Monthly Archives: August 2008

“Cut greenhouse gases to save coral reefs: scientists”

Posted on by
Reply

 

Reuters, 27th August 2008

To keep coral reefs from being eaten away by increasingly acidic oceans, humans need to limit the amount of climate-warming greenhouse gases in the atmosphere, a panel of marine scientists said on Wednesday.

"The most logical and critical action to address the impacts of ocean acidification on coral reefs is to stabilize atmospheric carbon dioxide concentration," the scientists said in a document called the Honolulu Declaration, for release at a U.S. conference on coral reefs in Hawaii.

Ocean acidification is another threat to corals caused by global warming, along with rising sea levels, higher sea surface temperatures and coral bleaching, the scientists said.

Coral reefs are a "sentinel ecosystem," a sign that the environment is changing, said one of the experts, Billy Causey of the U.S. National Marine Sanctuary Program.

"Although ocean acidification is affecting the health of our oceans, the same thing — increased carbon dioxide in the atmosphere — is going to in fact be affecting terrestrial environments also," Causey said by telephone from Hawaii.

Coral reefs offer economic and environmental benefits to millions of people, including coastal protection from waves and storms and as sources of food, pharmaceuticals, jobs and revenue, the declaration said.

Continue reading →

“Shipwrecks Wreak Havoc on Coral Reefs”

Posted on by
Reply

 

ScienceNow News, 21st August

Warming seas and ocean acidification aren’t the only hazards facing the world’s coral reefs. A new study suggests that the communities can be thrown quickly and seriously out of balance by the iron from sunken ships. Scientists hope the findings will encourage the prompt removal of derelicts before they can damage the fragile ecosystems.

The problem with shipwrecks appears to be a particularly aggressive reef-dwelling creature called Rhodactis howesii, a type of sea anemone. When nutrients are abundant and there are no predators, R. howesii thrives. Unfortunately, it also eats coral, threatening the foundation of the ecosystem.

Several previous studies have linked shipwrecks and reef degradation, but researchers in Hawaii decided to measure the effect in detail. They surveyed a coral reef off Palmyra, an isolated atoll in the middle of the Pacific Ocean. There they found high densities of R. howesii near a longline fishing boat that sank in 1991. Those densities steadily declined with distance from the wreck; and within about 100 meters, they dropped to zero–with a few exceptions. The exceptions, the team reports today in PLoS ONE, involve navigation buoys installed on the atoll in 2001.

Continue reading →

Researchers find large patch of algal reefs

Posted on by
Reply

 

Taiwan Journal, 22nd August 2008

Researchers from Academia Sinicia have uncovered the largest algal reef in eastern Taiwan along the coast of Shanyuan Bay in Taitung County.

"It’s quite surprising to discover such a large patch of algal reefs that are relatively undisturbed by human activities," said Allen Chao-lun Chen, an associate researcher at Academia Sinica’s Research Center for Biodiversity Aug. 14.

According to Chen, algal reefs, formed by crystalline calcium carbonates left by dead calcareous algae, usually grow at the extremely slow rate of 0.1 centimeters to 0.2 centimeters in thickness per year. Coral communities can be found in waters 1 kilometer off the coastline at a depth of 8 meters to 10 meters.

In addition to the newly-discovered algal reef, Shanyuan Bay also boasts a dense and diverse cornularia coral community in which a wealth of fish, shrimp and shell species live–a phenomenon not seen in other areas in Taiwan, Chen noted.

The largest algal reef in Taiwan was located off Taoyuan County in northwestern Taiwan, which is 4 kilometers long and 500 meters wide. Most of Taiwan’s coral reefs are found off the island’s southern coastlines, as well as its outlying islands.

The discovery coincides with a U.N. global coral reefs survey and the International Year of the Reef. Chen’s decade-long study to conduct a survey of the marine ecology in Shanyuan Bay, Green Island, and the Penghu Islands was commissioned by the ROC government this year.

According to the researcher, the most encouraging part of his find was that a stem of Oulophyllia bennettae coral was seen in the bay. Chen explained this was the first time the coral strain, which is normally seen in the Indian Ocean, had been recorded in Taiwanese waters.

But Chen expressed concern that unchecked tourism development could harm coral reefs in the region. "Since some areas of the algae reefs have already been damaged, the government should take immediate steps to better manage and protect Shanyuan Bay."

Continue reading →

Drilling for Oil Way, Way Offshore

Posted on by
3

 

Time Magazine, 18th August

Anyone who ever doubted the centrality of oil and natural gas to the global economy should have been convinced by the political events of the past few months. As petroleum prices have risen to record levels, the spiraling price of gasoline has become issue number one in the American Presidential election. That’s prompted Republican candidate John McCain to make expanded offshore oil drilling a focus of his campaign. For years, offshore drilling has been illegal outside parts of the Gulf of Mexico due to environmental concerns, with public support. But that has reversed in recent months, with even green Californians moving in favor of drilling. Barring a sudden national move to adopt alternative fuels, we can expect that reversal to continue — as oil prices rise, so will pressure to "drill here and drill now," as McCain has put it.

Whatever that means for offshore drilling in the U.S., the real victims of the global thirst for petroleum will be overseas — areas that, until the recent price rise, were too remote and forbidding to be worth drilling. Case in point: the vast, impenetrable western reaches of the Amazon. Touching parts of Bolivia, Peru, Ecuador, Columbia and Brazil, the western Amazon has remained relatively unscathed compared to the eastern stretches of the rainforest, which have been ravaged by logging. With few roads, the western Amazon has remained so undisturbed that there are still new indigenous tribes living somewhere inside the jungle who have never encountered the outside world.

Continue reading →

Blog wars – Marohasy and Rush Limbaugh to the rescue

Posted on by
Reply

August 09, 2008

HAS global warming stopped? The question alone is enough to provoke scorn from the mainstream scientific community and from the Government, which says the earth has never been hotter. But tell that to a new army of sceptics who have mushroomed on internet blog sites and elsewhere in recent months to challenge some of the most basic assumptions and claims of climate change science.

Their claims are provocative and contentious but they are also attracting attention, so much sothat mainstream scientists are being forced to respond.

The bloggers and others make several key claims. They say the way of measuring the world’s temperature is frighteningly imprecise and open to manipulation. They argue that far from becoming hotter, the world’s temperatures have cooled in the past decade, contrary to the overwhelming impression conveyed by scientists and politicians.

As such, they say there should be far greater scepticism towards the apocalyptic predictions about climate change. Even widely accepted claims, such as that made by Climate Change Minister Penny Wong that “the 12 hottest years in history have all been in the last 13 years”, are being openly challenged.

“She is just plain wrong,” says Jennifer Marohasy, a biologist and senior fellow of the Institute of Public Affairs. “It’s not a question of debate. What about the medieval warming period? The historical record shows they were growing wine in England, for goodness sake; come on. It is not disputed by anyone that the Vikings arrived in Greenland in AD900 and it was warmer than Greenland is now. What Penny Wong is doing is being selective and saying that is a long time ago.”

But selective use of facts and data is fast becoming an art form on both sides of the climate change debate now that real money is at stake as the West ponders concrete schemes to reduce carbon emissions. So what is the validity of some of the key claims being made by these new blogger sceptics?

Continue reading →

Queensland’s climate has shifted south, research shows

Posted on by
Reply

The Courier-Mail, August 07, 2008

TAKING a dip in the ocean at Redcliffe these days is like swimming at Maryborough in 1950, new research has revealed.

Scientists say global warming sceptics should dip their toes in the water off a Queensland beach if they want proof the phenomenon exists.

They claim climate zones have moved south by more than 200km in the past 60 years, so Brisbane’s climate has moved to Byron Bay to make way for a more balmy weather pattern.

Australian Institute of Marine Science researcher Janice Lough revealed the findings in a paper published by the American Geophysical Union.

She said she was in no doubt the changes were due to global warming caused by increased greenhouse gas emissions from human activity.

“Sea surface temperatures are significantly warming along the northwest and northeast coasts of Australia – regions containing well-protected and internationally significant tropical marine ecosystems,” she says in the research paper.

Dr Lough looked at sea surface temperatures recorded by ships and from satellite technology from 1950 to 2007.

She analysed results from measurements taken as far north as Thursday Island in the Torres Strait and south to Coffs Harbour. She also analysed temperatures off the northwest coast of Australia.

She found sea surface temperatures had been rising by as much as 0.12C per decade, which, with no further increases in greenhouse gas emissions, would make waters off southeast Queensland 2C warmer within the next 100 years.

Continue reading →

Two new studies on coral symbiont specificity released in the Proceedings of the National Academy of Sciences

Posted on by
Reply

"Dedicated partnership may be corals weakness"

(Sampayo et al 2008, PNAS 105[30] 10444-10449)

"Great Barrier Reef coral communities may not be able to recover from bleaching as easily as previously proposed, according to new UQ research. A two-year study by a team of UQ researchers, in the Centre for Marine Studies, has found that contrary to popular theory, it is not possible for bleached corals to recover or become more resistant to bleaching by taking up more heat tolerant species of their micro-algae partners. All corals have a symbiotic (sharing relationship) with single-celled dinoflagellates, commonly referred to as zooxanthellae. The coral provides a habitat for the zooxanthellae, which in turn produce essential nutrients for the corals.  Under stressful conditions, such as high or low water temperatures, the symbiotic zooxanthellae are expelled from their host, causing a whitening of the coral tissue or bleaching.  Coral bleaching events have caused significant mortality of corals worldwide and the frequency as well as intensity of bleaching events is predicted to increase as a result of climate change. Dr Eugenia Sampayo, who performed the research as part of her PhD, said past research had suggested that bleached corals could take up new, more tolerant symbionts, which would make them less susceptible to future bleaching events" (Read more)

 

 

"New indicator uncovered that can predict coral health"

(Stat et al 2008, PNAS 105[27] 9256-9261)

A new indicator of coral health has been discovered in a community of microscopic single-celled algae called dinoflagellates. The study, released in the July 8th edition of the journal Proceedings of the National Academy of Sciences, reveals that a particular type of these algae renders corals more susceptible to disease. "Corals are fascinating organisms whose survival is dependent on dinoflagellates that live inside the coral’s tissue," says lead author Michael Stat, an assistant researcher at the Hawaii Institute for Marine Biology (HIMB) at the University of Hawaii at Manoa. "The relationship between these dinoflagellates and corals has long been considered mutually beneficial, with the dinoflagellates supplying the coral with food via photosynthesis in return for recycled nutrients and shelter. Over the last 20 years it has been made clear that there are many different types of dinoflagellates in corals and that the unions or symbiosis between a given coral and their dinoflagellates can be very specific." It had previously been considered that all dinoflagellates found in coral are equally beneficial to their coral host, but in this study Stat, along with HIMB researchers Ruth Gates and Emily Morris, present evidence that a particular type of dinoflagellate can be found in corals that are diseased or show evidence of having had a disease. (Read more)

“More acidic ocean could spell trouble for marine life’s earliest stages”

Posted on by
Reply

EurekAlert!, 31st July 2008

Increasingly acidic conditions in the ocean—brought on as a direct result of rising carbon dioxide levels in the atmosphere—could spell trouble for the earliest stages of marine life, according to a new report in the August 5th issue of Current Biology, a publication of Cell Press. Levels of acidification predicted by the year 2100 could slash the fertilization success of sea urchins by an estimated 25 percent, the study shows. " If other marine species respond similarly—and there’s no evidence yet that they don’t—then we’re in trouble," said Jon Havenhand of the University of Gothenburg in Sweden. "The analogies are quite simple: we observed a 25 percent reduction in fertilization success at reduced pH, which is equivalent to a 25 percent reduction in the spawning stock of the species. Apply equivalent changes to other commercially or ecologically important species, such as lobsters, crabs, abalone, clams, mussels, or even fish, and the consequences would be far-reaching. It could be enough to "tip" an ecosystem from one state to another." However, he emphasized, more data about the response of growing acidic conditions on more species is needed before any such extrapolation can be made. Widely cited estimates show that the average level of acidity in the oceans has risen by about 25 percent in the last 150 years, since the advent of fossil fuel burning, Havenhand explained. The most recent data show that levels of ocean acidification predicted for the end of this century—about a three-fold increase over current levels—have already been measured in some coastal waters. Continue reading →