ScienceDaily (Oct. 13, 2010) — The Smithsonian Tropical Research Institute’s Bocas del Toro Research Station and Galeta Point Marine Laboratory are reporting an anomalous sea temperature rise and a major coral bleaching event in the western Caribbean.

Although the U.S. National Oceanic and Atmospheric Administration (NOAA) issued an advisory in July announcing above-average sea surface temperatures in the wider Caribbean region, there had been no clear indication of increased sea temperatures in Panama and the western Caribbean until late August-early September.

Scientists and local dive operators first noticed coral bleaching in the waters surrounding Isla Colon in Panama’s Bocas del Toro province in July. Smithsonian staff scientist Nancy Knowlton and colleagues documented an extensive bleaching event in late September. Station personnel recorded an extreme sea water temperature of 32 degrees C. Normal temperatures at this time of year are closer to 28 degrees C. This warming event currently affects the entire Caribbean coast of Panama from Kuna-Yala to Bocas del Toro and has also been reported at sites in Costa Rica.

An extensive coral reef monitoring network in Panama, established over a decade ago by staff scientist Héctor M. Guzmán of STRI and partially funded by the Nature Conservancy, consists of 33 sites along both the Pacific and Atlantic coasts of the Isthmus, with 11 sites in the Bocas del Toro area. As of Oct. 3, 95 percent of the seafloor at the Bocas del Toro sites had been checked for bleaching. Coral mortality was limited to shallow areas near Isla Colon and a semi-lagoon area in Bocas del Toro, which is considered to be particularly vulnerable to bleaching as water circulation there is slow and temperatures tend to rise quickly. Researchers expect to have a complete report of the state of the coral reefs in several weeks.

Coral polyps, the tiny organisms that make up a coral reef, contain photosynthetic algae called zoxanthellae. Coral bleaching occurs when corals lose their color as a result of the loss of their algal component, which is caused by increased water temperature or other stress factors. Bleaching impairs vital functions of the coral such as reproduction and growth.

With prolonged warming, corals begin to die releasing great quantities of mucous resulting in increasingly turbid waters. Oxygen levels may fall as bacteria and fungi proliferate. Anoxic conditions affect fish and coastal productivity. STRI has monitored the water column to a depth of 20 meters at 23 sites. “Dissolved oxygen dropped to less than 3 milligrams per liter at 10 meters and nearly zero milligrams per liter at the bottom,” said STRI technician Plinio Gondola, who recorded the measurements. It is still not clear if temperature rise is directly related to bleaching and anoxia at this site.

The final outcome of this event is uncertain. A similar event in 2005 in the wider Caribbean included intense bleaching in Panama. However, mortality was less that 12 percent in this zone and reefs have been relatively resilient. In Guzman’s opinion, hurricane season may be enhancing the current problem, resulting in low water circulation in the Southwestern Caribbean and thus creating a “warm pocket” of water along the coasts of Panama and Costa Rica.

SARASOTA, Florida — On Wednesday, Oct. 13, scientists with Mote Marine Laboratory released corals of four species at two sites in the Florida Keys National Marine Sanctuary. The release, permitted by Sanctuary officials and Florida Fish and Wildlife Conservation Commission, is designed to test the feasibility of using corals grown in land-based raceways and recirculating tank systems to restock damaged or depleted reef sites.
One of the release sites chosen was a site Mote is using as a coral nursery for the threatened stagorn coral. The second site was chosen because it was especially hard hit by the record cold temperatures that caused a rare coldwater bleaching event in January of this year.

“Now is an especially good time to do this study because of the cold snap in January,” said Dr. Kevan Main, director of Mote’s Center for Aquaculture Research and Development, which reared the coral fragments in partnership with Mote’s Center for Coral Reef Research at Mote’s Tropical Research Laboratory on Summerland Key. “During that cold event, many of the fragmented corals growing at the inshore release site were lost. This gives us an opportunity to see whether we can jump start the recovery of corals at this site with cultured fragments.”

Unlike the corals that Mote grows at Sanctuary nursery sites in the Lower Keys — which are grown for study and possible later outplanting in other reef locations — the corals “released” Wednesday are situated in their final location. “This is a permanent transplant,” Main said. About the release:

*Total number of corals: 138 *Half transplanted to an inshore site near Coopers Island *Half transplanted to an offshore reef nursery near Looe Key

Species

*Montastrea cavernosa (great star coral): 10 per site for a total of 20 *Montastrea annularis (boulder star coral): 20 per site for a total of 40 *Stephanocoenia intersepta (blushing star coral): 19 per site for a total of 38 *Siderastrea siderea (massive starlet coral): 20 per site for a total of 40

The corals will be checked and cleaned every two weeks and monitored for growth quarterly. A second release is planned for the spring.

The release and study is supported by the Protect Our Reefs Program, in which funds generated by sales of the Protect Our Reefs specialty license plate are used for coral reef research, education and conservation programs.

“Coral reef restoration is a key element of the Protect Our Reefs Program,” said Dr. Dave Vaughan, director of Mote’s Center for Coral Reef Research. “We hope this release will be successful and will help guide future restoration efforts with some the Keys’ threatened elkhorn and staghorn coral species.”

Other supporters include the Ocean Reef Foundation and the Rod & Gun Club.

Views expressed in this article do not necessarily reflect those of UnderwaterTimes.com, its staff or its advertisers.

 

Future of science – Which ecological solutions will shape our future? Watch it now! – futurenow.dw-world.de/ecological

When most people envision coral, they typically think of shallow-water reef-building corals found along beaches and tropical nearshore habitats. These “typical” corals are dependent upon photosynthetic algae (also known as Symbiodinium or zooxanthellae) found in their tissues to obtain nutrients to live off of. In deeper less known waters, closely related black corals were considered to be void of these algae because of the light shortage to support photosynthesis.

In fact, all black corals were considered to lack Symbiodinium (algae), because they are typically found at great depths where light levels are very low. Black corals are of substantial cultural and economic importance in Hawai’i. Some species are harvested commercially for the precious coral jewelry industry in deep waters off Maui, and black coral is considered the official gemstone of the State of Hawai’i. Even though most people have heard of black coral jewelry, very few ever get to see these corals in their natural environments because of the depths they are found in. As a result of their remote habitats, very little is known about the basic biology of black corals.

Scientists at the Hawai’i Institute of Marine Biology (HIMB), examined 14 black coral species collected between 10 and 396 m from around Hawai’i for the presence of algae using molecular and histological (tissue studies) techniques. Surprisingly, 71% of the examined species were found to contain algae, even at depths approaching 400 m. These black corals exhibited very similar traits to those of corals commonly found in shallow-water (use of algae). PhD student, Daniel Wagner at HIMB was the one who led the investigation.

He states: “because black corals are predominantly found in deep and dark environments, most people assumed that they could not harbor these photosynthetic symbiotic algae. At this point we do not know how these algae are able to exist in extreme environments, and it certainly highlights how little we know about deep reefs.”

This is a new and important discovery for coral biology, representing the deepest record of Symbiodinium to date. This research also implies that some members of these algae have extremely diverse habitat preferences and broad environmental ranges. The prestigious Royal Society will be publishing the full research report in their journal, Proceedings of the Royal Society B this month.

More information: “Azooxanthellate? Most Hawaiian black corals contain Symbiodinium”, Daniel Wagner, Xavier Pochon, Leslie Irwin, Robert J. Toonen and Ruth D. Gates

ScienceDaily (Aug. 31, 2010) — Coral reefs are sensitive to climate change and track sea level. New observations show that an extensive coral reef existed in the southern Pacific Ocean thousands of years ago. Woodroffe et al. used multi-beam sonar, coring, and dating to examine a relict reef discovered in water about 20-25 meters (65-82 feet) deep around Lord Howe Island in the southern Pacific Ocean.

They found that the reef thrived from about 9,000 to 7,000 years ago and covered an area 20 times larger than the modern reef, which is the southernmost Pacific coral reef. About 7,000 years ago, the reef was drowned, probably due to abrupt sea level rise, and then shrunk to its modern extent.

The observation shows the extent to which reefs grew 9,000 years ago. Today coral reefs exist mainly in shallow seawater with sea surface temperatures greater than 18 degrees Celsius (64 degrees Fahrenheit), at latitudes near the equator. The relict reef shows that corals previously existed at southern latitudes farther from the equator.

The researchers note that as ocean temperatures warm due to climate change, the relict reef could become a substrate for new coral reef growth.

Authors of the study include: Colin D. Woodroffe, Michelle Linklater, Brian G. Jones: School of Earth and Environmental Sciences, University of Wollongong, Wollongong, New South Wales, Australia; Brendan P. Brooke, Cameron Buchanan, Richard Mleczko: Geoscience Australia, Canberra, ACT, Australia; David M. Kennedy, School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington, New Zealand; Quan Hua, Australian Nuclear Science and Technology Organization, Kirrawee, New South Wales, Australia; Jian-xin Zhao, Radiogenic Isotope Facility, Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Queensland, Australia.

ScienceDaily (Feb. 26, 2011) — An international scientific team has shown that strong links between the corals reefs of the south China sea, West Pacific and Coral Triangle hold the key to preserving fish and marine resources in the Asia-Pacific region.

Research by Dr Johnathan Kool of the ARC Centre of Excellence for Coral Reef Studies and James Cook University, and his colleagues, has established that the richest marine region on Earth — the Coral Triangle between Indonesia, Malaysia and the Philippines — depends vitally for its diversity and resilience on coral and fish larvae swept in from the South China Sea and Solomon Islands.

“The currents go in various directions, but the prevailing direction is from east to west, and this carries coral spawn and fish larvae from areas such as round the Spratly Islands in the South China Sea and the Solomons/Papua New Guinea,” he explains.

“Maintaining the network of links between reefs allowing larvae to flow between them and re-stock depleted areas, is key to saving coral ecosystems threatened by human pressure and climate change.

“The Coral Triangle is home to more than one third of all the world’s coral reefs, including over 600 different species of reef-building coral and 3,000 species of reef fish. These coral ecosystems provide food and income for more than 100 million people working in marine based industries throughout the region,” Dr Kool explains.

“Knowing where coral spawn comes from is vital to managing our reefs successfully. Even though coral reef communities may not be connected directly to one another, reefs on the edge of the Coral Triangle have the potential to contribute significant amounts of genetic diversity throughout the region,” says Dr Kool.

He argues that recent evidence showing the region’s biology is closely inter-connected suggests it is in the interests of all Asia-Pacific littoral countries to work together more closely to protect it: “The science shows the region’s natural resources are closely interconnected. Nations need to co-operate to look after them — and that begins with recognising the resources are at risk and that collective action is needed to protect them.

Six nations within the Coral Triangle, (Indonesia, the Philippines, Malaysia, Papua New Guinea, The Solomon Islands and Timor L’Este) are now working together to strengthen coral reef governance and management, under an arrangement known as the Coral Triangle Initiative.

The paper “Connectivity and the development of population genetic structure in Indo-West Pacific coral reef communities” by Johnathan T. Kool, Claire B. Paris, Paul H. Barber and Robert K. Cowen appears in a recent issue of the journal Global Ecology and Biogeography.