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
TEXT SIZE - +
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

Multimedia Relatives of South Korean Ferry Victims Fire at Authorities

46 people are confirmed dead, but some 250 remain trapped inside sunken ferry More

War Legacy Haunts Vietnam, US Relations

$84 million project aims to clean up soil contaminated by Agent Orange More

Wikipedia Proves Useful for Tracking Flu

Technique gave better results than Center for Disease Control (CDC) and Google’s Flu Trends 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.
Ukraine, Russia, United in Faith, Divided in Politicsi
X
Michael Eckels
April 19, 2014
There is a strong historical religious connection between Russia and Ukraine. But what role is religion playing in the current conflict? In the run-up to Easter, Michael Eckels in Moscow reports for VOA.
Video

Video Ukraine, Russia, United in Faith, Divided in Politics

There is a strong historical religious connection between Russia and Ukraine. But what role is religion playing in the current conflict? In the run-up to Easter, Michael Eckels in Moscow reports for VOA.
Video

Video Face of American Farmer is Changing

The average American farmer is now 58 years old, and farmers 65 and older are the fastest growing segment of the population. It’s a troubling trend signaling big changes ahead for American agriculture as aging farmers retire. Reporter Mike Osborne says a new report from the U.S. Census Bureau is suggesting what some of those changes might look like... and why they might not be so troubling.
Video

Video Donetsk Governor: Ukraine Military Assault 'Delicate But Necessary'

Around a dozen state buildings in eastern Ukraine remain in the hands of pro-Russian protesters who are demanding a referendum on self-rule. The governor of the whole Donetsk region is among those forced out by the protesters. He spoke to VOA's Henry Ridgwell from his temporary new office in Donetsk city.
Video

Video Drones May Soon Send Data From High Seas

Drones are usually associated with unmanned flying vehicles, but autonomous watercraft are also becoming useful tools for jobs ranging from scientific exploration to law enforcement to searching for a missing airliner in the Indian Ocean. VOA’s George Putic reports on sea-faring drones.
Video

Video New Earth-Size Planet Found

Not too big, not too small. Not too hot, not too cold. A newly discovered planet looks just right for life as we know it, according to an international group of astronomers. VOA’s Steve Baragona has more.
Video

Video Copts in Diaspora Worry About Future in Egypt

Around 10 percent of Egypt’s population belong to the Coptic faith, making them the largest Christian minority in the Middle East. But they have become targets of violence since the revolution three years ago. With elections scheduled for May and the struggle between the Egyptian military and Islamists continuing, many Copts abroad are deeply worried about the future of their ancient church. VOA religion correspondent Jerome Socolovsky visited a Coptic church outside Washington DC.
Video

Video Critics Say Venezuelan Protests Test Limits of Military's Support

During the two months of deadly anti-government protests that have rocked the oil-rich nation of Venezuela, President Nicolas Maduro has accused the opposition of trying to initiate a coup. Though a small number of military officers have been arrested for allegedly plotting against the government, VOA’s Brian Padden reports the leadership of the armed forces continues to support the president, at least for now.
Video

Video More Millenials Unplug to Embrace Board Games

A big new trend in the U.S. toy industry has more consumers switching off their high-tech gadgets to play with classic toys, like board games. This is especially true among the so-called millenial generation - those born in the 1980's and 90's. Elizabeth Lee has more from an unusual café in Los Angeles, where the new trend is popular and business is booming.
Video

Video Google Buys Drone Company

In its latest purchase of high-tech companies, Google has acquired a manufacturer of solar-powered drones that can stay in the air almost indefinitely, relaying broadband Internet connection to remote areas. It is seen as yet another step in the U.S. based Web giant’s bid to bring Internet to the whole world. VOA’s George Putic reports.
AppleAndroid