As China’s Mudflats Disappear, Shorebird Populations Rapidly Decline

A Great Knot (Calidris tenuirostris) bird.

A Great Knot (Calidris tenuirostris) bird. JJ Harrison/Wikimedia

Populations of some migratory shorebirds are declining by as much as 8 percent per year as mudflats in the Yellow Sea between China and South Korea disappear due to rising sea levels and infrastructure projects, according to new research published in the journal Nature Communications.

Tidal mudflats in the Yellow Sea serve as critical stopping points for many species to rest and refuel during their annual migrations between summer Arctic breeding grounds and wintering spots in New Zealand and Australia. But, scientists reported, these ecosystems have shrunk by 65 percent in recent decades.

A team of Australian, U.S., and New Zealand scientists studied population data of 10 migratory bird species from 1993 to 2012. Seven of those species — including the eastern curlew, curlew sandpiper, and great knot — rely heavily on the mudflats, and all declined over the study period at rates of up to 8 percent per year. In contrast, the populations of those species that don’t rely on the tidal ecosystems, such as gray-tailed tattlers, remained stable.

The scientists wrote that “an enormous conservation intervention is needed” if governments hope to protect remaining migrating shorebird populations.