2004 Report of Assessment and Research Activities

The IPHC Report of Assessment and Research Activities is a compilation of progress reports relating to staff activities. Some of the information contained here has changed since printing as new data is gathered and analyzed.

  • Cover by Forsberg (pdf 108KB)
  • Contents (pp. 1-8, pdf 142KB)
  • Section 1 (pp. 9-30, pdf 258KB)
    • IPHC research program: Review of 2004 projects and proposals for 2005 
  • Section 2 - The Fishery (pp. 31-76, pdf 294KB)
    • Removals 
      • 2004 Commercial fishery and regulation changes
      • 2004 Sport Fishery
      • Wastage in the 2004 Pacific halibut fishery
      • Revised estimates of the 2004 personal use harvest, including new estimates for the subsistence fishery off Alaska
      • Retention of sublegal halibut in the Areas 4D/4E CDQ fishery: 2004 harvests
    • Sampling and Analysis
      • Commercial catch sampling
      • The presence of swivels on snapped hook gear in the halibut fishery
      • Age distribution of the commercial halibut catch for 2004
  • Section 3a - Population Assessment (pp. 77-148, pdf 690KB)
    • Simulations studies of mark-recapture estimates
    • Estimates of length-specific commercial selectivity from historical marking experiments
    • Assessment of the Pacific halibut stock at the end of 2004
    • Analysis of the constant harvest rate policy for 2005
    • Analysis of the 1985 hook spacing experiment 
    • Updated simulation analysis of the CCC harvest policy with separate accounting of males and females (pp. 149-210, pdf 793KB)
    • Yield per recruit analysis for a sex specific halibut assessment model
    • Investigation of the role of fishing in the Area 4C CPUE decline
    • Preliminary estimates based on the 2004 PIT tag recoveries
  • Section 3b - Bycatch (pp. 211-242, pdf 1.5 MB)
    • Incidental catch and mortality of Pacific halibut, 1962-2004
    • Pacific halibut discard mortality rates in the 2003 Alaskan groundfish fisheries, with recommendations for monitoring CDQ fisheries in 2005
    • The Bering Sea trawl fishery Prohibited Species Donation Program: Results from 1998-2004
  • Section 4 - Biological Research
    • General I (pp. 243-298, pdf 2.4 MB)
      • Cruise report for 2003-04 southeast Alaska juvenile Pacific halibut (Hippoglossus stenolepis) collection charters
      • Using otolith chemistry to determine halibut nursery origin:  an initial test of concept
      • Cruise report for 2004 IPHC winter charters
      • Deployment of the Seacat water column profiler in 2004
    • General II (pp. 299-344, pdf 2.6 MB)
      • Investigating seasonal migration of adult Pacific halibut (Hippoglossus stenolepis) along the Aleutian Chain using pop-up satellite transmitting archival tags
      • Thermal habitat preferences of Pacific halibut and the potential influence of hydrographic variability on a local coastal fishery:  project progress report
      • A project to test the use of digital video for monitoring the compliance of seabird avoidance devices and seabird mortality in halibut longline fisheries
      • Analysis of halibut gonad staging 
      • Occurrence of double-ring patterns in halibut otoliths
      • Incidence of crystallized otoliths from the 2000 to 2002 IPHC setline and NMFS trawl surveys
      • Description of a Pacific halibut chronology of bomb radiocarbon from 1944-1981 and a validation of ageing methods
      • Technique development and age determination of the Pacific sleeper shark (Somniosus pacificus)
      • Homogeneity test for the Pacific sleeper shark (Somniosus pacificus)
    • Tagging (pp 345-384, pdf 4.8 MB)
      • PIT tagging in 2004
      • Review of information on PIT tag loss and detection rates
      • Recoveries of double-tagged fish and PIT tag loss rate
      • Portside sampling for recovered PIT tags in Pacific halibut
      • Tagging studies
    • Survey results and analysis (pp. 385-458, pdf 3.3 MB)
      • 2004 Standardized stock assessment survey
      • Prior Hook Injuries (PHI):  Results from the 2004 IPHC SSA surveys and NMFS Bering Sea trawl surveys
      • Analysis of prior hooking injury (PHI) classifications on the IPHC setline survey and the effects of PHIs on the length at age of halibut
      • Cruise report for the 2004 NMFS Bering Sea trawl survey
      • Size and age composition of Pacific halibut in NMFS Bering Sea shelf trawl surveys 
      • Results from 2003 seabird occurrence data
      • Age distribution of Pacific halibut in IPHC stock assessment setline surveys

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