Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Return of the Slime

05.03.2012
The oozy, green, bottom-dwelling alga called Cladophora glomerata has squished around toes about as long as people have been wading in the Great Lakes.

It was never a serious nuisance, however, until the mid-twentieth century, when humans began discharging phosphorus into the Great Lakes in a big way. That led to an unprecedented number of huge, gooey mats of Cladophora (pronounced klah-DAH-for-uh) covering entire beaches with a thick layer of rotting muck.

Then came the Great Lakes Water Quality Agreement, and the mats of Cladophora all but disappeared, thanks to tough new regulations that limited phosphorus. Now Cladophora is back with a vengeance, thanks this time to billions of exotic zebra mussels that have created its perfect habitat.

First, the filter-feeders clarify the Great Lakes water, allowing in more sunlight--and allowing Cladophora to grow in areas that were once too dark. Second, they excrete a type of phosphorus that Cladophora love to ingest. And third, their hard shells covering the sandy lake bottom provide solid real estate where the algae can attach.

Is there hope? Maybe. With funding from the Environmental Protection Agency’s Great Lakes Restoration Initiative, Robert Shuchman, codirector of the Michigan Tech Research Institute, and his research team are helping resource managers get their arms around the Cladophora problem.

“The EPA asked us to find out where Cladophora is concentrated,” Shuchman said. With thousands of miles of Great Lakes shoreline, no one had a good estimate of the extent of the Cladophora beds.

Shuchman’s team uses remote-sensing data from satellites. They measure “radiance,” or reflective brightness, to distinguish Cladophora beds from areas where the lake bottom is clear. That’s relatively easy at a constant depth, but radiance drops as water gets deeper.

To account for the difference, Shuchman integrated the satellite data with information on the lake bottoms and developed an elegant algorithm that compensates for the depth of the water.

“By doing this, we can map Cladophora in a straightforward way,” he said. To verify their results, researchers boat along the shoreline and visually check for Cladophora, often using a remote-controlled mini-submarine camera. These surveys showed their remote-sensing analysis to be about 90 percent accurate.

Shuchman’s team will also track the historical ebb and flow of Cladophora by applying the algorithm to satellite images that go back decades.

Armed with this information, resource managers will be able to locate Cladophora beds and tell if their cleanup efforts are working. The EPA is already using their data to track the health of the Great Lakes. The researchers are also considering ways to track the algal mats, which typically slough off the lake bottom in midsummer, and possibly block them before they land on beaches or in the cooling water intakes of nuclear power plants.

The team members will map all US waters in the Great Lakes that are optically visible—those parts where light can be reflected off the bottom. Already they have determined that sunlight is reaching much more of the lake bottom than in years past, thanks to the mussels’ insatiable appetite for water-clouding plankton.

The team has already finished mapping Lake Michigan. They have found Cladophora on 591 square miles, or about a third of the optically visible area. Ironically, Cladophora is superabundant near Sleeping Bear Dunes National Lakeshore, where twenty-inch-thick algal mats lie just a few yards off shore.

In addition to creating a repulsive viewing experience, rotting Cladophora provides ripe conditions for avian botulism and has been implicated in the poisoning deaths of thousands of shorebirds.

The abundance of Cladophora could have even broader implications. “It’s a little bit scary,” Shuchman said, in part because the Michigan Department of Natural Resources reports that the exotic Asian carp can eat Cladophora. The voracious fish have infested the Mississippi River system, and many fear they will expand their range into the Great Lakes via the Chicago Shipping Canal.

The filter-feeding quagga mussels have essentially wiped out their potential food supply in the middle of Lake Michigan, “so the carp will never survive in deep water,” said Shuchman. “But there’s plenty of Cladophora near the shore for them to eat.”

Robert Shuchman | Newswise Science News
Further information:
http://www.mtu.edu

More articles from Ecology, The Environment and Conservation:

nachricht Global threat to primates concerns us all
19.01.2017 | Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung

nachricht Reducing household waste with less energy
18.01.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>