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One third of reef-building corals around the world are threatened with extinction, according to the first-ever comprehensive global assessment to determine their conservation status. The study findings were published yesterday by Science Express.

Leading coral experts joined forces with the Global Marine Species Assessment (GMSA) – a joint initiative of the International Union for Conservation of Nature (IUCN) and Conservation International (CI) – to apply the IUCN Red List Categories and Criteria to this important group of marine species.

“The results of this study are very disconcerting,” stated Kent Carpenter, lead author of the Science article, GMSA Director, IUCN Species Programme. “When corals die off, so do the other plants and animals that depend on coral reefs for food and shelter, and this can lead to the collapse of entire ecosystems.”

Built over millions of years, coral reefs are home to more than 25 percent of marine species, making them the most biologically diverse of marine ecosystems. Corals produce reefs in shallow tropical and sub-tropical seas and have been shown to be highly sensitive to changes in their environment.

Researchers identified the main threats to corals as climate change and localized stresses resulting from destructive fishing, declining water quality from pollution, and the degradation of coastal habitats. Climate change causes rising water temperatures and more intense solar radiation, which lead to coral bleaching and disease often resulting in mass coral mortality.

Shallow water corals have a symbiotic relationship with algae called zooxanthellae, which live in their soft tissues and provide the coral with essential nutrients and energy from photosynthesis and are the reason why corals have such beautiful colors. Coral bleaching is the result of a stress response, such as increased water temperatures, whereby the algae are expelled from the tissues, hence the term “bleaching.” Corals that have been bleached are weaker and more prone to attack from disease. Scientists believe that increased coral disease also is linked to higher sea temperatures and an increase in run-off pollution and sediments from the land.

Researchers predict that ocean acidification will be another serious threat facing coral reefs. As oceans absorb increasing amounts of carbon dioxide from the atmosphere, water acidity increases and pH decreases, severely impacting corals’ ability to build their skeletons that form the foundation of reefs.

The 39 scientists who co-authored this study agree that if rising sea surface temperatures continue to cause increased frequency of bleaching and disease events, many corals may not have enough time to replenish themselves and this could lead to extinctions.

“These results show that as a group, reef-building corals are more at risk of extinction than all terrestrial groups, apart from amphibians, and are the most vulnerable to the effects of climate change,” said Roger McManus, CI’s vice president for marine programs. “The loss of the corals will have profound implications for millions of people who depend on coral reefs for their livelihoods.”

Coral reefs harbor fish and other marine resources important for coastal communities. They also help protect coastal towns and other near-shore habitats from severe erosion and flooding caused by tropical storms.

Staghorn (Acroporid) corals face the highest risk of extinction, with 52 percent of species listed in a threatened category. The Caribbean region has the highest number of highly threatened corals (Endangered and Critically Endangered), including the iconic elkhorn coral (Acropora palmata) which is listed as Critically Endangered. The high biodiversity “Coral Triangle” in the western Pacific’s Indo-Malay-Philippine Archipelago has the highest proportions of Vulnerable and Near-Threatened species in the Indo-Pacific, largely resulting from the high concentration of people living in many parts of the region.

Corals from the genera Favia and Porites were found to be the least threatened due to their relatively higher resistance to bleaching and disease. In addition, 141 species lacked sufficient information to be fully assessed and were therefore listed as Data Deficient. However, researchers believe that many of these species would have been listed as threatened if more information were available.

The results emphasize the widespread plight of coral reefs and the urgent need to enact conservation measures. “We either reduce our CO2 emission now or many corals will be lost forever,” says Julia Marton-Lefèvre, IUCN Director General. “Improving water quality, global education and the adequate funding of local conservation practices also are essential to protect the foundation of beautiful and valuable coral reef ecosystems.”

Coral experts participated in three workshops to analyze data on 845 reef-building coral species, including population range and size, life history traits, susceptibility to threats, and estimates of regional coral cover loss.

The reef-building corals assessment is one group of a number of strategic global assessments of marine species the GMSA has been conducting since 2006 at Old Dominion University in Norfolk, Virginia. Other assessments are being conducted on seagrasses and mangroves that are also important habitat-forming species, all marine fishes, and other important keystone invertebrates. By 2012, the GMSA plans to complete its comprehensive first stage assessment of the threat of extinction for over 20,000 marine plants and animals, providing an essential baseline for conservation plans around the world, and tracking the extinction risk of marine species.

The results of the coral species assessment will be placed on the IUCN Red List of Threatened Species in October 2008. Currently, the assessments can be found at
http://www.sci.odu.edu/gmsa/about/corals.shtml

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Labels: coral, coral reef, environment, marine biology, research

Researchers on the third-largest atoll in the world, the Saba Bank in the Netherlands Antilles, have discovered and collected two new species of soft corals (gorgonians) and documented severe anchor damage with the aid of a Remotely Operated Vehicle (ROV) from Seabotix. Experts from Texas A&M University-Corpus Christi, Universidad de los Andes in Colombia, and the Rosenstiel School of Marine and Atmospheric Science at the University of Miami collected 40 species of soft corals, seventeen of which were collected using the ROV.

The SeaBotix LBV200L is rated to 200m (656 ft.) and includes fiber optic video, LED lighting, and powerful brushless thrusters. An optional grabber arm was used to collect the deepest new soft coral species at 70 m (230 ft.), a depth that would be impractical to explore using conventional diving techniques. Shelley Lundvall, Project Coordinator for the Saba Bank project, said, “The LBV (ROV) has helped us explore the deeper areas of the bank that nobody has seen before. We have also been able to add to the species diversity of gorgonians found on the Saba Bank”.

The ultimate goal of the research is to receive official recognition of the Saba Bank as a Particularly Sensitive Sea Area (PSSA) from the International Maritime Organization (IMO) in order to regulate international shipping that occurs within the Exclusive Economic Zone of the Netherlands Antilles. A management plan is now being drafted with the goal of enforcing existing and new regulations to protect the incredible diversity of Saba Bank marine life.

Another discovery emphasised the importance of the PSSA designation: “One of the most dramatic moments was when we found an anchor and chain scar on the bottom...The ability to document the damage done by these large ships is critical in getting the Saba Bank designated as a Particularly Sensitive Sea Area”, commented Shelley.

The video of this significant damage, as well as the actual recovery of the soft corals can be seen at www.youtube.com/slundvall


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Labels: coral, coral reef

Half a century after the last earth-shattering atomic blast shook the Pacific atoll of Bikini, the corals are flourishing again. Some coral species, however, appear to be locally extinct.

These are the findings of a remarkable investigation by an international team of scientists from Australia, Germany, Italy, Hawaii and the Marshall Islands. The expedition examined the diversity and abundance of marine life in the atoll.

One of the most interesting aspects is that the team dived into the vast Bravo Crater left in 1954 by the most powerful American atom bomb ever exploded (15 megatonnes - a thousand times more powerful than the Hiroshima bomb). The Bravo bomb vapourised three islands, raised water temperatures to 55,000 degrees, shook islands 200 kilometers away and left a crater 2km wide and 73m deep.

After diving into the crater, Zoe Richards of the ARC Centre of Excellence for Coral Reef Studies and James Cook University says, “I didn’t know what to expect – some kind of moonscape perhaps. But it was incredible, huge matrices of branching Porites coral (up to 8 meters high) had established, creating thriving coral reef habitat. Throughout other parts of the lagoon it was awesome to see coral cover as high as 80 per cent and large tree-like branching coral formations with trunks 30cm thick. It was fascinating – I’ve never seen corals growing like trees outside of the Marshall Islands.

“The healthy condition of the coral at Bikini atoll today is proof of their resilience and ability to bounce back from massive disturbances, that is, if the reef is left undisturbed and there are healthy nearby reefs to source the recovery.”

However the research has also revealed a disturbingly high level of loss of coral species from the atoll. Compared with a famous study made before the atomic tests were carried out, the team established that 42 species were missing compared to the early 1950s. At least 28 of these species losses appear to be genuine local extinctions probably due to the 23 bombs that were exploded there from 1946-58, or the resulting radioactivity, increased nutrient levels and smothering from fine sediments.

“The missing corals are fragile lagoonal specialists – slender branching or leafy forms that you only find in the sheltered waters of a lagoon,” Zoe explains. While corals in general have shown resilience, Zoe adds that the coral biodiversity at Bikini Atoll has proven only partially resilient to the disturbances that have occurred there.

Extensive decontamination works have been carried out at Bikini atoll making it safe to visit, however local produce is unsafe to eat, and it is unlikely the Bikinian people will return to live on Bikini Atoll in the near future.

For comparison the team also dived on neighbouring Rongelap Atoll, where no atomic tests were carried out directly although the atoll was contaminated by radioactive ash from the Bravo Bomb and local inhabitants were also evacuated and for the most part, have not returned. The marine environment at this Atoll was found to be in a pristine condition.

The team thinks that Rongelap Atoll is potentially seeding Bikini’s recovery, because it is the second largest atoll in the world with a huge amount of coral reef diversity and biomass and lies upstream from Bikini.

Because of its incredible history and current undisturbed character Bikini Atoll is now part of a larger project to have northern Marshall Island Atolls World Heritage listed. The expedition served to illustrate the tragic history of the Bikinian people is not entirely reflected below the surface because the reefs of Bikini are recovering to present themselves as havens of abundance to the marine life of the Northern Pacific Ocean.

Journal Reference: Elsevier’s Marine Pollution Bulletin No. 56, March 2008 page 5-3-1-515.

Further Reading: ARC Centre of Excellence for Coral Reef Studies

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Labels: coral, research, sealife

WWF-Canada have released a new study that identifies three coldwater coral "hotspots" off Newfoundland and Labrador and assesses the impact of fishing on these fragile organisms. The study provides the scientific basis for Canadian and European governments to protect sensitive coral habitat in the Northwest Atlantic.

Coldwater corals are long-lived animals that live along continental slopes, seamounts, and mid-ocean ridges. These corals are important parts of deep-sea ecosystems and provide habitat for other invertebrates and fishes. Coldwater corals can be damaged by fishing or other seafloor directed activities and may take centuries to grow back, if at all.

"Canada, Spain, Portugal and Russia are the countries that have the greatest potential to damage these globally important concentrations of corals," said Dr. Robert Rangeley, Vice President, Atlantic, WWF-Canada. "Their fleets are among the largest operating off Newfoundland and fish in and around the areas identified as hotspots. This also means they have the greatest opportunity to protect them."

"Our study mapped where corals are found, and identified areas where coral bycatch is highest for a variety of fisheries and gear types," said lead author of the study Dr. Evan Edinger. "Our research demonstrates that no matter what type of fishing gear is used, bottom-contact fishing in coral habitat damages corals. Therefore, it is very important that any areas established to protect corals exclude all bottom directed fishing activities." This research builds on a growing global movement to protect coldwater corals and seamounts. In 2006, the United Nations General Assembly called on fisheries management agencies like the Northwest Atlantic Fisheries Organization (NAFO) to implement vulnerable habitat protection measures by December 2008. In response, last year NAFO signalled their intent to protect seamount habitats.

The Report, Coldwater Corals off Newfoundland and Labrador: Distribution and Fisheries Impacts may be downloaded at: http://wwf.ca/coral

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Labels: coral, environment, marine biology, research

The rate and extent of coral loss are greater than expected, American researchers have found. And the reduction of coral rapidly causes a decline in the abundance and diversity of reef fish.

The estimated annual rate of coral cover loss in the Caribbean between 1977 and 2001 was approximately 1.5%, with the greatest decline occurring during the 1980s. In contrast, the estimated net annual loss of global humid tropical rainforest was only 0.4% from 1990–1997. Additionally, the patterns of coral reef degradation are very different from rainforest loss in that nearly all reefs have been affected; there are virtually no remaining pristine reefs and very few with coral cover close to the historical average.

Remarkably, in 2003, only 4% of the 390 surveyed Indo-Pacific reefs had coral cover greater than 50% and only 2% had cover greater than 60%. In contrast, cover was over 50% on nearly a third of the reefs surveyed between 1980 and 1983.

Despite the well-documented effects of several causes of mass coral mortality, there is substantial evidence that coral communities remain resilient, often recovering in ten to thirty years after major disturbances. However, such “recovery,” loosely defined as a return to pre-disturbance coral cover, often does not mean a return to original coral species composition because the recovery of slow-growing species can take centuries.

The general absence of quantitative data on reef health has led to several misconceptions about the causes, patterns, and best remedies for global coral decline. For example, in 2003, coral cover on the Great Barrier Reef (GBR), considered the “best-managed” and “one of the most ‘pristine’ coral reefs in the world”, was not significantly greater than on reefs in the Philippines and other subregions that are often thought to be highly threatened and poorly managed.

Additionally, based on the impression that Hawaiian reefs were “far further down the trajectory of decline” [than reefs in the Caribbean and Australia] a recent essay argued for a total overhaul of U.S. coral reef management policy. But Bruno and Sellig's analysis suggests that coral cover in the main Hawaiian islands, including frequently visited reefs close to urban and tourism centers, appears to have been as high as GBR cover over the last two decades.

The study highlights the urgent need for conservation policies to restore coral reefs and the ecosystem services they provide, estimated to be worth $23,100–$270,000 km−2 year−1. The researchers say halting and reversing coral loss will require actions across a range of scales including local restoration and conservation of herbivores that facilitate coral recruitment, and the reduction of fishing practices that directly kill corals, the implementation of regional land use practices that reduce sedimentation and nutrient pollution, and the institution of global policies to reduce anthropogenic ocean warming and acidification.

Source: Bruno JF, Selig ER (2007) Regional Decline of Coral Cover in the Indo-Pacific: Timing, Extent, and Subregional Comparisons. PLoS ONE 2(8): e711. doi:10.1371/journal.pone.0000711

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Labels: coral, environment

Table coral has a short, stout stem attached by a spreading base. Branches arise from the top of the stem and spread in a horizontal rather than a vertical direction, often fusing together. The closely set and interlocking branches form a roughly circular plate sometimes two or three metres in diameter.

Acropora species are among the fastest growing corals, with upward growth between 10 and 20 cm per year. This is achieved through their porous skeleton and the branched habit that will re-establish themselves readily when damaged.

In the Caribbean, Acropora colonies are brown or yellowish in colour, often with white tips. In the Indo-Pacific, though, they are among the most brightly coloured corals on the reef. Acropora is an important reef-building coral and often dominates shallow areas. It provides shelter for a variety of small fishes and other animals.

Table corals are the most vulnerable to storm damage. Their broad, flat top supported by a narrow stalk makes them more susceptable to strong wave forces than bushy or mounded corals. However, severe storms, by themselves, would do not pose a large threat to reefs. Young colonies do not form tables and the Acropora corals grow and mature quickly.

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Labels: coral, marine biology

Caribbean coral species are dying off, indicating dramatic shifts in the ecological balance under the sea, a new scientific study of Caribbean marine life shows.

The study found that 10 percent of the Caribbean’s 62 reef-building corals were under threat, including staghorn and elkhorn corals. These used to be the most prominent species but are now candidates to be listed as Critically Endangered on the IUCN Red List of Threatened Species.

A gathering of 23 scientists in Dominica analysed data on Western Tropical Atlantic corals, seagrasses, mangroves and algae, which are fundamental components of marine ecosystems providing food and shelter for numerous other organisms and local communities.

The threats to corals and other marine species include coastal pollution and human development; increased sedimentation in run-off water; thermal stress and heightened severity of hurricanes from climate change; and shifts in species dynamics due to over-fishing, according to the study. Scientists explained that the Caribbean has undergone the longest and most sustained impacts from human development since the colonization of the Americas.

Next to corals, mangroves appear to be the hardest hit. Mangrove cover in the region has declined by 42% over the past 25 years, with two of the eight mangrove species now considered Vulnerable to extinction and two more in Near Threatened status.

“Mangroves protect shorelines, shelter fish, and filter pollution,” said Aaron Ellison of Harvard University. “The Caribbean was blessed with an abundance of these useful plants, but the consensus of this workshop is that mangroves are in trouble everywhere and need to be protected and restored,” he added. Mangrove forests are being cut down to make way for coastal housing, tourism, and aquaculture development.

The scientists noted that some healthy Caribbean coral reefs still exist in well-managed marine protected areas such as Bonaire Marine Park in the Netherlands Antilles. Direct human impacts are reduced in these areas allowing most corals to thrive; however, thermal stress from global warming affects all corals in the Caribbean and must be reversed if these refuges of Caribbean beauty are to survive, they added.

Further Reading: Conservation International

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Labels: Caribbean, coral, environment

Beautiful Oceans
Coral Reef Ecosystem & Food Web Course
$59.55
http://www.beautifuloceans.com/

This new course for divers discusses the coral reef ecosystem and food web. It illustrates its points using animals and plants found in and around coral reefs. For instance, the Caribbean Reef Shark is discussed as a top-level, active, predator. The authors manage to pack loads of information on their example species into a small space, without the prose becoming uninteresting. And even when I thought I knew lots about a subject they managed to surprise me. For instance, did you know that sponges may be able to live to over 1000 years old?

Although much of the information applies to coral reefs throughout the world, the example species are found in the Caribbean.

By the end of the course its authors hope that you will have learnt to appreciate all life on coral reefs from the tiniest phytoplankton to the shark. You will also have learnt how each creature is interconnected with the others.

The course is available on-line, where you work through at your own pace at your computer. It includes videos of animal behaviour and interactive quizzes. You can also take the course at selected dive schools in the Caribbean.

The course materials are well written, with many interesting asides. The Manual, in pdf format, is 119 pages long. It has a comprehensive index and is lavishly illustrated with a high-quality photograph or diagram on nearly every page.

We are delighted to be able to offer our newsletter subscribers the chance to win the course. Subscribe at http://www.scubatravel.co.uk/news.html then send us an e-mail with "Beautiful Oceans" as the subject line. Closing date is 11 June. Your e-mail entries will not be passed to any other company unless you win, in which case Beautiful Oceans will be in touch with you.

For more information visit http://www.beautifuloceans.com/

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Labels: Caribbean, coral, environment, marine biology, sealife

Coral disease outbreaks have struck the healthiest sections of Australia's Great Barrier Reef, where for the first time researchers have conclusively linked disease severity and ocean temperature. Close living quarters among coral may make it easy for infection to spread, researchers have found.

"With this study, speculation about the impacts of global warming on the spread of infectious diseases among susceptible marine species has been brought to an end," said Don Rice, director of the National Science Foundation (NSF) Chemical Oceanography Program, which funded the research through the joint NSF-National Institutes of Health Ecology of Infectious Diseases Program.

For 6 years, the international research team, led by University of North Carolina (UNC)-Chapel Hill, tracked an infection called white syndrome in 48 reefs along more than 900 miles (1,500 kilometers) of Australia's coastline.

The colorful coral colonies that attract visitors to the Great Barrier Reef live atop a limestone scaffolding built from the calcium carbonate secretions of each tiny coral, or polyp. While polyps provide the framework, coral's vivid hues come from symbiotic single-celled algae that live in the polyps. The algae supply much of the food coral need to survive.

When disease or stressful environmental conditions strike a coral colony, the polyps expel their algae. This algae loss makes the coral appear pale.

"We're left with a big question. Can corals and other marine species successfully adapt or evolve, when faced with such change?" Rice said.

Understanding the causes of disease outbreaks will help ecologists protect reef-building corals, which support commercial marine species and buffer low-lying coastal areas.

"More diseases are infecting more coral species every year, leading to the global loss of reef-building corals and the decline of other important species dependent on reefs," said lead study author John Bruno at UNC. "We've long suspected climate change is driving disease outbreaks. Our results suggest that warmer temperatures are increasing the severity of disease in the ocean."

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Labels: Australia, coral, environment, marine biology