677,000 Jeju plaice die... 125.05 million nationwide affected by high water temperatures over five years

[Financial News Jeju = Reporter Jeong Yong-bok] Warming seas are becoming a constant business risk for the aquaculture industry. From 2022 through early September this year, more than 125 million farmed fish died from high water temperatures, and damages exceeded 200 billion won even excluding this year's losses. In Jeju, 677,000 plaice were provisionally recorded as having died this year.
An analysis of data submitted by the Ministry of Oceans and Fisheries (MOF) to Moon Dae-lim, a lawmaker of the Democratic Party of Korea, showed that 125,048,000 farmed fish died from high water temperatures over the five years from 2022 through September 4 this year.
By year, the number surged from 851,000 in 2022 to 31,779,000 in 2023. In 2024, it rose to 68,555,000, the highest figure in the past five years. Although it fell to 10,330,000 last year, this year's provisional damage total was 13,533,000.
As of September 4, this year's damage had occurred at 455 aquaculture households nationwide. Because the damage is still ongoing and the estimate has not yet been reviewed by the Fisheries Disaster Countermeasures Deliberation Committee, the final scale may change.
By region, Gyeongsangnam-do had the highest figure, with 6,337,000 fish affected at 171 aquaculture households. It was followed by Gyeongsangbuk-do with 2,798,000, Chungcheongnam-do with 2,315,000, and Jeollanam-do with 1,406,000.
In Jeju, 677,000 plaice were recorded as having died at 45 aquaculture households. The amount of damage in Jeju this year is still being calculated.
Jeju's aquaculture industry has also been unable to escape damage from high water temperatures. In 2024, 2,215,000 fish and abalone were affected at 77 aquaculture households in Jeju, causing property damage of 5.345 billion won. Last year, 1,803,000 fish died at 62 aquaculture households, with damages reaching 5.227 billion won.

The scale of the damage cannot be fully explained by the number of fish alone. Damage from high water temperatures also includes shellfish and other aquatic products such as oysters, mussels, and sea squirts, which are counted in different units such as lines, racks, and area. The figure of 125,048,000 represents only the combined mortality of comparable fish species.
Property damage has also increased. Although this year's damage has not yet been calculated, total damage from high water temperatures between 2022 and 2025 amounted to 205.56 billion won.
The amount of damage rose from 956 million won in 2022 to 43.829 billion won in 2023 and soared to 143.04 billion won in 2024. Last year, it fell to 17.735 billion won.
By species, Korean rockfish appeared particularly vulnerable to high water temperatures. An analysis by the Ministry of Oceans and Fisheries (MOF) of the five fish species with the highest annual mortality found that Korean rockfish had been among the species with the highest mortality every year from 2021 through last year.
In 2022, Korean rockfish had the highest mortality, while from 2023 through 2025, Korean rockfish, plaice, and Starry flounder repeatedly ranked among the top species. This indicates that high-temperature damage is recurring around particular fish species.
As high water temperatures recur, government spending on disaster insurance is also rising rapidly. Government subsidies for aquaculture disaster insurance premiums increased 96.6%, from 13.968 billion won in 2021 to 27.454 billion won last year. As of August this year, 28.12 billion won had already been provided, exceeding last year's annual support.
Compared with 2021, government subsidies have more than doubled over the past six years. As of August this year, total premiums amounted to 47.455 billion won, including 28.12 billion won from the national treasury and 12.204 billion won from local governments. Aquaculture households paid 7.131 billion won in premiums.

The government is also broadening its response beyond paying restoration costs and insurance claims after damage occurs to changing the structure of aquaculture itself.
The Ministry of Oceans and Fisheries (MOF) introduced the 'Climate Change Response Pilot Aquaculture Support Project' for the first time this year. The project supports the cost of replacing species at farms repeatedly damaged by high water temperatures with species that can withstand them, or relocating farms to areas with relatively lower temperature risks.
A total of 37 sites were selected through two rounds of applications this year. The average national funding per site is 84.6 million won. Project costs are divided into 50% national funding, 30% local funding, and 20% self-financing.
Examples include replacing plaice with Small yellow croaker in land-based aquaculture, or replacing Korean rockfish with Convict grouper and other species in the grouper family in marine aquaculture. In areas where high water temperatures recur, the cost of relocating aquaculture farms to other regions is also eligible for support.
The government has also expanded the supply of equipment for responding to high water temperatures. This year's budget for such equipment, including liquid-oxygen supply devices, was initially set at 7.6 billion won, up 31% from last year, and an additional 1.8 billion won was provided as the damage continued.
Advance insurance payments have also begun to ease the financial difficulties of affected aquaculture households. The Ministry of Oceans and Fisheries (MOF) began the process of paying approximately 900 million won in advance to 39 aquaculture households in Jeollanam-do and Gyeongsangnam-do whose detailed damage assessments had been completed by the 8th. About 2.3 billion won is expected to be paid in advance to approximately 52 households before Chuseok. Advance payment means providing 50% of the estimated insurance payout to households whose detailed damage assessments have been completed before the final insurance amount is determined.
As damage from high water temperatures recurs every year, critics say that focusing solely on post-disaster compensation is insufficient. The challenge for the aquaculture industry is how to support the transition costs that aquaculture households must bear as they adapt species, farming areas, and facilities to climate change.
Moon Dae-lim said, "High water temperatures are not a seasonal abnormal-weather event but a constant disaster threatening the survival of the aquaculture industry. We must move beyond compensating for damage after it occurs and establish a proactive response system that includes switching to varieties resistant to high water temperatures, relocating farms to suitable aquaculture sites, and strengthening coverage under aquaculture disaster insurance."


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