Incorporating Habitat Selection Behavior in MPA Design Theory

Marine protected areas (MPAs) are increasingly suggested as a means to achieve both fisheries and conservation objectives. However, a poorly understood component of MPA design theory is the manner in which movement behaviors mediate the exchange of juvenile and adult fish between no-take and fished areas. Simulation-based studies of reserve design often model movement as a random process, rather than as a set of directed behaviors associated with habitat selection. Our goal is to explore MPA design theory for a hypothetical reef-associated species when movement directed towards resource utilization occurs according to the fitness-seeking behaviors of individuals. A spatially-explicit individual-based model is used to combine resource distribution patterns with habitat selection behavior to describe spatial dynamics. Redistribution behavior is simulated using departure rules which determine when an individual will leave its current location and destination rules which determine how a new location is selected. On-going research is utilizing this decision framework to investigate how site-attachment (departure frequency) and density-dependent habitat selection (destination selection) influences exchange across MPA boundaries. Alternative management scenarios include combinations of exploitation level in fished areas and MPA number, size, and location. Management outcomes are calculated in the currencies of equilibrium yield, spawning biomass, and average weight in fished areas. This research will assist in clarifying expectations about the efficacy of MPAs for reef-associated species.