Marine Metapopulations

Abstract

Many marine populations of concern to conservation biologists appear to have a metapopulation structure driven either by larval dispersal among habitat patches or by juvenile dispersal and adult migration. Of key concern in this chapter is to establish the levels of variability in system connectivity and evaluate carefully how such variability interacts with local-scale demographic patterns to dictate both sub- and metapopulation-level dynamics. Both the reef fish and spiny lobster case studies have pointed out the importance of considering habitat and connectivity when seeking to understand local and metapopulation dynamics. For populations of species more controlled by migrations of juveniles and adults, such as sea turtles, there is a need to better understand the migratory pathways and the risks these species encounter along their route. New models will need to be based on recently determined population structure in which females tend to return to nest in their region of origin but males may wander among these subpopulations. It is no coincidence that the case studies presented in this chapter point to the same conclusion echoed in the ongoing evolution of place-based approaches to management of these systems—that is, the need to consider the dynamics of these systems at a larger scale for the sake of understanding them at the smaller scale.