Environment ministry agency finds rare beetle at new Inje habitat

The National Nakdong River Biological Resources Center said Thursday it confirmed a new habitat for a rare aquatic insect in Inje, Gangwon Province, using environmental DNA analysis, with four adult beetles found at the site.

The center, an agency under the Ministry of Climate, Energy and Environment, said researchers identified genetic material from Dytiscus marginalis czerskii in water samples collected around Seohwa-myeon and then found one male and three female adults during field surveys conducted with the Inje Insect Bio Center. The survey used environmental DNA, a technique that detects trace genetic material organisms leave in water or soil without capturing them; researchers analyzed water samples from six sites with a species-specific genetic marker they developed, and samples from Seohwa-myeon crossed the detection threshold at about the 32nd cycle, within the 35-cycle cutoff used to judge a positive signal. The samples were collected between September and recently.

The beetle is a cold-water species that lives in ponds and wetlands with low water temperatures and developed aquatic vegetation, and it is listed as endangered on South Korea's national red list. Its habitat has been shrinking under the effects of climate change and environmental pollution.

In a 2023 reassessment of 701 native insect species, four species, including Dytiscus marginalis czerskii, had their extinction risk categories raised, but the beetle is not designated or managed as an endangered wild species, and the need to update the list has been raised.

The two institutions plan to continue observing the newly identified habitat and pursue breeding research as part of cooperation on habitat protection and population conservation.

"This research is meaningful in that it found a new habitat for a rare organism that is difficult to discover directly through environmental DNA analysis," said Ryu Si-hyeon, head of the center's diversity conservation research division. "We will continue surveying freshwater organism habitats using related technology and expand research that links the results to conservation."