Improving assessments of marine protected areas

• 1. The use of experimental design and statistical analysis to evaluate the effects of marine protected areas (MPAs) is increasingly popular throughout the world.
• 2. However, in looking at historical approaches to MPA evaluations, flaws were identified in the execution of theoretically correct designs, as well as disconnects between the stated objectives of MPAs and those of assessment studies.
• 3. MPA assessments can be improved by: (1) considering the enforcement/compliance level; (2) linking explicitly the choice of indicator(s) to the MPA objectives; (3) accounting for habitat structure; (4) taking into account the age and size of the MPA; and (5) quantifying the fishing pressure outside the MPA (including possible displacement effects).
• 4. Neglecting social factors, using inappropriate indicators, and/or ignoring relevant covariates, carries the risk of having MPAs dismissed as an effective management tool. Societal expectations are strong that MPAs will confer benefits, and thus assessment studies need to be progressively improved using new methodologies and the best available scientific evidence. Copyright © 2009 John Wiley & Sons, Ltd.