A few weeks ago in our Project Lab blog, there was a discussion about what constitutes an “animal” and how this may influence the way we make decisions about conservation.  A polar bear may be more charismatic than a shrimp or a coral to some, but there are many invertebrate species that still need our attention even if they don’t have the same “cute” factor.  Have you ever heard of the Boreal digging frog (Kaloula borealis), or the Red-footed crab (Sesarma intermedium)?  These are two endangered species that reside on Jeju Island, an island off the southern coast of Korea. Island species can be especially sensitive to any changes in habitat due to their isolated evolution.  Whether it is inter-specific competition between native and non-native species or habitat degradation leaving species with limited space to relocate, population decline can happen quickly in smaller island populations.  While this frog and crab are not necessarily cuddly, they still are an important part of a local ecosystem and need to be recognized.




Jeju Island, situated about 270 miles off the southern coast of the Korean peninsula, is a distinctive island ecosystem and culture. Known for its great natural beauty, Jeju Island is home to the Jeju lava tubes, a UNESCO World Heritage Site designated in 2006, as well as beautiful soft coral reefs and bountiful farmland.  These soft coral reefs and coastline of volcanic rock, known as gureombi, are habitat to many different types of invertebrates that are harvested by haenyo, or free divers.  A group comprised mainly of women and representing the matriarchal structure in Jeju, these haenyo collect marine invertebrates from the coastline for food as well as income.  Leading into the ocean are freshwater streams and ponds that have created fertile farmland for a variety of crops.  Inhabiting the surrounding areas of terrestrial and freshwater ponds and streams are Sesarma intermedium, and Kaloula borealis, both considered Class II endangered species under the Ministry of the Environment of South Korea.  This means that these species are under threat of extinction due to natural or human factors.




The Red-footed Crab (Sesarma intermedium), is a terrestrial crab that lives in wetlands and freshwater close to the coastline.  Although they spend the majority of their time in these freshwater environments, once the females release their eggs, the eggs must travel downstream to saltwater in order to hatch.  Adult crabs have been known to rest and feed in the rocky coastline of gureombi.

The Boreal digging frog (Kaloula borealis), is a small amphibian with a range throughout Northeast Asia.  Living in farmlands such as rice paddy fields and breeding in small ponds or rainwater pools this frog is common in the majority of its habitat, but considered endangered within the Korean peninsula due to habitat degradation and loss of breeding areas.  These frogs belong to a group known as “narrow mouthed frogs,” meaning their body shape is more oval with the mouth area smaller than its wider anterior end.  A nocturnal species, these frogs emerge from an underground burrow at night to hunt small insects.



On the southern coast of Jeju Island is a small area designated an Absolute Conservation Area by the Korean government, as well as a Natural Memorial by the Cultural Heritage Administration of Korea and can be called home to both these endangered species.  Sitting amongst these protected areas is Gangjeong village.  Initially proposed in 1993 but starting in 2007, plans have moved forward to build a Republic of Korea/US military base in Gangjeong.  While not all the villagers oppose the base, it has become a deeply divisive issue within the community.  Those against the construction of the base fear it threatens a way of life of the people in Gangjeong, like haenyo and farmers who rely on the soft coral reefs, gureombi and surrounding freshwater for food and spiritual connection.  Once teeming with life, the gureombi has recently been paved over with concrete and pillars erected next to the soft coral.  Also considered a sacred space, the loss of the gureombi is seen as not only as loss of species habitat, but also a loss of cultural heritage.

The government has worked to relocate the endangered species on Jeju, however more long term data is usually needed for these types of studies to determine success.  Habitat restoration or relocation to new areas can sometimes be viable options for species facing loss of natural habitat, but ecosystems are complicated. Many of the finer complexities and connections are still unknown to researchers making it difficult to recreate ideal conditions.  This belief that natural habitat should be conserved for all species using the area has led to calls to halt construction efforts in Gangjeong.  Currently construction plans continue.  In situations like these, it can be tough to determine what is the best course of action. As mentioned before, conservation can be influenced by our perception of what needs protection and what species are important to a fully functioning ecosystem.  In the case of Gangjeong village, we can only hope that our voice is heard and that all sides are considered before completely and forever altering a habitat found nowhere else.


Codie Otte

Curatorial Assistant and Specimen Preparator

Ornithology & Mammalogy Department

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