Elkhorn coral infected with white pox.
What’s the News: Over the past decade, diseases, pollution, and warming waters have put coral populations across the globe in a dramatic decline. In an extreme case, the population of elkhorn coral, considered one of the most important reef-building corals in the Caribbean, has decreased by 90–95 percent since 1980, partly due to a disease called white pox.
Now, scientists have traced this lethal disease back to humans. Human feces, which seep into the Florida Keys and the Caribbean from leaky septic tanks, transmit a white pox-causing bacterium to elkhorn coral, researchers report in the journal PLoS ONE. “It is the first time ever that a human disease has been shown to kill an invertebrate,” ecologist James Porter told Livescience. “This is unusual because we humans usually get disease from wildlife, and this is the other way around.”
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The flooding created by enormous downpours near Brisbane in eastern Australia shows no signs of abating, and that region is now bracing for things to go from bad to worse.
Heavy rains pounded Brisbane’s region, called Queensland, in December. And things really started to get bad yesterday, when flooding caused by the constant rain sent a wall of water—evocatively being called an “inland tsunami”—crashing through the nearby town of Toowoomba. Brisbane, which is Australia’s third-largest city at about two million people, in next in the crosshairs.
Normally it is protected from periodic flooding of the Brisbane river by the Wivenhoe dam, 80 kilometres [50 miles] away. But Wivenhoe is already 81 per cent over capacity after last month’s heavy rains saturated Queensland. To save Brisbane from flooding, officials began releasing water from Wivenhoe last month. But because of the inland tsunami now hurtling towards the city, officials have increased the amount of water released from 140 million tonnes yesterday to 344 million tonnes today. [New Scientist]
But there’s only so much they can do. As of this morning, the Christian Science Monitor reports at least 30 deaths and 78 missing, with the number expected to grow as flooding threatens Brisbane.
[Brisbane] Mayor Campbell Newman warned 6,500 homes, businesses and other properties were likely to be flooded by Thursday. “Today is very significant, tomorrow is bad, and Thursday is going to be devastating for the residents and businesses affected,” he said. [BBC News]
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In the western Caribbean, some coral reefs have turned into eerie white ghost towns.
Scientists with the Smithsonian Tropical Research Institute have documented a major bleaching event in the reefs near Panama and the island of Curaçao. Such bleaching occurs when a reef loses the tiny photosynthetic algae that typically live in the coral, providing it with food (and color). Bleaching occurs when coral is under stress, most typically due to higher ocean temperatures. And this was a hot summer.
Abnormally warm water since June appears to have dealt a blow to shallow and deep-sea corals that is likely to top the devastation of 2005, when 80% of corals were bleached and as many as 40% died in areas on the eastern side of the Caribbean. [ScienceNOW]
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This past summer was hot. Russia burned, New York City experienced the hottest summer on record, and residents of the northern hemisphere in general agreed that a cool breeze would be rather welcome. Now more extensive climate data is coming in for 2010, and guess what? Scientists have confirmed that it was hot.
According to NASA’s Goddard Institute for Space Studies, the first 8 months of 2010 is the warmest such January-to-August period in climate records stretching back 131 years. This period was nearly 0.7˚C warmer than the average temperature from 1951 to 1980. (NOAA announced roughly the same finding today, using many of the same temperature stations but a different analysis method.) [ScienceNOW]
Researchers say that El Nino conditions in the Pacific Ocean are partly to blame for raising temperatures globally this past year. But, of course, man-made climate change is the larger culprit. This summer the Arctic sea ice shrank very quickly because the ice was already thin; at the end of the summer melt the Arctic ice area was the third smallest on record.
At its smallest extent, on 10 September, 4.76 million sq km (1.84 million sq miles) of Arctic Ocean was covered with ice — more than in 2007 and 2008, but less than in every other year since 1979. [BBC]
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The tiny islands of the Pacific Ocean appear to be the very the picture of climate change vulnerability—some rise such a short distance above current sea level that it seems like any rise would swallow them up. The Earth’s climate system, though, is a great deal more complex than the simplistic rhetoric that fills the political echo chamber. That’s demonstrated again in a new study that argues some the Pacific’s low-lying islands are actually increasing slightly in land area rather than decreasing. It’s good news, yes—but not without caveats.
First, the specifics. Arthur Webb and Paul Kench published their work, based on decades of aerial and satellite photos, in the journal Global and Planetary Change. During the years spanned by those images, the sea level in the area has been rising by about 2 millimeters per year. Nevertheless, they say that 23 of the 27 Pacific islands they studies either held firm in land area or saw a slight increase. How could this be?
Unlike the sandbars of the eastern US coast, low-lying Pacific islands are made of coral debris. This is eroded from the reefs that typically circle the islands and pushed up onto the islands by winds, waves and currents. Because the corals are alive, they provide a continuous supply of material. “Atolls are composed of once-living material,” says Webb, “so you have a continual growth.” Causeways and other structures linking islands can boost growth by trapping sediment that would otherwise get lost to the ocean [New Scientist].
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Over the weekend a huge Chinese freighter loaded down with coal and fuel oil crashed into part of the Great Barrier Reef off the Australian coast. Today, salvage teams are still struggling with how to extricate the Shen Neng 1 without dumping any more of its dirty cargo into the delicate marine ecosystem.
The ship had left the port of Gladstone just a few hours before striking the reef in Douglas Shoal. It ran aground in a restricted zone of the marine park, almost 30km [18.6 miles] from the authorised shipping channels it should have been using [Sydney Morning Herald]. Both the main engine and the rudders sustained serious damage. While rescuers debate how to orchestrate a salvage operation, the Shen Neng 1 has slid another 20 or 30 yards along the reef, destroying more coral in its path.
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The Convention on International Trade in Endangered Species (CITES) continues through Thursday of this week, and the fallout continues today.
On Friday we reported that the bluefin tuna trade ban failed thanks in large part to Japanese diplomatic efforts, denying new protections to the endangered fish, but also noted that the question of opening the ivory trade had yet to see a vote. Over the weekend the convention voted down those ivory proposals put forth by Tanzania and Zambia, which would have allowed one-off sales of ivory from government stockpiles. The ivory trade was banned in 1989, but two sales have since been granted to nations showing effective conservation [BBC News]. However, fears that such sales encourage poaching led the meeting’s attendees to reject the new proposals.
While most conservation groups lobbied against the ivory proposal, another of their pet causes—offering more protection for corals against harvesters who sell them as jewelry—failed at CITES. The proposed restrictions would have stopped short of a trade ban but required countries to ensure better regulations and to ensure that stocks of the slow-growing corals, in the family coralliidae, were sustainably harvested [The New York Times]. The provision garnered 64 “yes” votes to 59 for “no,” but needed a two-thirds majority to pass.
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Image: flickr / wwarby
Human beings are increasingly making their homes on the coasts of continents, but this demographic shift is taking a toll on a sensitive coastal ecosystem that is often overlooked: seagrass meadows. A new analysis of seagrass abundance around the world found that 27 percent of these meadows have disappeared since 1879, and the rate of loss is accelerating. The study’s authors write: “Seagrass loss rates are comparable to those reported for mangroves, coral reefs and tropical rainforests, and place seagrass meadows among the most threatened ecosystems on earth….. Our report of mounting seagrass losses reveals a major global environmental crisis in coastal ecosystems, for which seagrasses are sentinels of change” [Nature News].
Endangered species expert Susanne Livingstone notes that despite these losses seagrass rarely makes it into the public consciousness. “It’s probably because they’re not as sexy [as corals], they’re not as attractive,” she says. “They’re just as ecologically important if not more so” [Nature News]. Seagrass meadows provide grazing for a variety of marine animals, including the green turtle and the manatee-like dugong. The coastal areas also serve as nurseries for fish; both coral reefs and commercial fisheries would feel the impact if seagrass meadows vanish.
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Scientists have long known that coral reefs are being threatened by disease, global warming and other factors. Now a new study shows that that majority of Caribbean reefs have, in fact, been “flattened” in the past four decades, as ornate branched corals have died out and been replaced by flatter, fast-growing “weedy” species. Most of the reefs have lost all the intricate, tree-like corals that until the 1970s provided sanctuary for unique reef fish and other creatures, as well as protecting coastlines by sapping the energy of waves [New Scientist], according to the report, published in the journal Proceedings of the Royal Society B.
The coral reefs that were initially the most complex have almost been completely eliminated, says the researchers, who analysed changes in the structure of reefs using 500 surveys across 200 reefs conducted between 1969 and 2008. They found that 75 per cent of the reefs are now largely flat, compared with 20 per cent in the 1970s [ScienceDaily]. That’s bad news for sea life and storm defenses, says study coauthor Lorenzo Alvarez-Filip: “For many organisms, the complex structure of reefs provides refuge from predators…. This drastic loss of architectural complexity is clearly driving substantial declines in biodiversity, which will in turn affect coastal fishing communities” [ScienceDaily].
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A new study of fossilized coral reefs in Mexico has revealed that sea levels have risen abruptly in past epochs, which researchers say supports the theory that ocean levels could rise dramatically again in response to global warming. The study suggests that a sudden rise of 6.5 feet to 10 feet occurred within a span of 50 to 100 years about 121,000 years ago, at the end of the last warm interval between ice ages. “The potential for sustained rapid ice loss and catastrophic sea-level rise in the near future is confirmed by our discovery of sea-level instability” in that period, the authors write [The New York Times].
Other researchers have previously found evidence of rapid sea level rise as ice ages gave way to more temperate eras, causing vast ice sheets to melt. But because the coral shows evidence from a warmer interglacial period—similar to the one we’re in currently—the find boosts the chances that today’s melting ice sheets could trigger rapid sea-level rise, the study authors say [National Geographic News]. However, not everyone is convinced that the authors have proven their case. Some experts argue that the researchers haven’t definitively shown that the coral fossils date from 121,000 years ago.
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The blank spaces on the map of Google Earth are being filled in, as the company announced today that many of the flat blue oceans on its global replica have been replaced with detailed maps of the ocean floor. Now, users can soar from undersea mountains to the depths of the Marianas Trench, and can explore coral reefs and shipwrecks. Sylvia Earle, an oceanographer who was involved in the effort, says: “I cannot imagine a more effective way to inspire awareness and caring for the blue heart of the planet than the new Ocean in Google Earth. For the first time, everyone from curious kids to serious researchers can see the world, the whole world, with new eyes,” she added [BBC News].
Google’s usual satellite imaging can’t peer through deep water to map the seabed. Instead, sound is the tool of choice when mapping the ocean floor. Passing sonar arrays over every patch of ocean is beyond even Google’s means, so it has had to rely on the US navy for much of the information. As a result, some “sensitive” areas are blank. Other navies and research institutions around the world also provided data [New Scientist]. But the marine scientists who collaborated with Google note that only 5 percent of world’s sea floor is mapped in detail, and say they hope the Google Ocean will inspire the public to support further marine exploration.
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President Bush will establish three national monuments in the Pacific Ocean today in a move that will protect a vast marine ecosystem from mining, oil exploration, and commercial fishing. With the stroke of a pen this afternoon, Bush will have set aside more square miles of ocean for protection than any other political leader in history. The three new monuments, surrounding far-flung islands, reefs and atolls scattered across the Pacific, will add 195,000 square miles of protected waters to the nearly 140,000 square miles around the Northwest Hawaiian Islands that Bush protected in 2006 [Los Angeles Times]. The United States has authority over these waters because the tiny atolls and islands are U.S. territories.
The three areas are thronged with fish, sharks, coral reefs, and other forms of sea life, all of which will benefit from the new protections. Blue-water fish such as yellowfin, bigeye tuna, and marlin–all in decline–will be big winners because they breed in these waters. So will sharks, birds, turtles, and dolphins accidentally caught by the tuna long-line fleets [ScienceNOW Daily News]. One of the new national monuments also encompasses the deepest location of the earth’s crust. The Marianas Trench, which reaches depths of more than 36,000 feet in some locations, contains undersea volcanoes and hydrothermal vents around which cluster tough organisms that can withstand high temperatures and harsh chemicals. These “extremophiles” are of interest to scientists who think they signal forms that extraterrestrial life could take.
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The growth of the world’s largest coral reef system has slumped to its slowest rate in at least four centuries, according to a new report in Science [subscription required]. Researchers studying coral colonies in the Great Barrier Reef found that calcification, the process that builds the reefs, has dropped 13.3 percent since 1990. They fear the decline is indicative of a worldwide threat to coral reefs caused by rising seawater temperatures and ocean acidification. The loss of coral growth threatens food webs and may lead to “precipitous” changes in biodiversity, the authors said [Bloomberg].
The Great Barrier Reef along the northeast coast of Australia stretches more than 1,200 miles and is visible even in space. Coral reefs, delicate undersea structures resembling rocky gardens made by tiny animals called coral polyps, are important nurseries and shelters for fish and other sea life. They also protect coastlines, provide a critical source of food for millions of people, attract tourists and are potential storehouses of medicines for cancer and other diseases [Reuters]. Massive coral reefs materialize from the gradual accumulation of calcium carbonate by billions of coral polyps over thousands of years.
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While Indonesia is still rebuilding following the devastating 2004 earthquake and tsunami that killed more than 130,000 people on the island of Sumatra alone, scientists are warning that several other major earthquakes are likely to occur in the region over the next decades. A new study examined the growth records of coral reefs off the coast of Sumatra, and say they show evidence of repeated bursts of earthquakes that relieve pressure on the Sunda fault. A shock in 2007 may be the beginning of a new cycle, researchers say.
Says study coauthor Kerry Sieh: “If previous cycles are a reliable guide we can expect one or more very large west Sumatran earthquakes … within the next two decades” [Reuters]. As if to illustrate the point that the Indian Ocean is seismically active, reports are coming in that a 5.9 magnitude earthquake struck last night off the coast of Sumatra; happily, there have been no reports of casualties or damages, and authorities say there is no risk of a tsunami.
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The newly elected president of the Maldives, the island chain south of India, says his country must start saving up money to buy a new homeland, in case global warming causes sea levels to rise so much that the waves submerge the archipelago entirely. Says Maldivian President Mohamed Nasheed: “We can do nothing to stop climate change on our own and so we have to buy land elsewhere. It’s an insurance policy for the worst possible outcome…. We do not want to leave the Maldives, but we also do not want to be climate refugees living in tents for decades,” he said [The Guardian].
The Maldives are the lowest-lying nation on the planet: most of the islands are only a few feet above sea level, and the highest point, in the capital city of Malé, is about seven feet above sea level. But the white sandy beaches are a major tourist attraction bringing in billions of dollars every year…. Mr Nasheed’s plan is to create a “sovereign wealth fund” using tourism revenues to buy land so that future generations will have somewhere to rebuild their lives if they have to leave. He wants somewhere within the region, where the culture is similar – possibly India or Sri Lanka [BBC News]. However, Nasheed also mentioned Australia as a possibility, because of the vast swaths of unoccupied land on that continent.
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