Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tiny invasive snail impacts Great Lakes, alters ecology

12.08.2008
Long a problem in the western U.S., the New Zealand mud snail currently inhabits four of the five Great Lakes and is spreading into rivers and tributaries, according to a Penn State team of researchers. These tiny creatures out-compete native snails and insects, but are not good fish food replacements for the native species.

"These snails have an operculum, a door that closes the shell," says Edward P. Levri, associate professor of biology at Penn State's Altoona Campus. "They can be out of the water for longer than other snails and when fed to fish, they are not digested and sometimes come out alive. This has a potential to alter the salmon and trout fisheries because they alter the food chain."

The New Zealand mud snail grows to a maximum of a quarter of an inch and is more normally a sixteenth to an eighth of an inch in length. The hard shell is capable of sealing off the soft animal from outside influences. In New Zealand, the snails reproduce asexually, resulting in identical clones, or sexually. However, in invaded areas, asexual cloning is the only mode of reproduction.

This mud snail spread to England as early as 1850 and Europe in the late 1800s. It is found in Japan, but when the snail arrived there is unknown. The first mud snail found in the U.S. was in 1987 in the Snake River, Idaho, but the species did not appear in the east until 1991 in Lake Ontario. The western and eastern U.S. populations are separate episodes of introduction, because they represent different clones; in each case, only one snail needed to be introduced to begin the invasion. The snails in the Great Lakes region appear to be the same as one clone found in Europe.

"In the western U.S., this species is of special concern largely because of their ability to modify ecosystems," Levri told attendees today (Aug. 8) at the Ecological Society of America's annual meeting in Milwaukee.

The snails in western streams alter the nitrogen and carbon cycling. They are primarily grazers and detritus eaters with very wide food preferences. In some places in streams in Yellowstone National Park, they reach population densities of 323 individuals per square inch. Levri, working with undergraduates Warren J. Jacoby, Shane J. Lunen, Ashley A. Kelly and Thomas A. Ladson, found that densities in the Great Lakes are not anywhere near that in the West.

"In our most recent survey, we were lucky if we found a few hundred per square meter," says Levri. "In Lake Erie they are not very abundant, but it is unclear what they are doing 100 feet below the surface."

In New Zealand, the mud snails are not a problem because of native trematodes -- flukes -- that infect the snails and controls their population and reproduction. Some people have suggested that those who want to control the snail introduce this trematode to the U.S. to control the snails.

"There are two problems with introducing these trematodes," says Levri. "The first is that any introduction of a nonnative species can cause worse problems than they were expected to cure. The second is that these flukes have a multiple-host life cycle, infecting ducks that are apparently not affected before infecting the snails. This might work in the west where the snails are in shallow water, but no duck is going to dive 100 feet to get snails."

Levri and his team found that in Lake Ontario, the densities of the snails peak between 50 and 82 feet and they were rarely found in water less than 16 feet.

"What we can do is limit their expansion," says Levri. "That means that recreational water users must be very careful moving from one place to another. We advise anglers to freeze waders and fishing gear, or use Formula 409 or something like that to kill the snails."

He notes that signs are beginning to mark areas in New York where the snail is found to warn people to clean their gear.

The Penn State researcher warns that the snails are difficult to control, noting "I have frozen them for 12 hours at a time and about 50 percent of them survive."

Andrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu

Further reports about: carbon cycling ecosystem native snails native species trematodes

More articles from Ecology, The Environment and Conservation:

nachricht Scientists on the road to discovering impact of urban road dust
18.01.2018 | University of Alberta

nachricht Gran Chaco: Biodiversity at High Risk
17.01.2018 | Humboldt-Universität zu Berlin

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: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>