The use of total area protected as the predominant indicator of progress in building protected area (PA) networks is receiving growing criticism. Documenting the full dynamics of PA networks, both in terms of the gains and losses in protection, provides a much more informative approach to tracking progress. To this end, documentation of PA downgrading, downsizing, and degazettement (PADDD) has increased. Studies of PADDD events generally fail to place these losses in the context of gains in protection; therefore, they omit important elements of PA network dynamics. To address this limitation, we used a spatially explicit approach to identify every parcel of land added to and excised from the Australian terrestrial PA network and PAs that had their level of protection changed over 17 years (1997-2014). By quantifying changes in the spatial configuration of the PA network with time-series data (spatial layers for nine separate time steps), ours is the first assessment of the dynamics (increases and decreases in area and level of protection) of a PA network and the first comprehensive assessment of PADDD in a developed country. We found that the Australian network was highly dynamic; there were 5233 changes in area or level of protection over 17 years. Against a background of enormous increases in area protected, we identified over 1500 PADDD events, which affected over one-third of the network, which were largely the result of widespread downgrading of protection. We believe our approach provides a mechanism for robust tracking of trends in the world's PAs through the use of data from the World Database on Protected Areas. However, this will require greater transparency and improved data standards in reporting changes to PAs.

24Marine protected areas (MPAs) have proven to be a valuable tool for both promoting the 25 sustainable use of marine resources and long-term biodiversity conservation outcomes. Targets for 26 marine protection under the Convention on Biological Diversity have seen rapid growth in MPAs 27 globally, with progress judged using targets for total area protected rather than evaluating growth 28 based on the capacity to protect biodiversity. The value of a MPA network to biodiversity 29 conservation depends on a range of attributes of both individual MPAs and portfolios of MPAs, 30 which are not captured by simple area-based targets. Therefore, a clear and efficient set of metrics 31 are needed to effectively evaluate progress towards building MPA networks, considering the 32 representation and adequacy of protection for biodiversity. We developed a universally applicable 33 set of metrics that can evaluate network structure in relation to its capacity to conserve marine 34 biodiversity. These metrics combine properties of effective individual MPAs with metrics for their 35 capacity to function collectively as a network. To demonstrate the value of these metrics, we apply 36 them to the Australian MPA network, the largest in the world. Collectively, the indicators suggest 37 that while Australia has made significant progress in building a representative and well-structured 38 MPA network, the level of protection offered to marine biodiversity is generally low, with 39 insufficient coverage of no-take MPAs across many bioregions. The metrics reveal how the current 40 value of the MPA network could be greatly increased by reducing the prevalence of multi-use zones 41 that allow extractive activities known to negatively impact biodiversity. • Not all MPAs are equal, therefore total area is an inadequate indicator of progress. 48• Indicators of progress can draw on attributes of effective MPAs and MPA networks. 49• We developed a suite of metrics to evaluate MPA network structure and performance. 50• Strengths of the Australian MPA network: well-structured and representative. 51

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