Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Medicated ecosystems: human drugs alter key aquatic organism

07.08.2002


The overuse of antibiotics not only leads to more resistant strains of infection, but, according to new research from the University of Wisconsin-Madison, antibiotics also may be adversely affecting zooplankton, tiny organisms that underpin the health of all freshwater ecosystems.



In the last decade, European and American researchers have found more evidence that lakes and streams are tainted by common drugs, ranging from caffeine to anticancer agents.

This pollution, says Colleen Flaherty, a UW-Madison zoologist, has direct ties to humans, either through the improper disposal of unwanted pharmaceuticals or through the ingestion of the drugs.


"Up to 80 percent of drugs taken by humans and domesticated animals can be excreted in their biologically active form," explains Flaherty. This means that the antibiotics, antidepressants and anti-inflammatory pills we either take or throw out can eventually end up polluting the environment and harming the organisms that live in it.

Says UW-Madison zoologist Stanley Dodson, who studies freshwater ecology, "Pharmaceuticals can be detected in many surface water streams and lakes, yet we know little about how these strongly biologically active chemicals affect the ecology of aquatic organisms."

Flaherty will present findings from her study -- one of the first to document the effects of commonly-prescribed drugs on Daphnia, a zooplankton integral to freshwater ecosystems -- Thursday, Aug. 7, at the annual meeting of the Ecological Society of America.

"Daphnia play a key ecological role in freshwater sources," says Flaherty. "They are an intermediate organism in these ecosystems -- they eat the algae and are eaten by the fish. If something happens to Daphnia, it could affect both the algae and the fish populations."

To determine the influence of pharmaceuticals on this key freshwater species, Flaherty tested Daphnia’s biological response to commonly prescribed drugs that have been found in European and U.S. waters; the drugs include a cholesterol-lowering one (clofibric acid), an antidepressant (fluoxetine) and five antibiotics.

Flaherty performed short- and long-term studies to find out what happens to a female Daphnia and her offspring when exposed to a particular drug. Flaherty measured the survival, growth, number and sex of each female’s offspring. While the short-term studies looked at a single brood, the long-term ones examined all the offspring the female produced during her life span (about 30 days).

The effects Flaherty found varied. In the short-term studies, the antibiotics and cholesterol drug at concentrations of just 10 parts per billion -- an environmentally relevant concentration, says Flaherty -- appear to stunt growth and result in more male offspring.

In the long-term studies, these differences were diminished: offspring exposed to the antibiotics tended to have longer lifespans; those exposed to the cholesterol-lowering drug showed no apparent effects. While the other drug, an antidepressant, produced no differences in the shorter trials, it did result in a greater number of offspring in the longer studies.

"When Daphnia were exposed to a single pharmaceutical throughout their entire lifespan, as in the long-term studies, they seemed to become acclimated to the polluted environment," Flaherty says.

But, as Flaherty points out, Daphnia swim in waters tainted with not just one drug, but many: "Some of these drugs may not have significant effects by themselves," she says, "but, when you combine them in a ’pharmaceutical cocktail,’ the effects can be lethal."

When Flaherty exposed the organisms to a combination of the cholesterol drug and the antidepressant during the short-term studies, she found that the offspring were more likely to be female, have more deformities that hinder swimming and up to a 90 percent mortality rate. Flaherty says, "I never expected that two drugs that had virtually no individual effects could be so lethal when combined."

Because of these findings, Flaherty says that, in order to fully understand the ecological effects of pharmaceuticals or other man-made chemicals on freshwater ecosystems, scientists should look at not just one chemical, but combinations of them.

Emily Carlson (608) 262-9772, emilycarlson@facstaff.wisc.edu


Colleen Flaherty | EurekAlert!
Further information:
http://www.wisc.edu/

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: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

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,...

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

Corporate coworking as a driver of innovation

22.11.2017 | Business and Finance

PPPL scientists deliver new high-resolution diagnostic to national laser facility

22.11.2017 | Physics and Astronomy

Quantum optics allows us to abandon expensive lasers in spectroscopy

22.11.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>