Large marine protected areas – advantages and challenges of going big

The Aichi Biodiversity Targets were designed to promote and implement the Convention on Biological Diversity (CBD) by providing a framework for action to save biodiversity and enhance its benefits for people. Specifically, Target 11 aims to protect 10% of all seas by 2020. The percentage of the world's oceans that are protected has increased steadily in recent years, mainly due to very large marine protected areas (MPAs).

The issue of making major gains in achieving protection targets through ‘going big’ has brought added scrutiny to the subject of MPAs. There is economy in scale, but several people have called into question whether going large will protect representative habitat and result in true protection, or whether it is merely a politically expedient way for some nations to attain targets by creating paper parks, while avoiding tough conservation decisions.

The recent creation of large MPAs has greatly enhanced the chance of achieving global protection targets. Large areas typically contain several ecosystems and habitats that interact ecologically, and allow for more holistic conservation. The interactions between ecosystems in large MPAs occur without many of the problems associated with networks of smaller MPAs, where the connectivity between sites is often affected by human activities.

The disadvantages of large MPAs include difficulties of surveillance, enforcement and monitoring of vast offshore areas, as well as high total costs. While the cost per unit area may be lower for large MPAs, conducting surveillance and monitoring in such vast areas requires much more expensive technologies.

Large MPAs complement and add to existing management and conservation measures. Decision makers should consider designating them as one of a suite of possible protection measures. Besides greatly enhancing the chance of reaching agreed biodiversity targets, large MPAs improve the quality of conservation.