CANBERRA - Australian researchers on Tuesday said 36 percent of marine turtles are affected by marine rubbish, with soft plastic being the major villain.

Scientists from the University of Queensland surveyed turtles washed up in the eastern areas of Brisbane's Moreton Bay over a period of four years.

The latest research was released at a launch for the Earthwatch program - "Turtles in Trouble" in Melbourne's Federation Square on Tuesday.

Marine scientist Dr Kathy Townsend, who is part of the project, said the results of the project show the impact marine rubbish has on the death of turtles is more than 17 times higher than the two percent previously suggested.

"Turtles have been found to have eaten most plastic items, but the most common items eaten are soft plastics, such as plastic bags and lolly wrappers, and pieces of hard broken-down plastic," Dr. Townsend told ABC News on Monday.

"The ratio of soft plastics - plastic bags, bait bags and cling film - to hard plastics found in turtle gut contents compared to the ratio found in the environment was significantly higher."

She said this indicated that turtles select soft plastics as food, as has been suggested anecdotally.

The executive director of Earthwatch Australia, Richard Gilmore, said the new research and the work of Dr Townsend highlighted the need for the community to be more aware of the impact of marine rubbish.