Variability in recruitment, growth and sexual maturity of coastal cod (Gadus morhua L.) in a fjord system in northern Norway

Sammendrag

Growth, recruitment, age and length at sexual maturity of coastal cod ICC) were investigated in a north Norwegian fjord system in 1989-1993. There were marked differences between inner (Sorfjord) and outer (Ullsfjord) areas of the fjord system. In the inner part, growth was slower and the population was more dominated by the numerous 1987 year class. Average age at sexual maturity was 5.5 years in both areas, but due to faster growth, the cod in Ullsfjord were 10 cm longer than cod in Sorfjord at sexual maturity. This suggests that cod in Ullsfjord and Sorfjord may be considered as two stocks of CC, and that future management of CC stocks may have to consider variability in biological stock characteristics to fully utilise the production potential of each stock. Growth rate, length and age at maturity for the investigated coastal cod were lower than, and variation in recruitment out of phase with, similar parameters for north-east Arctic cod (NEAC). (C) 2001 Elsevier Science B.V. All rights reserved.