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 Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

nachricht A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

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: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

Im Focus: Artificial Enzymes for Hydrogen Conversion

Scientists from the MPI for Chemical Energy Conversion report in the first issue of the new journal JOULE.

Cell Press has just released the first issue of Joule, a new journal dedicated to sustainable energy research. In this issue James Birrell, Olaf Rüdiger,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

New quantum phenomena in graphene superlattices

19.09.2017 | Physics and Astronomy

A simple additive to improve film quality

19.09.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>