Japan has designated two coastal areas to be of international importance, raising the number of such domestic sites to 52, the only international conservationist body focused on wetlands said Thursday.

Seen as key habitats for waterfowls and other creatures, Shizugawa bay in the northeastern prefecture of Miyagi and Kasai Marine Park in Tokyo were recognized for their conservation value based on the Ramsar treaty.

(Shizugawa bay)

Japan joined the treaty in 1980 and Kushiro-shitsugen on the northernmost main island of Hokkaido became the first Ramsar site that year.

At Shizugawa bay, which is characterized by steep rocky coastline, more than 500 species of marine creatures live on abundant seaweeds and seagrasses. Brent geese, designated as a natural monument of Japan, spend the winter there.

Kasai Marine Park, a brackish wetland in Tokyo Bay created to restore the natural ecosystem which was once lost due to land reclamation, has become "an example of coexisting natural and urban environments," the convention said.

Along with the new registrations, Japan has extended the designated area of one of its sites in the western prefecture of Hyogo, as breeding and feeding grounds of storks have roughly doubled to 1,094 hectares.

(Kasai Marine Park)

Last month, the Ramsar Convention urged policymakers around the world to do more to protect wetlands as they reported such sites have disappeared by 35 percent between 1970 and 2015 -- a rate three times that of forests due to climate change and other causes.

While the global outlook report did not look at individual nations, the Ramsar Convention has mentioned that Japan recognizes the importance of wetlands and is attentive to conservation efforts.

The Ramsar Convention has been ratified by 90 percent of U.N. members, including major polluters such as the United States and China. Since coming into force in 1975, it has designated more than 2,300 sites of international importance.