• Conservation planning;
  • opportunity;
  • systematic;
  • marine;
  • Maxent;
  • implementation;
  • ad hoc


The marginal benefits of systematic over ad hoc selection of protected areas are rarely measured, even though this information is crucial to investing limited conservation resources effectively. We developed a method to predict the marginal benefits of systematic over ad hoc approaches to conservation over time. We tested it in Fiji, where ambitious national conservation goals for inshore marine waters rely on community support to implement the required management. We used Maxent to develop a suitability layer for different forms of marine resource management based on predictors derived from interviews with key informants. This suitability layer, together with data on established marine protected areas (MPAs) and the software Marxan with Zones, informed simulations of the expansion of ad hoc and systematic conservation. With the same constraints on the additional extent of MPAs, the ad hoc approach achieved quantitative conservation objectives for half the ecosystems in our analysis, although all objectives were achieved or nearly achieved with the systematic approach. By defining the likely upper and lower bounds of plausible futures given different decisions about conservation investments, this work was designed to guide conservation strategies and actions in Fiji. This work is currently influencing the development of policies in Fiji to promote more strategic use of limited conservation resources.