The bloodied carcasses of two male dugongs washed up on the bank of Seven Mile Creek in Gladstone last week, following the mysterious death of two dolphins on Boyne and Turtle Islands last month.

In April, 22 dead turtles were found washed up at the mouth of the Boyne River.

It is not known if the dugongs suffered heavy lacerations on their body before or after their deaths.

Environment Minister Kate Jones said a panel of marine science experts would now work with the Department of Environment and Resource Management to determine the cause of death.

“There have been two dugongs and three dolphins found in waters and on beaches in the area since the start of May," she said.

“I take any death of a marine animal seriously, and as minister for the environment I want to understand the causes behind these casualties.

“The scientific panel will bring the best minds around a table to look at all the evidence and provide the best advice to government and the community on these particular cases.”

The Department of Environment and Resource Management said the animals appeared to have been in good health prior to their deaths and pollution was not believed to have been a factor in their deaths, although the department is awaiting pathology reports to confirm this.

The local community has raised about increasing shipping activity in Gladstone Harbour, as the Gladstone Ports Corporation works towards becoming one of the world's major liquid natural gas exporters.

Ms Jones conceded that the dolphins and dugongs most likely died after being struck by a boat or caught in commercial fishing nets.

“We will not pre-empt the advice of the scientific panel in relation to the recent dugong and dolphin deaths near Gladstone, but I will not hesitate to act on their advice once it is provided," she said.

The dugong population off the central Queensland coast also has been under heightened stress, due to the depletion of their main food source seagrass, as a result of the washout from the summer floods.