Home  |  Top News  |  Most Popular  |  Video  |  Multimedia  |  News Feeds  |  Feedback
  Medicine  |  Nature & Earth  |  Biology  |  Technology & Engineering  |  Space & Planetary  |  Psychology  |  Physics & Chemistry  |  Economics  |  Archaeology
Top > Biology > Environmental Concerns Increasing Infectious Disease… >

Environmental Concerns Increasing Infectious Disease in Amphibians, Other Animals

Published: July 18, 2012.
Released by Oregon State University  

CORVALLIS, Ore. – Climate change, habitat destruction, pollution and invasive species are all involved in the global crisis of amphibian declines and extinctions, researchers suggest in a new analysis, but increasingly these forces are causing actual mortality in the form of infectious disease.

Amphibians are now, and always have been hosts for a wide range of infectious organisms, including viruses, bacteria and fungi, scientists said in a review published in Philosophical Transactions of the Royal Society B.

But in recent decades, disease seems to have taken a more prominent role in causing mortality. Because of multiple stresses, many induced by humans, amphibians now succumb to diseases they may historically have been better able to resist or tolerate.

"There's more and more evidence of the role of disease in the biodiversity crisis, in both amphibians and other types of animals," said Andrew Blaustein, a distinguished professor of zoology at Oregon State University and author of the recent analysis.

"It's normal for animals to deal with infectious organisms, often many of them simultaneously," he said. "But in the face of pollution, a reduced immune response, climate change, evolving pathogens and many other stresses in such a short period of time, many species now simply can't survive."

The current extinction rates of amphibians - which existed even before dinosaurs roamed the Earth - may be more than 200 times the background rate of extinction, the scientists note in this report. From an evolutionary perspective, amphibians that survived for hundreds of millions of years may be undergoing a major extinction event.

Because they have both terrestrial and aquatic life stages amphibians are exposed to various environmental forces more than some other animals, scientists say, and a higher percentage of them are threatened with extinction than are birds or mammals. However, similar concerns may become apparent in many animal species, including humans, as environmental changes and stresses grow, they said.

Among the observations in this report:

  • Infectious disease around the world is increasing at an unprecedented rate.

  • Natural stresses such as competition and predation have been joined by human-induced stresses, ranging from pollution to global warming.

  • These forces can reduce immune competence in amphibians, even as climate change, invasive species and other factors increase pathogen spread, persistence, growth and mortality.

  • Some amphibians deal with stress by hormonal changes such as increased production of glucocorticoids, but on a sustained basis, that approach can further suppress their immune system.

  • Warmer winters and night-time temperatures may reduce the cycle of pathogen die-offs that would naturally occur in colder regions.

These forces are complex, the researchers noted. The effects of climate change on amphibian disease, for instance, my cause some pathogens to increase in prevalence and severity, while others decline.

Understanding the driving forces behind these changes, the scientists said, will be important not only to address amphibian declines but also to deal with emerging infections in many other plants and animals, including humans. Such impacts can affect wildlife conservation, economic growth and human health.




The above story is based on materials provided by Oregon State University.

Translate this page: Chinese French German Italian Japanese Korean Portuguese Russian Spanish


comments powered by Disqus


Related »

Infection 
2/14/13 
Biodiversity Protects Against Disease, Scientists Find
The richer the assortment of amphibian species in a pond, the more protection that community of frogs, toads and …
Infection 
2/13/13 
CU-Boulder Amphibian Study Shows How Biodiversity Can Protect Against Disease
The richer the assortment of amphibian species living in a pond, the more protection that community of frogs, toads …
Biodiversity 
9/20/11 
Biodiversity Helps Dilute Infectious Disease, Reduce Its Severity
CORVALLIS, Ore. – Researchers at Oregon State University have shown for the first time that loss of biodiversity may …
Researchers 
4/26/11 

Catastrophic Amphibian Declines Have Multiple Causes, No Simple Solution
Ufz 
1/21/14 

Micropredators Dictate Occurrence of Deadly Amphibian Disease
Rohr 
10/23/13 
Early-life Exposure of Frogs to Herbicide Increases Mortality from Fungal Disease
The combination of the herbicide atrazine and a fungal disease is particularly deadly to frogs, shows new research from …
Predators 
2/23/15 
Small Predator Diversity Is an Important Part of a Healthy Ecosystem
Biodiversity, including small predators such as dragonflies and other aquatic bugs that attack and consume parasites, may improve the …
More » 
 
© Newsline Foundation  |  About  |  Privacy Policy  |  Feedback  |  Mobile