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 A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

nachricht Value from wastewater
16.08.2017 | Hochschule Landshut

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>