A recent investigation by the National Institute of Fisheries Science has concluded that a mass death of sardines in Masan Bay, Gyeongsangnam-do, South Korea, in late September was caused by asphyxiation due to low oxygen levels in the water. The investigation, which ruled out other possible causes such as infectious agents, algal organisms, or harmful substances, found that the water column was deficient in oxygen from a depth of 4 meters to the bottom. Despite this, other aquaculture products like oysters, clams, and cage-cultured fish were not affected. The institute is continuing to monitor the fishery environment for further insights.