Featured Research

from universities, journals, and other organizations

Intricate, often invisible land-sea ecological chains of life threatened with extinction around the world

Date:
May 18, 2012
Source:
Stanford University
Summary:
Intricate, often invisible chains of life are threatened with extinction around the world. A new study quantifies one of the longest such chains ever documented.

The researchers found a link between replacing native trees with non-native palms and the health of the manta ray population off Palmyra Atoll in the Pacific.
Credit: Gareth Williams

Douglas McCauley and Paul DeSalles did not set out to discover one of the longest ecological interaction chains ever documented. But that's exactly what they and a team of researchers -- all current or former Stanford students and faculty -- did in a new study published in Scientific Reports.

Related Articles


Their findings shed light on how human disturbance of the natural world may lead to widespread, yet largely invisible, disruptions of ecological interaction chains. This, in turn, highlights the need to build non-traditional alliances -- among marine biologists and foresters, for example -- to address whole ecosystems across political boundaries.

This past fall, McCauley, a graduate student, and DeSalles, an undergraduate, were in remote Palmyra Atoll in the Pacific tracking manta rays' movements for a predator-prey interaction study. Swimming with the rays and charting their movements with acoustic tags, McCauley and DeSalles noticed the graceful creatures kept returning to certain islands' coastlines. Meanwhile, graduate student Hillary Young was studying palm tree proliferation's effects on bird communities and native habitats.

Palmyra is a unique spot on Earth where scientists can compare largely intact ecosystems within shouting distance of recently disturbed habitats. A riot of life -- huge grey reef sharks, rays, snapper and barracuda -- plies the clear waters while seabirds flock from thousands of miles away to roost in the verdant forests of this tropical idyll.

Over meals and sunset chats at the small research station, McCauley, DeSalles, Young and other scientists discussed their work and traded theories about their observations. "As the frequencies of these different conversations mixed together, the picture of what was actually happening out there took form in front of us," McCauley said.

Through analysis of nitrogen isotopes, animal tracking and field surveys, the researchers showed that replacing native trees with non-native palms led to about five times fewer roosting seabirds (they seemed to dislike palms' simple and easily wind-swayed canopies), which led to fewer bird droppings to fertilize the soil below, fewer nutrients washing into surrounding waters, smaller and fewer plankton in the water and fewer hungry manta rays cruising the coastline.

"This is an incredible cascade," said researcher Rodolfo Dirzo, a professor of environmental science and senior fellow with the Stanford Woods Institute for the Environment. "As an ecologist, I am worried about the extinction of ecological processes. This dramatically illustrates the significance of such extinctions."

Equally important is what the study suggests about these cascades going largely unseen. "Such connections do not leave any trace behind," said researcher Fiorenza Micheli, an associate professor of biology affiliated with the Stanford Woods Institute. "Their loss largely goes unnoticed, limiting our understanding of and ability to protect natural ecosystems." McCauley put it another way: "What we are doing in some ecosystems is akin to popping the hood on a car and disconnecting a few wires and rerouting a few hoses. All the parts are still there -- the engine looks largely the same -- but it's anyone's guess as to how or if the car will run."

By way of comparison, researcher Robert Dunbar, a professor of earth sciences and Stanford Woods Institute senior fellow, recalled the historical chain effects of increasing demands on water from Central California's rivers. When salmon runs in these rivers slowed from millions of fish each year to a trickle, natural and agricultural land systems lost an important source of marine-derived fertilizer. These lost subsidies from the sea are now replaced by millions of dollars' worth of artificial fertilizer applications. "Humans can really snip one of these chains in half," Dunbar said.


Story Source:

The above story is based on materials provided by Stanford University. The original article was written by Rob Jordan. Note: Materials may be edited for content and length.


Journal Reference:

  1. Douglas J. McCauley, Paul A. DeSalles, Hillary S. Young, Robert B. Dunbar, Rodolfo Dirzo, Matthew M. Mills, Fiorenza Micheli. From wing to wing: the persistence of long ecological interaction chains in less-disturbed ecosystems. Scientific Reports, 2012; 2 DOI: 10.1038/srep00409

Cite This Page:

Stanford University. "Intricate, often invisible land-sea ecological chains of life threatened with extinction around the world." ScienceDaily. ScienceDaily, 18 May 2012. <www.sciencedaily.com/releases/2012/05/120518132706.htm>.
Stanford University. (2012, May 18). Intricate, often invisible land-sea ecological chains of life threatened with extinction around the world. ScienceDaily. Retrieved December 18, 2014 from www.sciencedaily.com/releases/2012/05/120518132706.htm
Stanford University. "Intricate, often invisible land-sea ecological chains of life threatened with extinction around the world." ScienceDaily. www.sciencedaily.com/releases/2012/05/120518132706.htm (accessed December 18, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Thursday, December 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ivory Trade Boom Swamps Law Efforts

Ivory Trade Boom Swamps Law Efforts

Reuters - Business Video Online (Dec. 17, 2014) Demand for ivory has claimed the lives of tens of thousands of African elephants and now a conservation report says the illegal trade is overwhelming efforts to enforce the law. Amy Pollock reports. Video provided by Reuters
Powered by NewsLook.com
Indictments in West Virginia Chemical Spill Case

Indictments in West Virginia Chemical Spill Case

AP (Dec. 17, 2014) A grand jury indicted four former executives of Freedom Industries, the company at the center of the Jan. 9, 2014 chemical spill in Charleston, West Virginia. The spill contaminated the Elk River and the water supply of 300,000 people. (Dec. 17) Video provided by AP
Powered by NewsLook.com
Uphill Battle to Tackle Indonesian Shark Fishing

Uphill Battle to Tackle Indonesian Shark Fishing

AFP (Dec. 17, 2014) Sharks are hauled ashore every day at a busy market on the central Indonesian island of Lombok, the hub of a booming trade that provides a livelihood for local fishermen but is increasingly alarming environmentalists. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
France's Sauternes Wine Threatened by New Train Line

France's Sauternes Wine Threatened by New Train Line

AFP (Dec. 16, 2014) Winemakers in southwestern France's Bordeaux are concerned about a proposed high speed train line that could affect the microclimate required for the region's sweet wine. Duration: 01:06 Video provided by AFP
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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