tagged w/ calcification
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By 2030, more than 90% of coral reefs could be threatened by local activities like overfishing and global-wide events like climate change, say researchers at the World Resources Institute.
Destruction of these valuable ecosystems would be a devastating environmental and economic tragedy. While only 0.1% of total ocean area, coral reefs host around 25% of marine life. They also help drive economic activity from fishing, tourism and help protect communities from storm surges — providing a benefit that stretches far beyond the oceans.
Different reefs are at risk for different reasons. The World Resources Institute has been working on tracking damages to these ecosystems for the last three years, providing detailed maps and data on the health of reefs in different regions of the world.
Researchers at WRI just put together a fascinating video using Google Earth maps to illustrate how reefs in the Caribbean, Middle East, Indian Ocean, Southeast Asia, Australia and the Pacific are fairing — and what kind of impact that could have to communities in those regions.
At 14 minutes long, the video is quite long. But it’s worth a watch. If you don’t have time to see the whole thing, check out the range of maps and charts on the health of these reefs.
More at the linkBy 2030, more than 90% of coral reefs could be threatened by local activities like... more
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Man-made carbon emissions have acidified the world's oceans far beyond their natural levels, new research suggests.
In some regions, acidity levels rose faster in the last two centuries than it did in the previous 21,000 years, a study from the University of Hawaii has shown. Ocean acidity makes it harder for organisms such as molluscs and coral to construct the protective layers they need to survive.
Measuring changes in ocean acidity is difficult because it varies naturally between seasons, years and regions. Scientists looked at changes in the saturation level of aragonite, a form of calcium carbonate used to measure ocean acidification.
As seawater acidity rises, the saturation level of aragonite falls. Direct observations only date back 30 years, which is not long enough to reveal a meaningful trend. However the new research used simulations of ocean and climate conditions going back 21,000 years to the Last Glacial Maximum and forward in time to the end of the 21st century.
In several key coral reef regions aragonite saturation is already five times below its lowest pre-industrial range, according to the model. This translates to a decrease in overall calcification rates of corals and other shell-forming organisms of 15%, scientists at the university believe.
They fear calcification rates of some marine organisms could drop by more than 40% of their pre-industrial levels within the next 90 years.
Dr Tobias Friedrich, from the University of Hawaii, who led the study published in the journal Nature Climate Change, said: 'Any significant drop below the minimum level of aragonite to which the organisms have been exposed to for thousands of years and have successfully adapted will very likely stress them and their associated ecosystems.
'In some regions, the man-made rate of change in ocean acidity since the industrial revolution is 100 times greater than the natural rate of change between the Last Glacial Maximum and pre-industrial times.'
He added: 'When Earth started to warm 17,000 years ago, terminating the last glacial period, atmospheric CO2 (carbon dioxide) levels rose from 190 parts per million (ppm) to 280 ppm over 6,000 years.
'Marine ecosystems had ample time to adjust. Now, for a similar rise in CO2 concentration to the present level of 392 ppm, the adjustment time is reduced to only 100 - 200 years.'
Co-author Professor Axel Timmermann, also from the University of Hawaii, said: 'Our results suggest that severe reductions are likely to occur in coral reef diversity, structural complexity and resilience by the middle of this century.'
Read more: http://www.dailymail.co.uk/sciencetech/article-2090253/Oceans-acidified-200-years-did-previous-21-000-years-claims-new-climate-change-research.html#ixzz1kJIObunQMan-made carbon emissions have acidified the world's oceans far beyond their... more
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Carbon dioxide bubbles in the extreme low acidity zone. The brown landscape below is devoid of the sea urchins, gastropods and worms, found in areas with a normal level of acidity in the Mediterranean Sea. Credit: Kristy J. Kroeker
Stanford researchers have gotten a glimpse into an uncertain future where increasing levels of carbon dioxide in the Earth's atmosphere will lead to higher levels in the ocean as well, leaving the water more acidic and altering underwater ecosystems.
The glimpse comes from waters near Ischia, Italy, where unusual shallow-water volcanic vents in the floor of the Mediterranean Sea bubble carbon dioxide into the water, creating a local underwater neighborhood that may resemble the ocean of the future.
If the results are a prediction of the future, "you are left with a dramatically different ecosystem that is likely going to be less able to deal with stress and is going to have less biomass available to feed organisms higher up the food chain," said Kristy Kroeker, a graduate student in biology at Stanford's Hopkins Marine Station.
More at the linkCarbon dioxide bubbles in the extreme low acidity zone. The brown landscape below is... more
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Today is World Oceans Day which is a day of celebrating the oceans of our planet and reflection on our mistreatment of them. Without oceans all life on Earth would cease. They drive our climate and weather and the web of life from the tiniest plankton to the largest whale, each species with a distinct part to play in our web of life.
They are mystical, beautiful, peaceful and colorful, but now also polluted, overfished, toxified, overdrilled, over saturated with Co2, depleted of oxygen, overheated and used as trash cans by humans who do not truly appreciate nor understand the wonder of it all.
So today if you can, try to give a thought to the oceans and their majesty and reflect on what you have done to allow the continued killing of them and just what will be left for future generations to enjoy, explore and survive.
The oceans are our lifeline. And we have forgotten.Today is World Oceans Day which is a day of celebrating the oceans of our planet and... more
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Despite what you may read or see in the mainstream media, out in the real world, massive and rapid changes are taking place in many ecological systems as a result of global warming. The Earth seems to be already convinced of global warming and is responding quickly.
Perhaps the most significant, and likely most enduring, are the shifts taking place in the Earth's oceans. Whilst many readers may have read or heard about Ocean Acidification, there are numerous other changes taking place in the oceans which should be equally as concerning. One such phenomena to appear in the last few decades is mass coral bleaching, a consequence of the continued warming of the oceans. Once vast stretches of colourful reefs teeming with marine life are being reduced to lifeless rubble covered in seaweed or slime. Many areas are not recovering, and the scale and frequency of bleaching worldwide is getting worse. In fact, early reports suggest 2010 may have witnessed the largest single bleaching event ever recorded.
The lowdown on coral bleaching
Reef-coral are actually a symbiosis (a mutually beneficial relationship) between the coral polyp, an anemone-like creature, and tiny algae called zooxanthellae. The coral provide shelter and nutrients for the algae , and in exchange the algae provide carbohydrates (food) to the polyp, using energy from the sun (photosynthesis) and the nutrients provided by the coral. These algae live in the skin tissue of the polyp and produce the coloured pigments which make coral reefs so visually spectacular. When this partnership breaks down the polyps expel the algae, which leads to the "bleached" effect. Although the polyp does feed using its tentacles to snare food, the bulk of its nutrition (90%+) comes from the algae, and they are a critical component of coral skeleton formation and therefore reef maintenance and growth. Without symbiotic algae, the coral can die from starvation, or become so weakened by a lack of food, that it succumbs to harmful bacteria (Mao-Jones 2010), and/or seaweeds which can poison and kill coral on contact.
Because reef-coral have adapted tolerance to a narrow band of environmental conditions, bleaching can occur for a number of reasons, such as ocean acidification, pollution, excess nutrients from run-off, high UV radiation levels, exposure at extremely low tides and cooling or warming of the waters in which the coral reside. Typically these events are very localized in scale and if bleaching is mild, the coral can survive long enough to re-acquire new algal partners. So bleaching in itself is not something new, but mass coral bleaching on the huge scale being observed certainly appears to be, and represents a whole new level of coral reef decline.
Ocean warming is driving mass coral bleaching
As coral reefs operate very near to their upper limit of heat tolerance (Glynn & D'Croz 1990), bleaching en masse happens when the surface waters get too warm above their normal summer temperature, and are sustained at this warmer level for too long. The intensity of bleaching corresponds with how high, and how long temperatures are elevated and, as one might expect, the intensity of bleaching affects the rate of survival. Small rises of 1 -2 degree C, for weeks at a time, usually induce bleaching.
This episodic ocean warming has been most pronounced worldwide during El-Nino events, when the Pacific Ocean exchanges heat to the atmosphere and surface waters. In recent years though, severe mass bleaching is happening outside of El-Nino because of the "background" ocean warming. The huge mass bleaching in the Caribbean in 2005, a non El-Nino year, and again this year is a prime example of this (Eakin 2010) . Evidence connecting warm surface waters and mass coral bleaching has strengthened to the extent that the National Oceanic and Atmospheric Administration (NOAA) has a coral bleaching alert system in place. This alert system accurately forecasts mass coral bleaching based on satellite data of sea surface temperatures.
Hot water + Coral = Dead coral
So how does hot water kill coral?. It requires both high water temperatures and sunlight. Oxygen is released as waste during photosynthesis and like all chemical processes this is affected by temperature, speeding up as more energy (warmth) is applied. When water temperatures rise too high the protective mechanisms to prevent heat damage, employed by the coral and the algae, are overwhelmed. The zooxanthellae algae produce high levels of oxygen waste which begin to poison the coral polyp. In acts of self-preservation the coral kick out the algae, and in doing so become susceptible to starvation, opportunistic diseases, competitive seaweeds and macroalgae (slime to you and me) . Coral can succumb to the effects of bleaching years later, and for those coral that survive, growth effectively ceases and full recovery can take anything up to a decade.
Coral resilience is futile
On a world scale coral reefs are in decline, and it makes for rather depressing reading for an avid diver like myself. Over the last 30-40 years 80% of coral in the Caribbean have been destroyed (Gardner 2003) and 50% in Indonesia and the Pacific (Bruno & Selig 2007). Bleaching associated with the 1982 -1983 El-Nino killed over 95% of coral in the Galapagos Islands (Glynn 1990), and the 1997-1998 El-Nino alone wiped out 16% of all coral on the planet. Globally about 1% of coral is dying out each year. Not all of this continual decline is solely down to bleaching of course, pollution and other human activities are also contributing, but bleaching is speeding up the loss of coral.
cont.Despite what you may read or see in the mainstream media, out in the real world,... more
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The ocean surface is 30 percent more acidic today than it was in 1800, much of that increase occurring in the last 50 years - a rising trend that could both harm coral reefs and profoundly impact tiny shelled plankton at the base of the ocean food web, scientists warn.
Despite the seriousness of such changes to the ocean, however, the world has yet to deploy a complete suite of available tools to monitor rising acidification and other ocean conditions that have a fundamental impact on life throughout the planet.
Marine life patterns, water temperature, sea level, and polar ice cover join acidity and other variables in a list of ocean characteristics that can and should be tracked continuously through the expanded deployment of existing technologies in a permanent, integrated global monitoring system, scientists say.
The Partnership for Observation of the Global Oceans (POGO), representing 38 major oceanographic institutions from 21 countries and leading a global consortium called Oceans United, will urge government officials and ministers meeting in Beijing Nov. 3-5 to help complete an integrated global ocean observation system by target date 2015.
It would be the marine component of a Global Earth Observation System of Systems under discussion in Beijing by some 71 member nations of the intergovernmental Group on Earth Observations.
The cost to create an adequate monitoring system has been estimated at $10 billion to $15 billion in assets, with $5 billion in annual operating costs.
Some 600 scientists with expertise in all facets of the oceans developed an authoritative vision of characteristics to monitor at a 2009 conference on ocean observations.
Furthermore, as documented in the forthcoming proceedings of the 2009 conference (to be published shortly by the European Space Agency), the value of such information to the world's financial interests and to human security would dwarf the investment required.
"Although the US and European Union governments have recently signaled support, international cooperation is desperately needed to complete a global ocean observation system that could continuously collect, synthesize and interpret data critical to a wide variety of human needs," says Dr. Kiyoshi Suyehiro, Chairman of POGO.
"Most ocean experts believe the future ocean will be saltier, hotter, more acidic, and less diverse," states Jesse Ausubel, a founder of POGO and of the recently completed Census of Marine Life. "It is past time to get serious about measuring what's happening to the seas around us."
The risks posed by ocean acidification exemplify the many good reasons to act urgently.
POGO-affiliated scientists at the UK-based Sir Alister Hardy Foundation for Ocean Science recently published a world atlas charting the distribution of the subset of plankton species that grow shells at some point in their life cycles.
Not only are these shelled plankton fundamental to the ocean's food web, they also play a major role in planetary climate regulation and oxygen production. Highly acidic sea water inhibits the growth of plankton shells.
The Foundation says the average level of pH at the ocean surface has dropped from 8.2 to 8.1 units, "rendering the oceans more acidic than they have been for 20 million years," with expectations of continuing acidification due to high concentrations of carbon dioxide in the atmosphere.
Because colder water retains more carbon dioxide, the acidity of surface waters may increase fastest at Earth's high latitudes where the zooplankton known as pteropods are particularly abundant. Pteropods (see links to images below) are colorful, free-swimming pelagic sea snails and sea slugs on which many animals higher in the food chain depend.
Scientists caution that the overall global marine impact of rising carbon dioxide is unclear because warming of the oceans associated with rising greenhouse gases in the air could in turn lead to lower retention of carbon dioxide at lower latitudes and to potential countervailing effects.
cont.The ocean surface is 30 percent more acidic today than it was in 1800, much of that... more
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This year’s extreme heat is putting the world’s coral reefs under such severe stress that scientists fear widespread die-offs, endangering not only the richest ecosystems in the ocean but also fisheries that feed millions of people.
From Thailand to Texas, corals are reacting to the heat stress by bleaching, or shedding their color and going into survival mode. Many have already died, and more are expected to do so in coming months. Computer forecasts of water temperature suggest that corals in the Caribbean may undergo drastic bleaching in the next few weeks.
What is unfolding this year is only the second known global bleaching of coral reefs. Scientists are holding out hope that this year will not be as bad, over all, as 1998, the hottest year in the historical record, when an estimated 16 percent of the world’s shallow-water reefs died. But in some places, including Thailand, the situation is looking worse than in 1998.
Scientists say the trouble with the reefs is linked to climate change. For years they have warned that corals, highly sensitive to excess heat, would serve as an early indicator of the ecological distress on the planet caused by the buildup of greenhouse gases.
“I am significantly depressed by the whole situation,” said Clive Wilkinson, director of the Global Coral Reef Monitoring Network, an organization in Australia that is tracking this year’s disaster.
According to the National Oceanic and Atmospheric Administration, the first eight months of 2010 matched 1998 as the hottest January to August period on record. High ocean temperatures are taxing the organisms most sensitive to them, the shallow-water corals that create some of the world’s most vibrant and colorful seascapes.
Coral reefs occupy a tiny fraction of the ocean, but they harbor perhaps a quarter of all marine species, including a profusion of fish. Often called the rain forests of the sea, they are the foundation not only of important fishing industries but also of tourist economies worth billions.
Drastic die-offs of coral were seen for the first time in 1983 in the eastern Pacific and the Caribbean, during a large-scale weather event known as El Niño. During an El Niño, warm waters normally confined to the western Pacific flow to the east; 2010 is also an El Niño year.
Serious regional bleaching has occurred intermittently since the 1983 disaster. It is clear that natural weather variability plays a role in overheating the reefs, but scientists say it cannot, by itself, explain what has become a recurring phenomenon.
“It is a lot easier for oceans to heat up above the corals’ thresholds for bleaching when climate change is warming the baseline temperatures,” said C. Mark Eakin, who runs a program called Coral Reef Watch for the National Oceanic and Atmospheric Administration. “If you get an event like El Niño or you just get a hot summer, it’s going to be on top of the warmest temperatures we’ve ever seen.”
Coral reefs are made up of millions of tiny animals, called polyps, that form symbiotic relationships with algae. The polyps essentially act as farmers, supplying the algae with nutrients and a place to live. The algae in turn capture sunlight and carbon dioxide to make sugars that feed the coral polyps.
The captive algae give reefs their brilliant colors. Many reef fish sport fantastical colors and patterns themselves, as though dressing to match their surroundings.
Coral bleaching occurs when high heat and bright sunshine cause the metabolism of the algae to speed out of control, and they start creating toxins. The polyps essentially recoil. “The algae are spat out,” Dr. Wilkinson said.
The corals look white afterward, as though they have been bleached. If temperatures drop, the corals’ few remaining algae can reproduce and help the polyps recover. But corals are vulnerable to disease in their denuded condition, and if the heat stress continues, the corals starve to death.
Even on dead reefs, new coral polyps will often take hold, though the overall ecology of the reef may be permanently altered. The worst case is that a reef dies and never recovers.
In dozens of small island nations and on some coasts of Indonesia and the Philippines, people rely heavily on reef fish for food. When corals die, the fish are not immediately doomed, but if the coral polyps do not recover, the reef can eventually collapse, scientists say, leaving the fishery far less productive.
Research shows that is already happening in parts of the Caribbean, though people there are not as dependent on fishing as those living on Pacific islands.
It will be months before this year’s toll is known for sure. But scientists tracking the fate of corals say they have already seen widespread bleaching in Southeast Asia and the western Pacific, with corals in Thailand, parts of Indonesia and some smaller island nations being hit especially hard earlier this year.
snip
Parts of the northern Caribbean, including the United States Virgin Islands, saw incipient bleaching this summer, but the tropical storms and hurricanes moving through the Atlantic have cooled the water there and may have saved some corals. Farther south, though, temperatures are still remarkably high, putting many Caribbean reefs at risk.
Summer is only just beginning in the Southern Hemisphere, but water temperatures off Australia are also above normal, and some scientists are worried about the single most impressive reef on earth. The best hope now, Dr. Wilkinson said, is for mild tropical storms that would help to cool Australian waters.
“If we get a poor monsoon season,” he said, “I think we’re in for a serious bleaching on the Great Barrier Reef.”This year’s extreme heat is putting the world’s coral reefs under such... more
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The icy Arctic waters around Norway's archipelago of Svalbard may seem pristine and clear, but like the rest of the world's oceans they are facing the threat of growing acidity.
Oceans have always absorbed part of the carbon dioxide, or C02, present in the air, which in turn makes them acid. But with CO2 levels soaring, the scientific community is getting worried about acidification harming marine life.
Off the coast of Ny-Aalesund, a tiny coal mine village turned scientific outpost just 1,200 kilometres (745 miles) from the North Pole, researchers from nine European countries conducted in July an unprecedented effort to analyse the phenomenon.
To do so, they submerged nine tubes, each weighing two tonnes and the height of two double-decker busses, in the icy waters of the remote fjord framed by snow-capped mountains.
They then injected the water-tight tubes, called mesocosms, with CO2, to reproduce sea life under different acidity levels expected from now until 2150 with the aim of studying the potentially disastrous effects of acidification on marine life.
"It's here in the Arctic that the ocean will become corrosive the fastest," Jean-Pierre Gattuso, with France's National Center for Scientific Research, said, explaining why the researchers chose to turn these waters thick with icy slush into a laboratory.
The threat to the world's oceans is not so much the absolute concentration of acidity, but rather the pace at which it is changing, Gattuso explained, pointing out that "cold water swallow up gas faster than hot or temperate water."
Oceans absorb more than a quarter of the CO2 emitted by humans, which in one way is fortunate since this natural absorption mitigates the impact the gas has on the climate.
However the soaring levels of man-made CO2 in the atmosphere are proving devastating to the oceans themselves: since the beginning of the industrial era they have become 30 percent more acidic, reaching an acidity peak not seen in at least 55 million years, scientists say.
And with no sign of CO2 emissions slowing down, ocean acidification will likely keep increasing in the decades to come.
This is especially worrisome since higher acidity levels have been shown to sharply slow calcification in corals, shellfish and other species.
Corals, a source of rich biodiversity that prevents land area from being submerged and draws much-needed tourists to some of the world's poorest corners, might thus have trouble shaping their skeletons, while shellfish could lose their shells.
Adaptation is less likely
Ulf Riebesell, a German oceanographer, said not all sea creatures were equal in their ability to adapt to their increasingly acid environment.
"For micro-organisims which have generation times of a few days, adaptation may happen during the next 100 years or so as the ocean continues to acidify to critical levels," explained the researcher from the IFM-Geomar centre, braving glacial winds in a bright yellow padded windbreaker and a woolen hat.
But for organisms with long life spans, like corals, "adaptation is much less likely because they need so many generations to change their genetic set-up," Riebesell said.
Scientists caution the current frantic increase of seawater acidity is already causing serious problems for the pteropod, a sort of sea snail vital for the Arctic food chain.
The tiny, translucent mollusc could end up naked in the near future, unable to shape its shell in an increasingly acid environment, explained Jan Buedenbender, another German researcher from the IFM-Geomar institute. This could have far-reaching consequences, he warned.
"They're a key species for the Arctic food system because they're feeding on very small particles and on phytoplankton, and they're getting quite big and really big animals like whales and birds and fish can feed on them," he explained.
They are also key because their shell contributes to fighting climate change, since it helps the sea snail sink to the bottom when it dies, dragging down all the CO2 ingested over its short lifespan.
By doing so "they're helping the ocean take up more CO2," Buedenbender said. There is still a chance to save species like the pteropod, according to Iris Menn, a marine biologist with Greenpeace which shipped the giant test-tubes up to Svalbard.
But there is no easy solution. To make a difference, industrialised countries will have to slash their CO2 emissions by 40 percent by 2020, she said.
"We can't stop the trend anyway. We will have a high level of acidity in the water no matter what," she said.
"But what we can do is stop CO2 emissions, so the effect will be reduced."The icy Arctic waters around Norway's archipelago of Svalbard may seem pristine... more
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We cannot continue to emit the amount of CO2 that we are without a way to balance it. Our oceans are breaking down because of carbon saturation and the acidity is causing calcification to the point where shellfish can no longer survive. In the past months I have seen and read countless articles and reports about the acidification of our oceans and what we must do to meet this challenge. I simply do not understand why we continue to drag our feet. Is it really because so many people do not realize the importance of and the connection we have to the oceans and the life found within them? Do even our oceans seem like a world away from our day to day routines?
We the human species are simply part of a vast biosphere and chain of life that extends from the smallest phytoplankton to the largest mammal. And when one link in that chain is cut off it effects all of the other links. I truly believe it is imperative that scientists in this country and abroad begin to get much more vocal about the effects of calcification, acidification and in general relaying to the public the urgency of what we are now facing in the coming decades. I do not want to leave this world this way for my child. I simply cannot comprehend that even with all of the information at our disposal that so many still continue to choose to be ignorant of what their actions are doing to change the face of this planet.We cannot continue to emit the amount of CO2 that we are without a way to balance it.... more
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In the year 1750, over 98 percent of coral reefs (magenta dots) grew in optimal conditions with aragonite saturation greater than 3.5 (blue colors). Such water is rapidly disappearing and will be gone in several decades if current carbon dioxide emission trends continue. Atmospheric CO2 levels are 280 ppm and 550 ppm for years 1750 and 2050, respectively.
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As a child I never would have thought that the Great Barrier Reef of all places would have the possibility of becoming extinct. I truly do hope this report is wrong, but based on the fact that we humans will more than likely do nothing but continue to argue about this instead of really doing something, I'm beginning to think it is right. And yes, we can do something about it.In the year 1750, over 98 percent of coral reefs (magenta dots) grew in optimal... more
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The Center for Biological Diversity today notified the U.S. Environmental Protection Agency of its intent to file a lawsuit against the agency for its failure to respond to the threat of ocean acidification. Last year, the Center filed a formal petition asking EPA to impose stricter pH standards for ocean water quality and publish guidance to help states protect U.S. waters from ocean acidification. Todays notice of intent to sue urges EPA to promptly respond to the Centers petition.
The oceans cover about 70 percent of the Earths surface and absorb about 22 million tons of carbon dioxide each day. The absorption of carbon dioxide is changing seawater chemistry, causing it to become more acidic. This process, known as ocean acidification, impairs the ability of marine animals to build the protective shells and skeletons they need to survive.
Already, the pH level of the ocean has decreased 0.1 units on average due to carbon dioxide pollution caused by human activity — especially emissions from such sources as automobiles and electrical power plants. If carbon dioxide emissions continue unabated, seawater pH may decrease an additional 0.4 units — more than a 100 percent change in acidity. A recent article in the journal Science noted that rapid changes in pH would have adverse effects on a number of marine organisms and highlighted the need to update EPAs water-quality standard for pH, according to the authors of the July 4 Science article, "Carbon Emissions and Acidification. The seawater quality criteria of the U.S. Environmental Protection Agency date back to 1976 [t]hese standards must be re-evaluated based on the latest research on pH effects on marine organisms, the authors wrote.
The federal Clean Water Act requires the EPA to update water-quality criteria to reflect the latest scientific knowledge. Since the agency developed the pH standard back in 1976, an extensive body of research has developed on the impacts of carbon dioxide on the oceans.
Ocean acidification is global warmings evil twin, said Miyoko Sakashita, an attorney with the Center for Biological Diversitys oceans program. The EPA has a duty under the Clean Water Act to protect our nations waters from pollution, and today, carbon dioxide is one of the biggest threats to our ocean waters.
According to the Centers notice of intent to sue, the EPAs current water-quality criterion for pH is outdated and woefully inadequate in the face of ocean acidification. A decline of 0.2 pH allowed under the current standard would be devastating to the marine ecosystem. Twenty-five leading scientists researching ocean acidification concluded in a Sept. 25, 2007 commentary in the Geophysical Research Letters that a decrease of this magnitude would pose a risk to the physiology and health of a variety of marine organisms.
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The EPA needs to face many lawsuits for their total apathy to the environment and the dereliction of their duties. However, in addressing ocean acidification they will then have to address the CO2 emissions that are soaked up by the oceans in the first place and their sources. I will not hold my breath waiting for that to happen.The Center for Biological Diversity today notified the U.S. Environmental Protection... more
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THE world's reefs, including Australia's Great Barrier Reef, will be dead within 30 years unless human activity changes quickly, a leading researcher says.
Addressing the 11th international River symposium in Brisbane, Ove Hoegh-Guldberg said it was crunch time for the world's reefs.
Let's say we delay another 10 years on having stern actions on emissions at a global level, we will not have coral reefs in about 30 to 50 years, he said.
Professor Hoegh-Guldberg, from the Centre for Marine Studies at the University of Queensland, said rising CO2 levels and melting ice caps meant the ocean was becoming uninhabitable for reefs.
This worldwide change in climatic conditions was in addition to land-based pollution spilling from Queensland's coastal river systems, a symposium session into the impacts of river systems on the reef was told.
We're rapidly rising to (CO2) levels which will be unsustainable for reefs in the very near future, Professor Hoegh-Guldberg said.
If you ask the question, `Will we have coral reefs in 30 years' time?', I would say at the current rate of change and what we're doing to them, we won't. But it's all up to us right now.
We're at the fork in the road. If we take one road - the one we're on right now - we won't have coral reefs.
If we make some very, very, very aggressive actions, if we reform how we do things, both at the global and local level, we'll have a really good chance of bringing coral reefs through in some shape or form, which will still provide the basis for the 100 million people that they support.
He said ice core samples showed CO2 levels were the highest for at least a million years, possibly 20 million years.
That changes the circumstances under which corals form their skeletons, so they become less vibrant, Professor Hoegh-Guldberg said.
Then if you keep hitting them with things like bleaching events, they just don't bounce back as much.
So we're changing essentially the rules under which biology is trying to operate, and that's the problem.
He also warned that an increasing incidence of coral bleaching was a growing threat.
If we have them (bleaching events) now every four to five years, we're getting to a point where reefs no longer have time to recover.
The impact on Queensland's $6 billion-a-year earnings from reef-based tourism would be enormous, he said.
So we might have an industry that's half the size, but it certainly won't have the pull that it does today, he said.
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This is not natural.THE world's reefs, including Australia's Great Barrier Reef, will be dead... more
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Silently and steadily, a tragedy is unfolding beneath the ocean's waves: Coral reefs around the world are disappearing. According to some projections, there could be few, if any, left by the end of the century.
This dire and credible prediction has shocked many marine scientists, who had not realized how close to the tipping point coral reefs are. The news is especially disheartening because 2008 is the International Year of the Reef.
The culprit here is carbon dioxide, the greenhouse gas that is responsible for global warming and that also is turning our oceans into an acid bath.
snip
Here's the problem. When carbon dioxide enters the ocean, it reacts with water to form carbonic acid. A few other chemical steps ensue, with the outcome that fewer carbonate ions are available for biological systems. Corals are not the only organisms that suffer. All shell-forming marine creatures are adversely affected.
Taking a human analogy, it would be as if your bones could no longer keep growing.
We are seeing the effects of ocean acidification. Today, the concentration of carbon dioxide in Earth's atmosphere is more than 380 parts per million. That's more than at any time during the past 20 million years.
About 25 percent of this carbon dioxide ends up being absorbed by the oceans. As carbon dioxide levels have risen during the industrial era, the average pH level in the ocean, an indicator of acidity, has dropped by 0.1 pH unit. (On the pH scale, a lower number means more acidic.)
That might not sound like much, but evidence from Antarctic ice cores shows that the global average is lower than at any time over almost half a million years. As the Science article notes, changes in atmospheric carbon dioxide over the last century "are 2 or 3 orders of magnitude higher than most of the changes seen in the past 420,000 years."
Silently and steadily, a tragedy is unfolding beneath the ocean's waves: Coral... more
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