First Confirmed Habitat of Endangered Fiddler Crabs Found in Daebudo Tidal Flats

A newly discovered habitat of the fiddler crab, designated as an endangered wildlife species Grade II and a marine protected species, has been confirmed for the first time in the tidal flats of Daebudo Island in Ansan City.

The Gyeonggi Province Marine and Fisheries Resources Research Institute, which has been conducting an 'Ecological Survey of Gyeonggi Tidal Flats' since June, announced that the discovery of ovigerous females and juvenile specimens indicates that fiddler crabs are not temporarily appearing but rather are actively breeding and maintaining their population in the area.

The fiddler crab is known to inhabit the upper intertidal zone of tidal flats, which refers to the highest zone closest to land within the entire intertidal zone where tides ebb and flow.

This small crab is characterized by one of the male's claws being abnormally large compared to its body size and snow white in color. Due to habitat loss and development, its population has significantly declined, leading to its classification as an endangered species requiring protection.

The Gyeonggi Province Marine and Fisheries Resources Research Institute discovered a fiddler crab habitat covering approximately 2,600 square meters in Daebudo's tidal flats, where no previous records of habitation existed. Two separate habitats covering approximately 1,600 square meters and 1,000 square meters respectively were confirmed, and based on the institute's analysis of population density, it is estimated that at least 30,000 or more crabs inhabit the area.

The institute obtained collection permits from the Ministry of Environment and the Ministry of Oceans and Fisheries, and conducted morphological and DNA analysis on the collected specimens to confirm their identification as fiddler crabs. The institute and Ansan City plan to implement habitat protection measures, including the installation of informational signs.

During the survey, a small habitat of the bean crab, a marine protected species, was also identified. The institute has been continuously conducting surveys on the habitats of rare and protected species in Gyeonggi's tidal flats, having confirmed bean crab habitats within the province in 2022 and 2023 as well.

"This discovery demonstrates the meaningful achievement that Gyeonggi Province's tidal flats are pristine ecological spaces with biodiversity," said Kim Seong-gon, Director of the Gyeonggi Province Marine and Fisheries Resources Research Institute. "In cooperation with Ansan City, we will continuously observe changes in the fiddler crab habitat and population, promote field-oriented conservation activities, and make efforts to preserve biodiversity and protected species habitats in Gyeonggi's tidal flats," he added.