News / USA

Invasive Asian Carp Threaten Ecosystems in Midwestern Waterways

Asian Carp jumping in the Illinois River, where they are overtaking the native fish
Asian Carp jumping in the Illinois River, where they are overtaking the native fish

Asian Carp now outnumber native fish in many areas of the United States and their expansion particularly threatens the fragile ecosystems of the Great Lakes.

In an effort to control algae growth, catfish farmers in the southern United States introduced Asian Carp - a species of fish found in China - into their ponds in the 1970s.  Flooding throughout the last several decades washed the fish out of those ponds into other waterways.  Gradually, the species multiplied and spread north along major rivers such as the Mississippi and the Illinois.  

Anywhere else in the world, this would be a fisherman's dream, rivers so abundant with fish they jump out of the water, and often right into the boat.  But these are not the kind of fish that get anglers in the United States excited.  They are known as Asian Carp and the explosion of their population in the Illinois River is a concern to large-river ecologist Kevin Irons.

"They compete with every other fish that's in our water," said Irons.  Irons is part of a team with the Illinois Natural History Survey, which is spearheading an effort to kill or contain Asian Carp before they reach Lake Michigan.  The group routinely patrols the Illinois River near Havana - searching for Asian Carp, which are not hard to find.  To understand where and how much the invasive species is spreading, Irons and his crew use a method known as electro fishing to stun the Asian Carp so they can be captured and counted.

"There's as many as 4,100 adult silver carp per mile here on the middle Illinois River," said Irons.  "So they very quickly turn into about 13 tons per mile, and when you look at an eighty mile [129 kilometer] reach, it's phenomenal how much bio mass is taken up by these Asian Carp."

There are two types of Asian Carp in the Illinois River - bighead and silver.  Both eat the same food as other - native - fish, such as catfish and buffalo.  Asian Carp can weigh up to 45 kilograms each, and eat up to half their body weight in food per day.

Gradually, Asian Carp edge out the other native species in the river until they are one of the only kinds of fish left.  It is catastrophic to the natural ecosystem, and a problem for the fishing industry in the U.S., which looks at Asian Carp as an undesirable fish to eat.

"Americans in general don't like a bony fish," said Irons.  "The rest of the world eats silver carp, they're actually the most cultured fish in the world.  And they're overfished almost everywhere because they are so desired for human consumption."

With no natural predator in the water, and almost no domestic market to sell them as food, Asian Carp threaten to expand into waterways through the city of Chicago, and into Lake Michigan, about 320 kilometers northwest of Havana.

"This is where we decided to draw the battle lines," said John Rogner, the assistant director of the Illinois Department of Natural Resources.  "We have an electrical barrier in place that we are confident will keep them from moving en masse into the Great Lakes.  And then our job is to put out the brush fires so to speak.  The fish that, for one reason or another, that found their way past the barrier, we suppressed them and try to take them out of the system to keep them from establishing in Lake Michigan."

In June, a bighead Asian Carp was found above the electrical barrier about ten kilometers from Lake Michigan.  The discovery raised the level of concern that the invasive species was closer to Lake Michigan than previously thought.  But the Illinois Department of Natural Resources is confident their containment measures are working, as they have yet to find more Asian carp above the electric barrier.

You May Like

Guatemala Mudslide Death Toll Rises to 86

Death toll is expected to continue to rise as emergency crews dig through tons of earth for an estimated 350 people still missing More

Debris Found in Search for Missing Ship

Objects located Sunday have not yet been confirmed to be from the 240 meter container ship, El Faro, which disappeared in the eye of Hurricane Joaquin, according to US Coast Guard More

Survivor: Gunman Spared 'Lucky One' to Give Police Message

Law enforcement official says a manifesto of several pages was recovered; contents not revealed More

This forum has been closed.
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.
Russia’s Syria Involvement Raising Concerns in Europei
Luis Ramirez
October 02, 2015 4:45 PM
European nations are joining the United States in demanding that Russia stop targeting opposition groups other than the Islamic State militants as Russian warplanes continue to conduct raids in Syria. The demand came in a statement from Britain, France, Germany, Qatar, Saudi Arabia, Turkey and the United States Friday. VOA Europe correspondent Luis Ramirez reports.

Video Russia’s Syria Involvement Raising Concerns in Europe

European nations are joining the United States in demanding that Russia stop targeting opposition groups other than the Islamic State militants as Russian warplanes continue to conduct raids in Syria. The demand came in a statement from Britain, France, Germany, Qatar, Saudi Arabia, Turkey and the United States Friday. VOA Europe correspondent Luis Ramirez reports.

Video First Self-Driving Truck Debuts on European Highways

The first automated semi-trailer truck started its maiden voyage Friday, Oct. 2, on a European highway. The Daimler truck called 'Actros' is the first potentially mass-produced truck whose driver will be required only to monitor the situation, similar to the role of an airline captain while the plane is in autopilot mode. VOA’s George Putic reports.

Video Nano-tech Filter Cleans Dirty Water

Access to clean water is a problem for hundreds of millions of people around the world. Now, a scientist and chemical engineer in Tanzania (in East Africa) is working to change that by creating an innovative water filter that makes dirty water safe. VOA’s Deborah Block has the story.

Video Demand Rising for Organic Produce in Cambodia

In Cambodia, where rice has long been the main cash crop, farmers are being encouraged to turn to vegetables to satisfy the growing demand for locally produced organic farm products. Daniel de Carteret has more from Phnom Penh.

Video Migrant Influx Costs Europe, But Economy Could Benefit

The influx of hundreds of thousands of refugees and migrants is testing Europe’s ability to respond – especially in the poorer Balkan states. But some analysts argue that Europe will benefit by welcoming the huge numbers of young people – many of them well educated and willing to work. Henry Ridgwell reports from London.

Video Botanists Grow Furniture, with Pruning Shears

For something a bit out of the ordinary to furnish your home, why not consider wooden chairs, crafted by nature, with a little help from some British botanists with an eye for design. VOA’s Jessica Berman reports.

Video New Fabric Helps Fight Dust-Related Allergies

Many people around the world suffer from dust-related allergies, caused mainly by tiny mites that live in bed linen. Polish scientists report they have successfully tested a fabric that is impenetrable to the microscopic creatures. VOA’s George Putic has more.

Video Burkina Faso's Economy Deeply Affected by Political Turmoil

Political turmoil in Burkina Faso over the past year has taken a toll on the economy. The transitional government is reporting nearly $70 million in losses in the ten days that followed a short-lived coup by members of the presidential guard earlier this month. The crisis shut businesses and workers went on strike. With elections on the horizon, Emilie Iob reports on what a return to political stability can do for the country's economic recovery.

Video Fleeing Violence, Some Syrians Find Refuge in Irbil

As Syrians continue to flee their country’s unrest to seek new lives in safer places, VOA Persian Service reporter Shepol Abbassi visited Irbil, where a number Syrians have taken refuge. During the religious holidy of Eid al-Adha, the city largely shut down, as temperatures soared. Amy Katz narrates his report.

Video Nigeria’s Wecyclers Work for Reusable Future in Lagos

The streets and lagoons of Africa's largest city - Lagos, Nigeria - are often clogged with trash, almost none of which gets recycled. One company is trying to change that. Chris Stein reports for VOA from Lagos.

Video Sketch Artist Helps Catch Criminals, Gives a Face to Deceased

Police often face the problem of trying to find a crime suspect based on general descriptions that could fit hundreds of people in the vicinity of the crime. In these cases, an artist can use information from witnesses to sketch a likeness that police can show the public via newspapers and television. But, as VOA’s Greg Flakus reports from Houston, such sketches can also help bring back faces of the dead.

Video Thailand Set to Build China-like Internet Firewall

Thai authorities are planning to tighten control over the Internet, creating a single international access point so they can better monitor content. VOA Correspondent Steve Herman reports from Bangkok on what is being called Thailand’s own "Great Firewall."

Video Croatian Town’s War History Evokes Empathy for Migrants

As thousands of Afghanistan, Iraqi and Syrian migrants pass through Croatia, locals are reminded of their own experiences with war and refugees in the 1990s. VOA's Daniel Schearf reports from the town of Vukovar, where wartime scars still are visible today.

Video Long Drought Affecting California’s Sequoias

California is suffering under a historic four-year drought and scientists say even the state's famed sequoia trees are feeling the pain. The National Park Service has started detailed research to see how it can help the oldest living things on earth survive. VOA’s George Putic reports.

VOA Blogs