Cause of Mass Sardine Death in Masan Bay, Changwon: 'Oxygen Deficiency' Again

The National Institute of Fisheries Science announced that the cause of the mass sardine die-off in Changwon Special City, Gyeongnam, was suffocation due to oxygen deficiency, the same as last year.

Changwon City stated that on the 11th, it sent samples of the dead sardines to the Institute of Fisheries Science for analysis of the cause of death, and on the 19th, it received a phone notification of the results from the institute.

Hong Nampyo, Mayor of Changwon Special City, Gyeongnam, is collecting dead sardine bodies in the sea near Masan Haeyang Nuri Park.
[Photo by Changwon City Hall]

According to the institute's results, a large number of sardines, which consume a lot of oxygen, entered a semi-enclosed sea area with oxygen-deficient water masses and suffocated due to lack of oxygen.

The oxygen-deficient water mass, called a hypoxic water mass, occurs in semi-enclosed areas where seawater circulation is poor, as microorganisms decompose organic matter accumulated in the lower layers, consuming dissolved oxygen in the water.

The scale and intensity of this phenomenon can vary depending on changes in water temperature or seawater movement.

A school of sardines is dying in the sea in front of Masanhaeyang Nuri Park, Masanhappo-gu, Changwon Special City, Gyeongnam.
Photo by Lee Seryeong

The institute analyzed that in Jinhae Bay, hypoxic water masses mainly occur between June and October, and this year, after sardine schools entered the seas near Namhae County in June and July, and near Geoje and Masan in September and October, a strong hypoxic water mass formed near Masan Marine New City on October 10, causing the mass sardine die-off.

With the increase in sardine resources, it was advised that Masan Bay reduce the organic matter flowing from land into the inner bay and periodically conduct dredging operations to remove sediment.

Kim Hyun-su, Director of Fisheries, said, “The cause of death results from the institute are the same as last year, and it has been identified that fish die-offs are occurring not only in Gyeongnam but also across the southeastern coast including Busan and Jeju.” He added, “We will explore various measures with the management department and propose these measures to the Ministry of Oceans and Fisheries to establish fundamental countermeasures and do our best.”

Earlier, on the 11th, a school of sardines gathered and died off in the sea area from the Kim Ju-yeol Martyr Memorial Park in Masanhappo-gu, Changwon City, to the Masan Marine Nuri Park area.

Starting from the afternoon of the same day, Changwon City deployed coastal gillnet fishing vessels to retrieve the carcasses, and by the 15th, a total of 55 people including public officials, related agencies, and fishermen were mobilized to collect a total of 45 tons of dead sardines.

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