Getbol (Korean: 갯벌) are mudflats, or tidal flats, which are coastal areas where sediment accumulates over time. These areas serve as important homes for many different animals, including birds that travel long distances and marine animals like clams, crabs, octopuses, and snails. In 2021, four getbol areas in South Korea were added to the UNESCO World Heritage List because of their special natural features. Each of these areas represents a different kind of getbol: estuarine type, open embayed type, archipelago type, and semi-enclosed type.
Description
The four getbol sites listed are Seocheon Getbol, Gochang Getbol, Shinan Getbol, and Boseong-Suncheon Getbol. Three of these sites are located on Korea's western coast, while Boseong-Suncheon Getbol is on the southern coast. These sites were added to the list under criterion (x), which includes areas that "contain the most important natural habitats for protecting biological diversity, including those with threatened species of great scientific or conservation value." Some species found in getbols include the mud octopus, Japanese mud crab, fiddler crab, bristle worm, Stimpson's ghost crab, and Yellow Sea sand snail. Suspension feeders, such as clams, also live in these areas. Getbols provide stopover sites for endangered migratory birds traveling along the East Asian–Australasian Flyway. Twenty-two species listed by the IUCN Red List have been recorded visiting these sites, including the critically endangered spoon-billed sandpiper. In addition, 375 species of benthic diatoms, 118 waterbirds, 857 macrobenthos, 152 marine macroalgae, 47 endemic, and 5 endangered marine invertebrate species have been recorded in the protected areas.
The tidal flats formed after the Last Glacial Maximum through the interaction of rivers depositing sediments and the movement of these sediments by tidal currents, wave action, and wind. These tidal flats developed mainly in the estuaries of large rivers and along island coasts. Due to the monsoon climate, erosion and chemical weathering occur on the coast during winter, while sediment is deposited during summer.
Threats
All four sites are carefully protected as Wetland Protected Areas (WPA) under the Wetlands Conservation Act. However, certain activities still pose risks to the environment, such as digging in ports and sea channels, building bridges connecting land to islands and between islands, developing wind power plants far from the shore, mining materials from the ocean floor, introducing species that harm the ocean environment, and fishing by local people. The most harmful activity is taking land from the water, but this is not allowed in World Heritage Sites. Other possible problems include pollution, climate change, erosion of coastlines, and oil spills.