ABSTRACT:The relationship between marine reserve design and metapopulation persistence has been analyzed only for cases of spatially homogenous advective-diffusive larval dispersal. However, many coastlines exhibit more complex circulation, such as retention zones in which slower-moving currents shorten dispersal distances and larvae can accumulate. We constructed metapopulation models that incorporated 3 types of spatial variability in dispersal associated with retention zones: (A) reduction of both advective (L A ) and stochastic (L S ) length scales of dispersal within the retention zone, (B) reduction of L A only, and (C) accumulation of larvae in the retention zone, followed by redistribution along the coastline. For each scenario, we examined reserve networks with a range of size and spacing configurations. The scenarios differed in the relative number of self-persistent reserves, i.e. those which can survive in isolation, and network-persistent reserves, i.e. those which rely on connectivity through space and across generations to offset shortfalls in direct self-replenishment. When dispersal was dominated by stochastic movements (L S > L A in scenarios A and B), metapopulations typically consisted of self-persistent reserves. As dispersal became increasingly advective (L A > L S ), retention aided persistence, and network persistence became more prevalent. Persistence in scenario C decreased with the amount of redistribution. The specific patterns of persistence depended on the size and number of reserves and demographic parameters, but self-persistence was always more likely for reserves in the retention zone. Thus, placing a reserve in a retention zone to promote population persistence is advisable for all 3 dispersal scenarios.KEY WORDS: Larval dispersal 路 Dispersal kernel 路 Headland 路 Metapopulation 路 Marine reserve 路 Persistence 路 Self-recruitment
Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 398: [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67] 2010 ment influences metapopulation dynamics. Adequate reserve size and placement depends critically on larval dispersal patterns: reserves must be large enough or close enough together to ensure metapopulation persistence (e.g. Botsford et al. 2001, Walters et al. 2007. In this paper, we consider metapopulations made up of many discrete local populations, and define persistence in a deterministic way: when the metapopulation is near extinction, population density will tend to increase rather than decrease. Our interest is in both overall persistence (Does the metapopulation persist in at least one location?) and the spatial pattern of persistence (Where are the persistent local populations?).Recent empirical and theoretical results suggest that persistence of a metapopulation in a system of marine reserves depends on 2 mechanisms: (1) selfpersistence of local populations and (2) persistence that depends on connectivity among all or many locations in the network , Lipcius et al....