The findings show that managing parks to protect species and their habitats is crucial – and without such management, parks are more likely to be ineffective.
Later this year world leaders will gather in China to set the agenda of global conservation efforts for the next decade, with plans to formally protect 30% of the Earth’s surface by 2030 gathering pace.
But this alone will not guarantee the conservation of biodiversity, according to the authors of this study. They are arguing that targets need to be set for the quality of protected areas, not just the quantity.
The study used a "before-after-control-intervention" method – comparing waterbird population trends before protected areas were established with trends afterwards, and also comparing the trends of similar waterbird populations inside and outside protected areas.
This provided a much more accurate and detailed picture than previous studies.
The study focussed on waterbirds, examining the impact of 1,500 protected areas (in 68 countries). Waterbirds were chosen as they are well studied and found in many locations worldwide, and their mobility means they can quickly colonise or leave a location based on the quality of the conditions.
Professor Julia Jones from Bangor University, a co-author of the study, said:
This paper gives really useful indications of how conservation can be improved to deliver better outcomes for species. The analysis shows us that some protected areas are really working for nature while others are failing to have a positive effect. Rather than look at how much land area is protected, to slow biodiversity loss, we need a much better understanding of which conservation approaches work, and which don’t.
The research team included Wetlands International and the universities of Bangor, Cambridge, Exeter, Queensland, Copenhagen, and Cornell, and the research relied on the efforts of many thousands of volunteers contributing to national schemes across the world to collect the data on waterbird population numbers, largely from the International Waterbird Census coordinated by Wetlands International. Data on waterbirds in North America came from the National Audubon Society.
The paper is entitled: "Protected areas have a mixed impact on waterbirds, but management helps."