Comparison of larval, age-0 juvenile and age-2 recruit abundance indices of walleye pollock,Theragra chalcogramma, in the western Gulf of Alaska

• Published in: ICES Journal of Marine Science
• Main Authors: Bailey, Kevin M., Spring, Stella M.
• Format: Text
• Language: English
• Published: Oxford University Press 1992
• Subjects: Articles; Gulf of Alaska; Theragra chalcogramma; Alaska
• Online Access: http://icesjms.oxfordjournals.org/cgi/content/short/49/3/297; https://doi.org/10.1093/icesjms/49.3.297

Abundance indices were formulated from historical data on larvae, age-0 juveniles and age-2 recruits of walleye pollock, Theragra chalcogramma, in the western Gulf of Alaska.Indices were examined for linear and rank correlations to determine when year-class strength is established. Age-0 juveniles and recruits were significantly correlated, and the rank ordering of year-class strength did not change significantly between these life stages.The same situation was observed between larvae and age-0 juveniles. However, the levels of larval and age-2 recruit abundance were not significantly correlated and the rank ordering was not significant; the cause for this dissociation was 2 years of very high larval abundance that resulted in below average year classes. Years of low larval abundance resulted in weak year classes as age-0 juveniles and age-2 recruits. These data indicate that larval surveys may be useful to predict year-class failures (when larvae are not abundant), although not necessarily strong year classes; age-0 juvenile surveys can detect relatively strong or weak year classes.