Sunbathing not good for tadpoles

Feb 17, 2011

(PhysOrg.com) -- The thinning ozone layer in the upper atmosphere may be a key factor in the collapse of frog populations worldwide, new research shows.

Tadpoles exposed to higher levels of UV-B are more susceptible to predators, a University of Queensland study found.

The research by PhD student Lesley Alton is reported this month in .

Amphibians – including , toads and salamanders – are facing an extinction crisis worldwide.

Almost one in three species is threatened, with factors including the loss and fragmentation of habitat, disease, pollution, climate change and introduced predators.

At least 150 species have disappeared since 1980, compared with a natural extinction rate of about one species every 250 years.

The UQ researchers looked particularly at the interactive effects of UV-B and predation risk in the early-life stages of the striped marsh frog.

Ms Alton, from UQ's School of Biological Sciences, said ozone depletion in the past 40 years had increased UV-B radiation. Her work studied the effects on of a five per cent rise in UV-B.

“Embryos exposed to the lower UV-B treatment hatched as well as those exposed to the higher UV-B treatment,” Ms Alton said. “These tadpoles were also the same size and shape, and were able to swim just as fast.”

But the survival time of tadpoles exposed to the higher UV-B treatment fell by nearly 30 per cent when they were exposed to predatory shrimp.

“This finding is significant because it shows that for tadpoles living with exposure to elevated UV-B levels can have lethal consequences,” Ms Alton said.

“Given that the detrimental effects of UV-B radiation were only evident in predation trials, this study also demonstrates the importance of examining the effects of UV-B radiation in an ecologically relevant context, because otherwise the significance of UV-B radiation as an environmental stressor may be misinterpreted.

“The phenomenon of global amphibian declines is a testament to the profound effects of human-induced global change on natural environments.

“With amphibians being the most threatened of all vertebrates, and also important indicators of environmental health, understanding the causes of their declines is critical for their conservation, and possibly the conservation of other species.

“Our study suggests that the human destruction of the ozone layer has the potential be an important contributor to the global decline in amphibian populations.”

Explore further: Deep sea fish eyesight similar to human vision

More information: rspb.royalsocietypublishing.org/

Related Stories

Research questions amphibians' UV vulnerability

May 23, 2010

(PhysOrg.com) -- New research recently conducted by two ecologists, Wendy Palen at Simon Fraser University and Daniel Schindler at the University of Washington, finds that Pacific Northwest amphibian species ...

Beyond sunglasses and baseball caps

Jan 26, 2010

A new study reported in Investigative Ophthalmology & Visual Science found that UV-blocking contact lenses can reduce or eliminate the effects of the sun's harmful UV radiation.

Amphibians in losing race with environmental change

May 01, 2007

Even though they had the ability to evolve and survive for hundreds of millions of years - since before the time of the dinosaurs and through many climatic regimes - the massive, worldwide decline of amphibians can best ...

Duke develops new UV measurement tool

Nov 02, 2005

Researchers at Duke University's Pratt School of Engineering have developed a new way to measure microbes' exposure to ultraviolet light.

Frogs with disease-resistance genes may escape extinction

Jul 16, 2008

As frog populations die off around the world, researchers have identified certain genes that can help the amphibians develop resistance to harmful bacteria and disease. The discovery may provide new strategies to protect ...

Recommended for you

Male sex organ distinguishes 30 millipede species

17 hours ago

The unique shapes of male sex organs have helped describe thirty new millipede species from the Great Western Woodlands in the Goldfields, the largest area of relatively undisturbed Mediterranean climate ...

Dogs hear our words and how we say them

Nov 26, 2014

When people hear another person talking to them, they respond not only to what is being said—those consonants and vowels strung together into words and sentences—but also to other features of that speech—the ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.