Reconstructing the stock-recruit relationship for Northeast Arctic cod using a bioenergetic index of reproductive potential

Correlation and simulation analyses suggest that, for the Northeast Arctic (NA) cod stock, the total lipid energy (TLE (kJ)) contained in the livers o f mature females is proportional to total egg production, making TLE a pote ntial predictor of recruitment. Accordingly, the TLE of NA cod was estimate d for a 51-year time period (1946-1996), using estimates of numbers at leng th derived from virtual population analysis, modelled values of proportion mature and weight at length, and observed values of the liver-condition ind ex. A significant linear relationship between TLE and recruitment to age 3 was observed. The temporal trend in TLE suggests that the reproductive pote ntial of the NA cod stock has been in decline since the mid-1970s. A multip le-regression model that included TLE, mean temperature, and mean alongshor e wind stress as independent variables explained approximately 43% of the v ariation in recruitment. Reconstructing stock-recruit relationships using m ore sensitive measures of reproductive potential is the first step in resol ving environmental effects on recruitment and in developing biological refe rence points that are more effective in stock conservation.