CANBERRA, Aug. 1 (Xinhua) -- South Australian state authorities are investigating a mass bird mortality event after more than 80 dead and sick greater crested terns were found on an island off the state's southeast coast.
Testing is underway to determine whether the birds were infected with the H5 strain of avian influenza, the Australian Broadcasting Corporation (ABC) reported on Saturday.
State aerial surveillance on Friday detected 49 dead and 35 sick greater crested terns on Baudin Rocks, about 5 km south of Cape Jaffa, the ABC reported.
The state's Chief Veterinary Officer Skye Fruean said it was "very unlikely" the birds would test negative for H5, although laboratory results were still pending.
The state of South Australia has now recorded 39 of Australia's 53 confirmed H5 bird flu cases, according to official updates.
Australian Chief Veterinary Officer Beth Cookson said the risk to agriculture and humans remained low. ■