Featured Research

from universities, journals, and other organizations

Coral-eating sea star invaders turn out to be locals

Date:
February 21, 2012
Source:
University of Hawaii ‑ SOEST
Summary:
Researchers have disproven the secondary outbreak hypothesis in the Central Pacific. One of the greatest biological threats to tropical coral reefs can be a population outbreak of crown-of-thorns (COT) sea stars (Acanthaster planci). Outbreaks can consume live corals over large areas, a change that can promote algal growth and alter reef fish populations.

Juvenile Crown-of-Thorns sea star hiding among corals. A single animal is not much of a threat. But one of the greatest biological threats to tropical coral reefs can be a population outbreak of crown-of-thorns (COT) sea stars (Acanthaster planci). Outbreaks can consume live corals over large areas, a change that can promote algal growth and alter reef fish populations.
Credit: S.Holzwarth

Researchers at the Hawai'i Institute of Marine Biology (HIMB), the Joint Institute for Marine and Atmospheric Research (JIMAR), organized research units in the University of Hawai'i at Mānoa's School of Ocean and Earth Science and Technology, and Rutgers University have disproven the secondary outbreak hypothesis in the Central Pacific.

Related Articles


One of the greatest biological threats to tropical coral reefs can be a population outbreak of crown-of-thorns (COT) sea stars (Acanthaster planci). Outbreaks can consume live corals over large areas, a change that can promote algal growth, alter reef fish populations, and reduce the aesthetic value of coral reefs, which in turn negatively affects tourism. Despite more than 30 years of research, the triggers and spread of COT outbreaks are not fully understood. Human impacts such as urbanization, runoff, and fishing have been correlated with outbreaks, but some outbreaks continue to occur in the absence of known anthropogenic triggers. Waves of a spreading outbreak that moves southerly along the Great Barrier Reef are termed secondary outbreaks because they are thought to be seeded from dispersing larvae of a primary outbreak upstream.

This secondary outbreak hypothesis has been widely accepted as the mechanism by which COT outbreaks spread across broad regions of the Pacific Ocean and impact remote locations such as Hawai'i, Guam, or French Polynesia -- until now. A team of scientists from the Hawai'i Institute of Marine Biology and the Joint Institute for Marine and Atmospheric Research at the University of Hawai'i and Rutgers University have recently used genetic techniques to evaluate the spatial scale at which COT outbreaks can occur via larval dispersal across the central Pacific Ocean.

The results of this work have demonstrated that unlike on the Great Barrier Reef, COT larvae are not moving en masse among central Pacific archipelagos. In fact, contrary to expectations under the secondary outbreak hypothesis, all COT outbreaks in the study came from local populations. On a finer scale, genetic differences were detected among reefs around islands and even between lagoon and forereef habitats of the same island, indicating that the larvae of this species are not routinely reaching their full dispersal potential, and are certainly not fueling outbreaks at distant sites. This research has proved that outbreaks are not some rogue population that expands and ravages across central Pacific reefs. Instead, the authors hypothesize that nutrient inputs and favorable climatic and ecological conditions likely fuel outbreaks of local populations.

This work is particularly important because most current management strategies are focused on stopping secondary spread rather than preventing human activities that can start an outbreak. This study is the first genetic survey of COT populations in which both outbreak and non-outbreak populations are surveyed across a broad region of the Pacific and the results are pretty clear that outbreaks are not jumping across large expanses of open ocean. Dr. Rob Toonen, one of the researchers involved in this project, explains "the genetic differences found among COT populations clearly indicate that outbreaks are not spreading from the Hawaiian Archipelago to elsewhere. Furthermore, the similarity between outbreak and non-outbreak COT populations within each archipelago indicates that outbreaks are a local phenomenon. Our recommendation to managers is to seriously consider the role that environmental conditions and local nutrient inputs play in driving COT outbreaks."


Story Source:

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


Journal Reference:

  1. Molly A. Timmers, Christopher E. Bird, Derek J. Skillings, Peter E. Smouse, Robert J. Toonen. There's No Place Like Home: Crown-of-Thorns Outbreaks in the Central Pacific Are Regionally Derived and Independent Events. PLoS ONE, 2012; 7 (2): e31159 DOI: 10.1371/journal.pone.0031159

Cite This Page:

University of Hawaii ‑ SOEST. "Coral-eating sea star invaders turn out to be locals." ScienceDaily. ScienceDaily, 21 February 2012. <www.sciencedaily.com/releases/2012/02/120221165918.htm>.
University of Hawaii ‑ SOEST. (2012, February 21). Coral-eating sea star invaders turn out to be locals. ScienceDaily. Retrieved January 27, 2015 from www.sciencedaily.com/releases/2012/02/120221165918.htm
University of Hawaii ‑ SOEST. "Coral-eating sea star invaders turn out to be locals." ScienceDaily. www.sciencedaily.com/releases/2012/02/120221165918.htm (accessed January 27, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Tuesday, January 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Aquaponics Turn Suburban Industrial Park Into Farmland: Hume

Aquaponics Turn Suburban Industrial Park Into Farmland: Hume

The Toronto Star (Jan. 27, 2015) — Ancient techniques of growing greens with fish and water are well ahead of Toronto bylaws. Video provided by The Toronto Star
Powered by NewsLook.com
Madagascar Locust Plague Could Mean Famine For Millions

Madagascar Locust Plague Could Mean Famine For Millions

Newsy (Jan. 27, 2015) — The Food and Agriculture Organization says millions could face famine in Madagascar without more funding to finish locust eradication efforts. Video provided by Newsy
Powered by NewsLook.com
Storm Slams New England, Spares Mid-Atlantic

Storm Slams New England, Spares Mid-Atlantic

AP (Jan. 27, 2015) — A howling blizzard with wind gusts over 70 mph heaped snow on Boston along with other stretches of lower New England and Long Island on Tuesday, but failed to live up to the hype in Philadelphia and New York City. (Jan. 27) Video provided by AP
Powered by NewsLook.com
Mexico's Volcano of Fire Erupts Again

Mexico's Volcano of Fire Erupts Again

Reuters - News Video Online (Jan. 26, 2015) — A huge plume of smoke shoots into the air as activity in Mexico&apos;s Volcano of Fire picks up again. Rough Cut (no reporter narration). Video provided by Reuters
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