Heart and gout medications, pesticides, herbicides and other industrial chemicals have all been found in the blood of green sea turtles in the Great Barrier Reef, according to researchers.
The discovery was made as part of project led by the World Wildlife Fund (WWF), which compared samples from turtles in urban areas to the more remote locations.
Environmental chemist Amy Heffernan from the University of Queensland said she was surprised to see the chemicals in the sea-going turtles.
“What you put down your sink, spray on your farms, or release from industries ends up in the marine environment and in turtles in the Great Barrier Reef,” Dr Heffernan said.
Chemical exposure has been linked to stress and other side effects in wildlife, and the indications of inflammation and liver dysfunction were found in some green turtles.
Dr Heffernan said a cocktail of unknown chemicals present in the turtles' systems was even more concerning.
“The worrying thing is there are more chemicals we could not identify than chemicals we could,” she said.
Dr Heffernan said it was impossible for researchers to understand exactly what chemicals were going into the environment at any given time.
“Humans are putting a lot of chemicals into the environment and we don't always know what they are and what effect they are having, we need to be conscious of that,” she said.
“There is one new chemical registered for use every six seconds, so the libraries and the databases that we use to identify these chemicals just can't keep up.”
The researcher believes turtles could be used to monitor chemicals entering reef waters and the health of marine life.
The blood samples were collected from green turtles at Cleveland Bay in Townsville, Upstart Bay at the Burdekin River and the remote Howicks island group of Cape York.
Across the three sites, the researchers found indicators for hundreds of thousands of different chemicals present in turtles.
Dr Heffernan is part of joint University of Queensland and Queensland Health team responsible for analysing samples for the Rivers to Reef to Turtles project, but she said it was one element of a much larger project.
“WWF is also working with farmers and people from industry so that we can all responsibly manage the situation and the environmental impact,” she said.