View on Private Sector: Insuring against climate change

Aamna Modhin in SciDev.net: A recent UN report said that global warming will cause trillions of dollars of damage to coral reefs in the Caribbean. It also warned that small island states will be disproportionally affected by the impact of climate change: their coral reefs, which their economies depend on, are under significant environmental stress.

One news report on the document noted that the insurance industry could play a role in safeguarding such nations’ economies by providing stronger theoretical frameworks in which to understand risks to reefs.

I asked Mike Maran, chief science officer at insurance firm Catlin Group, what such efforts might look like. He tells me the firm is sponsoring a global scientific survey of coral reefs, including some in the Caribbean, with the aim of monitoring their health over the coming years.

Why would an insurance company do such a thing? Maran explains that scientific evidence helps insurers understand what might happen to reefs in the future, and how fast. Although firms do not insure the reefs directly, Maran says they have a broad obligation to study the risks society will face in the future so as to understand and manage those risks. The collection of robust scient
ific information gives insurers a good understanding of how the planet is changing and the impact these changes will have on policyholders.

Many of the risks involved in policies firms do provide — for example insurance for homes, other properties and businesses — could be linked to climate change, and so understanding changes to reefs as a proxy measure of that will help quantify those risks. For example, reef degradation could have an impact on fishing or tourism industries and so indirectly change the value of insured assets....

A coral reef in Biscayne National Park in Florida, shot by a Park Service employee

Coral cultivation offers hope to devastated western Indian Ocean reefs

Wanjohi Kabukuru at the Thomson Reuters Foundation: Marine scientists in the Seychelles are propagating and replanting corals resistant to bleaching in the hope of replacing destroyed reefs in the western Indian Ocean with ones that are more resilient.

Each workday, Claude Reveret and Sarah Frias-Torres of Nature Seychelles, a not-for-profit environmental organisation, lead a team of scuba divers down to the ocean floor around Praslin, the country’s second-largest island, and the nearby Cousin Island Special Reserve.

There they take part in an unusual undersea gardening project – cultivating corals that have proven resistant to the stress caused by warming water, which has led to the collapse of coral reef systems in the western Indian Ocean.

The large-scale death of coral reefs has exposed the Seychelles to increased erosion and the loss of fisheries that the reefs had harboured. The Indian Ocean island nations of Mauritius and Comoros and the eastern African countries of Mozambique, Tanzania, Kenya and Somalia are also affected.

The restoration project, which began in 2010 with over $700,000 in funding from the US Agency for International Development and the UN Development Programme, “is our response to climate change effects,” says Reveret....

Marie Louise Island, Amirantes, Outer Islands of the Seychelles. Shot by Acp at de.wikipedia, Wikimedia Commons,  under the Creative Commons Attribution-Share Alike 3.0 Unported license 

Coral sperm frozen to protect Australia’s Great Barrier Reef

Phil Mercer in Voice of America: Coral sperm in Australia's Great Barrier Reef is being cryogenically frozen to protect some of the animal species from extinction.  A sperm bank has been set up hundreds of kilometers away at a zoo in the New South Wales outback that should allow researchers to re-introduce the samples into the Reef in the future.

The coral sperm bank is an insurance policy against the various threats that the Great Barrier Reef faces, such as warming temperatures, ocean acidification and pollution.  Human fertility techniques are being used to deep freeze billions of sperm in liquid nitrogen.  The cryogenic process was developed in Hawaii and could one day allow researchers to reseed vulnerable parts of Australia’s greatest natural treasure.

“I had been developing this technology in the United States and had successfully cryo-preserved coral sperm and embryonic cells there. But we thought that we could now start to actively apply this in terms of conservation in Australia and have it impact on the Great Barrier Reef,” said Dr. Mary Hagedorn, who is from the Smithsonian Institute.

The coral gene bank has been set up at the Western Plains Zoo in Dubbo in the state of New South Wales, many hundreds of kilometers from the reef.

Scientists say some of the samples could be stored for hundreds of years until such time as they are needed.  Some samples have already been used to help fertilize new coral and replenish ailing parts of the Great Barrier Reef...

A coral outcrop at Flynn Reef, shot by Toby Hudson, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Great Barrier Reef report warns of cumulative effect of development

Oliver Milman in the Guardian (UK): The health of the Great Barrier Reef is declining and requires an urgent "net benefit policy" to ensure development along the Queensland coast does no further damage to the vast coral ecosystem, according to a major government assessment.

The Great Barrier Reef strategic assessment warns that the reef faces numerous threats, including erosion of water quality, a plague of crown-of-thorns starfish and climate change, which is described as the "most serious long-term risk facing the reef".

The Great Barrier Reef Marine Park Authority's report, which analysed the health of the World Heritage-listed marine park area, identified the need to reduce sediment, nitrogen and nutrient flows onto the reef. A parallel report, conducted by the Queensland government, looked at the condition of the coastline alongside the Great Barrier Reef.

The marine park assessment states that "urgent and effective" intervention is required. It proposes that a "net benefit policy" should ensure coastal activities produce an overall benefit to the reef, with more focus on the overall impact of human activities and weather events such as cyclones, rather than individual events....

A satellite image of the Great Barrier Reef, from NASA

Human deforestation outweighs climate change for coral reefs

University of Western Australia: Better land use is the key to preventing further damage to the world's coral reefs, according to a study published this week in the online science journal Nature Communications. The study, by an international team including a researcher from The University of Western Australia's Oceans Institute, has important implications for Australia's Great Barrier Reef.

The study authors write that preventing soil erosion and sediment pollution arising from human activities such as deforestation are crucial to reef survival.

The study - ‘Human deforestation outweighs future climate change impacts of sedimentation on coral reefs' - looked at the effects of future climate change on the hydroclimate of Madagascar's reefs and different deforestation scenarios.

"The findings are very relevant for Australia since intense land use and past deforestation have transformed the river catchments tremendously and are seen as a major threat to coral reefs in the Great Barrier Reef and elsewhere," said Dr Jens Zinke, of UWA's Oceans Institute.

"Managing hinterland land use is the major action needed to buy time for corals growing near rivers." Dr Zinke said the study looked at four watersheds near coral reef ecosystems in Madagascar, which has different climate zones that mimic most of the world's coral reef climate and a range of different land uses...

In the Great Barrier Reef, shot by Steve Evans, Wikimedia Commons via Flickr,  under the Creative Commons Attribution 2.0 Generic license

Catastrophic climatic events leave corals with a decade-long fight for recovery

University of Plymouth News Centre: Marine conservationists from Plymouth University, and the Universidad Federal da Bahia in Brazil, have spent more than 17 years analysing the diversity and density of coral colonies off the coast of South America.

That coincided with the catastrophic El Niño event of 1997-98, creating an opportunity for the first detailed assessment of the long-term impact a major environmental incident of this nature can have on coral assemblages.

Professor Martin Attrill, Director of Plymouth University’s Marine Institute, said: “Coral reefs are perhaps the most diverse marine ecosystem on Earth, potentially holding 25% of the known marine species. Yet they are under intense threat from a range of local human activities and, in particular, climate change. Any impact on the corals is going to have major knock on effects on the organisms that live on coral reefs, such as the fish, and if climatic events become more frequent, as is suggested, it is likely corals will never be able to fully recover."

...For this study, the research team used their own observations of eight species of scleractinian corals, and data from the Brazilian Meteorological Office, to create a full picture of environmental conditions and species behaviour that resulted.  It showed a significant rise in air and seawater temperatures in 1998, with increased mortality across all species and, in one case, it disappearing completely from the reefs for more than seven years.

The density of the coral in the area also fell after 1998, but then increased continuously until 2007, with recent measurements showing it is now mostly back to pre-1998 levels.  Professor Attrill added: “El Niño events give us an indication of how changing climate affects ecosystems as major changes in the weather patterns within the Pacific impact the whole world. If the reefs can recover quickly, it is probable they can adapt and survive the likely changes in water temperature ahead of us. However, we found it took 13 years for the coral reef system in Brazil to recover, suggesting they may be very vulnerable to regular climate-related impacts. This has major consequences for how we consider climate change impacts on coral reefs.”...

A brain coral off the coast of Belize, shot by Pgbk1987, Wikimedia Commons via Flickr,  under the Creative Commons Attribution-Share Alike 2.0 Generic license

Air pollution stunts coral growth

University of Exeter News: A new study has found that pollution from fine particles in the air – mainly the result of burning coal or volcanic eruptions – can shade corals from sunlight and cool the surrounding water resulting in reduced growth rates.

Although coral reefs grow under the sea it seems that they have been responding to changes in the concentration of particulate pollution in the atmosphere, according to a paper published in the journal Nature Geoscience by a team of climate scientists and coral ecologists from the UK, Australia and Panama. Corals are colonies of simple animal cells but most rely on photosynthetic algae for their energy and nutrients.

Lead author Lester Kwiatkowski, a PhD student from Mathematics at the University of Exeter, said: “Coral reefs are the most diverse of all ocean ecosystems with up to 25% of ocean species depending on them for food and shelter. They are believed to be vulnerable to climate change and ocean acidification, but ours is the first study to show a clear link between coral growth and the concentration of particulate pollution in the atmosphere.”

Dr Paul Halloran of the Met Office Hadley Centre explained: “Particulate pollution or ‘aerosols’ reflect incoming sunlight and make clouds brighter. This can reduce the light available for coral photosynthesis, as well as the temperature of surrounding waters. Together these factors are shown to slow down coral growth.”...

Soft white coral in East Timor, shot by Nhobgood, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Remote reefs can be tougher than they look

ARC Centre of Excellence/Coral Reef Studies: Isolated coral reefs can recover from catastrophic damage as effectively as those with nearby undisturbed neighbours, a long-term study by marine biologists from the Australian Institute of Marine Science (AIMS) and the ARC Centre of Excellence for Coral Reef Studies (CoECRS) has shown.

Scott Reef, a remote coral system in the Indian Ocean, has largely recovered from a catastrophic mass bleaching event in 1998, according to the study published in Science today. The study challenges conventional wisdom that suggested isolated reefs were more vulnerable to disturbance, because they were thought to depend on recolonisation from other reefs. Instead, the scientists found that the isolation of reefs allowed surviving corals to rapidly grow and propagate in the absence of human interference.

Australia’s largest oceanic reef system, Scott Reef, is relatively isolated, sitting out in the Indian Ocean some 250 km from the remote coastline of north Western Australia (WA). Prospects for the reef looked gloomy when in 1998 it suffered catastrophic mass bleaching, losing around 80% of its coral cover. The study shows that it took just 12 years to recover.

Spanning 15 years, data collected and analysed by the researchers shows how after the 1998 mass bleaching the few remaining corals provided low numbers of recruits (new corals) for Scott Reef. On that basis recovery was projected to take decades, yet within 12 years the cover and diversity of corals had recovered to levels similar to those seen pre-bleaching.

“The initial projections for Scott Reef were not optimistic,” says Dr James Gilmour from AIMS, the lead author on the publication, “because, unlike reefs on the Great Barrier Reef, there were few if any reefs nearby capable of supplying new recruits to replenish the lost corals at Scott Reef. However, the few small corals that did settle at Scott Reef had excellent rates of survival and growth, whereas on many nearshore reefs high levels of algae and sediment, and poor water quality will often suppress this recovery...."

Scott Reef, via NASA

Fluorescent light revealed as gauge of coral health

UC San Diego's News Center: Reef-building corals create an oasis of life and diversity in a sparse ocean. Because branching Acropora corals such as those pictured here in the Central Pacific are in peril from climate change, the whole ecosystem is in danger of collapse. Photo credit: Melissa Roth

Coral reefs not only provide the world with rich, productive ecosystems and photogenic undersea settings, they also contribute an economic boost valued at hundreds of billions of dollars. But their decline in recent years due to a variety of threats—from pollution to climate warming—has lent urgency to the search for new ways to evaluate their health.

A new study by Scripps Institution of Oceanography at UC San Diego scientists has revealed that fluorescence, the dazzling but poorly understood light produced by corals, can be an effective tool for gauging their health.

As described in the March 12 edition of Scientific Reports (a publication of the Nature Publishing Group), marine biologists Melissa Roth and Dimitri Deheyn describe groundbreaking research using fluorescence to test coral stress prompted from cold and heat exposures.

In experimental studies conducted at Scripps, Roth and Deheyn tested the common Indo-Pacific reef-building branching coral Acropora yongei under various temperatures. Branching corals are susceptible to temperature stress and often one of the first to show signs of distress on a reef. Roth and Deheyn found, at the induction of both cold and heat stress, corals rapidly display a decline in fluorescence levels. If the corals are able to adapt to the new conditions, such as to the cold settings in the experiment, then the fluorescence returns to normal levels upon acclimation....

Blue coral in Papua New Guinea, shot by Brocken Inaglory, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Scientists create new maps depicting potential worldwide coral bleaching by 2056

EurekAlert via the University of Miami Rosenstiel School of Marine & Atmospheric Science: In a study published today in Nature Climate Change researchers used the latest emissions scenarios and climate models to show how varying levels of carbon emissions are likely to result in more frequent and severe coral bleaching events.

Large-scale 'mass' bleaching events on coral reefs are caused by higher-than-normal sea temperatures. High temperatures make light toxic to the algae that reside within the corals. The algae, called 'zooxanthellae', provide food and give corals their bright colors. When the algae are expelled or retained but in low densities, the corals can starve and eventually die. Bleaching events caused a reported 16 percent loss of the world's coral reefs in 1998 according to the Global Coral Reef Monitoring Network.

If carbon emissions stay on the current path most of the world's coral reefs (74 percent) are projected to experience coral bleaching conditions annually by 2045, results of the study show. The study used climate model ensembles from the upcoming Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).

Around a quarter of coral reefs are likely to experience bleaching events annually five or more years earlier than the median year, and these reefs in northwestern Australia, Papau New Guinea, and some equatorial Pacific islands like Tokelau, may require urgent attention, researchers warn.

...The findings emphasize that without significant reductions in emissions most coral reefs are at risk, according to the study. A reduction of carbon emissions would delay annual bleaching events more than two decades in nearly a quarter (23 percent) of the world's reef areas, the research shows.

..."More so than any result to date, this highlights and quantifies the potential benefits for reefs of reducing emissions in terms of reduced exposure to stressful reef temperatures."

Coral shot by Janine, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

US study says El Nino, climate change link fuzzy

Space Daily via AFP: The frequency and volatility of El Nino, a weather pattern that hammers the tropical Pacific Ocean every five years or so, does not seem linked to climate change, said US research released Thursday. The study involved scientists measuring the monthly growth of ancient coral fossils found on two tropical Pacific islands to determine what, if any, impact the warming climate had on the weather phenomenon.

By reconstructing temperatures and precipitation over the millenniums, the study compared it to the frequency and intensity of El Nino and found that the latter had indeed become more intense and frequent in the 20th century.

But although the increase was statistically significant and could be linked to climate change, the long historic record provided by the coral fossils allowed the researchers to determine that the El Nino Southern Oscillation, or ENSO, has also had large natural variations in past centuries. Thus, it is not clear that changes seen in recent decades can be linked to climate change caused by rising levels of carbon dioxide, the researchers said.

"The level of ENSO variability we see in the 20th century is not unprecedented," said climatologist Professor Kim Cobb, from the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology. "But the 20th century does stand out, statistically, as being higher than the fossil coral baseline," she added....

Fossilized coral stones, shot by Irwan Holmes, Wikimedia Commons, under the Creative Commons Attribution 3.0 Unported license

Indonesia's fisheries most 'vulnerable to collapse'

Clara Rondonuwu in SciDev.net: Indonesia and Liberia's coral reef fisheries are most vulnerable to collapse, says a study that has ranked the vulnerability of coastal nations based on indicators for their coral reef management, fisheries and food security.

The study, published in this month's Environmental Science and Policy, looked at 27 countries that depend significantly on coral reef fisheries for food and ranked them according to their exposure and sensitivity to the effects of climate change and man-made disturbances, as well on their capacity to adapt to changes.

Coral reefs are globally valued for their high biodiversity. For millions of people, they are a productive source of food. An average Indonesian gets almost 60 per cent of its animal protein from fish, while in Pacific island countries this figure is between 50 to 90 per cent. However, coral reef fisheries are expected to decline with climate change and other human caused disturbances.

In the new study, a higher sensitivity indicates that a country is highly dependent on coral reef fisheries for human protein sources, and is already close to or below the minimum protein consumption level, while capacity to adapt is the potential to respond to changes in the contribution of reef fisheries to the food system.

They found that Indonesia is the most vulnerable because of the combined effects of man-made disturbance and very high sensitivity. Liberia, the second most vulnerable, has very high sensitivity to coral reef fisheries decline and the lowest level of adaptive capacity. Kenya, Ivory Coast and the Philippines complete the top five most vulnerable....

Hundreds of fisherman boats on the beach at Pangandaran, Indonesia, shot by Danumurthi Mahendra, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

Great Barrier Reef coral halved in 27 years

Amy Coopes in AFP: Australia's Great Barrier Reef has lost more than half its coral cover in the past 27 years due to storms, predatory starfish and bleaching linked to climate change, a study found Tuesday. The research by scientists from the Australian Institute of Marine Sciences (AIMS) and the University of Wollongong warned that coral cover on the heritage-listed reef -- the world's largest -- could halve again by 2022 if trends continued.

Intense tropical cyclones -- 34 in total since 1985 -- were responsible for much of the damage, accounting for 48 percent, with outbreaks of the coral-feeding crown-of-thorns starfish linked to 42 percent. Two severe coral bleaching events in 1998 and 2002 due to ocean warming also had "major detrimental impacts" on the central and northern parts of the reef, the study found, putting the impact at 10 percent.

Two-thirds of the loss had occurred since 1998, with the rate of decline increasing substantially and only three of the 214 individual reefs surveyed across the sprawling 345,000 square kilometre site escaping any impact. "This loss of over half of initial cover is of great concern, signifying habitat loss for the tens of thousands of species associated with tropical coral reefs," the study said.

Author Hugh Sweatman said the findings, which were drawn from the world's largest ever reef monitoring project involving 2,258 surveys over 27 years, showed that coral could recover from such trauma....

A giant clam in the Great Barrier Reef, shot by Janderk, public domain

Most coral reefs are at risk unless climate change is drastically limited

Science Blog: Only under a scenario with strong action on mitigating greenhouse-gas emissions and the assumption that corals can adapt at extremely rapid rates, could two thirds of them be safe, shows a study now published in Nature Climate Change. Otherwise all coral reefs are expected to be subject to severe degradation.

Coral reefs house almost a quarter of the species in the oceans and provide critical services – including coastal protection, tourism and fishing – to millions of people worldwide. Global warming and ocean acidification, both driven by human-caused CO2 emissions, pose a major threat to these ecosystems.

“Our findings show that under current assumptions regarding thermal sensitivity, coral reefs might no longer be prominent coastal ecosystems if global mean temperatures actually exceed 2 degrees Celsius above the pre-industrial level,” says lead author Katja Frieler from the Potsdam Institute for Climate Impact Research. “Without a yet uncertain process of adaptation or acclimation, however, already about 70% of corals are projected to suffer from long-term degradation by 2030 even under an ambitious mitigation scenario.” Thus, the threshold to protect at least half of the coral reefs worldwide is estimated to be below 1.5 degrees Celsius mean temperature increase.

This study is the first comprehensive global survey of coral bleaching to express results in terms of global mean temperature change. It has been conducted by scientists from Potsdam, the University of British Columbia in Canada and the Universities of Melbourne and Queensland in Australia. To project the cumulative heat stress at 2160 reef locations worldwide, they used an extensive set of 19 global climate models. By applying different emission scenarios covering the 21st century and multiple climate model simulations, a total of more than 32,000 simulation years was diagnosed. This allows for a more robust representation of uncertainty than any previous study....

A coral reef in Papua New Guinea, shot by Brocken Inaglory, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Coral reef thriving in sediment-laden waters

EurekAlert: Rapid rates of coral reef growth have been identified in sediment-laden marine environments, conditions previously believed to be detrimental to reef growth. A new study has established that Middle Reef – part of Australia's iconic Great Barrier Reef – has grown more rapidly than many other reefs in areas with lower levels of sediment stress.

...The research team collected cores through the structure of Middle Reef to analyse how it had grown. They used radiocarbon dating to map out the precise growth rate of the reef. Results show that the reef started to grow only about 700 years ago but that it has subsequently grown rapidly towards sea level at rates averaging nearly 1 cm per year. These rates are significantly higher than those measured on most clear water reefs on the Great Barrier Reef and elsewhere. Most intriguingly, the periods of most rapid growth – averaging 1.3 cm a year – occurred when the accumulation rates of land-derived sediment within the reef structure were also at their peak. They discovered that, while the reef faced high sediment levels after the European settlers arrived in the 1800s, these same conditions were also part of the long-term environmental regime under which the reef grew.

Although there is evidence that other reefs have suffered degradation from high levels of sediment, these findings suggest that in some cases reefs can adapt to these conditions and thrive. For Middle Reef, rapid rates of vertical reef growth have, paradoxically, probably been aided by the high sedimentation rates. The team believe this is because the accumulating sediment rapidly covers the coral skeletons after their death, preventing their destruction by fish, urchins and other biological eroders, thus promoting coral framework preservation and rapid reef growth.

Professor Chris Perry of Geography at the University of Exeter said: "Our research challenges the long-held assumption that high sedimentation rates are necessarily bad news in terms of coral reef growth. It is exciting to discover that Middle Reef has in fact thrived in these unpromising conditions. It is, however, important to remain cautious when considering what this means for other reefs. Middle Reef includes corals adapted to deal with high sedimentation and low light conditions. Other reefs where corals and various other reef organisms are less well adapted may not do so well if sediment inputs increased....

The Great Barrier Reef off the coast of Queensland, from NASA

Pacific Coral Triangle 'at risk of collapse'

Nora Gamolo in SciDev.net: The Coral Triangle, a roughly triangular marine zone in the Indo-Pacific region that is considered to have the world's richest concentration of marine biodiversity, is facing potential ecological collapse due to heavy pressure inflicted by human activities, according to a new report.

The warning appears in a collaborative study, 'Reefs at Risk Revisited in the Coral Triangle', produced by a consortium led by the World Resources Institute, a global environmental think-tank based in Washington DC, United States.

It serves as a status report on the wellbeing of coral reefs in or near the six countries comprising the triangle. The study aimed to identify where reefs are most threatened and to provide "baseline data to help groups establish and prioritise specific management strategies," Kathleen Reytar, a lead author of the study, told SciDev.Net.

According to the report, 85 per cent of reefs in the Coral Triangle are directly threatened by local human activities such as overfishing, the use of poisons and dynamite in fishing, watershed-based pollution (fertilisers, pesticides and other runoff from the land), and coastal development....

Image by Eurobas, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported

Indo-Pacific coral reefs: In trouble - but tougher than we thought

ARC Centre of Excellence, Coral Reef Studies: Coral reefs in the Indo-Pacific region, including the Great Barrier Reef, recover faster from major stresses than their Caribbean counterparts, leading marine scientists said today. Dr George Roff and Professor Peter Mumby from the ARC Centre of Excellence for Coral Reef Studies and The University of Queensland told the 12th International Coral Reef Symposium in Cairns that coral reefs in the Indo-Pacific Ocean are naturally tougher than the Caribbean reefs.

“The main reason that Indo-Pacific reefs are more resilient is they have less seaweed than the Caribbean Sea,” Dr Roff says. “Seaweed and corals are age-old competitors in the battle for space. When seaweed growth rates are lower, such as the Indo-Pacific region, the reefs recover faster from setbacks. This provides coral with a competitive advantage over seaweed, and our study suggests that these reefs would have to be heavily degraded for seaweeds to take over.

“This doesn’t mean that we can be complacent – reefs around the world are still heavily threatened by climate change and human activities,” he says. “What it indicates is Indo-Pacific reefs will respond better to protection, and steps we take to keep them healthy have a better chance of succeeding.”

“Many of the doom and gloom stories have emanated from the Caribbean, which has deteriorated rapidly in the last 30 years,” says Professor Mumby. “We now appreciate that the Indo-Pacific and Caribbean are far more different than we thought.”

...“We’re not sure why this happens, but a plausible theory is that Caribbean waters are highly enriched in iron,” they say. “For thousands of years, the Caribbean Sea has received dusts that blow across the Atlantic from the Sahara, and the dust contains iron – an essential element for algae to grow....

A heart-shaped reef off the coast of Queensland, shot by Marlène BOUGARD, Wikimedia Commons, Copyleft: This work of art is free; you can redistribute it and/or modify it according to terms of the Free Art License.

Coral reefs may be able to adapt to climate change with help from algae

Science Daily: A new study by scientists at the University of Miami's Rosenstiel School of Marine & Atmospheric Science suggests that many species of reef-building corals may be able to adapt to warming waters by relying on their closest aquatic partners -- algae. The corals' ability to host a variety of algal types, each with different sensitivities to environmental stress, could offer a much-needed lifeline in the face of global climate change.

Using a highly sensitive genetic technique, Ph.D. student Rachel Silverstein analyzed 39 coral species from DNA collected in the Indo-Pacific and Caribbean collected over the last 15 years. Most of these species had not previously been thought capable of hosting more than one type of the single-celled symbiotic algae, called zooxanthellae, which live inside the coral and help to supply them with energy.

Silverstein's results revealed that at least one colony of all 39 species tested had at least two varieties of algae, including one thought to be heat tolerant. Over half of the species were found to associate with all four of the major types of algae found in corals.

"This study shows that more coral species are able to host multiple algal symbionts than we previously thought," said Andrew Baker, associate professor at UM's Rosenstiel School and co-author of the study. "The fact that they all seem to be capable of hosting symbionts that might help them survive warmer temperatures suggests they have hidden potential that was once thought to be confined to just a few special species."

..."Although our study shows that different coral species do tend to have preferences in their algal partners, the fact that these preferences are not absolutely rigid means that we cannot ignore the possibility that most corals might change partners in response to environmental changes in the future," said Silverstein....

A Red Sea coral reef, shot by Hagainativ, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Coral reefs indicate ancient 'mega-flood'

The Tehran Times via UPI: Studies of corals off Tahiti hint an ancient "mega flood" occurred when massive ice sheets collapsed and raised sea levels by 45 feet, European researchers say. Scientists from Aix-Marseille University in France and Britain's Oxford University said they've confirmed the event occurred between 14,650 and 14,310 years ago, during a period of rapid climate change known as the Bolling warming.

Scientists modeling future climate-change scenarios can use the findings to factor in the dynamic behavior of major global ice sheets, they said. "Our work gives a window onto an extreme event in which deglaciation coincided with a dramatic and rapid rise in global sea levels -- an ancient 'mega flood,'" Alex Thomas of Oxford University's Department of Earth Sciences said.

"Sea level rose more than 10 times more quickly than it is rising now! This is an excellent test bed for climate models: if they can reproduce this extraordinary event, it will improve confidence that they can also predict future change accurately," he said in an Oxford release.

During the so-called Bolling warming high latitudes of the Northern hemisphere warmed as much as 27 degrees Fahrenheit in less than a century, the researchers said....

The Wilkins Ice Bridge collapsing in March, 2009

Overfishing, deforestation and climate change cause declines in Caribbean coral reefs

Science Codex: The decline of Caribbean coral reefs has been linked to the recent effects of human-induced climate change. However, new research led by scientists at Scripps Institution of Oceanography at UC San Diego suggests an even earlier cause. The bad news – humans are still to blame. The good news – relatively simple policy changes can hinder further coral reef decline.

Employing a novel excavation technique to reconstruct the timeline of historical change in coral reefs located on the Caribbean side of Panama, a team of scientists led by Scripps alumna Katie Cramer and current Scripps Professor of Oceanography and Smithsonian Tropical Research Institute (STRI) Emeritus Staff Scientist Jeremy Jackson has determined that damage to coral reefs from land clearing and overfishing pre-dates damage caused by anthropogenic climate change by at least decades.

"This study is the first to quantitatively show that the cumulative effects of deforestation and possibly overfishing were degrading Caribbean coral and molluscan communities long before climate change impacts began to really devastate reefs," said lead author Cramer, currently based at the Global Coral Reef Monitoring Network at the International Union for Conservation of Nature.

Coral reefs have suffered alarmingly since the 1980s due to coral bleaching and coral disease, thought to stem from the warming of the oceans due to anthropogenic, or human-induced, climate change. However, until recently, the impact of prior human activities on Caribbean coral reefs had not been studied with experimental techniques.

Historical records and qualitative surveys provide hints that declines in corals in some parts of the Caribbean occurred as far back as the early 1900s after coastal lands began to be cleared to make way for plantations. However, the current study is the first to quantify the changes that reef corals and mollusks have undergone as a result of long-term stress caused by the deposition of silt, nutrients, and pollution onto coral reefs from land clearing and the depletion of reef fish that prevent algae from overtaking reefs...

Fish and coral, shot by Maniacduhockey, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license