Historical roots of the migration triangle

The first principle guiding our understanding of how migration affects population dynamics is philopatry. Harden Jones (1968) codified philopatry as the migration triangle, a series of seasonal and ontogenetic migrations arranged to guarantee homing and reproduction at localized spawning grounds. The concept of philopatry has supported the assumption of closed populations and allowed important theoretical development of surplus yield and stock-recruitment relations (Smith, 1994). The underlying theory of philopatry is, in fact, quite complex, particularly in the evidence initially required to prove it. Early fisheries scientists within ICES and elsewhere had to demonstrate: