KOTA KINABALU: The state government is implementing strict and comprehensive measures to address the outbreak of pelian fish deaths confirmed to be caused by Koi Herpesvirus (KHV), following reports of incidents since August 1, 2025.
Minister of Agriculture, Fisheries, and Food Industry, Datuk Jamawi Jaafar, said that the mass fish deaths are affecting several major rivers in the districts of Keningau, Tambunan, Tenom, Penampang, Tuaran, Ranau, and Sipitang.
He mentioned that laboratory analysis by the Biosecurity Laboratory of the Sabah Fisheries Department at the Likas Fisheries Complex confirmed KHV as the primary cause of the incident.
According to him, KHV is a dangerous pathogenic virus that attacks fish from the Cyprinidae family and is classified as a high-impact aquaculture disease with a very high mortality rate.
“Scientific data indicates that the mortality rate can reach between 80 and 100 per cent in infected populations, and this virus is active in water temperatures around 18 to 28 degrees Celsius, becoming more aggressive with sudden temperature changes.
“It can also remain latent before reactivating under environmental stressors such as drought, and it spreads through water, direct contact, contaminated equipment, and the transfer of live fish,” he said in a statement today, addressing the viral issue on platforms regarding the pelagic fish deaths, while providing an official explanation of the true cause and the control measures being implemented by the state government.
Jamawi noted that field investigations revealed that the primary cause of the outbreak is the release of foreign fish, particularly koi and other species from the Cyprinidae family that are not endemic to Sabah, into public waters without control.
He emphasised that such irresponsible actions violate biosecurity principles and have led to serious infections in local species, including pelagic fish.
