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 Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.

nachricht 100 % Organic Farming in Bhutan – a Realistic Target?
15.06.2018 | Humboldt-Universität zu Berlin

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: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Creating a new composite fuel for new-generation fast reactors

20.06.2018 | Materials Sciences

Game-changing finding pushes 3D-printing to the molecular limit

20.06.2018 | Materials Sciences

Could this material enable autonomous vehicles to come to market sooner?

20.06.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>