Featured Research

from universities, journals, and other organizations

Why are some corals flourishing in a time of global warming?

September 10, 2013
University at Buffalo
As Earth’s temperature climbs, stony corals are in decline. Less discussed, however, is the plight of gorgonian corals — softer, flexible, tree-like species. Divers have noted that gorgonians seem to be proliferating in parts of the Caribbean, and a new study will look to quantify this phenomenon.

A gorgonian coral-dominated coral reef community at St. John, U.S. Virgin Islands. Stony corals are present but much of the three-dimensional structure of the reef community is created by the gorgonian corals.
Credit: Credit Howard Lasker

As Earth's temperature climbs, the stony corals that form the backbone of ocean reefs are in decline.

It's a well-documented story: Violent storms and coral bleaching have all contributed to dwindling populations, and increasing acidity of seawater threatens to take an additional toll.

Less discussed, however, is the plight of gorgonian corals -- softer, flexible, tree-like species that can rise up like an underwater forest, providing a canopy beneath which small fish and aquatic life of all kinds can thrive.

Divers have noted in recent years that gorgonian corals seem to be proliferating in certain areas of the Caribbean, even as their stony counterparts struggle. Now, a new study will look to quantify this phenomenon.

Scientists from the California State University, Northridge and University at Buffalo will examine 27 years of photographs from reefs off the Caribbean island of St. John to determine how gorgonian numbers have changed, and run field experiments to see how competition with stony corals -- or a lack of it -- influences gorgonian growth.

The study will also document what gorgonian coral populations look like now at St. John, which is part of the U.S. Virgin Islands, and track future development there.

Understanding coral reefs is important as they are one of the planet's most biologically diverse ecosystems.

"When you look at these gorgonian corals, it seems that they're increasing in abundance, and that's an anecdotal observation that many people have made," said UB geology professor Howard Lasker, one of three investigators heading the project. "Does this mean that as stony corals continue to decline, we're going to see reefs transforming into these gorgonian coral-dominated communities? That's what we're trying to find out."

"With climate change and ocean acidification, there certainly is a realistic possibility that coral reefs as we know them could pretty much disappear," said Cal State Northridge biology professor Peter Edmunds, another principal investigator. "The question is, what will coral reefs look like in the future?"

The nearly $1 million project, funded by the National Science Foundation (NSF), started officially on Sept. 1.

It brings together a powerful team. There's Lasker, a leading authority on the biology of Caribbean gorgonian corals, and Edmunds, who studies the region's stony corals and has amassed an archive of photographs dating back to 1987 that document changes on the reefs at St. John. The third partner is postdoctoral researcher Lorenzo Bramanti, currently working in France at the Universitι Pierre et Marie Curie (UPMC), who is an expert on underwater communities in the Mediterranean where gorgonian corals are dominant.

Corals, both gorgonians and stony corals, are aquatic animals that assemble themselves into colonies formed from tiny individuals called polyps.

Stony corals play an important role in reefs: When stony coral polyps die, they leave behind a rock-like skeleton, which forms a platform on which other life forms can grow, including new generations of corals.

Gorgonian corals serve a different purpose. They form tree-like colonies that give reefs 3-dimensional complexity, providing a habitat for fishes and invertebrates, Lasker said. For this reason, Bramanti and other Mediterranean researchers use a poetic descriptor to refer to gorgonian-dominated communities: "animal forests."

Though gorgonians often grow on the remains of stony corals, they can also grow on any solid surface. What the Buffalo and California team is trying to figure out is how and why the balance between gorgonian and stony corals is changing as Earth warms.

Preliminary data from Edmunds' 27-year photo set suggests that gorgonian coral density has indeed been increasing on the shallow reefs surrounding St. John. The researchers need to take a closer look at the archive, but pictures from five-year intervals show a notable rise in gorgonians starting around 1997, even as stony corals have declined.

The team's field studies will try to explain why gorgonians may flourish when stony corals are in decline. The experiments, taking place in St. John's waters, will look at how two or three species of gorgonians fare when growing alongside different combinations and densities of stony corals and algae.

Using the historical data and observations from the field, the scientists hope to model how the reef -- and others like it -- may look decades from now as Earth's climate continues to shift.

The study will fill in important gaps in knowledge, said Lasker, pointing out that gorgonian corals have historically drawn less attention than their stony counterparts, in part because individual species are extremely difficult to identify.

As their NSF project abstract states, "Reefs are more than the (stony) corals and fishes for which they are known best, and their biodiversity is affected strongly by other groups of organisms."

Story Source:

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

Cite This Page:

University at Buffalo. "Why are some corals flourishing in a time of global warming?." ScienceDaily. ScienceDaily, 10 September 2013. <www.sciencedaily.com/releases/2013/09/130910165051.htm>.
University at Buffalo. (2013, September 10). Why are some corals flourishing in a time of global warming?. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2013/09/130910165051.htm
University at Buffalo. "Why are some corals flourishing in a time of global warming?." ScienceDaily. www.sciencedaily.com/releases/2013/09/130910165051.htm (accessed September 17, 2014).

Share This

More Plants & Animals News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations

Featured Videos

from AP, Reuters, AFP, and other news services

Chimp Violence Study Renews Debate On Why They Kill

Chimp Violence Study Renews Debate On Why They Kill

Newsy (Sep. 17, 2014) — The study weighs in on a debate over whether chimps are naturally violent or become that way due to human interference in the environment. Video provided by Newsy
Powered by NewsLook.com
Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) — The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) — Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) — Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) 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.


Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News


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