Protected areas (PAs) are an essential tool for freshwater biodiversity conservation. Given past and expected future global increases in dams and impacts of dams on freshwater ecosystems, we document the number of dams existing or planned within PAs, their history, and the extent of PA downgrading, downsizing, and degazettement (PADDD) proximally caused by dams. Globally, at least 1,249 large dams are located within PAs; two‐thirds (907) were built before PA establishment. Additionally, 14% of planned geolocated hydropower dams (509 dams) are located within PAs. PADDD events have also legalized dam construction within existing PAs. Environmental safeguards should preclude development of dams within or adjacent to PAs and prioritize dams within PAs for possible removal and restoration.

中文翻译：

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大坝和保护区：量化保护区内全球大坝建设的时空范围

保护区是淡水生物多样性保护的重要工具。考虑到过去和未来全球水坝的增加以及水坝对淡水生态系统的影响，我们记录了水坝内现有或计划中的水坝数量，它们的历史以及水坝造成的水坝近端降级，小型化和脱宪的程度（PADDD） 。在全球范围内，PA内至少有1,249座大水坝；三分之二（907）是在建立PA之前建造的。此外，计划中的地理定位水电大坝（509个大坝）中有14％位于水坝内。PADDD事件还使现有PA内的大坝建设合法化。环境保护措施应防止在保护区内或附近建造水坝，并优先考虑在保护区内建造水坝，以进行可能的拆除和恢复。