Protecting stopover habitat for migratory shorebirds in East Asia

Many migratory species depend on staging sites at which they refuel while on migration, and effective protection of such habitats is crucial to their conservation. Here we investigate the extent to which protected areas cover and ameliorate loss of tidal flats in East Asia, the key staging habitat for threatened and declining shorebirds migrating through the East Asian–Australasian Flyway. We discover rapid losses of the tidal flat ecosystem both inside (−0.42\ua0%\ua0year) and outside (−0.89\ua0%\ua0year) protected areas. In China, tidal flats are well represented within protected areas (22.9\ua0% of current tidal flats occur within protected areas), but habitat loss continued despite protection (−0.55\ua0%\ua0year inside, −0.97\ua0%\ua0year outside). By contrast, in South Korea, where 12.1\ua0% of remaining tidal flat is in protected areas, the rate of habitat loss outside protected areas was the highest in our study region (−1.83\ua0%\ua0year), yet inside protected areas there was tidal flat aggradation (+1.13\ua0%\ua0year), indicating either that protected area placement is biased away from vulnerable habitats, or protected areas are highly effective in South Korea. Tidal flats across our study area were lost most rapidly in internationally important sites for migratory shorebirds (−1.66\ua0% year), suggesting that transformative land use change of coastal areas is occurring disproportionately in regions that are important for migratory birds. We urge (1) improved management of existing protected areas in East Asia, particularly in China, (2) targeted designation of new protected areas in sites crucial for supporting migratory birds and (3) integrated decision-making that simultaneously plans for coastal development and coastal conservation