Lessons in Coral Reef Survival

The complex relationship we see today between fishes and corals developed relatively recently in geological terms – and is a major factor in shielding reef species from extinction, says Professor David Bellwood of the ARC Centre of Excellence for Coral Reef Studies and James Cook University.

"Our latest research provides strong evidence for a view that today's coral hotspots are both a refuge for old species and a cradle for new ones," said Peter Cowman, lead author of a recent report. "This is the first real inkling we've had that just protecting a large area of reef may not be enough – you have to protect the right sorts of reef."

Early coral reefs, 300-400 million years ago were much simpler affairs than today's colourful and complex systems, Prof. Bellwood says. The fish were not specialised to live on or among corals – either lacking jaws altogether, or else feeding on detritus on the seabed or preying on one another.

"By 200 million years ago we are starting to see fish with jaws capable of feeding on corals, but the real explosion in reef diversity doesn't occur till about 50 million years ago when we see fishes very like today's specialist coral feeders emerging."

It is the ever-increasing complexity of this relationship between corals and fishes over the last 20 or 30 million years that produces the wondrous diversity of today's reefs, he says. Each has become more critical to the survival of the other as their lives have become more interwoven.

"When people think of coral reefs, they usually think of the beautiful branching corals like staghorn (Acropora) – well the evidence is now fairly clear that Acropora needs certain fish for it to flourish. But, it now appears that this may be a reciprocal relationship with Acropora being important for the evolution and survival of fishes on coral reefs. "

Unfortunately Acropora corals are highly vulnerable to external impacts like Crown-of-Thorns starfish, coral bleaching, climate change and ocean acidification. Their demise will have far reaching effects on the fishes which interact with them, such as damsels, butterfly fish, cardinals and wrasses.

"The study of the past tells us that reefs are all about relationships and, like a family, for them to survive those relationships need to remain strong," Peter Cowman said. 
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Carbon dioxide is "Driving Fish Crazy" by Prof. Munday

Rising human carbon dioxide emissions may be affecting the brains and central nervous system of sea fishes with serious consequences for their survival, an international scientific team has found.

Carbon dioxide concentrations predicted to occur in the ocean by the end of this century will interfere with fishes’ ability to hear, smell, turn and evade predators, says Professor Philip Munday of the ARC Centre of Excellence for Coral Reef Studies and James Cook University.

“For several years our team have been testing the performance of baby coral fishes in sea water containing higher levels of dissolved CO2 – and it is now pretty clear that they sustain significant disruption to their central nervous system, which is likely to impair their chances of survival,” Prof. Munday says.

In their latest paper, published in the journal Nature Climate Change, Prof. Munday and colleagues report world-first evidence that high CO2 levels in sea water disrupts a key brain receptor in fish, causing marked changes in their behaviour and sensory ability.

“We’ve found that elevated CO2 in the oceans can directly interfere with fish neurotransmitter functions, which poses a direct and previously unknown threat to sea life,” Prof. Munday says.

Prof. Munday and his colleagues began by studying how baby clown and damsel fishes performed alongside their predators in CO2-enriched water. They found that, while the predators were somewhat affected, the baby fish suffered much higher rates of attrition.

“Our early work showed that the sense of smell of baby fish was harmed by higher CO2 in the water – meaning they found it harder to locate a reef to settle on or detect the warning smell of a predator fish. But we suspected there was much more to it than the loss of ability to smell.”

The team then examined whether fishes’ sense of hearing – used to locate and home in on reefs at night, and avoid them during the day – was affected. “The answer is, yes it was. They were confused and no longer avoided reef sounds during the day. Being attracted to reefs during daylight would make them easy meat for predators.”

Other work showed the fish also tended to lose their natural instinct to turn left or right – an important factor in schooling behaviour which also makes them more vulnerable, as lone fish are easily eaten by predators.

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The Future of Earth's Coral Reefs by Keith Sherwood and Craig Idso

A video produced in collaboration with Earth-Touch that presents a future in which coral reefs no longer exisit because of climate change, over-fishing and ocean acidification. It provides a stark warning that action has to be taken now to prevent the loss of this amazing ecosystem

In a major review article published in Science, Pandolfi et al. (2011) summarize what they describe as "the most recent evidence for past, present and predicted future responses of coral reefs to environmental change, with emphasis on rapid increases in temperature and ocean acidification and their effects on reef-building corals." This they do, in their words, because "many physiological responses in present-day coral reefs to climate change are interpreted as consistent with the imminent disappearance of modern reefs globally because of annual mass bleaching events, carbonate dissolution and insufficient time for substantial evolutionary responses," all of which interpretations, they go on to demonstrate, may not be correct.

With respect to the past, the four researchers report that shallow water tropical reef organisms existed throughout the entire 540 million years of the Phanerozoic, which included times when sea surface temperatures (SSTs) were more than 7°C higher than those of today and the air's CO2 concentration was as much as 6000 ppm higher. And with respect to what they call "the most recent reef crisis," they say that "the Paleocene-Eocene Thermal Maximum (PETM; 55.8 million years ago), was characterized by rapid SST rise and a similar order of magnitude of CO2 increase as present," yet they state there is evidence that "reef assemblages in at least one oceanic setting were unaffected (Robinson, 2011)," while noting that other reefs have also shown "greater resilience to past rapid warming and acidification than previously thought."

More recently, during the Holocene, Pandolfi et al. say that "evidence from high-resolution proxy records suggests that tropical SSTs had the potential to repeatedly warm over centennial to millennial time scales (Rosenthal et al., 2003; Schmidt et al., 2004)." And in one location, they say that SSTs rose "at rates comparable to those projected for the coming century (Lea et al., 2003)," yet they add that "none of these post-Last Glacial Maximum warming episodes appear to have interrupted reef growth."
 
As for current coral responses to SST increases, the four scientists note that "numerous characteristics of coral hosts have the potential to confer differences in bleaching susceptibility," and they report that "these characteristics vary substantially within and among coral species (Baird et al., 2009a; Csaszar et al., 2010)." In addition, they note that "some coral species also harbor multiple strains of zooxanthellae, which confer differential susceptibility of their hosts to bleaching (Rowan, 2004)." And they say there is also "substantial variation in reef recovery in the aftermath of bleaching events (Baker et al., 2008)."

The story is much the same with respect to coral responses to ocean acidification. Pandolfi et al. note, for example, that there have been studies where calcification actually increased under moderately elevated partial pressures of CO2 (Rodolfo-Metalpa et al., 2010; Jury et al., 2010; Reynaud et al., 2003), as has also been observed for some coralline algae, crustacea and echinoderms (Ries et al., 2009)." And they add that sensitivity of calcification to ocean acidification "appears to be reduced when (i) studies are conducted over weeks or months (Ries et al., 2009; Rodolfo-Metalpa et al., 2010; Marubini et al., 2001; Reynaud et al., 2003) as opposed to less than one day (Langdon and Atkinson, 2005; Ohde and Hossain, 2004) or (ii) corals are reared under nutritionally replete conditions by feeding or elevating inorganic nutrient concentrations (Langdon and Atkinson, 2005; Ries et al., 2009)."
Read more @ co2science.org 

Reef Fish at Risk as Carbon Dioxide Levels Build

        An increase in CO2 interferes with the ability of the fish to hear, smell, turn and evade predators.

RISING carbon dioxide (CO2) emissions threaten the survival of some fish species by sending their central nervous systems haywire.

Researchers from the Australian Research Council Center of Excellence for Coral Reef Studies and James Cook University say concentrations of CO2 are predicted to reach between 700 and 900 microatmospheres before the end of the century, interfering with the ability of the fish to hear, smell, turn and evade predators.

''It is now pretty clear that they sustain significant disruption to their central nervous system, which is likely to impair their chances of survival,'' Professor Philip Munday said yesterday.

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''We've found that elevated carbon dioxide in the oceans can directly interfere with fish neurotransmitter functions, which poses a direct and previously unknown threat to sea life.''

The team examined how baby clown and damsel fish and their predators dealt with water enriched by carbon dioxide. While the predators were slightly affected, the baby fish suffered to a much greater degree.

''They found it harder to locate a reef to settle on or detect the warning smell of a predator fish,'' Professor Monday said. The team looked more closely and found the hearing of the fish was affected as well as its smell. Then they started to lose their natural instinct to turn left and right.

''All this led us to suspect it wasn't simply damage to their individual senses that was going on but rather that higher levels of CO2 were affecting their whole central nervous system.''

The team concluded that high levels of carbon dioxide stimulates a receptor in the fishes' brains called GABA-A. The receptor's function is reversed and some nerve signals become overexcited.

Read more @ Theage.com.au 

 

 

Complete Information on Conservation of Coral Reefs by Jayaprakash Kakada

Coral reefs are diverse and vulnerable ecosystem characterized by a complex inter-dependence of plants and animals.

They are massive limestone structures built up through the constructional cementing process and depositional activities of the animals of the class Anthozoa as well as other calcium carbonate secreting animals.

Coral reefs are the centers of high biological productivity, sites of carbon dioxide sink and sources of huge deposits of calcium carbonate. They provide many natural raw materials of pharmacological importance including life saving drugs.

In the Indian sub continent, the reefs are distributed along the East and West coasts at restricted places. Fringing reefs are found in the Gulf of manner and Palk Bay as well as the Andaman and Nicobar islands. Platform reefs are seen along the Gulf of Kutch and Atoll reefs are found in the Lakshadweep Archipelago.

Increasing human population and anthropogenic pressure has severely affected coral distribution and biodiversity. Natural calamities cause considerable damage to the coral reef structure through direct and indirect means. Global warming leads to adverse impact on the survival of the coral reefs.

The bleaching phenomenon of 1998 in the Indian Ocean is reported to have caused considerable damage to the coral reef in the Indian coast. Further, some factors causing damage to coral reefs include industrial settlements, over exploitation of fish resources, pollution, dredging of coral sands for cement industry, causing considerable loss of flora and fauna, deforestation and reclamation of wetlands and mangrove areas. Hence, we need proper planning to protect and conserve our coral reefs. The regional planning to conserve coral reefs in India requires the following strategies:

(i) A proper environmental planning unit should monitor the status and exploitation level of coral reefs in different coastal areas of India.

(ii) Mangroves committee should monitor the activities of over commercial exploitation of coral reefs.

(iii) People should be prohibited to enter coral reef areas in the coastal ecosystem.

(iv) Periodic survey on biodiversity status of coral reefs in different coastal ecosystem must be undertaken.

Efforts should be made to forestall or avert the accumulation of pollutants around the area of coral reefs.

From Preservearticles.com 

Sea Cucumbers Dissolve Coral Reefs

A new study has uncovered the important role that humble sea cucumbers play in the balance of coral reefs, as it turns out their acidic gastric emissions cause coral reefs to dissolve.

Researchers at One Tree Island on Australia’s Great Barrier Reef originally made measurements of seawater that showed that during the night, a significant portion of the coral reef dissolved away – and they didn’t know why. But they did notice that there were a lot of sea cucumbers hanging out in the area, and they wondered if they perhaps were to blame.

 

In the tropics these unprepossessing tubular relatives of starfish and sea urchins, spend much of their lives laying about on the seabed acting like living vacuum cleaners, slurping up mouthfuls of sand and coral rubble, and squirting out – from the other end - piles of cleaned up sediment.  In the process they release dissolved calcium carbonate into the water.

The team, led by Kenny Schneider from the Carnegie Institution for Science in California took some sea cucumbers into the lab and essentially measured what went in and what went out of them.

And they estimate that sea cucumbers are responsible for around half the carbonate dissolution every night on the coral reef. That might sound bad, but in fact sea cucumbers are doing a vital job of recycling nutrients back into the ecosystem to make them available to primary producers.

The dissolved calcium carbonate they release also helps to buffer against the rising levels of acidity in the oceans that’s taking place because of increasing levels of carbon dioxide dissolving from the atmosphere.

It goes to show that there is still so much we need to learn about the complex interactions of species in ecosystems like coral reefs, and emphasizes the importance of maintaining all those different species – because even if they look like just harmless critters, lounging about on the seabed, they could be playing a very important role in the overall health of the ecosystem. 

From one of my favorite science sites "The Naked Scientists" 

Coral Reefs are a Tell Tale Sign for Climate Change by Kate Pellow

Coral Reefs are at the forefront of climate change and at least two of the three main impacts you will have noticed: coral bleaching and storm damage, both of which derive from increased sea temperatures. The third major change to coral reefs however is a little less obvious, and that is the acidification of the ocean. Acidification happens when the sea absorbs increasing levels of CO2 from the atmosphere. At its most simple, the more CO2 in the atmosphere, the more the sea absorbs and the current levels are 50 times higher than normal (Cadeira, 2006). The result? Less carbonate is available for biological systems such as coral reefs, which will weaken the reef system. Weak reefs mean less resiliency to pollution, storm damage, disease, a shift in biodiversity (an abundance of parrot fish for example who love to chomp on the reefs) and damage by humans.

Climate change has extremely high awareness levels but incredibly low response rate – people know what it is but feel they do not have the capacity to change it themselves (Tomkinson 2005). Knowledge is often the key to change and climate change action gets caught up in a myriad of scientific debate, which muddies the waters of understanding for normal people. However, reefs are a little more straightforward when it comes to the impacts of climate change, as they are generally visible. Being able to see real change helps give it a very real context. 

Read more: 

Belize Fishing Bans Helping Barracuda Recovery by Bob Berwyn

Fishing closures in protected marine areas around the spectacular Mesoamerican reef near Belize have helped recover populations of barracuda, groupers, snappers, and other predatory fish, but herbivorous fish that clean algae from the coral are not faring as well.

Results of a long-term study by the Wildlife Conservation Society show that parrotfish an surgeonfish in the Glover’s Reef study area make only sight recoveries — not enough to reverse the degradation by caused by algae overgrowing the reefs and replacing the coral that once covered 75 percent, but now represent less than 20 percent, of the seafloor cover.

“The fishing ban in the fully protected portion of the lagoon was expected to result in an increase in predatory fish and — more importantly — herbivorous fish such as parrotfish that in turn reverse the degraded condition of algal dominance in this reef,” said Dr. Tim McClanahan, lead author of the study and head of WCS’s coral reef research and conservation program.

“What happened was a recovery of predatory fish, but not of the herbivorous fish, a finding that is forcing us to come up with a more effective model of reef management and recovery,” McClanahan said. “If the nation-wide ban on parrotfish is successful, then we can see if this type of large-scale management is the only effective solution for protecting coral reefs,” he addd.

The study appears in an online version of Aquatic Conservation: Marine and Freshwater Ecosystems. The authors include: Tim McClanahan, N.A. Muthiga, and R.A. Coleman of the Wildlife Conservation Society.

The authors note that a recent national-level ban by the Belizean government on the fishing of parrotfish—a widespread herbivorous species—may be the key to reef recovery, provided that the fishing ban is enforced and met with compliance. WCS provided valuable data through its monitoring program at Glover’s Reef to justify the landmark measure to protect reef grazers.

A number of factors could be contributing to the unpredicted responses of fishing closures. The complex web of species interactions may produce unexpected cascading effects because of underestimates in the possible responses to bans on fishing.

Read more: 

Fishing closures in protected marine areas around the spectacular Mesoamerican reef near Belize have helped recover populations of barracuda, groupers, snappers, and other predatory fish, but herbivorous fish that clean algae from the coral are not faring as well.

Results of a long-term study by the Wildlife Conservation Society show that parrotfish an surgeonfish in the Glover’s Reef study area make only sight recoveries — not enough to reverse the degradation by caused by algae overgrowing the reefs and replacing the coral that once covered 75 percent, but now represent less than 20 percent, of the seafloor cover.

“The fishing ban in the fully protected portion of the lagoon was expected to result in an increase in predatory fish and — more importantly — herbivorous fish such as parrotfish that in turn reverse the degraded condition of algal dominance in this reef,” said Dr. Tim McClanahan, lead author of the study and head of WCS’s coral reef research and conservation program.

“What happened was a recovery of predatory fish, but not of the herbivorous fish, a finding that is forcing us to come up with a more effective model of reef management and recovery,” McClanahan said. “If the nation-wide ban on parrotfish is successful, then we can see if this type of large-scale management is the only effective solution for protecting coral reefs,” he addd.

The study appears in an online version of Aquatic Conservation: Marine and Freshwater Ecosystems. The authors include: Tim McClanahan, N.A. Muthiga, and R.A. Coleman of the Wildlife Conservation Society.

The authors note that a recent national-level ban by the Belizean government on the fishing of parrotfish—a widespread herbivorous species—may be the key to reef recovery, provided that the fishing ban is enforced and met with compliance. WCS provided valuable data through its monitoring program at Glover’s Reef to justify the landmark measure to protect reef grazers.

A number of factors could be contributing to the unpredicted responses of fishing closures. The complex web of species interactions may produce unexpected cascading effects because of underestimates in the possible responses to bans on fishing.

Additionally, the size of the closure may be too small to produce the desired effect, or there may not be enough compliance and enforcement. The study also mentions that environmental factors such as oceanographic oscillations and warming waters complicate any attempt to establish cause-and-effect relationships in these systems, as they noted a loss in coral cover across the 1998 El Niño that killed many corals worldwide.

“It is encouraging to see the recovery of large predatory fish such as groupers and snappers under significant pressure elsewhere in Belize, but the lagging herbivorous fish is a warning that there is no single solution to coral reef conservation,” said Dr. Caleb McClennen, Director of WCS’s Marine Program. “While no-take zones are critical, more comprehensive ecosystem-based management is essential throughout the range of targeted species for long term recovery of the entire Meso-American Barrier Reef.”

From SummitCountyVoice.com 

A 14-year study by the Wildlife Conservation Society in an atoll reef lagoon in Glover's Reef, Belize has found that fishing closures there produce encouraging increases in populations of predatory fish species. However, such closures have resulted in only minimal increases in herbivorous fish, which feed on the algae that smother corals and inhibit reef recovery.

The findings will help WCS researchers in their search for new solutions to the problem of restoring Caribbean reefs damaged by fishing and climate change.

The study appears in an online version of Aquatic Conservation: Marine and Freshwater Ecosystems. The authors include: Tim McClanahan, N.A. Muthiga, and R.A. Coleman of the Wildlife Conservation Society.

Specifically, the fishing closures have resulted in the recovery of species such as barracuda, groupers, snappers, and other predatory fish. Herbivorous fish such as parrotfish and surgeonfish, however, managed only slight recoveries, along with a small amount of the herbivory needed to reduce erect algae and promote the growth of more hard corals. This modest recovery of herbivorous fish has not been sufficient in reversing the degradation of the reefs by algae that have overgrown the reef and replaced the coral that once occupied 75 percent, but now represent less than 20 percent, of the seafloor cover. The authors note that a recent national-level ban by the Belizean government on the fishing of parrotfish -- a widespread herbivorous species -- may be the key to reef recovery, provided that the fishing ban is enforced and met with compliance. WCS provided valuable data through its monitoring program at Glover's Reef to justify the landmark measure to protect reef grazers.

"The fishing ban in the fully protected portion of the lagoon was expected to result in an increase in predatory fish and -- more importantly -- herbivorous fish such as parrotfish that in turn reverse the degraded condition of algal dominance in this reef," said Dr. Tim McClanahan, lead author of the study and head of WCS's coral reef research and conservation program. "What happened was a recovery of predatory fish, but not of the herbivorous fish, a finding that is forcing us to come up with a more effective model of reef management and recovery. If the nation-wide ban on parrotfish is successful, then we can see if this type of large-scale management is the only effective solution for protecting coral reefs."

Read more: 

Coral reef Successfully Restored After 2002 Boat Grounding in Florida Keys

Corals damaged in 2002 when a boat ran aground in the Florida Keys National Marine Sanctuary are now thriving following a restoration and near decade-long monitoring effort, according to a new NOAA report released today. With hundreds of groundings happening each year in the sanctuary, lessons learned from this coral reef restoration and monitoring will guide future restoration efforts.

In August 2002, the 36-foot long boat Lagniappe II ran aground on a shallow coral reef near Key West, Fla., damaging approximately 376 square-feet of living coral in the sanctuary. After sanctuary staff assessed the damage to the reef, restoration biologists used special cement that hardens under water to reattach 473 corals and coral fragments that had been toppled or dislodged during the grounding. The majority of affected corals were boulder star coral, a primary reef building coral in the Florida Keys.

To determine the progress of their restoration efforts, the sanctuary and the National Coral Reef Institute of Nova Southeastern University’s Oceanographic Center, used digital photographs and highly specialized computer software to count the types and amounts of coral in the damaged area as well as an adjacent unaffected reference site. Sanctuary biologists could then compare the restoration area with the reference area and note changes over time. 

The sanctuary tracked coral condition at the restoration site over an eight-year period, beginning in 2002. By 2009, the reattached coral fragments were undistinguishable from the adjacent uninjured coral colonies. A year later, the amount of coral at the restoration site was higher than at the reference site.

“The monitoring allowed us to document changes to the restored coral and measure the success of this restoration,” said Hatsue Bailey, Florida Keys National Marine Sanctuary restoration biologist. “With continued use of these methods, as well as additional monitoring, we learn more about habitat changes at this location and improve upon existing restoration strategies.”

Hundreds of vessel groundings are reported annually in the Florida Keys. A boat hitting the reef can topple coral heads or grind coral colonies into tiny fragments, damaging and killing coral which may have taken centuries to build. Most vessel groundings are preventable through preparation, patience, and experience.

The owner of Lagniappe II paid $56,671.27 in a negotiated settlement. Those funds were used to pay for response, damage assessment, monitoring and some restoration costs. 

The coral restoration study, “Lagniappe II Coral Reef Restoration Monitoring Report, Monitoring Events 2002 to 2010, Florida Keys National Marine Sanctuary, Monroe County, Florida,” and other Office of National Marine Sanctuaries’ Conservation Series reports are available online.

Florida Keys National Marine Sanctuary protects 2,900 square nautical miles of critical marine habitat, including coral reef, hard bottom, sea grass meadow, mangrove communities and sand flats. NOAA and the State of Florida manage the sanctuary.

NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter and our other social media channels.

Fish Can Be Bred To Cope With Warmer Seas

Some tropical fish may be able to cope with rising sea temperatures better than previously thought, Australian scientists have discovered.

The finding that some fish can adjust to warmer sea temperatures over several generations comes amid rising concern about the future of coal reefs due to global warming.

Researchers at the ARC Centre of Excellence in Coral Reef Studies, James Cook University and CSIRO were seeking to discover how fish would cope with the elevated sea temperatures expected by 2050 and 2100.

Lead researcher Jennifer Donelson said when damsel fish were exposed to water temperatures 1.5 degrees and three degrees above normal, there was an expected decline in their aerobic capacity.

"This affects their ability to swim fast and avoid predators," she said.

But when the fish were bred for several generations at higher temperatures, the second generation offspring had almost completely adjusted.

"We were amazed, stunned even," Ms Donelson said.

"It shows that some species can adjust faster than the rate of climate change."

Read more: 

Coral Gardeners at RSMAS ( Rosenstiel School of Marine and Atmospheric Science )

Around the world, coral reefs have drastically declined due to coastal development, increased water temperatures and storm frequency, global climate change, disease, pollution, and overfishing. In particular, populations of the threatened staghorn coral (Acropora cervicornis) have declined by up to 95% in the Caribbean. To help combat the continuing decline of staghorn coral and assist in their recovery, the Benthic Ecology Lab at the Rosenstiel School is growing corals at an in-water coral nursery to use in restoration activities. The coral nursery is located just east of Boca Chita Key within Biscayne National Park, about a 45-minute boat ride south from the RSMAS dock. 

Staghorn coral reproduces naturally through the process of fragmentation, so we collect small pieces of coral called fragments from wild colonies and place them in a coral nursery. The nursery is constructed of cinderblock platforms with 10 pedestals where coral fragments are secured with underwater epoxy. Once secured in the nursery, staghorn fragments can grow up to 15 cm per year. When the fragments have grown to about 30 cm, they can be fragmented again to create more fragments without needing to collect more from wild colonies. 

Currently, there are 542 small staghorn coral colonies at the RSMAS coral nursery totaling over 250 meters of healthy coral tissue. The coral nursery attracts many fish and invertebrate species such as snapper, grunts, urchins, lobster, and squid. SCUBA divers regularly clean the nursery with wire brushes to prevent algae and other encrusting organisms like sponges from overgrowing the corals. This process, known as “coral gardening” produces a sustainable, healthy stock of corals which can be transplanted to local coral reefs to help replenish declining staghorn populations. Corals from the RSMAS coral nursery are planned to be outplanted in Spring 2012.

-Stephanie A. Schopmeyer
Senior Research Associate

http://www.rsmas.miami.edu/ 

Corals Near Submarine Springs Offer Global Warming Hints

                        Coral reef ecosystems are likely to change dramatically as oceans absorb more carbon dioxide.

Submerged springs along the Yucatan coast may offer a hint of what the coral reefs will look like in coming decades, as global warming inexorably increases concentrations of carbon dioxide in the world’s oceans.

The naturally low pH (a measure of acidity) in the water around the springs creates conditions similar to those that will result from the widespread acidification of surface waters that scientists expect to occur as the oceans absorb carbon dioxide from the atmosphere.

A team led by scientists at the University of California, Santa Cruz, has been studying the submarine springs at Puerto Morelos near the Mesoamerican reef for the past three years.

In a paper published online Nov. 20 in the the journal Coral Reefs, the researchers reported that they found  small, patchily distributed colonies of only a few species of corals, without the structurally complex corals that compose the framework of the nearby Mesoamerican Barrier Reef, one of the Caribbean’s largest coral reef ecosystems.

“This study has some good news and some bad news for corals,” said coauthor Adina Paytan, a research professor in the Institute of Marine Sciences at UC Santa Cruz. “The good news is that some species of corals are able to calcify and grow at very low pH. The bad news is that these are not the ones that build the framework of the coral reefs. So if this is an indication of what will happen with future ocean acidification, the reefs will not be as we know them today.”

The submarine springs, known as “ojos,” occur along the eastern coast of the Yucatan Peninsula. Limestone “karst” landforms near the coast feature underground drainage systems that discharge brackish water at the ojos. The discharged water has lower pH than the surrounding seawater, and these conditions have existed for thousands of years. Lowering the pH affects the chemical equilibrium of seawater with respect to calcium carbonate, reducing the concentration of carbonate ions and making it harder for organisms such as corals to build and maintain structures of calcium carbonate.

Read more: 

Swimmers' Sunscreen Killing Off Coral

Normal coral (left) exposed to ultraviolet filters found in sunscreen "bleaches" white (right) when the algae living inside it die.

The sunscreen that you dutifully slather on before a swim on the beach may be protecting your body—but a new study finds that the chemicals are also killing coral reefs worldwide. 

Four commonly found sunscreen ingredients can awaken dormant viruses in the symbiotic algae called zooxanthellae that live inside reef-building coral species.

The chemicals cause the viruses to replicate until their algae hosts explode, spilling viruses into the surrounding seawater, where they can infect neighboring coral communities.

Zooxanthellae provide coral with food energy through photosynthesis and contribute to the organisms' vibrant color. Without them, the coral "bleaches"—turns white—and dies.

"The algae that live in the coral tissue and feed these animals explode or are just released by the tissue, thus leaving naked the skeleton of the coral," said study leader Roberto Danovaro of the Polytechnic University of Marche in Italy.

The researchers estimate that 4,000 to 6,000 metric tons of sunscreen wash off swimmers annually in oceans worldwide, and that up to 10 percent of coral reefs are threatened by sunscreen-induced bleaching. 

Read more @ National Geographic 

Australia to create world’s largest marine reserve in Coral Sea

CANBERRA, Australia — Australia says it will create the world’s largest marine reserve in the Coral Sea.

The Environment Ministry says the area has shallow reefs that support tropical ecosystems with sharks, coral, sponges and many fish species. The proposal includes seas beyond the already protected Great Barrier Reef Marine Park off northeast Australia.

The reserve would cover almost 400,000 square miles (nearly 1 million square kilometers).
Fishing would be allowed in parts of the reserve. Some conservationists raised concern such exceptions would make management of the reserve more difficult.

The proposal announced in a ministry statement Friday is now open for a 90-day comment period.
Copyright 2011 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

The Guilty Coral Killers

The elusive culprits that are killing countless coral reefs around the world can now be nabbed with technology normally used to diagnose human diseases, marine researchers say.

Coral researchers and reef managers will be able to identify coral infections using a new method that allows them to classify specific diseases based on the presence of microbes.
This could lead to more effective action to reduce the impact of disease on the world's imperilled coral reefs.

"Current classification of coral diseases is mostly based on a description of how the coral has deteriorated, such as the pattern of tissue loss and abnormal colours," says Joseph Pollock, a PhD student at the ARC Centre of Excellence for Coral Reef Studies. "This is an ineffective way to identify coral diseases because different diseases can often look very similar. For instance, in the Caribbean alone, more than six "white" diseases show the same characteristics of tissue loss exposing white coral skeletons.

Coral diseases can be caused by a number of different microbes, including viruses, bacteria and fungi. Knowing exactly which toxic organism leads to a particular disease is therefore important for accurate diagnosis – and for planning how to manage or control its impact.

One of Pollock's supervisors, David Bourne from the Australian Institute of Marine Science, says that the recent worldwide decline of coral reefs has been accompanied by increased disease, creating an urgent need for a deeper understanding of the various diseases, including what harmful bacteria and viruses contribute to different coral diseases, what triggers them and how they spread.
"Instead of relying on appearances to tell us what disease the corals have, we need to determine what's happening to them before the symptoms show. This will help us to control, or reduce the impacts."
Read more: 

US Residents Say Hawaii's Coral Reef Ecosystems Worth $33.57 Billion Per Year

A peer-reviewed study commissioned by NOAA shows the American people assign an estimated total economic value of $33.57 billion for the coral reefs of the main Hawaiian Islands.

"The study shows that people from across the United States treasure Hawaii's coral reefs, even though many never get to visit them," said Jane Lubchenco, Ph.D., under secretary of commerce for oceans and atmosphere and NOAA administrator. "It illustrates the economic value of coral reefs to all Americans, and how important it is to conserve these ecosystems for future generations."

"We are pleased that research is being done to look at the value of Hawaii's coral reefs, but before we consider any potential applications of the study we will consult closely with local communities," said William J. Aila, Jr., chairperson of the Hawaii Department of Land and Natural Resources.

The study employed a scientifically developed national Internet survey of more than 3,200 households -- a representative sample of all U.S. residents, not just Hawaii or coastal residents. From June through October 2009, the survey allowed the public to express its preferences and values for protection and restoration of the coral reef ecosystems around the main Hawaiian Islands. In this study, total economic value includes so-called passive use values, such as the willingness to pay to protect the coral reef ecosystem for future generations, as well as direct use values, such as snorkeling over a coral reef or consuming fish supported by coral reef ecosystems.

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Clownfish

In a symbiotic mutualism, the clownfish feeds on small invertebrates which otherwise potentially could harm the sea anemone, and the fecal matter from the clownfish provides nutrients to the sea anemone. The clownfish is additionally protected from predators by the anemone's stinging cells, to which the clownfish is immune.

There has to be something special about a place for it to be nominated as one of the seven natural wonders of Oceania.

In a region encompassing such idyllic island destinations as Palau, Fiji, Tonga, Vanuatu and Samoa, not to mention New Zealand's stunning landscapes, some stiff competition exists for the title of "natural wonder".

Marovo Lagoon in the Solomon Islands is one of those candidates and its nomination is well-deserved.

As the largest saltwater lagoon in the world, Marovo is a treasure trove of deserted beaches, winding mangroves streams and some of the best coral- reef diving in the world.

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