Population richness of marine fish species

Abstract

Within the distributional range of a species the number of self-sustaining populations can vary, from one for panmictic species such as American eel to many populations as observed in Atlantic salmon. This species-level characteristic is defined here as population Aspects of geographic patterns in richness in the northern Atlantic for Atlantic salmon, American shad, rainbow smelt, Atlantic herring, Atlantic cod, haddock, winter flounder, yellowtail flounder, Atlantic mackerel, and European eel are described. It is concluded that events at the early life-history stages, involving retention of the eggs and larvae in relation to particular physical oceanographic features, are involved in the definition of richness.