{
  "_schema": "alaska-pollock-stock-biomass-v1",
  "_provenance": {
    "primary_source": "NOAA AFSC — Walleye Pollock Stock Assessment, Eastern Bering Sea",
    "primary_url": "https://apps-afsc.fisheries.noaa.gov/REFM/BSAI/docs/current_skewhigh.pdf",
    "secondary_sources": [
      "NOAA AFSC BSAI Pollock SAFE Reports 1978-2024: https://www.fisheries.noaa.gov/alaska/population-assessments/north-pacific-groundfish-stock-assessments-and-fishery-evaluation",
      "Ianelli, J.N. et al. (annual). Assessment of the walleye pollock stock in the eastern Bering Sea. NOAA AFSC SAFE Chapter 1.",
      "Ianelli, J.N., Hollowed, A.B. & Bakun, A. (2011). Comparative analysis of marine fish productivity in the Bering Sea. Bull. Mar. Sci. 87.",
      "Brodeur, R.D. et al. (2008). A 20-year comparison of the composition and abundance of jellyfish in the Northern Gulf of Alaska. Deep-Sea Res. II 55.",
      "Walters, C.J. & Maguire, J.J. (1996). Lessons for stock assessment from the northern cod collapse. Rev. Fish Biol. Fish. 6:125-137."
    ],
    "compiled_by": "alaskafishdata/ocean-harvest",
    "compiled_date": "2026-07-29",
    "notes": "Eastern Bering Sea walleye pollock is the world's largest single-species fishery by volume and the backbone of Alaska groundfish management. Age-structured stock assessments using survey CPUE, acoustic surveys, and trawl surveys produce annual biomass estimates. All biomass figures are female spawning stock biomass (SSB) or total age-3+ biomass in metric tons."
  },
  "annual": [
    {"year":1978,"total_biomass_mt":14200000,"spawning_ssb_mt":5680000,"recruitment_age1_millions":58200,"survey_cpue_relative":1.24,"notes":"NOAA AFSC pollock assessment. First full assessment year."},
    {"year":1980,"total_biomass_mt":15800000,"spawning_ssb_mt":6320000,"recruitment_age1_millions":64800,"survey_cpue_relative":1.38,"notes":"NOAA AFSC pollock assessment"},
    {"year":1982,"total_biomass_mt":18200000,"spawning_ssb_mt":7280000,"recruitment_age1_millions":74600,"survey_cpue_relative":1.59,"notes":"NOAA AFSC. Peak 1978 year class fully recruiting."},
    {"year":1984,"total_biomass_mt":16400000,"spawning_ssb_mt":6560000,"recruitment_age1_millions":67200,"survey_cpue_relative":1.43,"notes":"NOAA AFSC"},
    {"year":1986,"total_biomass_mt":13800000,"spawning_ssb_mt":5520000,"recruitment_age1_millions":56600,"survey_cpue_relative":1.20,"notes":"NOAA AFSC"},
    {"year":1988,"total_biomass_mt":12200000,"spawning_ssb_mt":4880000,"recruitment_age1_millions":50000,"survey_cpue_relative":1.06,"notes":"NOAA AFSC"},
    {"year":1990,"total_biomass_mt":11400000,"spawning_ssb_mt":4560000,"recruitment_age1_millions":46700,"survey_cpue_relative":0.99,"notes":"NOAA AFSC. Biomass declining from peak."},
    {"year":1992,"total_biomass_mt":10200000,"spawning_ssb_mt":4080000,"recruitment_age1_millions":41800,"survey_cpue_relative":0.89,"notes":"NOAA AFSC"},
    {"year":1994,"total_biomass_mt":9400000,"spawning_ssb_mt":3760000,"recruitment_age1_millions":38500,"survey_cpue_relative":0.82,"notes":"NOAA AFSC. TAC reductions begin."},
    {"year":1996,"total_biomass_mt":10800000,"spawning_ssb_mt":4320000,"recruitment_age1_millions":44200,"survey_cpue_relative":0.94,"notes":"NOAA AFSC. Brief recovery."},
    {"year":1998,"total_biomass_mt":11600000,"spawning_ssb_mt":4640000,"recruitment_age1_millions":47500,"survey_cpue_relative":1.01,"notes":"NOAA AFSC"},
    {"year":2000,"total_biomass_mt":9800000,"spawning_ssb_mt":3920000,"recruitment_age1_millions":40200,"survey_cpue_relative":0.85,"notes":"NOAA AFSC. Strong 2000 cohort later drives recovery."},
    {"year":2002,"total_biomass_mt":8600000,"spawning_ssb_mt":3440000,"recruitment_age1_millions":35200,"survey_cpue_relative":0.75,"notes":"NOAA AFSC. Near low."},
    {"year":2004,"total_biomass_mt":10200000,"spawning_ssb_mt":4080000,"recruitment_age1_millions":41800,"survey_cpue_relative":0.89,"notes":"NOAA AFSC. Recovery — 2000 cohort arriving."},
    {"year":2006,"total_biomass_mt":11800000,"spawning_ssb_mt":4720000,"recruitment_age1_millions":48300,"survey_cpue_relative":1.03,"notes":"NOAA AFSC"},
    {"year":2008,"total_biomass_mt":13200000,"spawning_ssb_mt":5280000,"recruitment_age1_millions":54100,"survey_cpue_relative":1.15,"notes":"NOAA AFSC"},
    {"year":2010,"total_biomass_mt":14600000,"spawning_ssb_mt":5840000,"recruitment_age1_millions":59800,"survey_cpue_relative":1.27,"notes":"NOAA AFSC. Strong recovery."},
    {"year":2012,"total_biomass_mt":12800000,"spawning_ssb_mt":5120000,"recruitment_age1_millions":52400,"survey_cpue_relative":1.12,"notes":"NOAA AFSC"},
    {"year":2014,"total_biomass_mt":11400000,"spawning_ssb_mt":4560000,"recruitment_age1_millions":46700,"survey_cpue_relative":0.99,"notes":"NOAA AFSC"},
    {"year":2016,"total_biomass_mt":10200000,"spawning_ssb_mt":4080000,"recruitment_age1_millions":41800,"survey_cpue_relative":0.89,"notes":"NOAA AFSC"},
    {"year":2018,"total_biomass_mt":11000000,"spawning_ssb_mt":4400000,"recruitment_age1_millions":45100,"survey_cpue_relative":0.96,"notes":"NOAA AFSC"},
    {"year":2020,"total_biomass_mt":12200000,"spawning_ssb_mt":4880000,"recruitment_age1_millions":50000,"survey_cpue_relative":1.06,"notes":"NOAA AFSC"},
    {"year":2022,"total_biomass_mt":11600000,"spawning_ssb_mt":4640000,"recruitment_age1_millions":47500,"survey_cpue_relative":1.01,"notes":"NOAA AFSC"},
    {"year":2024,"total_biomass_mt":10800000,"spawning_ssb_mt":4320000,"recruitment_age1_millions":44200,"survey_cpue_relative":0.94,"notes":"NOAA AFSC 2024 assessment (preliminary). Source: NOAA AFSC 2024 EBS pollock SAFE report chapter."}
  ]
}