1991 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. For the most up-to-date information, please contact the author by visiting the staff directory or by phoning the Seattle office at (206) 634-1838.

  • The Fishery (pp. 1-37, pdf 1.1 MB)
    • 1991 Commercial fishery
    • Sport fishery
    • Wastage in the Pacific halibut fishery
    • Commercial catch sampling
  • Stock Assessment (pp. 39-98, pdf 1.9 MB)
    • Population assessment
      • Population assessment, 1991
      • Population assessment, 1991 Technical supplement
      • Halibut subsistence catches
      • Assessment methods 
      • Features of Area 2A age composition data
      • Age composition and size at age of the commercial fishery for 1991
    • CPUE Studies (pp. 99-166, pdf 1.9 MB)
      • A progress report on the use of hook timers on longline gear
      • An age-structured Kalman Filter for Pacific halibut stock assessment
    • Biomass Estimates
      • Validation of the IPHC length-weight relationship for halibut
      • Re-examination of halibut growth and the size limit
      • Stock abundance estimation using depth dependent trends and spatially correlated variation
      • Estimates of halibut abundance in Area 2A from NMFS trawl surveys
      • Trends in abundance of juvenile halibut indicated by NMFS trawl surveys
      • Documentation of long-term trends in size at age in the commercial catch
      • Retrospective catch-age analysis: Implications on assessment of harvesting policies
      • Using data on biomass and fishing mortality in stock production modeling of flatfish
      • Mark-recapture methods for Pacific halibut assessment: A feasibility study conducted off Newport, Oregon
  • Bycatch (pp. 167-230, pdf 2.7 MB)
    • Incidental catch and mortality of Pacific halibut: through 1991
    • The 1991 Alaska groundfish fishery: Groundfish catches, halibut bycatches, and bycatch rates
    • Revised estimates of Pacific halibut discard mortality rates in the 1990 groundfish fisheries off Alaska
    • Comparison of day and night bycatch rates in Bering Sea domestic trawl fisheries
    • Canadian domestic trawl observer program
    • Report of the halibut bycatch work group
    • Status of bycatch management planning
  • Biological Research (pp. 231-305, pdf 2.3 MB)
    • General studies
      • Underwater video observations of fish behavior to baited circle hooks
      • Underwater observations of interactions between Pacific halibut and bottom trawls
      • Stock identification using DNA analysis
      • Parasites and Pacific halibut
      • Halibut culture project - Pacific Biological Station
      • Results of Pacific halibut rearing experiments at the University of Washington
      • Collection of halibut gonads in Area 2A
      • Comparison of age and length compositions between sport and commercial fisheries in Area 2A
      • A report on the use of the IPHC photography database
    • Otolith Studies 
      • Estimation of halibut body size from otolith size
      • Estimating sex of halibut using Fourier Shape Analysis of otoliths
      • Elemental composition of halibut otoliths
      • A comparison of classifier systems for automated aging of halibut otoliths
      • 1991 Otolith collection cruises
    • Tagging studies
      • Tagging studies
      • Movement of juvenile halibut in IPHC Regulatory Areas 2 and 3
      • Age dependent tag recovery analysis of Pacific halibut data

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