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 Waste in the water – New purification techniques for healthier aquatic ecosystems
24.07.2018 | Eberhard Karls Universität Tübingen

nachricht Plenty of habitat for bears in Europe
24.07.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

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: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>