Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Large-Scale Forces Shape Local Ocean Life, Global Study Shows

21.10.2004


Ecological research, 30 feet down - Jon Witman, professor of biology, photographs an 18-by-24-inch sample of a Caribbean rock wall. He and his team produced and analyzed more than 1,500 such marine images from around the world.


Latitude matters - A photographic sample taken from a ledge off Cape Town, South Africa, is packed with sponges, anemones, soft corals, sea fans and bryzoans, whose name, taken from the Greek, means “moss animals.”


In an epic research project spanning 14 years and seven continents, a research team based at Brown University has photographed and cataloged nearly 3,000 species of sponges, corals and other shallow water ocean invertebrates from Antarctica to Australia. The key finding: Large-scale forces play a pivotal role in local species diversity. Results are published in the current online early edition of the Proceedings of the National Academy of Sciences.

In a groundbreaking, globetrotting study of sea life in shallow waters, a research team led by a Brown University marine ecologist has found that the richness of species diversity in a small patch of ocean is powerfully shaped by far-away forces.

Jon Witman, associate professor of biology at Brown, said this finding was a surprise. At the start of the project, Witman expected to find that forces specific to a small area of ocean – predation, species competition and disturbances such as hurricanes or landslides – would play a central role in limiting the number of species found there.



But Witman and his team found that species diversity in local areas, no bigger than a half-mile square, was directly proportional to species diversity in that region, which can span thousands of square miles. Researchers came to this conclusion after examining 1,500 photographic samples taken of invertebrates clinging to rock walls in every corner of the world.

For example, Witman and his team sampled five sites from Maine to Massachusetts and found anywhere from 26 to 51 species. This reflects the comparatively low marine diversity in the Gulf of Maine. In contrast, in the warm, teeming waters off of the Palau Islands near the Philippines, divers counted as many as 300 species living in an area smaller than a basketball court. This reflects the high level of diversity found in Micronesia. With a few exceptions, these patterns held true around the globe.

Witman believes that local interactions, such as storms and predators, still exert a strong influence on biodiversity, but the associate professor in the Department of Ecology and Evolutionary Biology now sees that regional forces are critical to maintaining species variation. These large-scale influences include currents that disperse larvae across hundreds of miles or the creation of new species caused by geological upheaval and biotic isolation millions of years ago. Global warming and pollution are other regional forces that can impact local diversity. “The work is a wake-up call,” Witman said. “We need to think about regional processes if we want to preserve biodiversity.”

Witman said results from the project, published in the current early online edition of the Proceedings of the National Academy of Sciences, have implications for conservation efforts.

Governments or non-profits interested in maintaining biodiversity in the ocean – or on land – shouldn’t simply create single preserves or parks. Instead, Witman said, they should create as many as possible across a broad area. Of particular importance, he said, is safeguarding “source areas” for high biodiversity that act as wellsprings of eggs, seeds or vital nutrients or that provide important habitat for critical species. While scientists know that tropical coral reefs and the Amazon rainforest act as source areas, Witman said more areas must be identified. “This is particularly true in the marine environment,” he said. “We don’t know much about source pools. We need a lot more research in this area.”

The project focused on invertebrate species found in shallow water, such as sponges, corals, mollusks, worms, barnacles, anemones, urchins and sea fans. These animals were studied in one habitat: flat, vertical rock walls, such as ones found along reefs, in fjords, or in other parts of coastline. Witman said the choice was practical: These invertebrates can’t move, so they could be counted. And rock walls can be found from the poles to coral reefs and leave few places for creatures to hide, so estimates would be comparable and highly accurate.

To get a true snapshot of the diversity of these species around the world, Witman and his team chose 12 distinct biogeographic regions and randomly sampled at a total of 49 sites within these regions, which included the Gulf of Maine, Iceland, the Northeast Pacific, the Galapagos Islands, Chilean Patagonia, the Antarctic Peninsula, the Eastern Caribbean, Southwest Africa, Southwest New Zealand, the Seychelles Islands, the Norfolk Islands and the Palau Islands.

At each site, scientists dove down 30 to 50 feet below the surface. Then they took standard-sized (18 by 24 inches) photographs of a rock wall area. They took anywhere from 18 to 200 of these photo samples at each site. Back in the lab, they examined a total of 1,500 slides and counted the species found in each frame.

The project took more than 14 years to complete. It led to another key finding: Latitude also plays a big role in local species richness.

At the poles, partly due to the harsh environment and glacial scouring, there are fewer species. But moving closer to the equator, the number of species increases. While this is a long-held and widely accepted phenomenon on land, it has been brought into question in the past decade as scientists have found a surprisingly varied array of ocean animals in Antarctica. This is the first global study to show that latitude affects species richness in shallow-water ocean animals.

The research team also included Ron Etter, a professor of biology at the University of Massachusetts–Boston and Franz Smith, a former research associate of Witman’s who is currently a marine scientist in New Zealand

The National Science Foundation primarily funded the work. The National Undersea Research Program, the Andrew Mellon Foundation, and the Helen and Merrill Bank Foundation also provided support.

Wendy Lawton | EurekAlert!
Further information:
http://www.brown.edu

More articles from Ecology, The Environment and Conservation:

nachricht How does the loss of species alter ecosystems?
18.05.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Excess diesel emissions bring global health & environmental impacts
16.05.2017 | International Institute for Applied Systems Analysis (IIASA)

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: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>