A detailed investigation by the Department of Environment and Science has been unable to definitively determine what caused a large number of black noddies to become unwell and die in the Mackay area recently.
Hundreds of deceased and sick birds were found in the Mackay Marina, around Bushy Island, and at other known roosting sites in late August and early September this year.
Water samples taken from the marina did not detect any contaminants or unusual water quality results.
Swab samples taken from feathers of deceased birds found in the marina were screened for organic contaminants such as pesticides, herbicides and hydrocarbons. No organic contaminants were detected and there was no direct evidence of death due to chemical exposure.
Disease testing was also conducted – for Newcastle Disease, Influenza A, Botulism poisoning, Murray River Encephalitis and Kunjin Virus – on deceased birds taken from Bushy Island were also negative.
Necropsies on some of the birds identified a lack of food in their digestive system, while others had suffered from heart disease, lung disorders and liver damage, but the cause of these conditions were not identified.
Based on consideration of these results, DES is unable to determine the cause of this death and disease incident in the noddies.
Queensland Parks and Wildlife Service rangers from the DES and Great Barrier Reef Marine Park Authority (GBRMPA) and Reef Joint Field Management Program are continuing to investigate incidents of similar bird deaths that have been reported in the waters of the Great Barrier Reef World Heritage Area.
Members of the public are encouraged to report evidence of sick or poisoned birds to the DES pollution hotline on 1300 130 372.
