South Korea's tidal flats earn expanded UNESCO World Heritage status

Tidal flats of Muan's Tando Bay [Provided by the Korea Tidal Flats World Heritage Inscription Promotion Committee]

"The Phase 2 expansion of Korea's tidal flats will build on the achievements of Phase 1 by adding species diversity and habitat value, and will enhance the overall authenticity and integrity of the serial property."

Tim Badman, director of the World Heritage Programme at the International Union for Conservation of Nature, made the remarks Saturday at a plenary session of the World Heritage Committee in Busan, in connection with the Phase 2 expansion inscription of Korea's tidal flats. Having demonstrated outstanding universal value and ecosystem integrity, Korea's tidal flats are now established as a key asset in addressing the climate crisis and preserving ecosystems.

At the 48th session of the World Heritage Committee, held Saturday, the Yeosu, Goheung, Muan and Seosan tidal flats were inscribed as Phase 2 components of the "Getbol, Korean Tidal Flats" World Heritage site. It is the first of South Korea's 17 World Heritage properties to undergo a Phase 2 expansion. With the addition, "Getbol, Korean Tidal Flats" has expanded into a serial property comprising six components — the Boseong-Suncheon-Yeosu-Goheung tidal flats, the Sinan-Muan Tando Bay tidal flats, the Muan Hamhae Bay tidal flats, the Gochang tidal flats, the Seocheon tidal flats and the Seosan tidal flats.

South Korean officials celebrate immediately after the Phase 2 expansion inscription of Korea's tidal flats was confirmed at the plenary session of the 48th World Heritage Committee in Busan on Saturday. Cultural Heritage Administration Commissioner Heo Min (second from right) and South Chungcheong Province Governor Park Soo-hyun (second from left) are among those present. [Provided by the Cultural Heritage Administration]

Of the 10 UNESCO natural heritage inscription criteria, Korea's tidal flats qualified under Criterion X, which recognizes "the most important and significant natural habitats for in-situ conservation of biological diversity, including those containing threatened species of outstanding universal value from the point of view of science or conservation."

Cultural Heritage Administration Commissioner Heo Min said immediately after the expansion was announced, "The tidal flats are a habitat for endangered species and a space of unparalleled biodiversity. We must remember that they are not Korea's alone but a heritage shared by all of humanity, and we will work to protect this universal value through coexistence with local communities and pass it on to future generations."

A colony of Suaeda japonica and hooded cranes at the Suncheon tidal flats [Provided by the Korea Tidal Flats World Heritage Inscription Promotion Committee]

Korea's tidal flats lie along the southwestern coast of the Korean Peninsula and the eastern shore of the Yellow Sea. Situated along the East Asian-Australasian Flyway, they serve as a critical stopover where waterbirds traveling from Australia and New Zealand to Siberia and Alaska replenish their energy. More than 100 species and millions of waterbirds use the area each year. Some 27 internationally threatened waterbird species depend on this zone, including the critically endangered spoon-billed sandpiper — of which only 400 to 600 individuals remain worldwide — as well as the black-faced spoonbill, far eastern curlew and hooded crane.

The coastal wetland environment, shaped by tidal inflows and outflows, supports roughly 2,100 species in total, including about 850 species of macrobenthic invertebrates, around 370 species of benthic diatoms and some 50 species of halophytes. Forty-seven species of endangered marine invertebrates and Yellow Sea endemic species — among them the marsh crab, red-footed sesarmid crab, white-handed fiddler crab and red-clawed fiddler crab — inhabit the heritage zone.

In terms of topography, organic matter carried from inland combines with islands and a rias coastline to concentrate a diverse range of tidal flat habitats — mudflats, sand flats, mixed flats and dunes. Primary productivity, a measure of organic output per unit area, averages 215.7 milligrams per square meter.

An Eurasian oystercatcher at the Sinan tidal flats [Provided by the Korea Tidal Flats World Heritage Inscription Promotion Committee]

On the social and environmental front, Korea's tidal flats absorb about 260,000 tons of carbon dioxide annually and store approximately 13 million tons of carbon, functioning as a blue carbon sink equivalent to the annual emissions of 110,000 passenger vehicles. Microorganisms and benthic organisms break down land-sourced pollutants to purify water quality, while the flats supply fishery resources — including octopus, short-necked clams and oysters — and underpin ecotourism, contributing to the livelihoods of fishing communities.

When the World Heritage Committee approved the Phase 1 inscription in 2021, it recognized the site's outstanding universal value while recommending that South Korea pursue a Phase 2 expansion to include additional tidal flat areas in order to strengthen ecosystem integrity. The government subsequently advanced the Phase 2 bid to protect the entire West Sea tidal flat network and ensure habitat connectivity for migratory waterbirds. The IUCN also assessed the Phase 2 candidate sites as meeting biodiversity conservation criteria and recommended their inscription.

Yeosu tidal flats [Provided by the Korea Tidal Flats World Heritage Inscription Promotion Committee]

The Yeosu tidal flats, newly added in the Phase 2 expansion, are built on rich silt deposits and support six legally protected species: the marsh crab, red-footed sesarmid crab, white-handed fiddler crab, Japanese ear snail, brackish periwinkle and finless porpoise. Among the candidate sites, Yeosu has the highest number of legally protected non-avian species, with particularly dense populations of the marsh crab and red-footed sesarmid crab. Nine of the 18 internationally endangered bird species that visit Yeoja Bay — including the black-faced spoonbill, Chinese egret, hooded crane, greater scaup, far eastern curlew, Nordmann's greenshank and Saunders's gull — are found here.

Goheung tidal flats [Provided by the Korea Tidal Flats World Heritage Inscription Promotion Committee]

The Goheung tidal flats are characterized by thick, fine-grained mudflats formed from accumulated silt and clay sediments within Yeoja Bay. They support 726 tidal flat species in total — 552 macrobenthic invertebrates, 55 halophytes, 54 seaweed species, 38 benthic diatoms, 26 fish species and one marine mammal — and boast the highest seaweed diversity among the candidate sites. In winter, more than 800 Saunders's gulls — representing about 2.3 percent of the global surviving population — overwinter here alongside the Boseong-Suncheon and Yeosu tidal flats. The site also serves as a stopover for long-distance migratory internationally endangered birds such as the far eastern curlew and Nordmann's greenshank.

Muan Hamhae Bay tidal flats [Provided by the Korea Tidal Flats World Heritage Inscription Promotion Committee]

The Muan tidal flats encompass a variety of habitats — salt marshes, mudflats, mixed flats, sand flats and rocky shores — and consist of the Muan Tando Bay and Muan Hamhae Bay tidal flats. The Tando Bay section supports 162 bird species and 1,318 tidal flat species, with the legally protected white-handed fiddler crab as the dominant species. The Hamhae Bay section hosts 17 internationally endangered bird species and sustains more than six species — including the Kentish plover, black-faced spoonbill and Chinese egret — whose local populations exceed 1 percent of their global populations. With 94 waterbird species and 94 halophyte species recorded, it shows the highest diversity among all components.

Seosan tidal flats [Provided by the Korea Tidal Flats World Heritage Inscription Promotion Committee]

The Seosan tidal flats, located in Garorim Bay adjacent to Gyeonggi Bay, are home to seven endangered wildlife and legally protected species and display the highest endemic species diversity among the candidate sites, with 11 endemic species recorded. They are the only inland habitat where spotted seals — apex predators of the marine ecosystem — regularly visit, with about 10 individuals appearing each year. A total of 174 bird species have been recorded, the highest avian diversity of any component. The site sustains more than 1 percent of the global surviving populations of the black-faced spoonbill, Chinese egret, far eastern curlew and grey-tailed tattler, and more than 180 Chinese egrets — representing over 5 percent of the species' global surviving population — have been confirmed here.

Bangudae Petroglyphs at Daegok-ri, Ulju [Provided by the Cultural Heritage Administration]

With this expansion, South Korea now holds 17 World Heritage properties in total — 15 cultural and two natural. The cultural heritage sites are Seokguram Grotto and Bulguksa Temple, Haeinsa Temple Janggyeong Panjeon, Jongmyo Shrine, Changdeokgung Palace Complex, Hwaseong Fortress, Gyeongju Historic Areas, Gochang, Hwasun and Ganghwa Dolmen Sites, Royal Tombs of the Joseon Dynasty, Historic Villages of Korea (Hahoe and Yangdong), Namhansanseong, Baekje Historic Areas, Sansa (Buddhist Mountain Monasteries in Korea), Seowon (Korean Neo-Confucian Academies), Gaya Tumuli and the Petroglyphs of Bangucheon. The two natural heritage sites are Jeju Volcanic Island and Lava Tubes, and the Getbol, Korean Tidal Flats.

terry@heraldcorp.com