Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Medicated ecosystems: human drugs alter key aquatic organism


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,

Colleen Flaherty | EurekAlert!
Further information:

More articles from Ecology, The Environment and Conservation:

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

nachricht Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus

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: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Oasis of life in the ice-covered central Arctic

24.10.2016 | Earth Sciences

‘Farming’ bacteria to boost growth in the oceans

24.10.2016 | Life Sciences

Light-driven atomic rotations excite magnetic waves

24.10.2016 | Physics and Astronomy

More VideoLinks >>>