A shark’s tale: is there something fishy in the waters off Newcastle?

shark 4

A shark off Burwood beach, Newcastle, on Thursday. Pic: Peter Stoop, courtesy Heliservices Newcastle

The coastal city of Newcastle is in the midst of a media frenzy, thanks to a string of shark sightings close to popular swimming beaches.

A 15 kilometre stretch of beaches has now been shut for a record six consecutive days, with lifeguards and police craft reporting shark sightings seemingly by the hour. Of most concern have been a purportedly 5 metre, 1,700kg White shark that has been lingering along the coastline; and what is suspected to be a 3 metre tiger shark that was photographed attacking and killing a small dolphin only 50 metres from the shore yesterday (warning: graphic images).

While no attacks on humans in the area have yet been recorded, the sharks have become national celebrities in their own right, with widespread media coverage and commentary. There has even been a Twitter account set up for the @Newy_Shark (which is one account you probably don’t want to be “followed” by).

So what’s the deal here? Are we seeing the real-life return of Jaws? Has a curse been struck down upon the town of Newcastle by Poseidon himself? Is a Sharknado next?

Our resident White shark expert, Barry Bruce, knows a thing or two about these ancient predators. He is one of Australia’s pre-eminent authorities on the species and is the head of our White Shark Research Program. But he is perhaps most famously known for having one of Finding Nemo’s most famous characters named after him.

According to Barry, the story behind Newcastle’s shark saga is far less salacious. Thankfully, we’re not gonna need a bigger blog.

The coastline just north of Newcastle (stretching from the appropriately named Stockton Bight to the even tastier-sounding Seal Rocks) is famously known as being a nursery ground for White sharks. These juveniles are usually about 2-3 metres in length, and a tagging program undertaken by Barry and his team has shown that they are more than prevalent in the area.

Satellite positions for 19 tracked juvenile White sharks in the Port Stephens region 2007 – 2010. Registered positions are colour-coded for each shark. Dotted pink line denotes approximate boundary of the White shark nursery area.

Satellite positions for 19 tracked juvenile White sharks in the Port Stephens region 2007 – 2010. Registered positions are colour-coded for each shark. Dotted pink line denotes approximate boundary of the White shark nursery area.

Seeing a larger sized White in this area, like the infamous #NewyShark, is slightly less common, but still not at all unusual.

Large White sharks are well known to move up and down the New South Wales coastline, stopping in certain areas when food is prevalent. White sharks have been exhibiting this exact behaviour for countless millennia – it is only when they stop near a heavily populated area like Newcastle that we would notice.

But these are nomadic creatures, and they won’t stay in one spot for too long. We know through collaboration with our colleagues in New Zealand that white Sharks will travel as far north as the Great Barrier Reef – and even across the Tasman to NZ – in a span of just months.

Bruce and his team tagging a white shark with an acoustic tagging device.

Barry and his team tagging a white shark with an acoustic tagging device.

Barry puts the current concentration of sharks in Newcastle purely down to natural variability. Sharks go where the food goes – if there are more sharks in one area at one point in time, it means there will be less in others.

And while we’re in the mood for debunking myths, here’s another one: dolphins are just as much a food source for sharks as are any other species of their size. While it is uncommon for us to observe – and the images were undeniably distressing – sharks are well-known to attack dolphins. Unfortunately, what Flipper taught us was wrong.

More than anything, Barry says that this is a positive advertisement for the health of marine ecosystems in Australia. That there is a large enough food source to sustain shark populations is a good thing, and should be celebrated.

But of course, it is important for beachgoers to take advice from authorities when entering the water. While this is a natural spectacle that should be enjoyed, it is advisable to do so from a distance – and on land. In time it will run its course, and we can all return to the water.

White shark fast facts:

    • A common mistake people make is calling these awesome creatures, ‘Great White Sharks’, it’s actually just ‘White shark’ (Carcharodon carcharias). But we still think they’re still pretty great.
    • Sharks play a vital ecosystem role as top predators. Declines in top predators can cascade through the food web, seeing some species groups increase while eliminating others.
    • We have one of the most comprehensive White shark research programs in the world, with over 250 tagged White sharks in Australian waters. Check out a few shark tracks on our website.
    • Our tagging program provides us with a good idea of migration patterns – we know for example that there is an East and a Southwest population.
    • Our research on White sharks is a collaborative project funded under the Australian Government’s National Environmental Research Program.
    • We tag these beauties in a very humane way – in a sling, in the water:


Bushfires kill, but knowing exactly how might make them less deadly

Whether leaving early or staying to defend, a reliable and adaptable bushfire survival plan is a must. AAP Image/David Mariuz

Whether leaving early or staying to defend, a reliable and adaptable bushfire survival plan is a must. AAP Image/David Mariuz

By Justin Leonard, CSIRO

The latest round of bushfires, which claimed 27 homes in the Adelaide Hills, has once again highlighted the importance of planning for the worst. Mercifully, no human lives were lost, and it will be important to learn whatever lessons we can to avoid future tragedies.

My colleagues and I analysed 825 deaths in 260 Australian bushfires from 1901 to 2011, and our research has revealed some compelling evidence to help guide residents to plan for future bushfires.

Most people (58%) lost their lives when caught out in the open. Strikingly, 72% of those people were within 200 m of their own homes (this statistic is based only on cases where details are accurately known).

I encourage you to imagine what circumstances and decisions might have led to these outcomes. Do a large number of people simply wait to see if the fire is really going to arrive on their doorstep?

Bushfire deaths within a house are most prevalent during our most severe fire events, representing 75% of all fatalities during bushfires that occurred on days with “catastrophic” (code red) fire danger conditions. This is despite them representing only 27% of all bushfire deaths.

Of those who died inside homes, 92% were in rooms that did not have a door that led directly to the exterior of the house (once again, this is based only on cases where circumstances are accurately known). This raises uncomfortable questions: why did these people apparently not try to leave the home as the house fire developed? Were they monitoring the conditions outside as the fire passed? Had they thought about which exit was the safest?

Homes under attack

When a fire arrives at a property, the house will experience “ember attack”. This attack is strongest as the main fire arrives and will persist for a long time after it has passed, and may also start to happen before the fire actually arrives. If the house is close enough to the bush it may also be affected by radiant heat, and if very close then direct flame contact is possible, although most houses are lost without any direct interaction from a bushfire front – which goes some way to account for the seemingly random loss patterns that occur.

Given the timing and intensity of ember attack, it is no surprise that our data show that houses can ignite before, during, and after a fire front’s passage – with the most likely time being during and immediately after the fire front has passed.

For the relatively small number of houses that ignite before the fire front arrives, the occupants may be faced with life-threatening conditions both inside and outside at the same time. There are also a few cases were houses are built so close to the bush or other combustible elements that even the low-level fire that persists after the main fire front has passed is too intense to survive outside.

Nevertheless, for the vast majority of homes that burn in bushfires, it is likely that at any given time, conditions would be survivable either inside or outside the house. That means that, with the right strategy, lives should not be lost.

Designing a lifesaving strategy

It is interesting to note that the current building codes for bushfire-prone areas include specific fire weather severity limits beyond which these standards may no longer be effective. The standards aim to reduce the risk that a building will catch fire, but they also rule out any guarantee that it won’t. The code also doesn’t address the issues of how fast burning homes might succumb, or of how to provide a safe or effective exit path from the building.

So even if your bushland home is fully up to code, you need to plan for a wide range of scenarios. Fire agencies across Australia have stressed the importance for people living in bushfire-prone areas to develop a fire survival plan, and your local fire agency is the best place to start on developing a plan and educating yourself about the specific local fire conditions you might face.

Once a plan has been developed I encourage residents to test their fire plan by checking whether it answers the following questions:

  • At what level of forecast fire weather severity will you retreat to a non-bushfire-prone area for the day?
  • Do you understand the local potential fire severity for weather conditions below this level?
  • For any given circumstances, what are the signs or triggers that indicate that it is no longer safe to evacuate to a non-bushfire prone area? For some isolated communities this will be when fire weather severity passes a certain level; for other, less isolated residents it will be when they are no longer certain that the roads are moving freely and fire will not impact their travel route.
  • What and where is your personal protective equipment and firefighting tools?
  • Is the property free from combustible items under or adjacent to the home?
  • Is the home in an acceptable state of repair to survive a bushfire?
  • Which areas would be the safest external location to move to if it becomes impossible to stay in the house?
  • Does the path leading to this cleared area involve walking over or past combustible elements such as vehicles and decking?
  • How do I monitor all rooms and cavity areas of the home for signs of ignition of fire development inside the house?
  • What do you have on hand to monitor and put out these fires (stored water, ladders to monitor internal roof space, etc.)?
  • If you can’t put them out, which exit path is the most appropriate?

And remember:

A deep understanding of the nature of bushfire threat is your best tool in assessing and managing your own risk.

This article was originally published on The Conversation.
Read the original article.


Christmas gift and book ideas for the sci-curious

Protozoan coaster

Your coaster can remind you to contemplate the yeasts that gave their lives to make your drink!

This is our final Christmas-themed post of the year. Promise. The first two can be found here and here.

Thought-provoking gifts are tricky to think up. So to help out, we took a wander around the interwebs to gather some ideas for those science-minded giftees in your life. From the social media team to you, here are our suggestions for science-themed presents – including crafts from Etsy, and pop-science books.

Scientific gifts from Etsy

Etsy is a great place to shop for niche gifts for loved ones. Here is a quick list of scientific present ideas from some e-stallholders on Etsy:

1. Serious Goose Designs

The owner of this stall is an ecologist and Ph. D. Candidate who crafts handmade jewellery and science-themed drink coasters. The coasters are marble and have antique-inspired scientific illustrations such as micro-organisms and cellular division:

Thirstphase, pourphase, sipphase, etc. We're very familiar with our biology already - we're scientists, you know.

Thirstphase, pourphase, sipphase, etc. We’re very familiar with our biology already – we’re scientists, you know.

 

2. Scientific shirts by Luddite Made and NonFictionTees

Luddite Made is based in Melbourne, and NonFictionTees in Chicago.

Luddite Made. I may or may not be the walrus. Or maybe I'm the mothman, who knows?

Luddite Made. Are you the walrus? Or are you the Mothman?

NonFictionTees. Circuit boards, minerals, and diatoms - it doesn't get better than that, folks.

NonFictionTees. Circuit boards, minerals, and diatoms – it doesn’t get better than that, folks.

3. iPhone and business card cases by T Rowan Design

This stall prints custom or science-themed images onto cases for Samsung and iPhones (generations 4-6) as well as business card cases.

Ever needed to tell your Drosophila from your Bactrocera? Or compare the homology of bats' and peoples' skeletons? T Rowan Design's on the case.

Ever needed to tell your Drosophila from your Bactrocera, or compare the homology of bats’ and humans’ skeletons? T Rowan Design’s on the case.

4. Scientific Prints from Antique Wall Prints, and vintage posters from Lunartics

Antique Wall Prints has more science-themed prints than there is wall space. They are based in Adelaide, too, so the shipping should be snappy.

Antique Wall Prints. Phrenology has no basis in modern science, but it still looks sciencey. Or maybe that’s our optimism-lobe speaking…

These educational scrolls from Lunartics are vintage, so they are more costly than the above prints. But, they look amazing and are in great condition.

Scrolls depicting the insides of Sir Lancelet, some newts 'n salamanders, and a flowering, devouring Drosera.

Scrolls depicting the insides of (sir) lancelet, some newts ‘n salamanders, and a flowering, devouring Drosera.

 

And of course, we can’t forget our beloved CSIRO shop for all of your microscopy and sticky, tumbling frog needs.

Popular science books of 2014

We at CSIRO love a good read, especially when it’s science material delivered at its most evocative. Here are six of this year’s pop-science books that we highly recommend this Christmas:

1. Night School: Wake up to the power of sleep by Richard Wiseman

Night School

Richard Wiseman is a psychologist, illusionist, and fantastic writer. In this book, Professor Wiseman expounds the latest research on sleep, dreams, nightmares, and other strange night-time phenomena. The book also has interactive elements, including sleep-related surveys, and downloadable, sleep-inducing tracks.

 

2. The Sense of Style: The Thinking Person’s Guide to Writing in the 21st Century by Steven Pinker

download

This is not strictly a science read, but it is written by a world-class science writer – Steven Pinker. Pinker is also a psychologist who specialises on the evolution and acquisition of language. In this book he advocates a common-sense use of language over the arbitrary rules of some grammarians. And he should know, Professor Pinker also chairs the Usage Panel of the American Heritage Dictionary. We highly recommend his previous books, too: The Blank Slate and The Better Angels of Our Nature.

 

3. Gulp: Adventures on the Alimentary Canal by Mary Roach

download (1)

Ever wanted to shrink down and travel through innerspace, all the way through the alimentary canal, from the mouth to the ar…other end? This book by Mary Roach might allow such a journey, albeit a vicarious version. Mary’s books tackle the quirkier and sometimes more vulgar aspects of science, and this book is no exception. The reader is taken on a ride into the mouth, down the oesophagus, into the belly, and then the various tubes that come afterwards, learning all the way how each section contributes to our greater good.

 

4. An Astronaut’s Guide to Life on Earth by Chris Hadfield

Chris Hadfield is a retired astronaut and a former commander on the International Space Stationdownload (2). He has gained widespread popularity through his use of social media, connecting the public with the processes and experiences of life in space. Last year Colonel Hadfield produced the first music video clip in space, a cover of David Bowie’s Space Oddity, which can be viewed here. His latest book describes the life of an astronaut (how to be the ultimate renaissance man) and his various trials as an astronaut, in space and on Earth.

 

5. Undeniable: Evolution and the Science of Creation by Bill Nye

download (3)

Here, Bill Nye, host of ‘Bill Nye the Science Guy’, uses his clear and accessible communication skills to explain one of the greatest ideas in all of science: Evolution by means of natural selection. Inspired by a recent debate on the topic, Nye took to writing a description of evolution for a popular audience. If you’re looking for a breezy brush up on biologists’ favourite subject – try this one.

 

6. The Accidental Universe: The World You Thought You Knew by Alan Lightman

download (4)

Alan Lightman is an MIT physicist and popular science writer. This book travels through space and time, to the beginning, to the smallest scale, and through dimensions – all in under 200 pages. In this pithy travel through physics, you also get a little bit of science-inspired philosophy, what a treat. As well as a genius physicist, Lightman is also a humanitarian, starting up foundations to support women in developing countries. This book is sure to get you thinking about sciences tell on reality and our place in it.

That’s it for our Christmas-themed posts this year. We hope you enjoyed them! In the New Year we’ll be compiling a list of staff-recommended scientific attractions for the holidays, as well as some science-themed apps for your smart machines. Wishing you a merry Christmas and happy New Year!


2014 – the year in ten posts

Miniature dragon

3D-printed dragon anyone?

With the year winding up, we thought we’d look back on the stories that struck a chord – or a nerve – in 2014. It was a mixed bag, ranging from the sublime to the implausible.

The sublime was definitely the Rosetta mission and Philae’s (not quite) perfect landing on the surface of the (not quite) evocatively-named comet 67P/Churyumov–Gerasimenko. Thanks to the wonders of modern communication, never before in the field of exploration have so many people so fervently urged a fridge-sized box on legs half a billion kilometres away to succeed against the odds.

We played a back-up role in the landing. Using the DSS34 antenna, NASA’s Deep Space Communication Complex (managed by CSIRO at the Tidbinbilla site) provided ongoing back-up communication coverage between Rosetta/Philae and the anxious science team at ESA’s mission control centre in Germany.

It’s a lot more down to earth, and of more practical use at the moment, but some news about renewable energy was just as exciting. If there was one good thing about the alarmingly warm autumn eastern Australia had in 2014, it was this: a team of solar thermal engineers and scientists at our Energy Centre in Newcastle used the sunlight flooding their solar fields to produce ‘supercritical’ steam, at the highest temperature and pressure levels ever recorded using solar power.

That sounds impressive when you just say it, but to realise how impressive it is, you need to know that supercritical steam is the ultra-hot, ultra-pressurised steam used to drive the world’s most advanced power plant turbines. This is the solar energy equivalent of breaking the sound barrier. Solar thermal power plants have traditionally only operated at ‘subcritical’ levels – the heavy lifting was left to fossil fuels. But now we’ve demonstrated that the power plants of the future could feasibly use the zero emission energy of the sun to reach peak efficiency levels – and at a cheaper price. The technology’s not ready for commercialisation yet, but the breakthrough has attracted a lot of interest.

There are other kinds of stories that always attract a lot of interest, and food safety – as we’re discovering yet again with the current raw milk controversy – is one of them. Fortunately, there was a pretty positive reaction to our story on whether it’s safe to cut the mould off food. Unlike supercritical steam, the comments generated more light than heat, which is always both gratifying and a relief. We came down firmly on the side of a conservative approach (and that’s not conservative of the food, more of the health). And in response to the comments, we published a clarification about spoilage in other kinds of food – the beauty of a blog is that you can incorporate the feedback from your readers. We love intelligent, constructive comments. So a big thanks to those who made them.

3D printed mouth piece

A personalised solution to sleep aponea: The 3D printed mouth piece.

We got quite a bit of interest, too, for a story about 3D-printed mouthpieces for people with sleep apnoea. Sadly, a lot of this interest seemed to be tinged with a note of desperation. While we were delighted to be able to tell a story that gave hope to so many stressed snorers and their loved ones, it wasn’t nearly as enjoyable to have to let people know they couldn’t be part of trials for the mouthpieces. On the up-side, however, Oventus, the company making the mouthguards, tells us that they’re steadily getting closer to being commercially available. Since we’ve had interest from several countries, we think they might have a hit on their hands. We just hope they’re able to help the man who told us his snoring is so bad that the cat left home. The cat would probably be grateful too. We suggested a cat hammock in the meantime.

And to continue on the camping theme, we got a lot of love for a story about backpacks. Bees with backpacks. This is just a terrific bit of research. We’ve put tiny 2.5mm sq RFID chips on the backs of 5000 bees. Now, this sounds a bit weird, but there’s an excellent reason for it. Collecting bee movement information at this scale will allow researchers to generate a four-dimensional model (three dimensions plus time) of bee behaviour and the way they move through the landscape. This is vital information: wild honey bee populations are dropping drastically or vanishing altogether. In some cases this is because of the parasitic Varroa mite. In others it’s Colony Collapse Disorder, believed to be caused by diseases and agricultural pesticides.

3D printed bike

Sam’s new 3D printed sweet ride.

Everybody seems to love stories about 3D printing (and who can blame them?). We had a couple of rippers this year. First, there was the 3D-printed bike. More specifically, the bike with 3D-printed titanium parts, specifically engineered to provide ‘infinite flexibility’ and give a far superior riding experience, along with quite a bit of bike envy. It also looks seriously good, and its proud owner/designer seems to be very pleased with it. We don’t know if the man at the centre of our other big 3D printing success this year (there’s one other, but we’ll come to that later) is a bike rider, but thanks to some brilliant work by our titanium printing team, he has the option. He had cancer in his heel bone, and the standard treatment for that is to amputate the leg below the knee. Fortunately, his surgeon had seen a story we did last year, about 3D-printed shoes for horses, and wondered if it was possible to print a new heel bone to replace the cancerous one. It was. One of the strengths of 3D printing is its ability to produce complex structures quickly: within two weeks of his surgeon making the call, the new heel bone was in place. We can now reveal that we sat on that story for months, busting to tell everyone, but couldn’t until after the three-month check-up showed everything was working well. We were very relieved – but not nearly as relieved as the recipient.

Not all health problems have as quick a fix as supplying a new part. It would be good if they did, but sometimes treatment is a long haul. Overweight and obesity fits into that category, but our new Impromy™ diet program helps to make the long haul as pleasant as it can be. Our talented team worked with Probiotec Ltd to develop a holistic program that includes meal replacements. This is a big help for people with busy lifestyles: often a reason that cooking and meal preparation fall down the priority list. It’s a research-based program that builds on our Total Wellbeing Diet research and leverages it to use with smart phone technology in a community pharmacy setting.

But we’d be very grateful if you disposed of the wrappers from the meal replacements carefully. Sometimes the big science stories aren’t good news, and this one certainly wasn’t. We went looking for rubbish, and what we found was sobering. In a survey of the entire Australian coast at 100 km intervals, with help from school groups and citizen scientists, we found that our shorelines are littered with debris. About 75 per cent of it is plastic, and, in a pretty grim indictment of our throwaway culture, you can expect to find anything from a few thousand to over 40,000 pieces of plastic per square kilometre in our coastal waters. Worse, we can extrapolate from this to predict that by 2050, 95 per cent of seabirds will have plastic in their gut.

If it’s bad news you want, though, our biannual State of the Climate report is – sadly – hard to beat. It’s getting warmer. Seven of the ten warmest years on record in Australia have occurred since 1998. When we compare the past 15 years with the period between 1951 and 1980, we find that very warm months are five times as frequent. The frequency of very cool months, conversely, has dropped by about a third. Extreme fire weather risk has increased, and the fire season has lengthened across large parts of Australia since the 1970s. Autumn and winter rainfall is declining, particularly in south-western and south-eastern Australia. Heavy rainfall with the potential for flooding is projected to increase. Australian average annual rainfall has increased slightly, largely from increases in spring and summer rainfall. Unfortunately, this doesn’t offset the autumn and winter declines in southern parts of Australia: it’s mainly concentrated in north-western Australia.

Sophie and Toothless.

Sophie and Toothless.

We don’t want to end on such a depressing note though, so … DRAGONS! This is the implausible bit, and it was absolutely, positively our biggest hit of the year. You might remember it. Seven-year-old Sophie wrote to us, asking if we could make her one. So we, er, did. Not a flying, screeching, fire-breathing one (we haven’t got the lab space), but a 3D-printed (there it is again) titanium (there’s that again too) one. This story captured the imagination of many people (140 000 page views worth), and might even have inspired Sophie, or another child, to become a scientist. We loved the comments we got on this story nearly as much as everyone seemed to love Sophie’s original letter. The erudite discussion on the history and physiology of dragons was a delight. Thank you to all the readers and dreamers who contributed.

Now, how would we go using dragons to generate supercritical steam? Just a thought…


Explainer: what is raw milk and why is it harmful?

There is no evidence that the health benefits of milk are compromised by pasteurisation. jacqueline/Flickr, CC BY-NC

There is no evidence that the health benefits of milk are compromised by pasteurisation. jacqueline/Flickr, CC BY-NC

By Edward Fox, CSIRO and Narelle Fegan, CSIRO

Milk is a highly nutritious food, and an important source of amino acids and minerals such as phosphorus and calcium, which contributes to bone health.

Historically, milk was prone to contamination by bacteria from cows that could cause severe illness in humans. This remains the case with raw (unpasteurised) milk. The tragic death of a Victorian toddler this week is a stark reminder of these risks.

Pasteurisation involves heating the product to 72°C for 15 seconds. The method was originally employed to destroy bacteria in wine and beer that caused these products to spoil. It was quickly realised that this process could also be applied to milk to destroy harmful bacteria, and make milk safer for human consumption.

Pasteurisation was first introduced in Australia in the late 1950s and remains a legal requirement for milk produced for human consumption in Australia.

Nowadays, some of the important bacteria that pasteurisation targeted, such as those that cause tuberculosis, are no longer as problematic. So why do we continue to pasteurise milk?

The animals we use for milking can sometimes carry other pathogenic organisms that are capable of causing disease in humans. They can be found on hides or shed in the faeces.

Even healthy animals may be a source of organisms that are harmful to people. Such pathogens may be present in the farm environment, including soil, water, on pasture and in animal feeds. These pathogens can enter the milk during milking and if such milk is consumed, it can cause disease.

The most common pathogens found in association with dairy farms and milking animals include bacteria such as Escherichia coli (E. coli), Campylobacter and Salmonella, but other pathogens such as parasites like Cryptosporidium, a type of gastro, may also be present.

As soon as milk is secreted from the udder, it is at risk of contamination by many different bacteria. cheeseslave/Flickr, CC BY

As soon as milk is secreted from the udder, it is at risk of contamination by many different bacteria.
cheeseslave/Flickr, CC BY

Campylobacter and Salmonella can cause severe diarrhoea and certain types of E. coli, particularly those known as Shiga toxin-producing E. coli (STEC), can cause very severe disease which impairs kidney function and may result in death.

Milk is highly nutritious to bacteria. Bacteria can quickly proliferate if their growth is not inhibited. Stopping the growth of bacteria in milk requires either heating to kill the bacteria, or chilling, which will not kill the bacteria but will slow down their growth.

E. coli, for instance, can go from ten cells to 100 million cells in just over six hours at 30°C. Only ten cells may be required to make someone ill. If such an organism is likely to be present, it’s important that any potential growth is stopped.

These harmful bacteria have caused outbreaks and disease associated with the consumption of raw milk in many countries. Data from the United States indicates that over a 13 year period to 2011, there were 2,384 illnesses, 284 hospitalisations and two deaths associated with the consumption of raw milk.

In Australia, raw milk contaminated by bacteria such as Campylobacter and Salmonella caused at least nine outbreaks of disease between 1997 and 2008, leading to 117 cases of illness.

So why do people choose to drink raw milk?

Advocates of raw milk often claim improved health benefit and nutritional value, or desiring a product which has not undergone further processing, retaining bacteria naturally present in milk.

But there is no evidence that the health benefits of milk are compromised by pasteurisation.

The defining difference between pasteurised and raw milk is the bacteria that are present. As soon as milk is secreted from the udder, it is at risk of contamination by many different bacteria as it makes its journey to our table. This includes harmful bacteria. These bacteria can lead to severe illness in humans, particularly children and the elderly.

For these reasons, raw milk continues to have a far higher risk of causing illness. Pasteurisation remains an important step in ensuring we can continue to enjoy safer, nutritious milk.

Further reading: Bath milk crisis must prompt better cosmetic safety regulation

This article was originally published on The Conversation.
Read the original article.


5 ways CSIRO has your back over summer

Sustainable prawns and low-fat recipes are just two of these five reasons CSIRO has your back over summer. There are a lot more than five, trust us, we just didn’t want to make you read too much when there’s Christmas fun to be had.

Sustainable prawns and low-fat recipes are just two of these five reasons CSIRO has your back over summer. There are a lot more than five, trust us, we just didn’t want to make you read too much when there’s Christmas fun to be had.

This is our second of three Christmas-themed posts – enjoy!

For many of us, the summer holidays are a chance to enjoy some of the sweeter things in life: catching up with loved ones over a bee-bee-cue, going for hikes through our unique Australian bush, kicking it at the beach, eating lavishly, or relaxing in the cool indoors and enjoying a new book. If you’re lucky, maybe it’s even all of the above.

We know to thank Gnowee, the solar goddess, for our glorious summer warmth, but you might not know a few of the ways CSIRO is helping to make your summer better. Here goes:

  1. Aerogard

This time of year you can’t leave the house without getting harassed by flies and mosquitoes trying to drink your blood, sweat, and tears (probably). Of course, for anti-fly protection we head straight for the Aerogard. But who do we thank for such miracle spray? Dr Doug Waterhouse, of course – former chief of CSIRO’s entomology (insect) division.

Mosquitoes are actually modified flies, so really there's only one type of insect to be upset with. Flickr/John Tann.

Mosquitoes are actually modified flies, so really there’s only one type of insect to be upset with. Flickr/John Tann

Doug was working on a spray to protect Australia’s sheep from blow flies when the Second World War broke out. This prompted Dr Waterhouse to develop his spray to protect Australia’s soldiers from malaria, instead.

Despite its success in World War 2, it wasn’t until the Queen used the spray during her visit in 1963 that its status as an effective anti-fly agent took off. It soon caught the nose of Mortein, who were ever-so-casually provided the formula by Dr Waterhouse. With Mortein on board it became known as Aerogard and the rest, as they smell, is history.

  1. Scanning the sands and seas
Dr Denise Hardesty cataloguing the stuff that missed the bin

Dr Denise Hardesty cataloguing the stuff that missed the bin.

Can’t stand the summer heat? Then get out of the kitchen and go to the beach. We wish our beaches were pristine oases, but instead, many of them are turning into stretches of refuse.

For three years, Dr Denise Hardesty and a devoted team of scientists and volunteers helped to survey Australia’s entire coastline, cataloguing the types of rubbish in and on the sands. The group found that three-quarters of the waste was plastic, and the majority of that waste didn’t wash up from distant lands, it was ours: Australians’ waste.

With these extensive surveys, we can identify the sources and hotspots of rubbish, and better target the problem. As well as fishing tackle, two major sources of marine debris were littering and illegal dumping. Click here to find out what else Denise and the team found.

Don't be a boob, put your rubbish in the bin for Crabst’s sake. Flickr/Scott Ableman.

Don’t be a boob, put your rubbish in the bin for Crabst’s sake. Flickr/Scott Ableman

  1. Wining and dining

Prawns

Who could say there was no such thing as a perfect creature when presented with our Perfect Prawns? We teamed up with the prawn industry, put our rostrums together, and came up with a larger and tastier Black Tiger prawn.

We analysed the genes of wild prawns to identify the ideal populations – and then worked out how to breed all our prawns with those best features! Our perfect prawns have won us a medley of gold medals from the Sydney Royal Easter Show.

Not only are they delicious, but you can eat them with a clear conscience because they are farmed sustainably (half of Australia’s prawns are imported from Asia with varying levels of sustainability). Our Black Tigers are fed with Novacq™, a CSIRO-developed solution made from microorganisms that makes the prawns grow faster, healthier, and without the need to be fed wasteful fish products. Click here to read more about our Perfect Prawns or Novacq™.

Fun fact (in our opinions): The nervous system and digestive system in crustaceans are flipped, and that’s why you pull their guts out of their spines rather than their bellies. Evolution is wacky like that.

Fun fact (in our opinions): The nervous system and digestive system in crustaceans are flipped, and that’s why you pull their guts out of their spines rather than their bellies. Evolution is wacky like that.

Wine

Wine grapes evolved in the Northern Hemisphere where they had plentiful water, cooler climates, and nutrient-rich soils. Australia’s often drought-stricken, scorching, and infertile soils are no place for such thirsty fruits. To help out Australia’s wine industry, we got our hands dirty – with Science.

The Catalonian Sumoll, a grape resistant to drought, and one of the varieties incorporated into our hybrids. Flickr/Angela Llop

The Catalonian Sumoll, a grape resistant to drought, and one of the varieties incorporated into our hybrids. Flickr/Angela Llop

We used traditional breeding and genetic methods to not only improve the root systems of vines – helping them cope with our soils – but also to foster characteristics for fruit colour, flavour, and aroma.

Apart from improving flavour, we’re also helping our grapevines survive the blights of various mildews. Since grapevine mildews are a distinctively American phenomenon, our vines have not had the chance to evolve any resistance. To fight the blight, our researchers analysed American grapevine varieties that were hardened to the mildews, identified genes for resistance, and then introduced them to the varieties of grapevines used here. Cheers to that!

Keep an eye out for the wines cultivated with our research: Tarrango, Tyrian, Cienna, and Rubienne.

  1. Wellbeing Diet

After pining over seafood and vineyard delicacies, we bring you our Total Wellbeing Diet: a worthy adversary to combat holiday kilos. Designed to reduce blood pressure, glucose, and insulin, minimising the chances of cardiovascular diseases, the CSIRO Total Wellbeing Diet is also crafted to please gourmands.

Portuguese chicken salad from the Total Wellbeing Diet. The asparagus is hiding beneath the chicken.

Portuguese chicken salad from the Total Wellbeing Diet. The asparagus is hiding beneath the chicken.

The diet was published with Penguin in 2005, and due its success has appeared in numerous releases since. More recent editions of our wellbeing diet cater to those on a budget and those with no meal preparation time to spare.

Our Total Wellbeing Diet online program launches on the 5th of January, and you can pre-register here.

  1. Bushfire prevention and control
That flammable leaf litter never stood a chance!

That flammable leaf litter never stood a chance!

For some Australians, summer is synonymous with bushfires and a constant state of high-alert. And until we can understand them better, bushfires will continue to be a destructive force, especially over summer.

Bushfires are chaotic systems. They can strike almost randomly, and grow and move unpredictably. Before we can predict and control bushfires, we must learn more about them. The best way to do this is through experimentation, but this is difficult precisely because bushfires are so chaotic.

Enter, the Pyrotron, a giant vacuum chamber to tame the bushfire beast. We made the Pyrotron so we can study bushfire movement under controlled conditions, allowing us to understand the fire’s behaviour better, and make more accurate predictions.

You can read more about our very own Decepticon, here.

Or watch this fun, fun, fun clip from the BBC:

Over the next couple of weeks when you’re enjoying the fermented fruits of our labour, there’s no need to thank us, because we love what we do.


Global and Australian warming continues

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By Dr Helen Cleugh, Science Director, CSIRO Oceans and Atmosphere Flagship

The World Meteorological Organization reports that 2014 is on track to be possibly the world’s hottest year on record. Meanwhile, there’s been a lot of public commentary lately about the so-called “hiatus” in global surface temperature over the past 18 years, recent sea-level rise, and what it all means.

So what do CSIRO’s research and observations tell us?

They show that average surface air temperatures have continued to rise during the past two decades, but not as fast as in preceding decades. In other words, while the rate of temperature increase is lower, the temperatures themselves are not lower.

It is also important to note that when climate scientists use the term “global-mean surface temperature” they refer to near-surface air temperatures. Surface air temperature is an incomplete measure of warming of the planet; oceans store huge amounts of heat, with about 93 per cent of the extra heat stored by the Earth over the past 50 years being found in the oceans.

 Changes in the global climate system indicating a world experiencing a consistent pattern of warming. Note (1) net increase in glacier volumes have regional variation (almost all glaciers worldwide losing mass but some gaining) but overall net loss; and (2) net decrease in global sea-ice extent has regional variation (over the period 1979–2012 it is very likely that the annual mean Arctic sea-ice extent decreased 3.5 to 4.1% per decade, and it is very likely that the annual mean Antarctic sea ice extent increased by 1.2 to 1.8% per decade) but overall net loss. Source: CSIRO and Bureau of Meteorology.

Changes in the global climate system indicating a world experiencing a consistent pattern of warming.*

The ocean today is warmer, and sea levels higher, than at any time since the instrumental record began. As the oceans warm, they expand and sea levels rise. Using a combination of coastal tide-gauge and satellite-altimeter data, CSIRO and others have shown that, globally, sea level has been rising since the late 1800s. Global-averaged sea level rose at an average rate of about 1.6 mm per year over the 20th Century, but this rate has accelerated to about 3 mm per year as measured by satellite altimetry and tide gauges since 1993. So the rate of sea-level rise has not slowed; it has increased.

Our measurements across the land, atmosphere and oceans show that warming has continued unabated throughout the past 18 years.

Last year was Australia’s warmest year on record, followed by 2005 and 2009. For global land and ocean temperatures, 2013 tied with 2003 as the fourth warmest year globally; and 13 of the 14 warmest years ever measured occurred in the 21st Century. As reported by the World Meteorological Organization, this year is shaping up to be the world’s warmest year – the year to the end of October is the planet’s warmest on record.

It is not unusual to see changes in the rate of surface warming. Over the past 120 years, there have been decades where global-mean air temperature has warmed more rapidly, and decades where relative cooling has occurred.

Increases in greenhouse gases provide a warming effect but, due to natural variability, climate trends based on short records are very sensitive to the beginning and end dates, and do not reflect long-term climate trends.

The rate of warming in any shorter period fluctuates because of factors such as short-term natural variability, ocean absorption of heat from the atmosphere, volcanic eruptions, changes in the 11-year solar cycle, and so on. This does not change any conclusion about the long-term trend of warming due to human activities, which have increased the concentration of greenhouse gases in the atmosphere.

CSIRO research has shown that there is less than 1 chance in 100,000 that global mean air temperature over the past 60 years would have been as high without human-caused greenhouse gas emissions. That is, the probability of global temperature increases being due to human activity exceeds 99 per cent.

The world is not cooling.

*Note (1) net increase in glacier volumes have regional variation (almost all glaciers worldwide losing mass but some gaining) but overall net loss; and (2) net decrease in global sea-ice extent has regional variation (over the period 1979–2012 it is very likely that the annual mean Arctic sea-ice extent decreased 3.5 to 4.1% per decade, and it is very likely that the annual mean Antarctic sea ice extent increased by 1.2 to 1.8% per decade) but overall net loss. Source: CSIRO and Bureau of Meteorology.

This article was originally published in The Canberra Times.


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