A model approach to identify the spawning grounds and describing the early life history of Northeast Arctic haddock (Melanogrammus aeglefinus)

The time-series of recruitment of Northeast Arctic (NEA) haddock (Melanogrammus aeglefinus) reveals larger interannual fluctuations than other gadoid species of the region. The position of spawning sites and the subsequent drift pattern of the offspring may contribute to the large transport variability, and hence, to the large variation in recruitment. A mechanistic individual-based biophysical model covering the egg stage to presettling juveniles, together with observations of 0-group distribution in the Barents Sea and time-series of abundance estimates are used to analyse these factors. The model indicates that spawning north of 67°N is favourable for offspring transport into the nursery grounds in the Barents Sea. The effect of latitude is stronger than across-shelf position for both growth and transport to the nursery grounds. The model predicts 0-group haddock outside the standard sampling area of the annual 0-group survey in the Barents Sea, which could partially explain the occasional occurrence of increase in cohort abundance from the 0-group to 1-year stage.