Based on the result of analysis on catch by set nets in the East Sea, NIFS announced that climate-change driven water temperature increase accelerated the emergence rate of warm current fish species. 

The East Sea Fisheries Research Institute of NIFS had analyzed the population rate of catch by set nets in Goseong and Yangyang, Gangwon Province and Uljin, Gyeongbuk for 20 years. The result showed that the emergence rate of warm current fish species- such as yellow tail, horse mackerel, spanish mackerel, etc.- surged for recent five years (’20-’24) compared to the past fifteen years (’05-’19). More specifically, the rate increased to 53% in Goseong, 64% in Yangyang, and even 90% in Uljin. 

In case of yellow tail population, the catch had increased steadily as it ranked no.1 in Goseong, the northernmost part of South Korea’s eastern coast, accounting for 21.6% of the catch by set nets. The analysis showed that the extended period to form the suitable temperature for yellow tail to live (from May-October to May-December) and expanded migration area (up to Goseong from exisiting Gyeongbuk) were behind the steady increase. 

As such, climate change-driven temperature increase made migratory fish in the East Sea further expand their migration coverage, bringing about changes in region-specific emergence fish species and dominant species.

Meanwhile, when the recent 5-year temperature changes were compared to the average water temperature(’05-’09), there was an outstanding change in the sea areas around Gangwon with an increase of 1.1℃, higher than the 0.7℃ increase in that of Gyeongbuk. 

This was because the isothermal lines (above 16℃) swiftly move northward to Gangwon sea areas due to persistently increasing volume of Tsushima Current coupled with increasing heat transfer from the atmosphere. 

*An isothermal line is a line on a map or graph that connects points having the same temperature. It helps visualize the spatial distribution of temperature, like northward and southward bends. 

The president of NIFS said, “In analyzing the data on long-term monitoring of the catch by set nets, we found that higher water temperature swiftly changed the fishing ground landscape in the East Sea. Just as Korean waters are not the exception to climate change, we will do our best to strengthen R&Ds on technology in diagnosis and prediction of subtropicalization as well as to explore the measures for sustainable fisheries.”