The intertidal zones of the Yellow Sea are crucial stopover sites along the East Asian-Australasian
Flyway for over 3 million migratory shorebirds.
During their annual migrations, significant numbers of 36 distinct species from Alaska,
much of Russia, Australia, New Zealand, Myanmar, and Southeast Asia travel to specific mudflats
and wetlands along the coastlines of South Korea, North Korea, and China.
Here they rest and feed on a unique diet that they've evolved to rely on over millions of years.
These food rich inter-tidal zones are among the most extensive in the world providing
an estimated 30 million dollars per year in eco-system services.
The narrow natural barriers, seemingly insignificant when viewed from space, buffer one of the
most populated coastal areas from storms and sea level rise.
Where Landsat data has been compared, we know that since 1950 roughly 2/3 of the tidal flat
areas in the Yellow Sea have disappeared.
Over 70% of China's mudflats are gone, and in many places, they have vanished completely.
Wetlands and tidal zones that were naturally formed and replenished by free flowing sediment
have been converted to permanent land for the expansion of coastal cities, agriculture,
and industry.
Much of the remaining mudflats have been inundated by the sea.
These present day satellite images
reveal how much has changed in a short period of time.
The blue colored regions are data points that indicate where the tidal zones used to be
roughly 50 years ago.
Habitat loss continues at a rate of nearly 2% each year.
Of the 36 species of shorebirds using these locations, most are in rapid decline.
Seventeen of them are likely to reach or approach extinction in the near future.
The rapid loss of habitat has led to these unprecedented declines as the birds are unable
to adapt.
Because migratory birds have evolved over thousands of generations to use very specific
feeding sites, we know that some mudflats are more important to a species’ survival
than others.
Using map data and field reports collected since the 1950s, conservation scientists have
isolated 11 tidal wetlands that need to be protected in order to ensure the existence
of these endangered birds.
Places like the Dandong coastal wetlands near the mouth of the Yalu River [are] necessary
for the survival of the Great Knot and the Bar-tailed Godwit.
The Luannan coastal wetland in Bohai Bay, [are] an essential stopover site for the spotted
the Curlew Sandpiper, and the Red Knot.
And the still vibrant Rudong mudflats in Jiangsu Province, [are] a crucial feeding area for
the nearly extinct Spoon-billed Sandpiper.
Birds are unrivaled indicators of our planets' health.
They respond quickly to changing habitat conditions that affect the environment both humans and
birds depend on.
Over the past 50 years, the loss of wetlands in the Yellow Sea has caused severe declines
in bird populations, but this wide scale change has also removed the natural barriers that
protect urban populations from rising sea levels and extreme weather events caused by
global warming.
With substantial economic expansion projected for the coming decade, preserving the ecosystem
services of this unique region will require conserving and restoring coastal wetlands
at key locations.