The genetic analysis revealed alarmingly low diversity: only about 5 differences per 10,000 base pairs among individuals found in South Korea, suggesting a high likelihood of inbreeding. (Image courtesy of the Ministry of Environment)
YEONGGWANG, South Korea, June 12 (Korea Bizwire) — South Korean researchers have fully decoded the genome of the Chinese crested tern, one of the world’s rarest birds, with an estimated global population of just 100 individuals. The breakthrough offers new hope for the survival of this critically endangered seabird.
The National Institute of Biological Resources for the Honam Region and the National Institute of Ecology announced Wednesday that they successfully mapped approximately 1.17 billion base pairs of the tern’s DNA at the chromosome level. The effort marks a critical step in understanding the species’ ecology and developing conservation strategies.
The genetic analysis revealed alarmingly low diversity: only about 5 differences per 10,000 base pairs among individuals found in South Korea, suggesting a high likelihood of inbreeding. For comparison, giant pandas show 12 differences per 10,000 base pairs, and red-crowned cranes show about 17.
Armed with this data, the two institutions plan to draft a structured preservation and restoration strategy, emphasizing the importance of genetic diversity for species resilience.
The Chinese crested tern is listed as “Critically Endangered” on the International Union for Conservation of Nature (IUCN) Red List — the third most urgent category after “Extinct” and “Extinct in the Wild.”
Once thought to have disappeared after 21 birds were last seen in China’s Shandong Peninsula in 1937, the species was rediscovered in 2000 when four breeding pairs were spotted on an uninhabited island in Taiwan.
Since then, conservation efforts in China have helped stabilize the population to around 100 birds globally. In South Korea, the tern was first spotted in 2016 nesting on Chilbal Island in Yeonggwang County, Jeollanam-do. Since then, 6 to 8 individuals have returned annually during the breeding season.
The species was designated a Class 1 endangered species in South Korea in 2022.
The tern’s critically low population is attributed to indiscriminate egg harvesting, natural disasters like typhoons, and competition or hybridization with larger tern species. Notably, the Chinese crested tern lays only one egg per breeding season, further hampering its recovery.
Researchers hope that the newly decoded genome will guide future cross-border conservation efforts, potentially offering a lifeline to one of the planet’s most imperiled seabirds.
Lina Jang (linajang@koreabizwire.com)
