[Anchor]

As water temperatures around the Korean Peninsula continue to rise recently, the underwater scenery is also changing. Creatures once seen only in the waters of Jeju are now making their way up to the South Sea.

Brought to you by reporter Jang Seon-i for "Signal," our year-round special series on climate change.

[Reporter]

It takes two hours by boat from Yeosu, Jeollanam-do, to reach Baekdo Island in Dadohaehaesang National Park.

We approached the island closely on a small boat.

This is the waters off Baekdo.

Because access is restricted and human touch is scarce, the creatures living here are changing as water temperatures rise.

A professional diving team went down to a depth of 20 meters.

Spreading out like fans, endangered orange soft corals and soft corals that were once only visible in the waters of Jeju catch the eye.

[Ahn Jung-gwan, Senior Researcher at the Marine Research Center, National Parks Research Institute: Subtropical soft coral species such as Dendronephthya gigantea, Euplexaura crassa, and Cirrhipathes sp., whose growth was previously reported only in Jeju Island, have moved quite far north.]

Soft corals have been expanding their habitats for three years.

The long-branched gorgonian, a natural monument, is also visible.

The long-branched gorgonian is one of the climate change indicator species showing the subtropicalization of the ocean.

Other climate change indicator species, such as the yellow damselfish, blue damselfish, and boxfish, were also confirmed during this survey.

Rising water temperatures are the direct cause.

[Kim Dae-won, Senior Researcher at the Korea National Park Service: Sea surface temperatures around our country have risen by about 1.36 degrees Celsius over the past 58 years, and warming is progressing at a very rapid pace, about 2.1 times the global average.]

In a 2014 survey, Baekdo was the island with the most seaweed species identified among 11 islands in the South Sea, totaling 117 species.

However, by 2024, the number of seaweed species decreased to 97.

Researchers analyze that as water temperatures rise, so-called "marine desertification" is underway, and even the population of rabbitfish, which graze on seaweed, is increasing, causing the "marine forests" to disappear.

Marine forests, which are seaweed communities, absorb 337 tons of carbon dioxide per square kilometer.

While the creation of artificial marine forests is underway in the East Sea, where water temperatures are rising nine times faster than the global average, the underwater scenery of the South Sea on the Korean Peninsula is also changing rapidly.

(Photo: Yonhap News / Video reporting: Yang Ji-hoon, Video editing: Park Chun-bae, Footage provided by Korea National Park Service)