples for characterizing the age composition of commercial discards. The current approach uses survey age-length keys. Recent communication with the NEFSC age and growth lab indicated there are some archived observer age samples but the number of samples appears to be very low.

• •
  Are there other important issues?

  As indicated earlier, the commercial landings age samples are a source of uncertainty in this assessment. Future evaluation of these samples is warranted to determine how best to use this information in future assessments. Supplementary material is available on the Stock Assessment Supplementary Information website (SASINF ).

Archival drawing: American Plaice.

Figure 42: Trends in spawning stock biomass of American plaice between 1980 and 2021 from the current (solid line) and previous (dashed line) assessment and the corresponding  SSB_Threshold  ( 1/2 SSB_{MSY proxy} ; horizontal dashed line) as well as  SSB_Target  ( SSB_{MSY proxy} ; horizontal dotted line) based on the 2022 assessment. The approximate  95%    log-normal  confidence intervals are shown.

Figure 43: Trends in the fully selected fishing mortality ( F_Full ) of American plaice between 1980 and 2021 from the current (solid line) and previous (dashed line) assessment and the corresponding  F_Threshold  ( F_{MSY proxy}= 0.414; horizontal dashed line). The approximate 95% lognormal confidence intervals are shown.

Figure 44: Trends in Recruits (age-1) ( 000s ) of American plaice between 1980 and 2021 from the current (solid line) and previous (dashed line) assessment. The approximate  95%    log-normal  confidence intervals are shown.

Figure 45: Total fishery catch of American plaice between 1980 and 2021 by disposition (landings and discards).

Figure 46: Indices of biomass for American plaice between 1980 and 2021 for the Northeast Fisheries Science Center ( NEFSC ) spring and fall bottom trawl surveys. The approximate  95%    log-normal  confidence intervals are shown.

13.  POLLOCK

State of Stock: The pollock (Pollachius virens) stock is not overfished and overfishing is not occurring (Figures 47–48). No retrospective adjustments were made to the model results. Spawning stock biomass (SSB) in 2021 was estimated to be 175,573 mt under the base model and 85,109 mt under theflat sel sensitivity model which is 191% and 150% (respectively) of the biomass target, an SSB_{MSY proxy} of SSB at F_40%SPR (92,130 mt and 56,817 mt; Figure 47). The 2021 age 5 to 7 average fishing mortality (F) was estimated to be 0.052 under the base model and 0.092 under the flat sel sensitivity model, which is 22% and 39% (respectively) of the overfishing threshold, an F_{MSY proxy} of F_40%SPR (0.235 and 0.237; Figure 48).