The North Atlantic

The Atlantic Ocean is vast. It stretches from the Arctic to the Antarctic. At its point of greatest width it is 5000 miles wide. It is a single ocean. However, these few remarks and the accompanying maps are intended to illuminate only the northern part, its adjacent seas and its fisheries.

Fish, crustaceans and molluscs have distributions, ranges or habitats which are determined by several criteria. One is the temperature of the water, another its salinity. A third, which is not of direct concern to pelagic fish, i.e. those which swim at the surface, is the depth of the water. A fourth is the availability of the foods on which the various species nourish themselves. A fifth, which applies to demersal fish, i.e. those which live on the sea bottom, is the nature of the bottom and its suitability to various needs, such as the requirement of many flatfish for sandy bottoms in which they can half bury themselves and that of lobsters for rocky crevices in which they can lurk. Finally, many species make migratory movements which may be determined by yet another factor, namely the need to find suitable places in which to spawn.