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 Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

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: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

Im Focus: The Future of Ultrafast Solid-State Physics

In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.

Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Diamond-like carbon is formed differently to what was believed -- machine learning enables development of new model

19.04.2018 | Materials Sciences

Electromagnetic wizardry: Wireless power transfer enhanced by backward signal

19.04.2018 | Physics and Astronomy

Ultrafast electron oscillation and dephasing monitored by attosecond light source

19.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>