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 Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University

nachricht Climate change: Urban trees are growing faster worldwide
13.11.2017 | Technische Universität München

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: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Heavy nitrogen molecules reveal planetary-scale tug-of-war

20.11.2017 | Earth Sciences

Taking a spin on plasma space tornadoes with NASA observations

20.11.2017 | Physics and Astronomy

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>