The Distribution of Cod (Gadus morhua) in the

Cod (Gadus morhua) distribution data for the period 1971–91 from the International Young Fish Survey conducted in February, and the period 1981–91 from the Dutch Ground-fish Survey conducted in October/November, were studied to determine possible trends in their abundance in different parts of the North Sea. Cod were widely distributed. Age groups 0 and 1 were most abundant in the German Bight, along the Dutch coast and northeast coast of England, while the age groups 3 and 4 were most abundant in the northern North Sea. For the southeastern North Sea, an important nursery area, the relation between abundance of cod and depth, temperature and salinity was studied. Although annual differences were pronounced, age groups 0 to 3 showed decreasing abundance with increasing depths with the tendency strongest for age group 0. The younger age groups also had highest densities at low temperature and low salinities, while the older fish were found in warmer water. These age specific differences in distribution were relevant to interpreting data from surveys