With large shark sightings increasing along the east coast, NIFS urged beachgoers to take safety precuations during summer holiday season. 

The East Sea Fisheries Research Institute of NIFS analyzed shark sightings in the East Sea this year and reported 46 sightings, a 3.8-fold increase from the 12 recorded in 2025. The institute attributed the increase to rising water temperatures and the growing population of warm-current fish species caused by climate change.

The average sea surface temperature (SST) along the east coast from April to June of this year was 16.3℃, which was 1.1℃ higher than usual and 1.9℃ higher than previous year. Another factor that contributed to the influx of large sharks was the expanding distribution of warm-water fish species, such as mackerel and bluefin tuna, which are important food sources for these sharks. 

In particular, the increasing presence of the shark species such as mako sharks, blue sharks, and copper sharks , which can pose a danger to people, requires extra precautions. Upon spotting a shark, beachgoers should leave the water immediately and report the sighting to the relevant authorities, such as the coast guard or local government. These organizations need to strengthen the inspection and maintenance of safety facilities, including shark prevention nets and shark-deterrent devices. 

“Recently, water temperatures along the east coast have surged. These warm waters could draw more large sharks closer to shore than before. To address the situation, NIFS will research on their migration route and their impact on the coastal ecosystem while swiftly shring the information about shark sightings with relevant organizations,” said Kwon Soon-wook, president of NIFS.