Warmer seas bring endangered whale shark to Jeju coast

A diver swims with a whale shark in the waters near the Philippines in this undated photo. Captured from Philippines' Department of Tourism

A fishing boat reported sighting a whale shark in the waters near Jeju Island, Wednesday.

A video uploaded to fishing vessel Seungryong's social media account shows the distinct white spots and the broad head shape of a whale shark, estimated to be around 3 meters in length.

While whale sharks are typically found in tropical waters, they have been sighted in waters near Korea in recent years, a trend attributed to warmer ocean temperatures as a result of climate change.

Korean waters have traditionally been a crossroads for cold and warm ocean currents, but a 2020 study found that the sea surface temperature of Korean waters has been increasing nearly 2.5 times higher than the global average.

As a result of climate change, the Kuroshio Current — the main source of heat from equatorial waters to Korea — has shifted northwards by roughly 1.7 degrees of latitude and continues to advance. Meanwhile, the North Korea Cold Current continues to weaken due to warming temperatures in subarctic regions.

Consequently, sightings of subtropical oceanic species such as chub mackerel and bluefin tuna have been increasing, especially around Korea's southernmost waters.

This is not the first time the massive species has made headlines in the region.

Two whale sharks were caught as bycatch in 2012 in the waters near Jeju and were relocated to Aqua Planet Jeju as a part of an exhibit. After one died after a month in captivity, the surviving whale shark was released into the wild.

In 2017, a juvenile whale shark was caught as bycatch in the waters near Yeosu, South Jeolla Province, and was successfully released.