First Paragraph
Understanding dispersal pathways and population connectivity is an essential prerequisite for devising effective fishery management strategies in at least two critical ways. The first concerns the delineation of appropriate spatial scales for management, while the second involves specification of subareas that are to be protected from exploitation and that are nested within broader management units. An understanding of dispersal patterns at all life-history stages is crucial to meeting both objectives. Spatial management units are typically defined on the basis of genetic structure, differences in morphological and demographic characteristics, fishing patterns, and/or movement and dispersal patterns of individual species (Cadrin et al., 2004). Classical models employed in single-species management typically assume that the population is well mixed throughout the management area. Today, our enhanced ability to resolve finer-scale population structure and patterns of connectivity with refined monitoring programs and advances in genetic techniques, elemental fingerprinting, and other tools (see Hedgecock et al., this issue; Thorrold et al., this issue) reveals the need to adopt a metapopulation perspective in which subpopulations linked through dispersal at one or more points in the life cycle comprise the management unit (Kritzer and Sale, 2006).