EFFECTS OF TEMPERATURE, HYPOXIA AND ACTIVITY ON THE METABOLISM OF JUVENILE ATLANTIC COD

Standard metabolic rate (SMR), active metabolic rate (AMR) and critica l oxygen saturation (S-crit) were measured in Atlantic cod Gadus morhu a at 5, 10 and 15 degrees C. The SMR was 35.5, 57.0 and 78.2 mg O-2 kg (-1) h(-1) and S-crit was 16.5, 23.2 and 30.3%, at 5, 10 and 15 degree s C, respectively. Previously reported SMR for Atlantic cod from arcti c waters at 4 degrees C was twice that measured at 5 degrees C in the present study. A possible intraspecific latitudinal difference in the SMR is discussed. The AMR was 146.6, 197.9 and 200.4 mg O-2 kg(-1) h(- 1) and the critical swimming speed (U-crit) was 1.6, 1.7 and 1.9 at 5, 10 and 15 degrees C, respectively. The maximum oxygen consumption was found to be associated with exercise, rather than recovery from exerc ise as previously reported in another study of cod metabolism. (C) 199 7 The Fisheries Society of the British Isles.