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

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

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: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Fraunhofer ISE Pushes World Record for Multicrystalline Silicon Solar Cells to 22.3 Percent

25.09.2017 | Power and Electrical Engineering

Usher syndrome: Gene therapy restores hearing and balance

25.09.2017 | Health and Medicine

An international team of physicists a coherent amplification effect in laser excited dielectrics

25.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>