Holidaymakers should be cautious of jellyfish spotted along the beaches of South Korea, authorities warned on Monday.

Hundreds of Koreans have already been treated for jellyfish stings and the number is expected to rise during the peak summer holiday season.

“The jellyfish population has soared recently and people visiting the beach should be careful to avoid being stung,” the National Fisheries Research and Development Institute said.

According to the agency, jellyfish found on local beaches on Saturday were identified as the type that can be deadly. Beachgoers worldwide are faced with a sudden global increase in jellyfish, which seems to be linked to the changing oceanic environment.

The proportion of poisonous jellyfish appearing in local coastal waters was 12.6 percent on July 25. The figure jumped to 27.5 percent on Aug. 1, and rose further to 42.6 percent on Thursday.

Monitoring agencies issued warnings for people to use caution in the water and avoid jellyfish.

By Im Woo-jung, Intern reporter
(iwj@heraldcorp.com)