The National Science Museum said on the 23rd that to mark the 20th anniversary of the Cheonggyecheon restoration, a joint freshwater fish survey conducted this year with the Seoul Facilities Corporation identified a total of 32 species and 1 variety, an eightfold increase from the 4 species before the restoration.
In particular, fry of the Korean shiner, which inhabit only riffles with clean water and abundant oxygen, were found for the first time in the upper reaches of Cheonggyecheon. Although only in some sections of Cheonggyecheon, it was confirmed that habitat conditions that can support the Korean shiner are being stably maintained.
The survey was conducted three times from April to September at six sites, from Mojeon Bridge near Cheonggye Plaza in the upper reaches to the confluence with the Jungnangcheon in the lower reaches, and was designed to select the same survey sites as 20 years ago to objectively compare changes in fish communities.
Through this year's joint academic survey, a total of 6,700 or so individuals from 7 orders, 9 families, 32 species, and 1 variety were identified. By taxonomy, cypriniform fishes were the most abundant with 23 species and 1 variety, followed by gobiiforms with 4 species. The dominant species was the pale chub, accounting for about 38.1% of all individuals, and the subdominant species appeared in the order of crucian carp (17.2%) and Chinese ricefish (12.7%).
Korean endemic species numbered six—striped bitterling, oily bitterling, Korean shiner, Korean chub, striped shiner, and spotted sleeper—and alien taxa were 2 species and 1 variety—Israeli carp, guppy, and largemouth bass. Among these, seven guppies, an ornamental species presumed to have been released due to human activity, and one largemouth bass, an ecosystem-disrupting wild species, were confirmed. Fish captured in the field were released back at the collection sites after on-site confirmation to protect the natural environment.
By survey section, species adapted to fast flows and oxygen-rich environments—such as Korean shiner, Korean dace, and striped shiner—were found in the upper reaches (Mojeon Bridge to Majon Bridge); species adapted to gentle flows and diverse substrates like rocks and sand—such as crucian carp, striped chub, and sandfish—were found in the midstream (Hwanghak Bridge to Gosanja Bridge); and species tolerant of slow flows and water quality—such as Chinese ricefish, rosy bitterling, and crucian carp—were confirmed in the lower reaches (confluence with the Jungnangcheon), showing distinct ecological characteristics by site.
The National Science Museum prepared a special exhibition of joint academic research achievements on Cheonggyecheon freshwater fish, Cheonggye Eorok, with the Seoul Facilities Corporation to share the results of this survey with citizens. Based on the academic survey results and a freshwater fish exploration education program, the exhibition is designed so that anyone can easily understand Cheonggyecheon through Korea's freshwater fish and imagine scientific thinking. A variety of content—including AI-enabled videos capturing the 20-year journey of Cheonggyecheon's restoration, detailed illustrations of Korea's freshwater fish, and records from the Cheonggyecheon freshwater fish exploration team—has been brought together so citizens can directly experience the value of an urban ecological stream.
Kwon Seok-min, director of the National Science Museum, said, "This academic survey is a valuable case that confirmed the possibility that even a damaged ecosystem can regain its self-sustaining resilience based on steady human effort and cooperation," adding, "In particular, based on this interagency collaboration model, we will continue working so that more citizens can cultivate interest in nature, scientific curiosity, careful observation, and inquisitiveness."