The lag effect in the World Database on Protected Areas
Terrestrial and marine protected area coverage is increasing each year, with marine protected areas covering almost 7% of the global ocean and terrestrial protected areas covering just under 15% of global land (UNEP-WCMC and IUCN March 2018). The trend in the marine realm is one of rapid growth, with the recent designation of large sites, such as the Ross Sea Region Marine Protected Area off Antarctica, whereas in the terrestrial realm a slower growth is being witnessed.
Although there are benefits to simplifying information for reporting purposes, by solely focusing on the overall trends we miss important details. As discussed in the end of year Protected Planet blog post which reviewed of the growth of protected areas in 2017 and in the recently published work by Lewis et al. (2017) on the "Dynamics in the global protected- area estate since 2004", it is worth highlighting that the World Database on Protected Areas (WDPA) is a dynamic data set. Throughout the 12 different versions produced each year there are additions and removals of sites which result in changes in area. Between years there can be considerable difference in the number of sites added and removed. An additional factor that adds to the complexity of the database, and should be highlighted, is that sites added to the WDPA are not always new on the ground.
How old are these “new" sites?
After conducting an analysis of the designation dates of all newly added sites each year between 2010 and 2017, we see that many have existed for several years on the ground prior to being added to the WDPA. For example, in 2011 32% of the sites newly added to the WDPA were in fact designated between 1900 and 2000. We therefore need to be aware of the time lag between the designation of a site and its reporting to the WDPA. This is particularly relevant in the lead up to 2020, when protected area coverage will be assessed in relation to the Convention on Biological Diversity's Aichi Target 11. Due to this time lag, the coverage of protected areas seen in 2020 through the WDPA may not be reflective of what is being protected on the ground at that particular time, though every effort will be made to ensure the WDPA is as up to date as possible. Users of the WDPA need to be aware of such factors in order to understand better the data they are using, and the implications of using older versions of the WDPA, which are simply snapshots of a particular moment in time.
What are the reasons for this?
Data supplied to UNEP-WCMC for inclusion into the WDPA includes sites that have been designated recently, updated information on existing sites and importantly sites that have existed for several years or decades but have not been previously reported. This means that the new additions are not just a cumulative addition to the month or year they are added, they are also additions to previous years, backfilling the database.
Spread of designations across the decades
We see a large variation in the designation dates of sites being added to the WDPA. The amount of backfilling of previous years depends on which countries, and how many, submit an update that year. Countries that update regularly have a shorter time lag between the designation of a site and its addition to the WDPA than those that do not update regularly, and the more countries that are updated in a year, the more backfilling there is of older sites from previous decades. In 2014 there was a big push for updates to create the UN List of Protected Areas, generating updates from many more countries than usual, many of which had not been updated in a number of years. This increased the number of older sites, particularly those designated prior to 1900, added to the WDPA, and had the knock on effect in of reducing both the number and age of the sites added to the WDPA in 2015.
What are we seeing in more recent years?
In 2017 we see a very different picture than in previous years, with over 70% of sites added in 2017 being designated since 2000. Furthermore, newly designated sites (from 2000 onwards) are being reported to the WDPA much more quickly than those prior to 2000. Historically, it was rare to have sites designated and added to the WDPA the same year, but this has changed in 2017, with the figure exceeding 3% of new records (previously the figure has been 1% or below). In addition to sites being added to the WDPA we also have instances of data being updated, of particularly relevance are updates to the year of designation, especially in cases where this has previously not been reported. In 2010 39% of the sites has no designation year reported, but this is now down to 7% at the end of 2017. The good news is that the lag time between designation and addition to the WDPA has been decreasing. This time lag is expected to continue decreasing, as updates are becoming more regular from countries and the updates are being reflected quickly in the monthly updated versions of the WDPA. The accuracy of the data being reported is also increasing, with all new sites being added to the WDPA in 2017 as polygons rather than points. We also managed to update 87% of the data in the WDPA in 2017, giving a much more accurate picture of protected area coverage.