Analysis of Pre-recruit Data from Surveys for Greenland Halibut in NAFO Subarea 2 and Divisions 3KLMNO by

• Main Authors: B. P. Healey, N. G. Cadigan, W. B. Brodie
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2002
• Subjects: Greenland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.597.7513; http://archive.nafo.int/open/sc/2002/scr02-021.pdf

Research survey data are analyzed to predict relative year-class strength from 1975 to 2000. Log-additive models with fixed year-class strength and survey-age effects that have common variance among pre-specified groups (e.g. group = survey-age combinations) and zero covariance between groups are utilized to model the error structure of the data. Variance estimation of each group is iteratively re-weighted. Likelihood ratio tests reduce the number of variance parameters estimated. The most parsimonious model indicates that the 1993, 1994, and 1995 estimates of year-class strength are predominant over the time period, and the two most recent year class strength estimates, the 1999 and 2000 cohorts are also relatively strong.