Seafood is on display at a supermarket in Seoul, Oct. 6. The average cost of seafood in Korea jumped by 14.2 percent compared to last year. Yonhap

The average water temperature in Korea's coastal waters has risen by 1.44 degrees Celsius over 56 years, twice the global average, while the water temperature in the East Sea has risen 1.9 degrees Celsius, causing pollock and squid to disappear.

According to the "2024 Impact of Climate Change in Fisheries Sector" report by the National Institute of Fisheries Science, Sunday, the global water surface temperature rose by 1.44 degrees Celsius between 1968 and 2023.

The increase in water surface temperature was 1.9 degrees in the East Sea, followed by 1.27 degrees in the West Sea and 1.15 degrees in the South Sea.

"In line with climate change, large-scale changes are severe in air masses surrounding Korea, such as strengthening high pressure in the North Pacific, and heat transportation of warm currents from low latitudes is also increasing," Han In-sung, director of climate change research at the Fisheries Research Institute, said of the rapid rise in water temperatures.

Among the coastal waters, the water temperature in the East Sea increased 1.5 times that of the West Sea, which experts view as a result of the change from cold water in the East Sea to warm water.

Due to the rising water temperature, pollock and squid harvests have dropped sharply in the East Sea.

The annual pollock catch exceeded 100,000 tons in the 1980s, but since 2007, it has become so rare that it has been only 1 to 2 tons. Then in 2019, their fishing became completely banned, making Koreans completely dependent on imports from Russia.

Squid was caught at an annual average of 200,000 tons in the 2000s, but last year, it decreased to a record low of 23,000 tons, and the price rose to the point that it is dubbed "gold squid."

The rise in water temperature has also dealt a blow to fishing production. Korea's coastal fishing production plummeted from an average of 1.51 million tons in the 1980s to 1.16 million tons in the 2000s and continued to decline to 930,000 tons in 2020.

The number of fish species that are caught in Korea is also changing.

According to a report by the Fisheries Research and Development Institute, the catch of cuttlefish has plummeted since the 2010s, while anchovies and mackerel have declined or stagnated.

On the other hand, yellowtail, horse mackerel and Spanish mackerel catches have increased steadily over the past 40 years.

The Fisheries Research and Development Institute analyzed that the number, population and density of subtropical fish species are clearly increasing as the water temperature rises along the coast of Jeju Island, and that subtropical fish species are already actively traded in the seafood markets of Jeju.

Last year, the average annual water temperature in Korea's seas was the highest the National Fisheries Research and Development Institute had ever recorded in its 34 years of observation.

Experts predict that Korea's seas will continue to become hotter. The Fisheries Research and Development Institute predicts that by 2100, the water temperature of the Korean seas will rise by 1 to 4 degrees.