Mixing it up, jellyfish style

With the advent of overfishing of the worlds oceans and climate change, jellyfish are slowly beginning to dominate oceanic ‘deadzones’ (see the ‘never-ending jellyfish joyride‘ for more details). Now, researchers are coming around to the idea that in such high numbers, jellyfish might just be able to stir up the oceans in a similar way to the tides and winds, according to a recent paper published in Nature. Sounds  crazy? Take a look at this video footage of the researchers squirting fluorescent dye into the water column infront of the Mastigias jellyfish. As the jellyfish swims through the watercolumn, the dyed water travels along with the jellyfish rather than being displaced – a mechanism apparently first described by Charles Darwin’s grandson that is enhanced by the viscosity of seawater. Read more at Live Science and over at Wired Magazine, and watch the video footage below:

“As a body moves in a fluid, a high-pressure field is created in front of the body, and a low-pressure field behind. Because fluid moves from high to low pressure, the fluid that’s adjacent to the rear of the body moves along with it,” said Katija. “You get a permanent displacement of the water.”

Katija and CalTech bioengineer John Dabiri have provided the first direct observation of this phenomenon. Using fluorescent dyes and underwater video cameras, they’ve made visible the invisible, producing videos of swimming jellyfish trailed by the water they came from.

If swimming generates tide-scale forces, then “it has an impact on global climate. This is a rather novel twist to the whole climate story,” said William Dewar, a Florida State University oceanographer. “How one would extend existing models to include a biosphere mixing input is not clear, largely because no-one has spent much time thinking about it.”


Revealed: the secret evidence of global warming Bush tried to hide

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Sensational headline by The Guardian newspaper? The Obama administration has unclassified over a thousand images of Arctic sea ice to aid scientists in the study of global warming and the impacts of climate change. The images are striking – see this comparison in Alaska between 2006 – 2007. The release of such images is great news – i’m not entirely sure whether these images were ‘kept secret’ by the Bush administration as claimed, but in the growing field of remote sensing, support from the US military satellite data is crucial to understanding local scale changes in the Arctic ice. Click here to see the images in full.

Graphic images that reveal the devastating impact of global warming in the Arctic have been released by the US military. The photographs, taken by spy satellites over the past decade, confirm that in recent years vast areas in high latitudes have lost their ice cover in summer months.

The pictures, kept secret by Washington during the presidency of George W Bush, were declassified by the White House last week. President Barack Obama is currently trying to galvanise Congress and the American public to take action to halt catastrophic climate change caused by rising levels of carbon dioxide in the atmosphere.

One particularly striking set of images – selected from the 1,000 photographs released – includes views of the Alaskan port of Barrow. One, taken in July 2006, shows sea ice still nestling close to the shore. A second image shows that by the following July the coastal waters were entirely ice-free.

The photographs demonstrate starkly how global warming is changing the Arctic. More than a million square kilometres of sea ice – a record loss – were missing in the summer of 2007 compared with the previous year.

Nor has this loss shown any sign of recovery. Ice cover for 2008 was almost as bad as for 2007, and this year levels look equally sparse. (Read More)

Future Tense: Australia’s safe climate vision

Australian ABC Radio National show “Future Tense” features a pretty interesting discussion of the Safe Climate Australia goal to restructure Australia’s economy by transitioning away from fossil fuels. Some great insight by Ove and Professor John Wiseman amongst others – click below to listen to the audio.


Al Gore: Safe Climate Australia is a wonderful initiative, apolitical, solutions-based, science-based, bringing together business leaders, leaders in the scientific community, the arts community, emergency firefighters, people from all walks of life, to respond to what many scientists have now been saying is truly a planetary emergency. And that phrase is one that still sounds a bit shrill to most ears, because we’re not used to hearing such a phrase.

A leader some 50 years ago in the aftermath of the attack in my country on Pearl Harbor during an investigation of why it wasn’t predicted in advance, and one of the explanations for why there were no preparations to anticipate that attack, was in an interesting phrase, they said, ‘We as human beings tend to confuse the unprecedented with the improbable.’ And of course if something’s never happened before, it’s a generally safe assumption that it’s not going to happen in the future.

The problem is, the exceptions can kill you, and this is one of those exceptions.

Ove Hoegh-Guldberg: Well we’ve known for a long while in the scientific community that it doesn’t take much CO2 into the atmosphere to have major effects on ecosystems. And over the years I’ve been studying the demise of the Great Barrier Reef, and we’ve known for a decade that if you double CO2, you don’t have a Great Barrier Reef any more.

I think the latest science, especially that which was presented in March in Copenhagen, has shaken us up even more, because it’s telling us that things like the great ice sheets of the world are now melting very rapidly. Now if they do, and we continue down this pathway which is above the worst case scenario of the IPCC, we end up in a world in which we may have — well, we certainly have one metre, we may actually have three to four metres of sea-level rise around the planet. Now that would be devastating. That’s a civilisation wrecker. You’ve just to think about this harbour where we’re sitting right now, two metres of sea level, you don’t have this very spot. The messages from Copenhagen were very clear, we’re above the worst case scenario, it’s happening a lot quicker than we thought, and we now have little time to fix it. It’s not going to be easy, but by the same token, we haven’t even started.

The analogy is always drawn to step changes in behavior, such as Pearl Harbor for the US, where you go from making cars to tanks within a month. You can turn an economy up on its head and still survive, and I think that’s what we’ve got to do with the climate change problem. It’s so massive, it’s really looming as a planetary tragedy, and we’ve got to treat it as it is. It’s an emergency, and it needs emergency action.

Local stressors act to reduce the resilience of corals to bleaching events

Researchers from SCRIPPS Oceanographic Institute have published an important article in the journal PLoS ONE, detailing research that confirms what has suspected for some time – that local stressors reduce the resilience of corals to bleaching events.

Jessica Carilli and colleagues set out to test the hypothesis that chronic local stress reduces coral resistance and resilience to bleaching, by investigating coral growth before and after the 1998 bleaching event in Belize. The authors took over 90 coral core samples from sites with relatively high and low chronic stress, and determined changes in growth rate over the past decade (much like the declining calcification on the GBR Science paper released earlier this year).

The results are striking – after the 1998 bleaching event, the massive star corals (Montastraea faveolata) from ‘healthy’ reefs (low chronic stressors) were able to to recover and grow normally within two to three years, whilst star corals from unhealthy (high chronic stressors) reefs showed no sign of a complete recovery in the 8 years following the bleaching event.

(A) Coral without the 1998 growth suppression, indicating resistance to bleaching in 1998. (B) Coral with the 1998 growth suppression, recognized by the bright high-density band, but with a quick return to pre-1998 extension rates, indicating resilience after bleaching. (C) Coral with the 1998 growth suppression and continuing depressed extension rates after 1998, indicating a lack of both resistance and resilience to bleaching. (D) A coral with relatively high average extension rate. (E) A coral with relatively low average extension rate. (F) A coral with a partial mortality scar on the left (noted by white arrow), coincident with the 1998 growth anomaly.

(A) Coral without the 1998 growth suppression, indicating resistance to bleaching in 1998. (B) Coral with the 1998 growth suppression, recognized by the bright high-density band, but with a quick return to pre-1998 extension rates, indicating resilience after bleaching. (C) Coral with the 1998 growth suppression and continuing depressed extension rates after 1998, indicating a lack of both resistance and resilience to bleaching. (D) A coral with relatively high average extension rate. (E) A coral with relatively low average extension rate. (F) A coral with a partial mortality scar on the left (noted by white arrow), coincident with the 1998 growth anomaly.

“You can imagine that when you are recovering from a sickness, it will take a lot longer if you don’t eat well or get enough rest,” said Jessica Carilli, Scripps graduate student and lead author on the study. “Similarly, a coral organism that must be constantly trying to clean itself from excess sediment particles will have a more difficult time recovering after a stressful condition like bleaching.”

“It is clear that Mesoamerican corals really fell off a cliff in 1998 — nearly everybody suffered mass bleaching,” said Dick Norris, Scripps professor of paleooceanography and co-author of the study. “There are no pristine reefs in the region, but the ones in the best shape clearly are more resilient than those that are long-suffering. It shows that a little improvement in growing conditions goes a long way in recovering coral health.” (Read More)

Almost as striking are the obvious ‘scars’ left by the 1998 bleaching event, as evidenced by the decline in coral growth (annual extension rate) across all four sites:

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Means (solid lines) and 95% confidence intervals (shading) for extension rates after 1955. Extension rates at Sapodilla and Utila remain suppressed after the 1998 bleaching event.

The authors show that the fastest recovering corals were collected from the offshore site at Turneffe Atoll, whilst the more heavily polluted sites at Sapodilla Cayes and Utila in Honduras suffer from significant impacts linked to local factors such as development, sewage and runoff. Considering that the entire Mesoamerican Barrier Reef was bleached during the 1998 bleaching event, it’s great to see that ameliorating local impacts can have a significant effect on reducing the effects of regional-scale bleaching:

“… local conservation efforts that reduce stress, such as reducing runoff by replanting mangroves at the coast or protecting an area from overfishing, could have significant impacts on the ability of corals to withstand the effects of climate change. Future research could investigate whether this interaction between local and global stressors extends to other coral species.”

Citation: Carilli JE, Norris RD, Black BA, Walsh SM, McField M (2009) Local Stressors Reduce Coral Resilience to Bleaching. PLoS ONE 4(7): e6324. doi:10.1371/journal.pone.0006324

Lightbulbs made from Salmon DNA, sea lion dies of heart failure following a marathon mating session (and other odd news stories from this week)

This week has been a great week for odd, random news stories – see below for a roundup of the best (including why the “killer squid” might not be so killer after all)

1. Fish shrinking due to global warming

1fishEarlier research has already established that fish have shifted their geographic ranges and their migratory and breeding patters in response to rising water temperatures. It has also been established that warmer regions tend to be inhabited by smaller fish. Mr Daufresne and his colleagues examined long-term surveys of fish populations in rivers, streams and the Baltic and North Seas and also performed experiments on bacteria and plankton. They found the individual species lost an average of 50 per cent of their body mass over the past 20 to 30 years while the average size of the overall fishing stock had shrunk by 60 per cent. This was a result of a decrease in the average size-at-age and an increase in the proportion of juveniles and small-sized species, Daufresne said. (Read More)

2. Researchers Use Salmon DNA To Make LED Lightbulbs

1ledResearchers from the University of Connecticut have created a new light-emitting material by doping spun strands of salmon DNA with fluorescent dyes. The material, which is robust because DNA is such a strong polymer, absorbs energy from ultraviolet light and gives off different colors depending on the amounts of dye it contains. A team led by chemistry professor Gregory Sotzing created the new material by mixing salmon DNA with two types of dye, then pumping the solution from a fine needle while a voltage is applied between the needle tip and a grounded copper plate covered with a glass slide. As the liquid jet comes out, it dries and forms long nanofibers that are deposited on the glass slide as a mat. The researchers then spin this nanofiber mat directly on the surface of an ultraviolet LED to make a white-light emitter. The color-tunable DNA material relies on an energy-transfer mechanism between two different fluorescent dyes, and the DNA keeps the dye molecules separated at a distance of 2 to 10 nanometers from each other. (Read More, via /.)

3.Mike the sea lion dies of heart failure after marathon mating session at German zoo

AAEE1XA male sea lion on has died of exhaustion after a marathon mating session at an zoo in Germany. The mammal, named Mike who was originally from California, was already a father of 12. He passed away yesterday after an extended session with the females at the park in Nuremberg proved too much for his heart. Mike – described as ‘good-natured’ by the zoo – had mated repeatedly with females Farah, Tiffy and Soda. The park said in a statement that the 550lb mammal began showing tiredness around midday: ‘Mike could no longer get out of the pool and was brought ashore by staff. ‘The extremely weakened animal was treated by a vet but died from acute heart failure around 3:30 pm. ‘Mating season is a common time for fatalities when bulls often stop eating for days to devote themselves fully to mating. ‘For sea lion bulls with a harem this is the most exhausting time. ‘He will be remembered fondly by visitors of the animal park for his appearances during shows in the dolphinarium where he had close contact with the dolphins,’ added the statement. Mike’s 12 children can be found in zoos all over Europe, from Berlin to Spain to the Netherlands, the zoo said. (Read More)

4. Discarded chicken parts may provide an abundant source of biodiesel fuel, scientists say

1kfcScientists in Nevada are reporting development of a new and environmentally friendly process for producing biodiesel fuel from “chicken feather meal,” made from the 11 billion pounds of poultry industry waste that accumulate annually in the United States alone. The researchers describe a new process for extracting fat from chicken feather meal using boiling water and processing it into biodiesel. Given the amount of feather meal generated by the poultry industry each year, they estimate this process could create 153 million gallons of biodiesel annually in the U.S. and 593 million gallons worldwide. In addition, they note that removal of fat content from feather meal results in both a higher-grade animal feed and a better nitrogen source for fertilizer applications. (Read More)

5. “Huge blob of Arctic goo floats past Slope communities”

1gooSomething big and strange is floating through the Chukchi Sea between Wainwright and Barrow. Hunters from Wainwright first started noticing the stuff sometime probably early last week. It’s thick and dark and “gooey” and is drifting for miles in the cold Arctic waters, according to Gordon Brower with the North Slope Borough’s Planning and Community Services Department. Brower and other borough officials, joined by the U.S. Coast Guard, flew out to Wainwright to investigate. The agencies found “globs” of the stuff floating miles offshore Friday and collected samples for testing. Later, Brower said, the North Slope team in a borough helicopter spotted a long strand of the stuff and followed it for about 15 miles, shooting video from the air. The next day the floating substance arrived offshore from Barrow, about 90 miles east of Wainwright, and borough officials went out in boats, collected more samples and sent them off for testing too. Nobody knows for sure what the gunk is, but Petty Officer 1st Class Terry Hasenauer says the Coast Guard is sure what it is not. (Read More)

6. ” Researcher Sheds Light On ‘man-eating’ Squid; ‘I Was Surprised At How Timid They Were'”

humboldt-squid“Based on the stories I had heard, I was expecting them to be very aggressive, so I was surprised at how timid they were. As soon as we turned on the lights, they were gone,” he said. “I didn’t get the sense that they saw the entire diver as a food item, but they were definitely going after pieces of our equipment.”

Seibel was surprised by the large number of squid he encountered, which made it easy to imagine how they could be potentially dangerous to anything swimming with them. Their large numbers also made Seibel somewhat pleased that they appeared frightened of his dive light. Yet he said the animals were also curious about other lights, like reflections off his metal equipment or a glow-in-the-dark tool that one squid briefly attacked. (Read More)

NOAA Coral Bleaching Outlook System Indicates Potential for High Level Coral Bleaching in the Caribbean and Parts of the Equatorial Pacific

Scientists from NOAA’s Coral Reef Watch Program are forecasting a significant potential for higher than normal thermal stress in the Caribbean, especially in the Lesser Antilles, through October 2009. Continued high water temperatures can lead to a high probability of significant coral bleaching and infectious coral disease outbreaks.  The forecast is based on the July NOAA Coral Reef Watch outlook.

Scientists are concerned that bleaching may reach the same levels or exceed those recorded in 2005, the worst coral bleaching and disease year in Caribbean history. There is also some potential for high stress in the central Gulf of Mexico and a region stretching from the Lesser Antilles, including the US Virgin Islands, across to Puerto Rico, and across to the southern coast of Hispaniola and the Caribbean coast of Nicaragua.

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Other areas of concern for coral bleaching this year are the central Pacific region including the equatorial Line Islands and Kiribati.  Some thermal stress may also develop between the Northern Mariana Islands and Japan.

An important caveat is that the model used for this outlook is not yet calling for El Niño development, whereas NOAA’s operational Climate Forecast System is now calling for development of an El Niño during 2009-10. If El Niño continues to strengthen, this could increase the bleaching risk in the central to eastern Pacific and Caribbean.

Just like any climate forecast, local conditions and weather events can influence actual temperatures. However, we are quite concerned that high temperatures may threaten the health of coral reefs in the Caribbean this year.

The Thermal Stress Outlook is based on sea surface temperature (SST) forecasts generated by the Linear Inverse Model (LIM) from the NOAA Earth System Research Laboratory. This system is the first to use sea surface temperature forecast models to provide seasonal outlooks of bleaching around the world.

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In the Pacific, the area of concern includes the equatorial Line Islands and Kiribati. This area is especially subject to stress if El Niño development continues.  There is a potential for some thermal stress to develop between the Northern Mariana Islands and Japan. There is also some indication of thermal stress along the Pacific coast of Mexico. However, the model is only generating small areas in the Pacific with a potential for abnormally high temperatures. Care should be taken that areas of warming in open areas of the Pacific are likely to move from the locations seen in the current forecast models. This region is also subject to intensification during El Niño conditions.

The NOAA Coral Reef Watch forecast comes on the heels of NOAA’s National Climatic Data Center reporting in June that the world’s ocean surface temperature was the warmest on record, breaking the previous high mark set in 2005, the last year of record-setting global coral bleaching incidents. Updates can be found here. Divers who see bleaching can report it at ReefBase.

In its inaugural year the forecast system did well in predicting the general patterns of mild Caribbean stress in 2008 and high thermal stress in the western Pacific in 2008-9, especially earlier in the season. The guidance issued in early December provided valuable guidance on the potential for bleaching 2-4 months in advance. The general pattern of warming in the outlook corresponded well with large-scale patterns of actual thermal stress. However, strong monsoonal activity along northeastern Australia cooled waters on the Great Barrier Reef (GBR) reducing thermal stress there. This was a fortunate difference between the forecast and actual conditions that protected these valuable reef resources.

Strange change in the weather?


I read a fascinating story about noctilucent clouds on EcoWorldy blog. Apparently, certain cloud formations have been appearing where they shouldn’t be:

My boss was in France on Bastille Day last week where the big event of the night actually became the sight of these strange glowing clouds – – like polar noctilucent clouds except they were not over the North Pole – but over Paris.

The story gets more interesting:

Over the last week, photographers in many places around the world outside the Arctic regions, have run outside to get photos of these strange Noctilucent (Night Glowing) clouds showing up this week from Poland to North Dakota:

So what does all this mean?

Formed by ice literally at the boundary where the earth’s atmosphere meets space 50 miles up, they shine because they are so high that they remain lit by the sun even after our star is below the horizon.

Noctilucent clouds are a fundamentally new phenomenon in the temperate mid-latitude sky, and it’s not clear why they’ve migrated down from the poles. Or why, over the last 25 years, more of them are appearing in the polar regions, too, and shining more brightly.

“That’s a real concern and question,” said James Russell, an atmospheric scientist at Hampton University and the principal investigator of an ongoing NASA satellite mission to study the clouds. “Why are they getting more numerous? Why are they getting brighter? Why are they appearing at lower latitudes?”

Is this strange change in the weather a sign of global change due to human causes? The EcoWorldy article does a great job in discussing the pros and cons, and Quite a few people seem to think so – particularly as these clouds were first observed only after the Krakatoa eruption in 1885:

… climate models have predicted that higher greenhouse gas emissions would cause mesosphere cooling, resulting in more frequent and widespread occurrences of noctilucent clouds.

But a competing theory is that larger methane emissions from intensive farming activities are producing more water vapour in the upper atmosphere where methane concentrations have more than doubled in the past 100 years.

Killer squid attacks divers

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Best headline ever: “Attack of the giant squids: Terror as hundreds of 5ft long creatures of the deep invade Californian coastline” (thanks to the Daily Mail). Turns out the backstory behind this one is even more interesting: the squid at hand (the humboldt squid) have envaded the San Diego coastline en masse due to unknown reasons (apparently global warming, shortage of food, predator avoidance and even underwater earthquakes have been cited as possible explanations). These squid are huge – up to 2m in length an weighing ~50kg, and school in numbers upto 1200.

Sounds relatively harmeless, right? Here’s how Scott Cassell, a commercial diver out of La Jolla described his experience diving with the Humboldt squid:

The monstrous squid remains motionless just ten feet away. Emotions gave way to cognitive thought and I trained my camcorder on him and begin to record. Almost on cue, he begins his approach. Then, with blinding acceleration, he lurches onto me with a powerful “thud crackle”. He slams into my chest. The impact was incredibly powerful, knocking the wind out of me. His huge arms envelope my complete upper body and camera and I can feel my chest plate move as his beak grinds against it. The crackle and scratching of thousands of chitenous ring teeth against my fiberglass/kevlar chest plate is unmistakable. (Read more)

The rest of Cassell’s article is fascinating:

The beak of a Dosidicus gigas is large and very powerful. The edges are assharp as trauma shears and are capable of gouging out an orange-sized chunk of flesh, regardless of tissue make up. I have seen a five-foot Dosidicus gigas bite through the thick bone of a tuna head, skull and all, with minimal effort removing fist-sized portions with each bite.

To hold their prey item firmly, this squid has about 2,000 suction disks; each lined with chitenous ring teeth. Chitin is a material similar to that of fingernails and that of beetle exoskeletons (A polysaccharide). These chitenous ring teeth are needle sharp and very effective. Every suction disk has up to 36 of these teeth. That means a Humboldt squid employs as many as 72,000 teeth upon its hapless victims. Prey has little chance of escaping a Humboldt squid’s deadly embrace.

Thousands of ring teeth cut into the flesh of their prey so deeply, you can hear it. When they drag their victim away with pulses from their massive jet funnel, the sounds of their hapless victim being ripped apart fills the water. It sounds a bit like heavy duty Velcro being pulled apart underwater. Then the beak can be heard, that huge knife-edged beak. The gouging of bone and tissue sound like the shredding of cabbage combined with that of hacking apart coconuts with a machete.

(Read More)

But to cut to the chase – skip to around 1.40 onwards in the video below for the footage (2.22 is also pretty freaky).

Al Gore, Ove and Ian Dunlop at the Safe Climate Australia Launch

Click below for the video seminars from Al Gore, Ove and Ian Dunlop from the SCA launch last monday.  Safe Climate Australia aims to mobilise Australia’s extensive technological, economic and political expertise and resources in planning the transition of the Australian economy to zero net carbon, the sequestering of dangerous levels of existing carbon from the atmosphere, and in assisting the building of a global consensus for restoring a safe climate.

Al Gore:
Ove Hoegh-Guldberg:
and Ian Dunlop