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'Alarming' Level Of Chemicals Found In Great Barrier Reef Turtles

Green turtles have been found with heart and gout medication, pesticides, industrial chemicals, and 'toxic' levels of cobalt in their blood.

A group of scientists is demanding greater testing for contaminants along the Great Barrier Reef after a four-year study discovered "stressed" green turtles with "alarming" levels of chemicals.

Researchers from World Wildlife Fund Australia have called for tests to be carried out along every major bay and estuary to identify "hotspots" of contamination, after green turtles in some coastal areas were found with up to 25 times the 'healthy' levels of cobalt.

Scientists have also recommended the animals themselves be routinely tested, after they were found with thousands of chemicals that could not be identified.

Image: WWF Australia

It follows a four-year project which compared populations in coastal and remote areas and found evidence that poor water quality harms green turtles.

The study saw researchers grow turtle skin cells in labs to test chemical impacts, without harming the animals.

Researchers now believe green turtles can be used as strong indicators of environmental health.

Green turtle skin cells were grown in the lab (left) and exposed to different doses of chemicals, with blue indicating a fatal dose (right). Image: WWF Australia

“Existing Reef monitoring programs do not test for many of the contaminants found by our project. That’s why we’re calling for checks on a wider range of chemicals, including metals,” Marine Species Project Manager, Christine Madden Hof, said.

“We have shown turtles are good indicators of Reef health because they absorb chemicals in their environment."

The Rivers to Reef To Turtles project began in 2012, sparked by the discovery of more than 100 green turtles which had washed up in Upstart Bay, located South of Townsville.

Since then researchers testing turtles in the area found the animals had cobalt levels a staggering 25 times higher than in remote populations, which are deemed "healthy references".

Image: WWF Australia

According to their report, the recorded levels are greater than those for any vertebrate species and within the range expected to cause "acute toxicity."

Testing in the coastal areas of Upstart Bay and Cleveland Bay also found elevated levels of metals such antimony and manganese in the turtles’ food and blood.

READ MORE: This Is How Much Plastic It Takes To Kill A Sea Turtle

Many of the animals showed signs of stress, including liver dysfunction and neurological inflammation.

Scientists also believe chronic stress may be the cause of eye lesions, which can impact feeding and reproduction -- found in one in five green turtles in Upstart Bay and nine percent of the population in Cleveland Bay.

Image: WWF Australia

Eye lesions in the remote Howick Islands were found in only 0.2 percent of the population.

Scientists believe their research methods could provide a cost-effective early warning system for poor water quality and chemical contamination.

READ MORE: Two Turtles Dead After Being Trapped In Rubbish Off QLD Coast

Green turtles are the most common turtle species found in the Great Barrier Reef.

They are listed as endangered or vulnerable by the Australian and Queensland governments and the World Conservation Union.

Featured Image: Twitter (WWF Australia)

Contact the author: vgerova@networkten.com.au