The Ministry of Oceans and Fisheries National Institute of Fisheries Science said on Oct. 20 that an analysis of the causes and characteristics of fisheries disasters that occurred in Korea's seas this year showed that, due to abnormal weather from climate change, marine environments and fisheries disasters displayed markedly different patterns by sea area.
The special advisory period for high water temperatures lasted from early July to early October for 85 days, up 14 days from last year, marking the longest period on record. The average water temperature in coastal and nearshore waters from July to September was 26.8–27.8 degrees, 2–4 degrees higher than normal and showing a high-temperature trend similar to last year, but the coasts showed large differences by area.
In the West Sea and Jeju coastal waters (22–30 degrees), there was no significant difference in temperature fluctuations compared with last year starting in August. However, the South Sea and East Sea coasts showed a much higher temperature distribution (18–27 degrees) than last year from early July to early August, then a distribution 2–4 degrees lower than last year from mid-August to late September.
In the southern waters, frequent development of stationary fronts led to record heavy rainfall, and sustained southerly winds under the influence of the North Pacific High formed a cold-water mass while creating a temperature range (24–27 degrees) favorable for red tide organisms. With increased nutrients and reduced competing organisms, red tide damage occurred for the first time in six years.
The impact of abnormal weather also appeared to affect the appearance of Nomura's jellyfish. A low-temperature phenomenon that appeared across East Asia, including waters around Korea, in the first half of the year reduced the appearance and growth of jellyfish, decreasing jellyfish damage to fishing activities and beachgoers by 44% from the previous year.
Damage to farmed organisms due to high water temperatures this year decreased to 13% of the previous year's level thanks to a slowdown in rising coastal temperatures in the South Sea and East Sea and preemptive response measures such as early shipment and emergency releases to reduce damage.
National Institute of Fisheries Science Director Choi Yong-seok said, "The environment of our seas is changing every year due to climate change, and the patterns of fisheries disasters are changing accordingly," adding, "We will do our best to advance climate change prediction technology and take preventive measures so we can respond to rapid ecological and environmental changes in our seas caused by climate change."