Targets for marine protection under the Convention on Biological Diversity have seen rapid growth in MPAs globally, with progress judged using targets for total area protected rather than evaluating growth based on the capacity to protect biodiversity.

However, the authors of this study state that the value of a MPA network to biodiversity conservation depends on a range of attributes of both individual MPAs and portfolios of MPAs, which are not captured by simple area-based targets. Therefore, they highlight the need of a clear and efficient set of metrics to effectively evaluate progress towards building MPA networks, considering the representation and adequacy of protection for biodiversity.

To solve this issue this study developed a universally applicable set of metrics that can evaluate network structure in relation to its capacity to conserve marine biodiversity. These metrics combine properties of effective individual MPAs with metrics for their capacity to function collectively as a network. It is highlighted that, collectively, the metrics allow tracking progress in the development of a MPA network and help guide efforts towards strengthening conservation of marine biodiversity.

Additionally, in order to demonstrate the value of the developed metrics, the authors applied them to the Australian MPA network, the largest in the world. The obtained results revealed opportunities to build on the strong progress towards a robust system of MPAs by extending no-take areas. In this sense, the authors conclude that the current value of the MPA network could be greatly increased by reducing the prevalence of multi-use zones that allow extractive activities known to negatively impact biodiversity.

Roberts KE, Valkan RS, Cook CN (2018) Measuring progress in marine protection: A new set of metrics to evaluate the strength of marine protected area networks. Biological Conservation 219:20-27