Interannual variations in the liver condition index of cod as an indicator of temperature and feeding conditions in the Barents Sea

Abstract

Background: Northeast Arctic cod, inhabiting the edge of the species area, experience variable environmental conditions and feeding resources, one of the main of them is capelin. Lipids are an important biochemical link between capelin and cod. Lipids constitute approximately 10-15% of the total wet weight of capelin at the peak of their seasonal cycle in lipid accumulation (Jangaard 1974). In contrast, approximately 1% of the wet weight of the muscle tissue of cod is composed of lipids (Lie et al. 1988). The liver is the primary site of stored lipid reserves in cod. These reserves are utilized during periods of food limitation and the annual cycle of gonad maturation. Starved cod can replenish liver reserves rapidly in response to increased food (Karlsen et al. 1995). Lliver weight is likely to be a dynamic index of the physiological condition of cod.