Mystery eye disease is latest blow for Australia’s sick turtles
is ivermectin over the counter in canada Turtles on Australia’s Great Barrier Reef can’t seem to catch a break. After an outbreak of herpes and a mass stranding, many have now developed a puzzling eye disease. Researchers are investigating whether metal run-off from mining and agriculture is affecting the turtles’ immune systems and making them more susceptible to illness.
annonce rencontre dans le 66 The first sign of trouble was in 2010, when two-thirds of the green turtles surveyed in Brisk Bay in the central Great Barrier Reef had developed fibropapillomatosis. The condition, which is triggered by a turtle-specific herpes virus stromectol prix en belgique proportionately that has since affected other areas, too, caused tumours to grow on their eyes, shells, flippers, tails and internal organs.
http://www.spicygrasshopper.com/3322-cs54698-roulette-royale.html Then in 2012, more than 100 green turtles became stranded at the nearby Upstart Bay. Most washed up dead, but those that were still alive experienced seizures, uncontrolled head movements and other neurological symptoms.
where can you buy ivermectin for dogs onward Now, many of Upstart Bay’s turtles have developed unexplained eye infections. The lesions are not fatal, but they cloud the animals’ vision, making it harder for them to find food and avoid predators.
A survey conducted last year found that a quarter of green turtles in the area had eye infections. The results were released by WWF-Australia this week. Preliminary work by Mark Flint at the University of Florida in Tampa suggests the infections are bacterial.
Cobalt culprit ?
To try to get to the root of the problem, Alex Villa at the University of Queensland in Coopers Plains, Australia, and his colleagues have been analysing blood samples from Upstart Bay turtles.
One of their most striking findings is that turtles there have between four and 25 times as much cobalt in their blood as is normal. Levels of antimony, molybdenum and manganese are also elevated, but not to the same extent.
In small amounts, cobalt is an essential metal for animal and human health, but at high levels it can damage vital organs such as the brain and heart.
Cobalt occurs naturally in soil and rock, and is washed into waterways by rain. But this process can be accelerated by farming and mining, says Jon Brodie at James Cook University in Townsville, Australia. He is examining whether livestock grazing and mining in the area are leaking excess cobalt into the bay.
It is still too early to know whether the high cobalt levels and spate of health issues are linked, says Flint. However, he says the metal may be placing pressure on the turtles’ immune systems and making them more vulnerable to bacterial and viral infections. This idea is backed up by the finding that turtles with high cobalt levels tend to have higher levels of immune cells in their blood.
Duan March at Southern Cross University in Coolangatta, Queensland, agrees. “It looks like those animals, or that environment, is stressed, and the ocular disease is most likely due to a secondary bacterial infection,” he says.
The 2012 mass stranding may also be connected to cobalt contamination, says Villa. “Many metals are directly neurotoxic.”
However, more evidence is needed, he says. “It would be tempting to point to the nearest mine and say ‘that’s the problem’, but the links between human activity and contaminant accumulation in wildlife are difficult to unravel,” Villa says. “At this stage, there’s still no smoking gun.”