TAMBUNAN: The Tambunan District Fisheries Office has attributed the mass death of pelian fish in Sungai Tagal at Kg Nuntunan and surrounding villages to prolonged hot weather that caused shallow water levels and deteriorated water quality.
This was revealed in a report by the Fish Health Management Unit of the Sabah Fisheries Biosecurity Division and confirmed by the Assistant Director of the Sabah Fisheries Biosecurity Division at the Likas Fisheries Complex.
The first report was received on Aug 8 following similar incidents at Sungai Tagal Kg Rantai earlier this month.
Both rivers are interconnected, with water flowing from Kg Rantai directly into Sungai Nuntunan.
Fish deaths have been detected across multiple villages in Tambunan, including Kg Kuala Monsok, Kg Tabilung, Kg Kaingaran, Kg Monsorulung, Kg Rompon and other nearby areas that receive water flow from the main river system.
Laboratory analysis of fish samples and water quality revealed elevated temperature and pH levels.
Clinical signs observed in affected fish included abdominal and fin bleeding, gill rot and fin damage, though internal organs remained normal with no unusual parasites detected.
Earlier samples from Sungai Kg Rantai indicated possible Vibrio cholera bacterial infection, though official laboratory confirmation is still pending.
New samples from Kg Nuntunan and affected villages will be sent for testing to detect potential bacteria and viruses, including Koi Herpesvirus and Spring Viraemia of Carp Virus.
As immediate measures, tagal communities have been advised to install nets to prevent dead fish from flowing downstream before proper disposal through burial or burning.
The public are warned against consuming undercooked pelian fish due to potential Vibrio cholera infection risks.
The use of fish fertiliser mixed with multivitamins has been recommended to boost the immunity of surviving fish populations.
While fish deaths in rivers are decreasing, the problem has now spread to pelian fish farms, causing concern among local fish farmers.
The Fisheries Department continues monitoring all affected areas, reporting ongoing but reduced fish mortality.
