News / Science & Technology

Species Loss Compromises Earth’s Vital Systems

Water quality improves in a more diverse ecosystem

Bradley Cardinale built 50 mock streams in his laboratory for the three-year experiment.
Bradley Cardinale built 50 mock streams in his laboratory for the three-year experiment.

Multimedia

Audio
Rosanne Skirble

Scientists have long thought that diverse ecosystems like forests, lakes and streams are especially good at removing pollutants that human activities put into the environment.

A new study in the journal Nature, confirms that theory.  

University of Michigan ecologist Bradley Cardinale demonstrates how water quality improves in a more diverse ecosystem.

In his laboratory Cardinale built 150 meter-long cases that enclosed mock streams. He cultured between one and eight common algae species in each waterway. The tiny micro-organisms are important actors in removing pollution from the water. He then exposed the streams to nitrate, a common pollutant from agricultural run-off and auto emissions.

University of Michigan graduate students monitor a water quality experiment.
University of Michigan graduate students monitor a water quality experiment.

It took Cardinale three years to set up the experiment, run it and process the data. On average streams with eight species were cleaned four-and-one-half times faster than water with just one species. Cardinale says specific algae species adapt to specific stream habitat.

"As you added more and more species to the stream what happened is that all of these different habitats got filled up and the stream as a whole became a much better bio-filter for this particular nutrient pollutant."

Cardinale says scientists as far back as Charles Darwin in the 1860s proposed that every species plays a specific role in the ecosystem and compliments each other.

"Basically a diverse world always comes down to having unique niches that allow species somehow to exist with each other. So any system where niche partitioning is a key biological phenomenon, the results of the study I’ve shown here and it’s implication for water quality should probably apply."

This sample mock stream contains algae growth after six months and represents between 12 to 15 generations and millions of algae cells.
This sample mock stream contains algae growth after six months and represents between 12 to 15 generations and millions of algae cells.

While Cardinale’s study showed that water quality improved in the streams with greater biodiversity, the ecologist notes it did not address how many species would be needed to completely remove the pollutant from soil and water.

"We previously expected that somewhere between three and five species was enough to clean nitrate out of soil and water. And my study extends those results to at least to eight species where we didn’t even begin to see a plateau."

Cardinale says he expects the number is more than eight, but far less than the several hundred found in a stream. The University of Michigan ecologist hopes future studies will determine that tipping point.

You May Like

US Imposes Sanctions on Alleged Honduran Drug Gang

Treasury department alleges Los Valles group is responsible for smuggling tens of thousands of kilograms of cocaine into US each month More

At 91, Marvel Creator Stan Lee Continues to Expand his Universe

Company's chief emeritus hopes to interest new generation of children in superheroes of all shapes and sizes by publishing content across multiple media platforms More

Photogallery New Drug Protects Against Virus in Ebola Family

Study by researchers at University of Texas Medical Branch, Tekmira Pharmaceuticals is first looking at drug's effectiveness after onset of symptoms More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Five Patients Given Experimental Ebola Drug Said to Be Improvingi
X
Carol Pearson
August 19, 2014 11:43 PM
The World Health Organization has approved the use of experimental treatments for Ebola patients in West Africa. The Ebola outbreak there is unprecedented, the disease deadly. The number of people who have died from Ebola has surpassed 1,200. VOA's Carol Pearson reports on the ethical considerations of allowing experimental drugs to be used.
Video

Video Five Patients Given Experimental Ebola Drug Said to Be Improving

The World Health Organization has approved the use of experimental treatments for Ebola patients in West Africa. The Ebola outbreak there is unprecedented, the disease deadly. The number of people who have died from Ebola has surpassed 1,200. VOA's Carol Pearson reports on the ethical considerations of allowing experimental drugs to be used.
Video

Video In Ukraine, Fear and Distrust Remain Where Fighting has Stopped

As the Ukrainian military reclaims control of eastern cities from pro-Russian separatists, residents are getting a chance to rebuild their lives. VOA's Gabe Joselow reports from the town of Kramatorsk in Donetsk province, where a sense of fear is still in the air, and distrust of the government in Kyiv still runs deep.
Video

Video China Targets Overseas Assets of Corrupt Officials

As China presses forward with its anti-graft effort, authorities are targeting corrupt officials who have sent family members and assets overseas. The efforts have stirred up a debate at home on exactly how many officials take that route and how likely it is they will be caught. Rebecca Valli has this report.
Video

Video Leading The Fight Against Islamic State, Kurds Question Iraqi Future

Western countries including the United States have begun arming the Kurdish Peshmerga forces in northern Iraq to aid their battle against extremist Sunni militants from the Islamic State. But there are concerns that a heavily-armed Kurdistan Regional Government, or KRG, might seek to declare independence and cause the break-up of the Iraqi state. As Henry Ridgwell reports from London, the KRG says it will only seek greater autonomy from Baghdad.
Video

Video In Rural Kenya, Pressure Builds Against Female Circumcision

In some Kenyan communities, female genital mutilation remains a rite of passage. But activists are pushing back, with education for girls and with threats of punishment those who perform the circumcision. Mohammed Yusuf looks at the practice in the rural eastern community of Tharaka-Nithi.
Video

Video For Obama, Racial Violence is Personal Issue

The racial violence in the St. Louis suburb of Ferguson is presenting U.S. President Barack Obama with an issue to which he has a deep personal connection. To many Americans, Obama's election as America's first black president marked a turning point in race relations in the United States, and Obama has made ending the violence a policy priority. On Monday he issued a new call for calm and understanding. Luis Ramirez reports from the White House.
Video

Video Clinton-Obama Relationship Could Impact 2016 Election

President Barack Obama and former Secretary of State Hillary Clinton have a long and complicated relationship. That relationship took another turn recently when Clinton criticized the president’s foreign policy. VOA National Correspondent Jim Malone reports there is renewed attention on the Clinton-Obama relationship as Hillary Clinton considers running for
Video

Video Iran Looks to Maintain Influence in Baghdad With New Shia PM

Washington and Tehran share the goal of stopping Syrian-based militants in Iraq. But experts say it's Iran, not the United States, that will most influence how the new government in Baghdad approaches internal reforms and the war in Syria. VOA State Department Correspondent Scott Stearns has the story.

AppleAndroid