Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Extinction in ocean’s mud presages key ecological changes

12.11.2004


The loss of seemingly inconsequential animal species in the marine benthos - the top 6 inches or so of mud and sediment on the floors of the world’s oceans - is giving scientists a new look ahead at the consequences of the steady decline of the world’s biological diversity.



In new work published today (Nov. 12) in the journal Science, an international team of scientists describe work in which the ocean mud and the many animals that live there are used to forecast how the extinction of species alters important ecological processes that sustain life at the bottom of the ocean.

The team’s work was funded by the National Science Foundation.


"This is one of the first stabs at trying to see what will happen in ocean ecosystems as species go extinct," says Bradley Cardinale, a University of Wisconsin-Madison postdoctoral fellow in zoology and a co-author of the paper. "What goes on in the sediment is important, not only because it affects life at the bottom of the ocean, but also because it has a big impact on the rest of the marine ecosystem."

In the mud and sediments that have accumulated during many thousands of years at the bottom of the world’s oceans lives an astonishing array of animals - such as crabs, clams, sea urchins, brittlestars and marine worms. These animals play an essential role in churning up and filling the sediments with oxygen, making it possible for other forms of marine life to flourish.

The new study rests on a comprehensive survey of 139 marine invertebrates that inhabit the sediment of Galway Bay, Ireland, led by Martin Solan of the University of Aberdeen, Scotland. By looking at how extensively the sediments are mixed there, and matching that with data on each species’ size, abundance and movement through the mud, it is possible to construct mathematical models to predict the ecological consequences of losing species, according to Cardinale.

Running the models, the group found that the extinction of species is generally expected to reduce the amount of sediment mixing, and consequently diminish the oxygen concentrations that sustain bottom-dwelling life. The amount of change, according to the study, depends on the reasons species are going extinct and the order in which animals disappear. "We know certain types of species are at greater risk of extinction than others," says Cardinale. "For example, large species often go extinct first, and that is important in the marine benthic environment because the bigger you are, the more sediment you are able to mix up."

And while the creatures that inhabit the mud at the bottom of the ocean may seem remote and unimportant, Cardinale pointed out that oceans cover 70 percent of the Earth’s surface, and that the productivity of the sea is intricately linked to sediments that generate nutrients and food for other organisms such as fish. In places where human activities have disrupted marine sediments, such as the enormous "dead zone" in the Gulf of Mexico - where excess fertilizers are dumped by the Mississippi River - nearly all life has vanished. "One thing our study suggests," Cardinale asserts, "is we need to know why species are going extinct in the first place. Even though extinction leads to less sediment mixing in our models, things can be far worse or not quite as bad, depending on the particular order in which species disappear."

To maintain the functional necessities of an ecosystem, the study also suggests, that both the total number of species and the particular types of species going extinct matter: "There are certain really high-impact species that, if they survive, sediment mixing can be maintained for some time," he says. "Even so, reducing the total number of species eventually leads to large changes. This suggests that conservation efforts should focus not just on the seemingly important species, but also on the total variety of life found in an ecosystem."

Despite that, the discovery that the order in which animals go extinct is important and essential to knowing what the long-term environmental effects will be. "The finding is important because it argues that the particular cause of extinction ultimately governs the ecosystem-level consequences of biodiversity loss," the researchers conclude.

In short, predicting how coastal environments will cope as animal species decline as a result of human activity will depend on a better grasp of why species are at risk and how that risk is amplified or minimized by an animal’s functional traits.

In addition to Cardinale and Solan, authors of the Science paper include Amy Downing of Ohio Wesleyan University, Katharina Engelhardt of the University of Maryland Center for Environmental Science, Jennifer Ruesink of the University of Washington and Diane Srivastava of the University of British Columbia.

Bradley Cardinale | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Ecology, The Environment and Conservation:

nachricht Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München

nachricht Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

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: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>