An evaluation of recruitment indices for Arcto-Norwegian cod ( Gadus morhua L.)

Abundance indices for Arcto-Norwegian cod ( Gadus morhua L.) at various life stages were analysed to determine the index that provides the earliest reliable prediction of year-class strength. The indices considered are an egg abundance index; an early juvenile (approximately 3-months old) abundance index; 0-group (age 4- to 5-months) abundance indices; bottom trawl and acoustic survey abundance indices for 1-, 2- and 3-year-old cod, and VPA estimates of the abundance of 3-year-old cod and of spawning stock biomass. Based on a regression analysis, a cohort’s relative abundance as early juveniles is the best early indication of its abundance as 2- and 3-year-olds.