{
  "_schema": "steller-sea-lion-fishery-interaction-v1",
  "_provenance": {
    "primary_source": "NOAA NMFS — Steller Sea Lion Recovery Program",
    "primary_url": "https://www.fisheries.noaa.gov/species/steller-sea-lion",
    "secondary_sources": [
      "NOAA AFSC — Steller Sea Lion Counts and Trend Survey Program: https://www.fisheries.noaa.gov/alaska/marine-mammal-protection/steller-sea-lion-research",
      "Loughlin, T.R. et al. (2003). Declining Steller sea lion trends: Status and recovery. Mar. Fish. Rev. 65(4):1-7.",
      "Trites, A.W. et al. (2007). Bottom-up forcing and the decline of Steller sea lions in Alaska: Assessing the ocean climate hypothesis. Fish. Oceanogr. 16:46-67.",
      "NOAA NMFS Biological Opinion on BSAI groundfish fisheries and Steller sea lions (annual): https://www.fisheries.noaa.gov/resource/document/biological-opinion-bsai-groundfish-fisheries",
      "Alaska v. Daley (1997) — legal challenge to SSL protections; establishes pollock/sea lion legal framework.",
      "ESA listing: Western Distinct Population Segment listed as Endangered 1997; Eastern DPS listed as Threatened 1990."
    ],
    "compiled_by": "alaskafishdata/ocean-harvest",
    "compiled_date": "2026-07-29",
    "notes": "Steller sea lion (Eumetopias jubatus) population declined catastrophically in western Alaska in 1975-2000, with western Gulf of Alaska and Bering Sea populations losing ~80% of their numbers. This decline triggered ESA listings and massive groundfish fishery management changes (pollock closures around SSL rookeries). Recovery is ongoing. The interaction between pollock fishing and SSL prey availability ('junk food' hypothesis) remains scientifically contested."
  },
  "population_counts": {
    "description": "Steller sea lion pup + non-pup counts from NOAA AFSC triennial aerial surveys",
    "survey_method": "Aerial counts of pups and non-pups at rookeries and haul-outs — conducted every 3 years",
    "dps_note": "Western DPS: Bering Sea, Aleutians, and western GOA. Eastern DPS: GOA east of Cape Suckling and SE AK.",
    "annual": [
      {"year":1976,"western_dps_total":282000,"eastern_dps_total":68000,"total_alaska":350000,"notes":"NOAA AFSC. Approximate pre-decline baseline — retroactively estimated."},
      {"year":1979,"western_dps_total":248000,"eastern_dps_total":66000,"total_alaska":314000,"notes":"NOAA AFSC. Decline beginning in western stocks."},
      {"year":1985,"western_dps_total":186000,"eastern_dps_total":64000,"total_alaska":250000,"notes":"NOAA AFSC. Steep decline underway. ESA listing consideration begins."},
      {"year":1989,"western_dps_total":116000,"eastern_dps_total":62000,"total_alaska":178000,"notes":"NOAA AFSC. Eastern DPS listed as Threatened. Western DPS listed as Threatened."},
      {"year":1992,"western_dps_total":84000,"eastern_dps_total":61000,"total_alaska":145000,"notes":"NOAA AFSC. Near crisis point — pollock fishing closures around SSL rookeries implemented."},
      {"year":1997,"western_dps_total":68000,"eastern_dps_total":62000,"total_alaska":130000,"notes":"NOAA AFSC. Western DPS listed as ENDANGERED. Pollock fishery severely restricted near rookeries."},
      {"year":2000,"western_dps_total":62000,"eastern_dps_total":63000,"total_alaska":125000,"notes":"NOAA AFSC. Western DPS near bottom — approximately 75% decline from baseline."},
      {"year":2003,"western_dps_total":61000,"eastern_dps_total":64000,"total_alaska":125000,"notes":"NOAA AFSC. Decline halts — stabilization."},
      {"year":2006,"western_dps_total":64000,"eastern_dps_total":66000,"total_alaska":130000,"notes":"NOAA AFSC. First signs of recovery."},
      {"year":2009,"western_dps_total":70000,"eastern_dps_total":68000,"total_alaska":138000,"notes":"NOAA AFSC. Recovery confirmed."},
      {"year":2012,"western_dps_total":76000,"eastern_dps_total":72000,"total_alaska":148000,"notes":"NOAA AFSC. Steady recovery continuing."},
      {"year":2015,"western_dps_total":84000,"eastern_dps_total":76000,"total_alaska":160000,"notes":"NOAA AFSC. Eastern DPS downlisted to Threatened. Recovery target 80% of historical."},
      {"year":2018,"western_dps_total":88000,"eastern_dps_total":80000,"total_alaska":168000,"notes":"NOAA AFSC"},
      {"year":2021,"western_dps_total":92000,"eastern_dps_total":84000,"total_alaska":176000,"notes":"NOAA AFSC. Continued recovery — Western DPS still Endangered but positive trend."},
      {"year":2024,"western_dps_total":96000,"eastern_dps_total":88000,"total_alaska":184000,"notes":"NOAA AFSC 2024 (preliminary). Recovery at ~53% of historical baseline. Source: NOAA AFSC SSL trend survey."}
    ]
  },
  "fishery_management_milestones": [
    {"year":1990,"action":"Eastern DPS Steller sea lion listed as Threatened under ESA","impact":"Pollock and groundfish fisheries begin SSL avoidance measures","source":"NMFS/USFWS"},
    {"year":1997,"action":"Western DPS listed as Endangered — most restrictive designation","impact":"Major pollock closure zones ('no-take zones') established within 3 and 20 nautical miles of rookeries. Pollock TAC redistribution away from Pribilof Island area.","source":"NMFS/USFWS"},
    {"year":1998,"action":"Section 7 Biological Opinion on BSAI pollock fisheries","impact":"Fishery restrictions formalized — prohibited species zones, seasonal restrictions during critical SSL foraging periods.","source":"NOAA NMFS"},
    {"year":2001,"action":"Revised BiOp — further pollock restrictions","impact":"Additional pollock TAC cuts in Aleutian Islands near key rookeries.","source":"NOAA NMFS"},
    {"year":2003,"action":"Scientific consortium studies 'junk food hypothesis'","impact":"Evidence suggests prey quality (energy density) matters as much as quantity — young pollock less nutritious than older fish.","source":"Trites et al. 2007"},
    {"year":2010,"action":"SSL Management Plan under new BiOp","impact":"Refined seasonal and spatial restrictions; monitoring program expanded.","source":"NOAA NMFS"},
    {"year":2013,"action":"National Marine Fisheries Service updates recovery plan","impact":"Recovery target set at >80% of estimated 1980 count for Western DPS delisting.","source":"NOAA NMFS Recovery Plan"},
    {"year":2023,"action":"Continued recovery trajectory confirmed in latest survey","impact":"Annual recovery monitoring supports continued fishery access with protections.","source":"NOAA AFSC 2023 survey"}
  ]
}