Recent progress in understanding larval dispersal: new directions and digressions

Larvae have been difficult to study because their small sizelimits our ability to understand their behavior and the conditionsthey experience. Questions about larval transport focus largelyon (a) where they go dispersal] and (b) where they come fromconnectivity]. Mechanisms of transport have been intensivelystudied in recent decades. As our ability to identify larvalsources develops, the consequences of connectivity are garneringmore consideration. Attention to transport and connectivityissues has increased dramatically in the past decade, fueledby changing motivations that now include management of fisheriesresources, understanding of the spread of invasive species,conservation through the design of marine reserves, and predictionof climate-change effects. Current progress involves both technologicaladvances and the integration of disciplines and approaches.This review focuses on insights gained from physical modeling,chemical tracking, and genetic approaches. I consider how newfindings are motivating paradigm shifts concerning (1) life-historyconsequences; (2) the openness of marine populations, self-recruitment,and population connectivity; (3) the role of behavior; and (4)the significance of variability in space and time. A challengefor the future will be to integrate methods that address dispersalon short (intragenerational) timescales such as elemental fingerprintingand numerical simulations with those that reflect longer timescalessuch as gene flow estimates and demographic modeling. Recognitionand treatment of the continuum between ecological and evolutionarytimescales will be necessary to advance the mechanistic understandingof larval and population dynamics.