Marine reserve networks for species that move within a home range

Marine reserves are expected to benefit a wide range of species, but most models used to evaluate their effects assume that adults are sedentary, thereby potentially overestimating population persistence. Many nearshore marine organisms move within a home range as adults, and there is a need to understand the effects of this type of movement on reserve performance. We incorporated movement within a home range into a spatially explicit marine reserve model in order to assess the combined effects of adult and larval movement on persistence and yield in a general, strategic framework. We describe how the capacity of a population to persist decreased with increasing home range size in a manner that depended on whether the sedentary case was maintained by self persistence or network persistence. Self persistence declined gradually with increasing home range and larval dispersal distance, while network persistence decreased sharply to 0 above a threshold home range and was less dependent on larval dispersal distance. The maximum home range size protected by a reserve network increased with the fraction of coastline in reserves and decreasing exploitation rates outside reserves. Spillover due to movement within a home range contributed to yield moderately under certain conditions, although yield contributions were generally not as large as those from spillover due to larval dispersal. Our results indicate that, for species exhibiting home range behavior, persistence in a network of marine reserves may be more predictable than previously anticipated from models based solely on larval dispersal, in part due to better knowledge of home range sizes. Including movement within a home range can change persistence results significantly from those assuming that adults are sedentary; hence it is an important consideration in reserve design.