CORVALLIS, Ore. Toad embryos in the Cascade Range of Oregon appear to be dying due to a chain of events that's ultimately linked to climate change, a new study suggests, demonstrating both the importance of large-scale global trends and the complexity of their impact on individual species.
The report by scientists from Oregon State University and Pennsylvania State University will be published Thursday in the journal Nature. It traces one link to another in a pattern that begins in the southern Pacific Ocean and ultimately results in masses of dead, rotting toad eggs in a small alpine lake many thousands of miles away, which are those of an amphibian species in decline.
"This study suggests a causal explanation for problems with one amphibian species in the mountains of Oregon," said Andrew Blaustein, a professor of zoology at Oregon State University. "But in a larger sense it shows that if we want to understand the complex ecology of the world around us, we must start looking at the big picture. There will not be simple or easy answers for all of our problems."
Blaustein co-authored this study with Lisa Belden of OSU and Joe Kiesecker, a professor of biology at Penn State and leader of the research team. For years these scientists have studied the level of amphibian declines around the world and those of the Pacific Northwest in particular. Among other findings, they have linked amphibian declines in Oregon to elevated level of exposure to UV-B radiation in sunlight, and also to infection of embryos by a fungus, Saprolegnia ferax.
In this study, they were able to identify connections in the struggle of this individual toad species to survive that took them all the way to global warming and the greenhouse effect.
"Although the results reveal the amazing complexity associated with understanding biological systems, they also demonstrate that there may be simple rules that we can follow to help us understand
Contact: Andrew Blaustein
Oregon State University