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Published byMercy Williams Modified over 9 years ago
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NPFMC--Jane DiCosimo NMFS --Loh-Lee Low Mike Sigler Grant Thompson Lowell Fritz Andy Smoker USF&W --Kathy Kuletz ADF&G --Ivan Vining Kristin Mabrey Univ.Alaska--Brenda Norcross WDF&W--Farron Wallace Halibut Comm--Bill Clark BSAI Plan Team Members (12 Members)
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Total U.S.Landings 4.9 million mt (1998-2001) Total U.S.Landings 4.9 million mt (1998-2001)
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Alaska Landings 2.5 million mt (1998-2001) Alaska Landings 2.5 million mt (1998-2001)
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Alaska Groundfish Landings 2.0 million mt (1998-2001) Alaska Groundfish Landings 2.0 million mt (1998-2001)
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Ex-Vessel Value of Alaska Landings 2.5 million mt (1998-2001 Average) Average Annual Ex-Vessel value = $822 Million Ex-Vessel Value of Alaska Landings 2.5 million mt (1998-2001 Average) Average Annual Ex-Vessel value = $822 Million
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Bering Sea-Aleutians Groundfish Catch 25 Year History (in thousands of mt)
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Exploitable Biomass By Major Species Groups
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BSAI Exploitable Biomass Yr 2003 Total = 19.66 MMT
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BSAI Flatfish Complex Biomass Yr 2003 Total = 4.88 MMT
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BSAI Rockfish Complex Biomass Yr 2002 Total = 596,000 MT
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Estimated ABCs By Major Species Groups
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BSAI Groundfish Complex ABCs Yr 2003 Total = 3.33 MMT (Up 147,000 mt from 2002)
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BSAI Flatfish Complex ABC Yr 2003 Total = 559,880 MT
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BSAI Rockfish Complex ABCs Yr 2003 Total = 24,663 MT
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Description Species-by-Species
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Assessment Theme ABC = Biomass x Exploitation Rate 1. Determine Biomass from -- Surveys….Hydroacoustics, Trawls -- Models…..Age or Length-Structure Models 2. Determine Exploitation Rates -- F msy -- F overfishing ……. Example F 35% -- F abc …………… Example F 40%
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Assessment Theme Fishing Rates chosen according to 6 Tiers of Data Quality (Pages 5-6 of SAFE Summary) Tier 1 -- reliable B, Bmsy, pdf of Fmsy Tier 2 -- reliable B, Bmsy, Fmsy, F35, F40 Tier 3 – reliable B, B40, F35, F40 Tier 4 – reliable B, F35, F40 Tier 5 -- reliable B and M Tier 6 –- reliable Catch History Data
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EBS Pollock
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EBS Pollock Assessment Notable Features 1. Year 2002 Surveys Bottom Trawl Biomass = 4.82 mmt, up 16% EIT Survey Biomass = 3.6 mmt, up 18% 2.Year 2002 Models 7 scenarios of Age-Structure Models, Used Model 1 Age3+ Biomass for 2003 = 11.8 mmt, up 6% 3. Recruitment 1998 & 1999 Year Classes both Above Average
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Aleutian Island Region Pollock Assessment 1. Model don’t work, Not unit stock 2. Survey Biomass Year Biomass 1991167,140 1994 77,503 1997 93,512 2000105,554 2002175,000 3. ABC = 0.75 * B 2002 (Tier 5)
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Bogoslof Region Pollock Survey Biomass
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Bogoslof Region Pollock ABC 1. Plan Team Method – Tier 5 ABC = Biomass x 0.75 M ABC = 34,000 mt 2. SSC Method – Use 2 mmt as Target Biomass ABC = 4,070 mt
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BSAI Pacific Cod 96
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Pacific Cod Assessment Notable Features 1. Year 2002 Surveys -- EBS Trawl Biomass = 617,000 t, down26% 2. Year 2002 Model -- Update of Last Year’s Model -- Estimated 2003 Age 3+ Biomass = 1.68 mmt, up 9% 3. Recruitment -- Year classes since 1992 have been below average -- Except for above average 1996 & 1999 year classes
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EBS Yellowfin Sole
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Yellowfin Sole Assessment Notable Features 1. Survey Biomass -- Relatively high biomass, doubled from 1975-79 -- Declining in recent years as strong year classes passes out of the population 2. Models -- Estimated 2003 Age 3+ Biomass = 1.55 mmt, down 1% -- biomass is still high but definitely declining 3.Recruitment -- Lowered recruitment in last decade
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EBS Greenland Turbot
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Greenland Turbot Assessment Notable Features 1. Survey Biomass -- EBS Trawl Biomass assess juveniles only 2. Modeling -- Yr 2003 Age 1+ biomass = 115,700 mt, down 5 -- biomass is generally low and relatively stable 3.Recruitment -- Generally Low recruitment in last 2 decades
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EBS Arrowtooth Flounder
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EBS Rock Sole
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EBS Flathead Sole
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EBS Alaska Plaice
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Bering Sea/Aleutians POP
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POP Assessment Notable Features 1. Present Assessment -- Single Model to Combined Bering Sea/Aleutians Areas 2. Biomass Trend -- Rather Stable Trend in recent years after some rebuilding 3. Recruitment -- Rather Poor Recruitment in recent years
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Other Red Rockfish Notable Features 1. Other Red Rockfish Split into: -- Northern -- Rougheye/Shortraker 2. Tier 5 ABC = Average 1991-2002 Survey Biomass x 0.75M StockEBSAleutians Northern18 mt6,6980 mt (99.7%) Rougheye-Shortraker 137mt 830 mt (85.8%)
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Other Rockfish Assessments Notable Features 1. Presently Managed as a Complex 2. Author Recommend separating out Dusky Rockfish -- Catch rate maybe as high as 34% 3.Plan Team disagree, maybe catch rate estimated high -- Noted survey biomass has not decreased 4.Tier 5 ABC = Survey Biomass x 0.75 M StockYearSurvey BiomassABC EBS200218,000 960 AI200215,000 634
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Aleutian Islands Atka Mackerel
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Atka Mackerel Assessment Notable Features 1. New Assessemnt Model – AD Model Builder 2. Authors ABC Considerations -- Survey Biomass 2002 = 773,000 mt up 51% from 2000 survey; Shows high variability -- Yr 2003 Model biomass = 358,000 mt, down 7 % from Yr 2002; -- Max Permissible F40 would yield ABC = 82,800 mt -- 1998 Year Class showing strength 3. Plan team favors using average F over last 5 years -- ABC = 51,000 mt -- slight increase over 2002 ABC of 49,000 mt 4. ABC apportioned by area using weighted last 4 survey biomass
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Sablefish-all areas
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Sablefish Assessment Notable Features 1. Longline Survey Abundance -- Increased 5% in numbers and 7% in weight 2. Modeling -- Abundance now appears moderate and increased from recent lows 3.ABC according to Tier 3b -- Max Permissible F 40 adjusted gives ABC = 25,400 mt -- Team and Author recommend ABC = 18,400 mt Simulation shows spawning biomass will have low probability of dropping below historic low biomass 4.ABC is apportioned by 5-year exponential weighting of abundance indices by region: EBS, AI & GOA
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Squid Assessment Notable Features 1.Squid ABC is calculated under Tier 6 …. average catch from 1977-1995 2.Begin managing by Major Taxonomic Groups a. For Sculpins & Skate …. ABC = Tier 5 Situation = 0.75M * Biomass b. For Sharks and Octopus ….. ABC = Tier 6 = Average 1977-1995
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Summary (From Table 4) (Pollock) StockBiomass (mt) ABC (mt)ABC Change (2003 from 2002) Pollock, EBS 11,100,0002,330,000Up 10 % Pollock, AI175,00039,400Up 65% Pollock, Bogoslof 232,00034,000Down 6%
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Summary ( fromTable 4) (Cod and Sablefish) StockBiomass (mt) ABC (mt)ABC Change (2003 from 2002) Pacific Cod, BSAI 1,680,000223,000Same Sablefish, EBS 31,0002,550Up 32 % Sablefish, AI 39,0002,740Up 7 %
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Summary ( fromTable 4) (Flatfishes) StockBiomass (mt) ABC (mt)ABC Change (2002 fr 2001) YellFn. Sole1,554,000114,000Down 2 % Grn. Turbot112,0005,880Down 27 % Arrow. Fl597,000112,000Down 1 % Rock Sole877,000110,000Down 51 % Flathead S550,00066,000Down 20 % Alaska Plaice 1,083,000137,000Down 4 % Other Flats107,00015,000 Down 17%
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Summary ( fromTable 4) (Rockfishes) StockBiomass (mt) ABC (mt)ABC Change (2003 fr 2002) POP, BSAI375,00015,100Up 2 % Northern R156,0007,000Up 4% ShortRaker- Rougheye 32,000967Down 6% Other R, EBS18,000960Up 165% Other R, AI15,000634 Down 6%
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Summary ( fromTable 4) (Atka Mackerel & Other Species) StockBiomass (mt) ABC (mt)ABC Change (2003 fr 2002) Atka Mackerel 358,30051,000Up 4 % SquidNA1,970No Change Other Species 695,00060,800Up 55 %
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2003 Female Spawning Biomass versus B 40 Target Levels
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4 Cases when Max Permissible ABC was Adjusted Down by Plan Team StockMaximum Permissible ABC (mt) Recommend PT ABC (mt) Main Reasons for Adjustment Pacific Cod278,000223,000Risk-Adverse Optimization Green. Turbot17,8005,880Low B & R Sablefish, All25,40018,400Simulated Catch Atka Mackerel82,80051,000Average 5-Yr F
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Spawning Biomass – Pacific Cod
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Spawning Biomass – Greenland Turbot
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Spawning Biomass – Sablefish
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Projected Spawning Biomass – Atka Mackerel
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Spawning Biomass – Yellowfin Sole
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Spawning Biomass – Arrowtooth Flounder
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Spawning Biomass – Flathead Sole
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Spawning Biomass – Alaska Plaice
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Spawning Biomass – Pacific Ocean Perch
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Adjustments to ABCs - due to Ecosystems The Team was unable to isolate individual cases where ABC adjustments are needed to be made to address ecosystem concerns.
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BSAI Groundfish Complex Yr 2000 to Yr 2003 Exploitable Biomass – 19.8 mmt for Yr 2003 – Near Historical High ABC – 3.33 mmt for Yr 2003 – Near Historical High
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Year 2003 Summary ABC = 3,331,001 mt TAC = 2,000,000 mt
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5 Cases when Plan Team ABC is different from SSC’s ABC StockPlan Team ABC (mt) SSC’s Recommend ABC (mt) Main Reasons for Adjustment Pollock, Bogoslof 34,0004,070SSC Adjusted F rate Sable fish (EBS & AI) 18,400 (2,550 & 2,740) 20,900 (2,900 & 3,100) PT – constant C SSC–similar trend Northern Rockfish 7,000121 EBS 6980 AI Reliability of Survey Biomass Atka Mackerel51,00063,000 PT – Ave 5yr F SSC – constant buffer Other Species60,80043,300
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From Harvest Strategy (F 40 ) Report From Page 121 “It is easy enough to say that a management system could be made more protective of ecosystem properties……. But current knowledge does not allow precise scientific specification of what margin or threshold would be appropriate to achieve what level of protection of various ecosystem properties”
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From Harvest Strategy (F 40 ) Report From Page 121 “The decision to use F 40% rather than F 35% was deliberately protective, and was intended to function as a buffer against several sources of uncertainty” “ Nevertheless, it is not clear how much of the margin between F 35% and F 40% was ‘allocated’ to ecosystem considerations”
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ABC Rates for Rockfishes StockBiomass (mt) ABC (mt)ABC Rate POP, BSAI375,00015,1004.03 % Northern R156,0007,0004.49 % ShortRaker- Rougheye 32,0009673.02 % Other R, EBS18,0009605.33 % Other R, AI15,0006344.22 %
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Adjust for Climatic Regime Shifts 3 Regimes – Years 1965 - 77 – Years 1978 - 88 – Period 1989 - 97 ? – Another Regime ? Earlier Regimes – 1899-1924 – 1925-47 – 1948-76 ?
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End of Slide Presentation
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Utilization of Resources
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BSAI Groundfish Complex Yr 2000 to Yr 2003 Exploitable Biomass – 19.8 mmt for Yr 2003 – Near Historical High ABC – 3.289 mmt for Yr 2003 – Near Historical High
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Spawning Biomass
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Spawning Biomass -- EBS Pollock
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Pacific Halibut Catch 25 Year History (in thousands of mt)
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Gulf of Alaska Groundfish Catch 25 Year History (in thousands of mt)
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EBS Pollock Long-Term Biomass Trend
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Year-class estimates -- EBS Pollock 78 82 89 92 96 98- 99
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BSAI Flatfish Complex Biomass Yr 2003 Total = 4.88 MMT, down
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BSAI Rockfish Complex Biomass Yr 2003 Total = 596,000 MT
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