The Agriculture, Fisheries & Conservation Department has confirmed botulism was the cause of death of 51 wild ducks found in Lok Ma Chau.

Carcasses of eight northern shovelers and 43 Eurasian wigeons were collected at the wetland compensation area of the Mass Transit Railway Lok Ma Chau Spur Line on March 25. These wild ducks are common winter migratory birds found in Hong Kong.

They had all tested negative for the H5 virus. Botulism is a disease caused by toxins produced by the bacteria Clostridium botulinum. The bacteria can be found in soil and lake sediment. Sporadic outbreaks of avian botulism, usually involving migrating waterfowl, are well documented globally and are usually seasonal in nature.

The department will continue its wild-bird monitoring and surveillance. To report dead or sick birds, call 1823.