The distribution of the three species overlap so that no clear lines of demarcation can be drawn.
To first approximation, however, it was noted that M. merluccius, is found principally in divisions 34.1.1 and 34.1.2, whereas Merluccius senegalensis and M. cadenati are most abundant in divisions 34.1.3 and 34.3.1.
It is uncertain to what extent the stocks of M. merluccius are part of the stocks of hake found further north and in particular off the coast of Portugal. It was noted, however, that off northern Morocco, catches per unit effort are low, and that Spanish vessels working out of ports in the South-West of Spain, have to steam a considerable distance south before they obtain commercially attractive catches.
It was agreed that, lacking data to suggest otherwise, the stocks of M. merluccius could be treated as separate from those further north and that the Straits of Gibraltar could be taken arbitrarily as a line of separation. M. senegalensis and M. cadenati have been treated together and referred to as Merluccius spp. in the remainder of the report.