A group of scientists in a government-led project have found four new types of toxic microorganism in the waters off Jeju Island.

They say their appearance could be evidence of the long-term rise in ocean temperatures here.

Two of them produce palytoxin, one of the deadliest toxins known to humans, the Ministry of Maritime Affairs said Wednesday. One gram of palytoxin can kill about 170 million mice.

The team led by Lee Won-ho of Kunsan National University and Jeong Hae Jin of Seoul National University published the findings in the September edition of Ocean Science Journal.

“The discovery underscores the need for close observation of harmful species that started to appear in our marine environment and for preemptive measures to preclude poison accidents for those who happen to consume toxic fish, given its rapid proliferation due to accelerating climate change,” the ministry noted.

Detecting toxic microorganisms has been a daunting challenge for the government. The detection requires a long, complex process to determine whether they pose a health risk, involving sample collections, experiments under controlled conditions and evaluations.

If consumed by humans, palytoxin affects every cell in the body, scientists say. The symptoms vary but the most common way of exposure to humans is oral. The onset of symptoms is swift, and death usually follows in a short period of time.

The ministry added that it would be able to indirectly track the advancement of a warming trend in Korea’s marine ecosystems by obtaining the distribution patterns of such protozoa, while utilizing their toxins in developing cancer treatment.

By Shin Hyon-hee (heeshin@heraldcorp.com)