Protected areas have mixed success in conserving wildlife, according to the largest study on the effects of reserves.
A team led by researchers from the U.K. examined waterbird data from 1,506 protected areas and analyzed more than 27,000 bird populations across the world. The authors write that their study, published in Nature, is the first robust, global assessment of protected area impact on populations. The scientists found that protected areas with management tailored toward waterbirds and their habitats were more likely to benefit those populations.
"Our study shows that, while many protected areas are working well, many others are failing to have a positive effect,” lead author Hannah Wauchope of the University of Exeter says in a statement. "Rather than focusing solely on the total global area protected, we need more focus on ensuring areas are well-managed to benefit biodiversity."
The study compared waterbird populations before and after the establishment of protected areas and also compared trends of similar populations within and outside of protected areas, per the statement.
"In the majority of places we looked, wildlife populations were still stable or were increasing, but they weren't doing any better than in unprotected areas," Wauchope tells BBC News’ Victoria Gill. "That's disappointing, but not surprising. There seems to be this disconnect between people talking about how much land is protected and whether those areas are actually doing anything positive."
This research comes ahead of a United Nations meeting in China to discuss biodiversity goals for the next decade. Several countries have already committed to protecting 30 percent of the planet by 2030, yet researchers say protection alone does not necessarily guarantee positive outcomes for species.
"An obsession with reaching a certain area-based target—such as 30 percent by 2030—without a focus on improving the condition of existing protected areas will achieve little," co-author Julia Jones from Bangor University tells BBC News. "When world leaders gather in China later this year to set targets for the next decade, I really hope to see a focus on effectiveness of protected areas, rather than simply how much surface area is devoted to them."
Thomas Brooks, chief scientist at the International Union for Conservation of Nature, who was not involved with the research, tells the Guardian’s Patrick Greenfield that waterbirds are a good example of a group facing the consequences of human behaviours that cause biodiversity loss. These animals face pressures from the impacts of climate change and unsustainable harvest, he tells the publication.
Waterbirds respond quickly to changes in site quality and are broadly distributed, making them a good group to look at the impact of protected areas, write the authors.
"We are not saying protected areas don't work," Wauchope concludes in the statement. "The key point is that their impacts vary hugely, and the biggest thing this depends on is whether they are managed with species in mind—we can’t just expect protected areas to work without appropriate management.”