[Edaily Reporter Yang Ji-yun ] It has been confirmed that 27 otters, classified as Class I endangered wildlife, inhabit the Han River. This represents an increase of approximately 80% compared to the 2022 survey, and as many as five otter families—consisting of parents and offspring—were discovered.

The National Institute of Biological Resources, under the Ministry of Climate, Energy, and Environment, announced on the 9th that genetic analysis of otter fecal samples collected from the Han River between January and April of this year confirmed a total of 27 individuals.

The survey was conducted at a total of 27 locations, including 13 sites along the main stem of the Han River and 14 sites along its tributaries, stretching from Gaya Bridge to Godeok Bridge. Genetic analysis of the 106 fecal samples collected confirmed the presence of 21 otters in the main stem and 6 in the tributaries. By sex, there were 16 females and 11 males.

Notably, this survey also confirmed kinship among the Han River otters. All 27 otters whose individual genetic information was identified were related to one another—such as siblings—and five families consisting of parents and offspring were discovered.

Otter families were primarily distributed in the eastern region of the Han River, including Seongnae Stream and Jamsil Bridge. Seongnae Stream was the location with the highest number of otters, with five individuals inhabiting the area. Four otters were confirmed at Han River Bridge, and three each were found at Yangjae Stream, Jamsil Bridge, and Jungnang Stream.

The otters’ habitat along the Han River was significantly reduced during the 1960s and 1970s due to concrete channelization projects. According to the National Institute of Biological Resources, their habitat expanded again in the 2000s as riparian ecological spaces were created through the Han River Restoration Project.

On the Han River, otters were first sighted in the Tancheon area in 2016, and four were officially confirmed in 2017. Currently, their range has expanded along the main stem of the Han River as far as the Gangseo District, and along tributaries as far north as the Jungnangcheon and as far south as the Anyangcheon.

Yoo Ho, Director of the National Institute of Biological Resources, stated, “The continued increase in the otter population along the Han River is a positive sign that the Han River ecosystem is recovering,” adding, “We will continue our scientific surveys, research, conservation, and management efforts so that people and urban wildlife can coexist healthily.”