Effectiveness of a feedback management procedure based on controlling the size of marine protected areas through catch per unit effort

The effectiveness of a feedback management procedure using marine protected areas (MPAs) was investigated. This procedure does not control fishing effort, but it does increase the size of the MPA when the catch per unit effort (cpue) is below a predetermined target level and reduces the size when the cpue is above this level. Stability analyses of the approach, which consisted of a population dynamics model and a model to control MPA size, suggest that this procedure can lead to recovery of a depleted population and sustain that population at a predetermined target level, even when there is hyperstability (a non-linear relationship between population size and cpue). An alternative procedure using fishing effort instead of MPA size may also function well, although both procedures may need a long time for a depleted population to approach the target level. Performance of both procedures was examined using numerical simulations focused on system dynamics in the short term after management implementation. The procedure using MPA size was more effective at preventing population collapse. Simulations suggest that if this procedure starts from a desirable level of initial MPA size, it has advantages over the alternative procedure through creating speedier population recovery and a higher level of short-term catch.