Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Wildlife researchers identify impacts of contamination in amphibians

22.02.2006


Bill Hopkins, fisheries and wildlife associate professor in Virginia Tech’s College of Natural Resources, and colleagues doing research at the Savannah River Ecology Laboratory and in the field, have demonstrated that amphibians are exposed to contaminants through maternal transfer, as has been proven for other vertebrates.



The research has been published in the National Institutes of Health (NIH) journal, Environmental Health Perspectives ("Reproduction, Embryonic Development, and Maternal Transfer of Contaminants in the Amphibian Gastrophryne carolinensis," by William Alexander Hopkins, Sarah DuRant, a fisheries and wildlife graduate student at Virginia Tech; Brandon Staub, a research technician with the University of Georgia; Christopher Rowe, an environmental toxicologist with the Chesapeake Biological Laboratory, University of Maryland; and Brian Jackson, an analytical chemist at Dartmouth College.)

While working as an assistant professor and research scientist with the Savannah River Ecology Laboratory in Aiken, S.C., Hopkins and colleagues collected dozens of reproductively active female eastern narrow mouth toads located around a settling basin near a coal burning power plant outside of Aiken.


The burning of coal is responsible for the release of mercury, selenium, and other harmful contaminants into the environment. The research team tested the toads and their offspring for the presence of chemical contaminants, and their offspring were examined for developmental abnormalities such as structural malformations and abnormal swimming. "We also looked at clutch size (number of eggs), how many eggs successfully hatched, along with developmental characteristics such as pigmentation and spinal formation," says Hopkins.

Both the adult females and their offspring from the power plant’s settling basin were compared to adults and their offspring from a reference site, which was free from contamination. The research identified particularly high levels of selenium in the offspring from the contaminated site. "Selenium is a fascinating trace element," says Hopkins. "Although it is nutritionally required as a micronutrient, there’s a fine line between its essentiality and toxicity. We found that females from areas near the power plant accumulated astonishingly high concentrations of selenium in their tissues, and then transferred nearly equivalent concentrations of selenium to their young."

The research team uncovered one of the primary means of exposure to environmental contaminants in amphibians. Female amphibians can transfer high levels of certain contaminants to their offspring, resulting in decreased offspring viability.

There have been numerous studies on the detrimental effects of selenium on fish and birds, as well as Hopkins’ study on alligators and lizards. Exposure to selenium is not always obviously harmful to fully-grown vertebrates, but is particularly disruptive to their reproduction function due to its propensity to transfer from mother to egg and its subsequent effects on the developing embryo.

Hopkins’ research is one of the first studies to demonstrate how amphibians are exposed to contaminants through maternal transfer, which is a proven means of exposure for other vertebrates such as fish, birds, humans, and other mammals. "Our study confirms that in amphibians, like all other vertebrate classes, this may be one of the most important means of exposure to some contaminants, such as selenium and polychlorinated biphenyls (PCBs)," says Hopkins. "The presence of reproductive abnormalities in animals that transfer contaminants to their eggs illustrates how maternal transfer is very ecologically relevant."

Hopkins and his research team were successful in showing the effects of chemical contaminants through actual conditions in the field instead of using a lab environment to simulate potential contaminant exposure. "Generally, many amphibian studies on contaminant exposure take place exclusively in the lab or other experimental setting, where the subject is exposed to a controlled dose of contaminants. However, we were able to look at how these toads are more realistically impacted by contaminants in a natural habitat polluted by human activities," Hopkins notes.

Lynn Davis | EurekAlert!
Further information:
http://www.vt.edu
http://ehp.niehs.nih.gov

More articles from Ecology, The Environment and Conservation:

nachricht Bioinvasion on the rise
15.02.2017 | Universität Konstanz

nachricht Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>