A vendor fans herself at the seafood section of Garak Agricultural and Marine Products Wholesale Market in Songpa-gu, Seoul, on Thursday, as a record heat wave continues. Seafood prices — including hairtail and mackerel — have risen amid high sea-temperature advisories, while vegetable prices for cucumbers and zucchini have also climbed in the sweltering weather. (Yoon Chang-bin)
A vendor fans herself at the seafood section of Garak Agricultural and Marine Products Wholesale Market in Songpa-gu, Seoul, on Thursday, as a record heat wave continues. Seafood prices — including hairtail and mackerel — have risen amid high sea-temperature advisories, while vegetable prices for cucumbers and zucchini have also climbed in the sweltering weather. (Yoon Chang-bin)

Fish are dying in large numbers along Korea's coasts as abnormally high sea temperatures persist.

Pohang city officials said Monday that fish kills began Tuesday at aquaculture farms due to high water temperatures, and more than 1.006 million fish had died at 27 farms by that day. Losses are estimated at 635 million won ($447,000).

As of Monday, water temperatures along the East Sea coast stood at 27.0 degrees Celsius off Guryongpo Hajeong in Pohang, 26.3 degrees in Yeongdeok and 26.2 degrees off Deokcheon in Uljin. Authorities upgraded a high sea-temperature advisory covering the Gyeongju-to-Uljin coastal zone to a full warning starting at 2 p.m. A high sea-temperature warning is issued when water temperatures in a given sea zone reach 28 degrees Celsius or above for three or more consecutive days, or when such conditions are forecast.

The southern coast faces an additional threat from red tide. A preliminary red-tide special advisory was issued for waters off the eastern part of South Jeolla Province and the western part of South Gyeongsang Province along the South Sea. The Ministry of Oceans and Fisheries raised its red-tide crisis alert to the Caution level effective 6 p.m. Monday. Officials warn that aquaculture losses could worsen significantly if red tide strikes while fish are already weakened by high water temperatures.

The red-tide crisis alert system rises through four levels: Attention, Caution, Alert and Serious. The Caution level is triggered when preliminary advisories are issued in two or more sea zones; Alert is declared when formal advisories cover two or more zones; and Serious is reached when full warnings are in effect across two or more zones.

Government agencies and local authorities are working to limit the damage. Pohang city is supplying affected farms with liquid oxygen, circulation pumps, immune-boosting agents, combination vaccines and ice. The Ministry of Oceans and Fisheries plans to activate a comprehensive operations center in response to this week's alert upgrade and will step up red-tide monitoring, spread-trend analysis and situation reporting.


siuu@heraldcorp.com