Featured Research

from universities, journals, and other organizations

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

Date:
October 21, 2004
Source:
Brown University
Summary:
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.

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.
Credit: Photo courtesy of Brown University

PROVIDENCE, R.I. — 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.


Story Source:

The above story is based on materials provided by Brown University. Note: Materials may be edited for content and length.


Cite This Page:

Brown University. "Large-Scale Forces Shape Local Ocean Life, Global Study Shows." ScienceDaily. ScienceDaily, 21 October 2004. <www.sciencedaily.com/releases/2004/10/041021083924.htm>.
Brown University. (2004, October 21). Large-Scale Forces Shape Local Ocean Life, Global Study Shows. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2004/10/041021083924.htm
Brown University. "Large-Scale Forces Shape Local Ocean Life, Global Study Shows." ScienceDaily. www.sciencedaily.com/releases/2004/10/041021083924.htm (accessed April 23, 2014).

Share This



More Plants & Animals News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Leopard Bites Man in India

Raw: Leopard Bites Man in India

AP (Apr. 22, 2014) A leopard caused panic in the city of Chandrapur on Monday when it sprung from the roof of a house and charged at rescue workers. (April 22) Video provided by AP
Powered by NewsLook.com
Iowa College Finds Beauty in Bulldogs

Iowa College Finds Beauty in Bulldogs

AP (Apr. 22, 2014) Drake University hosts 35th annual Beautiful Bulldog Contest. (April 21) Video provided by AP
Powered by NewsLook.com
805-Pound Shark Caught Off The Coast Of Florida

805-Pound Shark Caught Off The Coast Of Florida

Newsy (Apr. 22, 2014) One Florida fisherman caught a 805-pound shark off the coast of Florida earlier this month. Video provided by Newsy
Powered by NewsLook.com
Breakfast Foods Are Getting Pricier

Breakfast Foods Are Getting Pricier

AP (Apr. 21, 2014) Breakfast is now being served with a side of sticker shock. The cost of morning staples like bacon, coffee and orange juice is on the rise because of global supply problems. (April 21) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins