A. GULF OF MAINE COD ASSESSMENT SUMMARY FOR 2011

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Garm; atlantic cod; Gadus morhua
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.225.3127; http://nefsc.noaa.gov/publications/crd/crd1203/parta.pdf

State of Stock: A new stock assessment model (ASAP) is proposed as the best scientific information available for determining stock status for Gulf of Maine Atlantic cod (Gadus morhua). Spawning stock biomass (SSB) in 2010 is estimated to be 11,868 mt and the fully recruited fishing mortality (Ffull) is estimated to be 1.14 (Figure A1, Figure A2, Figure A3). An MSY could not be derived directly from the ASAP model; therefore an MSY proxy must be used for reference points. F40 % is recommended as the proxy for FMSY (the overfishing threshold). F40%, estimated on the fully selected age class, is 0.20. SSBMSY (the biomass target) is calculated from projections at F40 % and is estimated to be 61,218 mt. Comparing the current 2010 ASAP model estimates of SSB and fully recruited F to the newly accepted reference points, the Gulf of Maine cod stock is overfished and overfishing is occurring (Figure A1). By the convention developed in GARM III, because the point estimate of current stock status with a five-year peel was within the confidence intervals of the base model (Figure A1), no correction for a retrospective pattern was used for stock status determination or applied in the stock projections. All alternative parameterizations of the ASAP model led to the same conclusions regarding stock status. Moreover, all versions of the previously used VPA model also led to the same conclusions that the stock is overfished and overfishing is occurring. Projections: The ASAP model results indicate that the stock is overfished and overfishing is occurring (Figure A1), and there was a moderate retrospective pattern. Projections were made for three constant F scenarios: F = 0 (no fishing), F = 0.75*FMSY Proxy, and F = FMSY Proxy (Table A1). Based on the recommendations of the SARC-53 Review Panel, a revised method was used to conduct short term projections relative to the methods used in the previous GARM III assessment. Similar to the previous method, the revised projection model samples from a cumulative density function derived ...