New Queensland research is indicating that green turtles living alongside urban and farming areas are absorbing possibly thousands of chemicals, including many associated with industry and agriculture.
“There used to be a theory that the ocean was so huge it would dilute contaminants to such an extent that it remained a relatively healthy environment for marine creatures,” said Associate Professor Caroline Gaus from the University of Queensland.
“But people should be aware that many of the chemicals we flush down the toilet, apply to our gardens, spray on crops, or use in factories can end up in turtles and we don’t yet know how it is affecting them,” she said.
This revelation about the vast number of chemicals found in turtles is among the preliminary findings from a major research project investigating the impact of contaminants on turtles in the Great Barrier Reef.
In June and July, 2012 more than 100 green turtles were found stranded at Upstart Bay and the cause remains unknown.
This mystery inspired the River to Reef to Turtles research project, which is supported by major partner Banrock Station Wines Environmental Trust, and involves WWF-Australia, TropWATER (James Cook University), Entox and Vet-MARTI (The University of Queensland), the Queensland Government, the Great Barrier Reef Marine Park Authority (GBRMPA), and other collaborative partners.
During the first year, a total of 1131 turtles were sampled across the three study sites – the relatively pristine Howick Group of Islands and the two coastal sites of Upstart Bay and Cleveland Bay.
“We found chemicals associated with industry and agriculture in the blood of turtles from both Upstart Bay and Cleveland Bay,” said Associate Professor Gaus.
“But the preliminary data highlights that Upstart Bay turtles have particularly higher levels of the metals cobalt, molybdenum and antimony, and higher levels of stress-related compounds than turtles at the other locations. These stress-related compounds are often a sign of chemical exposure.
“Other tests indicate that turtles from Upstart Bay also have signs of systemic stress with markedly higher inflammatory responses in a high proportion (45%) of animals. However, it’s far too early to know if chemicals are connected to this response.
“Our team at Entox are using new forensic screening techniques for this research. There are more than 30,000 chemicals in wide commercial use and many of these have never been measured in the environment. We have found indications of potentially 1,000s of chemicals in coastal turtles and we will keep drilling down into the data to identify the substances of most concern.
“We think it is the combination of chemicals, rather than one or two chemicals on their own, that could be having the biggest impact on turtle health.
“The next step in our research is to see if we can we find a correlation between turtle health and the complex mixture of chemicals they are exposed to in urban locations,” she said.
GBRMPA Manager of Operations Support Dr Mark Read said the early findings were a significant step forward in improving our understanding of the links between the land, inshore areas and the animals that live there.
“This highlights the benefit of bringing together so many different experts to work on the same wildlife mystery – it is a true, multi-disciplinary approach.
“The Rivers to Reef to Turtles project is setting a high standard for how we investigate unknown causes of disease and declines in species,” he said.
Banrock Station Wetland Manager and Environmental Trust panel member, Dr Christophe Tourenq, said the early results were fascinating.
“Often researchers look for the single smoking gun to explain poor health in animals. But Rivers to Reef to Turtles is showing that the real answers are incredibly complex and there is probably not a single cause.
“We are proud our partnership provides us the opportunity to support this ground-breaking research.
"Through excellent research projects just like this, our hope is to understand what needs to done to be safeguard and protect the green turtles that call Upstart Bay home," he said.
Since 1995, Banrock Station has supported vital conservation efforts across the world, such as the turtle research project with WWF-Australia. To date the Banrock Station Environmental Trust has donated approximately $6million (AUD) to more than 130 projects in 13 countries.
WWF-Australia Media Contact:
Mark Symons, Senior Media Officer, 0400 985 571