Category Archives: coral

climate change, coral, coral reefs, reef health

CBC News: Algae on coral in UAE ‘gives hope’ against bleaching

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http://www.cbc.ca/news/technology/algae-on-coral-in-uae-gives-hope-against-bleaching-1.2974647

Technology & Science

Persian Gulf algae prevents coral bleaching in seawater that can reach 36 Celsius in summer

CBC News Posted: Feb 27, 2015 5:00 AM ET Last Updated: Feb 27, 2015 5:00 AM ET

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Algae living on coral in the Persian Gulf appear to protect the host coral from dying off. Seawater in the area gets so warm the same temperatures would kill off reefs elsewhere. (Jorg Wiedenmann, John Burt)

Scientists have discovered a new species of algae in the United Arab Emirates that helps corals survive in the warmest seawater temperatures on the planet.

Researchers from the University of Southampton and the New York University Abu Dhabi described the “heat-tolerant species” in a paper published this week in the journal Scientific Reports.

‘It gives hope to find that corals have more ways to adjust to stressful environmental conditions than we had previously thought.’- Jorg Wiedenmann, Coral Reef Laboratory at University of Southampton. Ocean waters in the Persian Gulf can reach temperatures of up to 36 degrees Celsius at the peak of summer — warm enough to kill off corals found anywhere else in the world.

How Gulf corals manage to thrive in such habitats likely has something to do with the nutrient-rich algae living in their tissue, the researchers believe.

It seems the algae living off Gulf corals in a symbiotic relationship give their coral hosts a heat-resistant edge not found in reefs elsewhere.

Climate change threat

“When analyzed by alternative molecular biological approaches, we found pronounced differences that set this heat-tolerant species clearly aside,” the researchers said in a statement.

In reference to its ability to survive unusually high temperatures, the researchers named the algae Symbiodinium thermophilum.

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Higher water temperatures often cause corals to lose their colour and die, a phenomenon known as coral bleaching. (Ove Hoegh-Guldberg/Centre for Marine Studies/The University of Queensland)

Algae are known to deliver nutrition to the coral they inhabit. However, algae are also sensitive to environmental changes, with even slight increases in seawater temperatures putting them at risk.

Loss of algae on corals in the symbiotic relationship often results in “coral bleaching,” in which the white skeletons of corals are left exposed once their algae tissue thins or dies.

“In Gulf corals, both the coral host and the associated algal partners need to withstand the high seawater temperatures,” Jörg Wiedenmann, head of the Coral Reef Laboratory at the University of Southampton Ocean, said in a statement.

John Burt, with NYU Abu Dhabi, said the team confirmed the new type of algae is prevalent year-round across several dominant species found near the coast of Abu Dhabi, the capital of the UAE.

Wiedenmann said more research must be done to better understand how the Gulf’s coral reefs can withstand extreme temperatures, in order to get a better grasp of how reefs elsewhere are dying as a result of climate change.

“It gives hope to find that corals have more ways to adjust to stressful environmental conditions than we had previously thought,” Wiedenmann said. “However, it is not only heat that troubles coral reefs. Pollution and nutrient enrichment, overfishing and coastal development also represent severe threats to their survival.”

coral, coral reefs, dredging, reef health

Coral Morphologic: Bad Year for Coral Bleaching & Sediment on Miami coral reefs

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Coral Morphologic

12:09 PM (3 hours ago)

to coral-list
A combination of hot weather and sunny days in summer 2014 has resulted in
very a bad year for coral bleaching in South Florida. Recently, we surveyed
the natural reef (‘first reef tract’) just offshore Fisher Island here in
Miami. Unfortunately, the water has been kept exceptionally silty from the
Army Corps’ ongoing dredging of nearby Government Cut. The water is 10-15
feet deep here, and nearly all of the coral heads on the reef were
bleached. However, the most alarming thing we observed, was the prevalence
of black band disease infecting many of the brain corals. As evidenced from
the video, the dredge silt has settled on the corals, and seems a likely a
culprit in causing this disease outbreak. Prior to this summer, we have
never observed BBD as prevalently on Miami’s corals. Currently, the dredge
ships are operating just outside the mouth of Government Cut jetties,
resulting in plumes of silt that smother corals on the natural reefs in
every direction.

See the video of the bleached and diseased corals here:

Miami Coral Bleaching Report (September 7, 2014)

Fortunately, the water temperatures have steadily decreased since the start
of September, so we are hopeful that the bleached corals throughout South
Florida will begin to recover soon. However, up here in Miami with the Deep
Dredge ongoing, our corals may be too stressed out, diseased, or smothered
to survive. We will be monitoring the situation closely, and will continue
to update as necessary.

Cheers,
Colin Foord
Co-Founder Coral Morphologic
www.coralmorphologic.com
________________________

climate change, coral, reef health

Huffington Post: 20 New Species Of Coral Listed As Threatened

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http://www.huffingtonpost.com/2014/08/27/coral-threatened_n_5724936.html?utm_hp_ref=email_share

The Center for Biologic Diversity deserves the credit for starting the process with NOAA to designate these corals. DeeVon

WASHINGTON (AP) — The federal government is protecting 20 types of colorful coral by putting them on the list of threatened species, partly because of climate change.

As with the polar bear, much of the threat to the coral species is because of future expected problems due to global warming, said David Bernhart, an endangered-species official at the National Oceanic and Atmospheric Administration. These coral species are already being hurt by climate change “but not to the point that they are endangered yet,” he said.

Climate change is making the oceans warmer, more acidic and helping with coral diseases like bleaching — and those “are the major threats” explaining why the species were put on the threatened list, Bernhart said in a Wednesday conference call.

Other threats include overfishing, runoff from the land, and some coastal construction, but those are lesser, Bernhart said.

Five species can be found off the Atlantic and Gulf of Mexico coasts of Florida, Puerto Rico and the Virgin Islands. They include pillar coral, rough cactus coral and three species of star coral. The other 15 are in the Pacific Ocean area near Guam and American Samoa, but not Hawaii.

The agency looked at listing 66 species, but Wednesday listed only 20 for various reasons. All are called threatened, not endangered. Two coral species were already listed.

Coral reefs, which are in trouble worldwide, are important fish habitats.

The agency did not create any new rules yet that would prevent coral from being harvested or damaged.

“There is a growing body of expert scientists talking about a risk of mass extinction in the sea and on land,” said Elliott Norse, founder and chief scientist of the Marine Conservation Institute of Seattle. Coral “are organisms on the front line of anything that humans do.”

“I hope this wakes people up and we don’t have to lose more coral,” Norse said.

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Online:

NOAA: http://www.fisheries.noaa.gov/stories/2014/08/corals_listing.html

coral

NSF: Press Release 14-025 Overfishing of Caribbean coral reefs favors coral-killing sponges

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http://www.nsf.gov/news/news_summ.jsp?cntn_id=130507

Caribbean-wide study shows protected coral reefs dominated by sponges with chemical defenses
Image of a sponge smothering a living coral head on a reef

SpongeOvergrowCoral_f

A sponge smothers a living coral head on a reef that lacks predatory angelfish.

February 24, 2014

Scientists had already demonstrated that overfishing removes angelfish and parrotfish that feed on sponges growing on coral reefs–sponges that sometimes smother the reefs. That research was conducted off Key Largo, Fla.

Now, new research by the same team of ecologists suggests that removing these predators by overfishing alters sponge communities across the Caribbean.

Results of the research, by Joseph Pawlik and Tse-Lynn Loh of the University of North Carolina Wilmington, are published this week in the journal Proceedings of the National Academy of Sciences (PNAS).

“In fact,” says Pawlik, “healthy coral reefs need predatory fish–they keep sponge growth down.”

The biologists studied 109 species of sponges at 69 Caribbean sites; the 10 most common species made up 51 percent of the sponge cover on the reefs.

“Sponges are now the main habitat-forming organisms on Caribbean coral reefs,” says Pawlik.

Reefs in the Cayman Islands and Bonaire–designated as off-limits to fishing–mostly have slow-growing sponges that manufacture chemicals that taste bad to predatory fish.

Fish numbers are higher near these reefs. Predatory fish there feast on fast-growing, “chemically undefended” sponges. What’s left? Only bad-tasting, but slow-growing, sponges.

Overfished reefs, such as those off Jamaica and Martinique, are dominated by fast-growing, better-tasting sponges. “The problem,” says Pawlik, “is that there are too few fish around to eat them.” So the sponges quickly take over the reefs.

“It’s been a challenge for marine ecologists to show how chemical defenses influence the structure of ocean communities,” says David Garrison, a program director in the National Science Foundation’s (NSF) Division of Ocean Sciences, which funded the research.

“With this clever study, Pawlik and Loh demonstrate that having–or not having–chemical defenses structures sponge communities on Caribbean coral reefs.”

The results support the need for marine protected areas to aid in coral reef recovery, believes Pawlik.

“Overfishing of Caribbean coral reefs, particularly by fish trapping, removes sponge predators,” write Loh and Pawlik in their paper. “It’s likely to result in greater competition for space between faster-growing palatable sponges and endangered reef-building corals.”

The researchers also identified “the bad-tasting molecule used by the most common chemically-defended sponge species,” says Pawlik. “It’s a compound named fistularin 3.”

Similar chemical compounds defend some plants from insects or grazers (deer, for example) in onshore ecosystems, “but the complexity of those ecosystems makes it difficult to detect the advantage of chemical defenses across large areas,” says Pawlik.

When it comes to sponges, the view of what’s happening is more direct, he says. “The possibility of being eaten by a fish may be the only thing a reef sponge has to worry about.”

And what happens to reef sponges may be critical to the future of the Caribbean’s corals.

-NSF-

Media Contacts
Cheryl Dybas, NSF, (703) 292-7734, cdybas@nsf.gov

Related Websites
NSF grant: Chemical ecology of sponges on Caribbean coral reefs: http://www.nsf.gov/awardsearch/showAward?AWD_ID=1029515&HistoricalAwards=false

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2014, its budget is $7.2 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives about 50,000 competitive requests for funding, and makes about 11,500 new funding awards. NSF also awards about $593 million in professional and service contracts yearly.

Useful NSF Web Sites:
NSF Home Page: http://www.nsf.gov
NSF News: http://www.nsf.gov/news/
For the News Media: http://www.nsf.gov/news/newsroom.jsp
Science and Engineering Statistics: http://www.nsf.gov/statistics/
Awards Searches: http://www.nsf.gov/awardsearch/

Special thanks to Richard Charter