Unknown Cause?...Mass Oyster Mortality Emergency on the South Coast

Lim Juntak, President of the National Federation of Fisheries Cooperatives, is inspecting the damage status of farmed oysters in the Tongyeong area on the 10th.
[Photo by National Federation of Fisheries Cooperatives]

[Asia Economy Yeongnam Reporting Headquarters Reporter Ju-cheol In] The industry is on high alert as an unusual mass oyster die-off continues in the southern coast of Gyeongnam, the largest oyster production area in South Korea.

According to Gyeongsangnam-do on the 11th, as of the 1st, 407 reports of oyster die-off damage were received in the areas of Jinhae, Tongyeong, Goseong, and Geoje. The damaged area amounts to 440.2 hectares, with losses reaching 7.924 billion KRW.

Some places reported 30-40% losses, while severely affected areas claimed 70-80% of farmed oysters died, suggesting that additional reports may be filed.

Oysters farmed along the southern coast, produced annually from October to May of the following year, are in season around this time. Normally, oysters hang densely on farming ropes measuring 7 to 15 meters in length during this period.

However, due to the unexplained mass die-off, when the ropes are pulled up, only empty oyster shells remain, or the shells fall off entirely, occurrences that have been happening frequently.

As the die-off has spread widely across the southern coast, local governments have formed a joint investigation team with the National Institute of Fisheries Science, the Fisheries Safety Technology Institute, and the Oyster Farming Cooperative to determine the cause of the damage. The team plans to identify the exact cause through on-site investigations and sample analyses.

The National Institute of Fisheries Science’s Southeast Sea Research Institute, which received the samples, is analyzing the cause of the die-off through marine environment, water quality, sediment surveys, and disease testing. If the analysis concludes that the die-off was caused by natural phenomena such as water temperature changes, the local governments plan to support disaster recovery efforts.

Although no clear cause has been identified yet, the industry suspects that the mass die-off is due to the effects of high water temperatures caused by abnormal weather. In fact, this year’s high-temperature warning period lasted 43 days, about twice as long as last year’s 22 days, and the warnings were issued about a month earlier than last year.

An official from the Oyster Cooperative said, “Oyster die-offs usually occur in summer, but this year it happened unusually during the production season in winter,” adding, “It is possible that the die-offs increased late due to the summer heatwave.”

Lim Joon-taek, Chairman of the National Federation of Fisheries Cooperatives, stated, “It is important to quickly identify the cause and prepare recovery measures for aquaculture farmers’ damages,” and added, “The Fisheries Cooperative will also make every effort to actively respond to minimize the damage to fishermen.”

This content was produced with the assistance of AI translation services.