McCarrs Creek, Mona Vale and Bayview Flood Study
The draft McCarrs Creek, Mona Vale and Bayview Flood Study (2015) will be on exhibition for public comment from Monday 29 February until Friday 1 April.
The draft study can be viewed online or at customer service centres and libraries at Avalon and Mona Vale and at the Coastal Environment Centre, North Narrabeen. For more information visit www.pittwater.nsw.gov.au/yoursay.
Draft McCarrs Creek, Mona Vale and Bayview Flood Study Report and Map
Full Report - McCarrs Creek, Mona Vale and Bayview Flood Study - Download (40mb pdf)
Report and Appendices as individual downloads
Main document excluding appendices Download (8.5mb pdf)
Appendix A Note: All maps have windows A, B and C
Peak Flood Depths - Figures A1 to A8 Download (10mb pdf)
Peak Flood Velocity, Provisional Flood Hazard, Hydraulic Categorisation - Figures A9 to A15 Download (9.5mb pdf)
Climate Change Mapping - Figures A16 to A23 Download (8.8mb pdf)
Development Control Mapping - Figures A24 to A25 Download (2.8mb pdf)
Appendix B
Community Consultation Information Download (239kb pdf)
Appendix C
Design Hydrographs Download (337kb pdf)
Community information sessions
You may book a 15 minute appointment with a flooding specialist to discuss what the draft study means for your property. You may choose in person or over the phone during these times:
In Person
Tuesday 8 March 1 - 3pm
Tuesday 8 March 4 - 8pm
Tuesday 16 March 1 - 3pm
Tuesday 16 March 4 - 8pm
Thursday 17 March 1 - 3pm
Thursday 17 March 4 - 8pm
Over the Phone
Wednesday 9 March 2pm - 4pm
Wednesday 9 March 10am - 12 noon
Wednesday 16 March 10am - 12 noon
Wednesday 16 March 2pm - 4pm
Note - The in person appointments are held in the Mona Vale Conference Room. It is located above Mona Vale Library, 1 Park Street, Mona Vale and is accessed via Council’s Customer Service office.
You will need to provide your name, email address and a contact phone number. You will also need to supply the property address that has been identified as subject to flooding risk under the draft study.
Wildlife Carers and Organisations in Pittwater:
Sydney Wildlife rescues, rehabilitates and releases sick, injured and orphaned native wildlife. From penguins, to possums and parrots, native wildlife of all descriptions passes through the caring hands of Sydney Wildlife rescuers and carers on a daily basis. We provide a genuine 24 hour, 7 day per week emergency advice, rescue and care service.
As well as caring for sick, injured and orphaned native wildlife, Sydney Wildlife is also involved in educating the community about native wildlife and its habitat. We provide educational talks to a wide range of groups and audiences including kindergartens, scouts, guides, a wide range of special interest groups and retirement villages. Talks are tailored to meet the needs and requirements of each group.
Sydney Wildlife's Wallaby and Kangaroo Rehabilitation Facility at Waratah Park
Found an injured native animal? We're here to help.
Keep the animal contained, warm, quiet and undisturbed. Do not offer any food or water.
Call Sydney Wildlife immediately on 9413 4300, or take the animal to your nearest vet. Generally there is no charge.
Find out more at: www.sydneywildlife.org.au
Southern Cross Wildlife Care was launched over 6 years ago. It is the brainchild of Dr Howard Ralph, the founder and chief veterinarian. SCWC was established solely for the purpose of treating injured, sick and orphaned wildlife. No wild creature in need that passes through our doors is ever rejected.
People can assist SCWC by volunteering their skills ie: veterinary; medical; experienced wildlife carers; fundraising; "IT" skills; media; admin; website etc. We are always having to address the issue of finances as we are a non commercial veterinary service for wildlife in need, who obviously don't have cheque books in their pouches. It is a constant concern and struggle of ours when we are pre-occupied with the care and treatment of the escalating amount of wildlife that we have to deal with. Just becoming a member of SCWC for $45 a year would be a great help. Regular monthly donations however small, would be a wonderful gift and we could plan ahead knowing that we had x amount of funds that we could count on. Our small team of volunteers are all unpaid even our amazing vet Howard, so all funds raised go directly towards our precious wildlife. SCWC is TAX DEDUCTIBLE.
Find out more at: southerncrosswildlifecare.org.au/wp/
Antarctica could be headed for major meltdown
February 23, 2016
Antarctica's glaciers are the size of the United States and Mexico combined, and they contain enough water to raise the world's sea level by 180 feet. (Stock image) Credit: © pranodhm / Fotolia
In the early Miocene Epoch, temperatures were 10 degrees warmer and ocean levels were 50 feet higher -- well above the ground level of modern-day New York, Tokyo and Berlin.
It was more than 16 million years ago, so times were different. But there was one important similarity with the world we live in today: The air contained about the same amount of carbon dioxide. That parallel raises serious concerns about the stability of ice sheets in Antarctica, according to a study published in the Proceedings of the National Academy of Sciences.
All told, Antarctica's glaciers are the size of the United States and Mexico combined, and they contain enough water to raise the world's sea level by 180 feet. And although no humans live permanently in Antarctica, what happens there impacts everyone, said Aradhna Tripati, a geochemist at UCLA's Institute of the Environment and Sustainability who collaborated on the research.
"The ice sheets serve as huge stores of water," Tripati said. "As the ice melts, it gets dumped in the ocean and the sea level rises."
The study is the latest revelation of ANDRILL, a $20 million research project focused on the South Pole. The effort, now 12 years old, has involved 100 researchers from seven countries. ANDRILL researchers were the first to bore holes through Antarctic ice shelves and sea ice to sample the ocean floor below.
Previous research showed that ice shelves -- the parts of the ice sheets that extend over water -- are vulnerable to even small increases in greenhouse gases. But the new study, which was written by Richard Levy of GNS Science, a New Zealand research organization, was the first to demonstrate that the huge, land-based glaciers are also vulnerable.
David Harwood, a University of Nebraska paleontologist who led the study, said the project's goal was to see what prehistoric environments could tell us about the modern era of climate change.
"We're drilling back into the past to understand the future and how dynamic our planet can be," he said.
To do that, researchers set 90 tons worth of drilling equipment on a floating sea ice in McMurdo Sound, where conditions can be particularly harsh: The average August temperature is minus 23 degrees Fahrenheit, and savage windstorms can occur at a moment's notice. Using a diamond-tipped tubular drill, researchers bored through 24 feet of ice, 1,200 feet of water and 3,300 feet of ocean floor. The rock samples they collected preserve a chronological record of environmental conditions dating back 20 million years.
The samples were sent to Tripati for analysis. As she looked at the sedimentary layers, a story began to emerge. Samples that were formed during warmer times, when the ice shelf was gone or unstable, were tan-colored and rich with fossils. But samples drawn from years when the sea was covered with ice, were mostly rock with fossils from only a few deep sea organisms.
Looking even closer, Tripati examined individual molecules from the samples to determine air and water temperatures at different times in history. Warmer times correlated with higher levels of carbon dioxide in the atmosphere, melting ice shelves and the loss of parts of the East Antarctic ice sheet.
According to Tripati, scientists are seeing early signs of the same conditions today.
"If carbon dioxide is sustained at current levels, we run the risk of Antarctic ice shelf disappearance," she said.
The ice shelves are critical because they act like a cork in a Champagne bottle, holding back the huge, land-based flows of glacial ice on the Antarctic continent, Tripati said. But they are particularly sensitive to temperature changes. Just a few degrees of increased warmth can make them disappear because they are warmed by both the air and the sea.
And disappearing ice shelves lead to even more warming because of something called the albedo effect: Light-colored ice reflects the sun's radiation away from Earth. After it melts, the darker-colored seas absorb more radiation and more heat.
That process could take hundreds of years, but signs of rapid change are already here. In 2002, the Larsen B ice shelf -- which was made up of more than 1,250 square miles of 720-foot-thick ice -- disintegrated into the ocean over the course of a month, shocking scientists and observers. Over the past several decades, seven out of 12 ice shelves on the Antarctic Peninsula have collapsed.
"They've just been going like dominoes," Tripati said.
Still, researchers say the PNAS findings offer a glimmer of hope. Policymakers rely on computer models to predict future climate change, and the models now can be refined based on the new information about changes that occurred millions of years ago, Tripati said.
The big question that remains is how fast melting will occur. Harwood said the ANDRILL findings emphasize the fragility of ice shelves and the urgency of taking action on a global scale.
"The models simulate thresholds, points of no return," he said. "It's good for policymakers to know how fast we have to get off this train or turn it in a new direction."
Richard Levy, David Harwood, Fabio Florindo, Francesca Sangiorgi, Robert Tripati, Hilmar von Eynatten, Edward Gasson, Gerhard Kuhn, Aradhna Tripati, Robert DeConto, Christopher Fielding, Brad Field, Nicholas Golledge, Robert McKay, Timothy Naish, Matthew Olney, David Pollard, Stefan Schouten, Franco Talarico, Sophie Warny, Veronica Willmott, Gary Acton, Kurt Panter, Timothy Paulsen, Marco Taviani. Antarctic ice sheet sensitivity to atmospheric CO2variations in the early to mid-Miocene. Proceedings of the National Academy of Sciences, 2016; 201516030 DOI:10.1073/pnas.1516030113
SUNDAY MORNING BIRDWATCHING with PNHA
Would you like to know more about our local birds and explore our bushland reserves? Then join us on one of our bird walks:
17 April, Deep Creek Reserve, near Narrabeen Lagoon
21 August, Chiltern Track, Ingleside (birds and wildflowers)
25 September, Irrawong Reserve, North Narrabeen
27 November, Warriewood Wetlands
Most walks start at 7.30 or 8am and last a couple of hours. Bring binoculars and morning tea for afterwards if you like. Contactpnhabirdwatching@gmail.com for details of each walk.
El Niño prolongs longest global coral bleaching event
February 23, 2016
The top images show the maximum thermal stress levels measured by NOAA satellites in 2014 and 2015 along with locations where the worst coral bleaching was reported. The bottom image shows the Four Month Bleaching Outlook for February-May 2016 based on the NOAA Climate Forecast System model along with locations. Credit: NOAA
Global warming and the intense El Niño now underway are prolonging the longest global coral die-off on record, according to NOAA scientists monitoring and forecasting the loss of corals from disease and heat stress due to record ocean temperatures. The global coral bleaching event that started in 2014 could extend well into 2017, researchers report at the Oceans Sciences Meeting here this week.
Coral bleaching happens when corals are stressed by conditions such as high temperatures. The bleaching, or whitening, occurs when the corals expel the symbiotic algae that live in their tissues. Without the algae, corals lose a significant source of food and are more vulnerable to disease. In a severe bleaching event, large swaths of reef-building corals die. This causes reefs to erode, destroying fish habitat and exposing previously protected shorelines to the destructive force of ocean waves.
Warmer ocean temperatures caused by El Niños and global warming can lead to coral bleaching. The first mass bleaching occurred during the 1982-83 El Niño. A global bleaching event was then confirmed in 1998 during a strong El Niño that was followed by a very strong La Niña, which brings warmer waters to places like Palau and Micronesia. A second global bleaching event occurred in 2010, during a less powerful El Niño.
Scientists first observed the current global coral bleaching event beginning in mid-2014 when bleaching began in the western Pacific Ocean. In October 2015, as the current El Niño was still strengthening, NOAA scientists declared the third global bleaching event on record was underway.
New research finds that this bleaching event has persisted for 20 months and could reach into 2017, said Mark Eakin, a biological oceanographer at NOAA in College Park, Maryland, and coordinator of NOAA's Coral Reef Watch.
"This time we're in the longest coral bleaching event," Eakin said. "We're maybe looking at a 2- to 2-1/2-year-long event. Some areas have already seen bleaching two years in a row."
Eakin and his colleagues will be presenting the latest update and outlook for the global bleaching event Friday at the 2016 Ocean Sciences Meeting co-sponsored by the Association for the Sciences of Limnology and Oceanography, The Oceanography Society and the American Geophysical Union.
The length of the event means corals in some parts of the world have no time to recover before they are hit by another bleaching event, Eakin said. The current global bleaching event is hammering some reefs repeatedly. Reefs bleached in 2015 in the Caribbean and Florida Keys, for instance, have just started to recover, but may start bleaching all over again as early as July, according to Eakin. In the Pacific, reports are just coming in that corals in Fiji's nearshore waters are bleaching with lots of dead coral.
"This is now two years in a row for Fiji and it's looking like 2016 may be worse than 2015," Eakin said.
The rate of return of bleaching events has been faster than some reefs can recover, he noted. In 1998 in Southeast Asia, for example, there was a severe bleaching event, followed by twelve years of recovery that allowed some of the more rapid-growing, branching corals to grow back. However, the slower-growing corals that build the backbone of reefs did not recover. In 2010, the same area was hit again by a global bleaching event, killing off newly-grown branching corals and many of the surviving massive corals. These reefs may see bleaching again later this year, Eakin said.
"That was only six years ago," he said. "We're seeing global bleaching again now. The frequency of mass bleaching events are going up because of global warming. We are hitting the corals, then we are hitting them again, and then again."
The above is reprinted from materials provided by American Geophysical Union.
Bat 'super immunity' could help protect people
February 22, 2016: CSIRO
Black-headed flying fox amongst a grey-headed colony. Credit: Michelle Baker CSIRO
For the first time researchers have uncovered a unique ability in bats which allows them to carry but remain unaffected by lethal diseases.
Unlike humans, bats keep their immune systems switched on 24/7 and scientists believe this could hold the key to protecting people from deadly diseases like Ebola.
Bats are a natural host for more than 100 viruses, some of which are lethal to people, including Middle Eastern Respiratory Syndrome (MERS), Ebola and Hendra virus, however, interestingly bats do not get sick or show signs of disease from these viruses.
Published today in the Proceedings of the National Academy of Sciences(PNAS), this new research examines the genes and immune system of the Australian black flying fox, with surprising results.
"Whenever our body encounters a foreign organism, like bacteria or a virus, a complicated set of immune responses are set in motion, one of which is the defense mechanism known as innate immunity," leading bat immunologist at CSIRO's Australian Animal Health Laboratory Dr Michelle Baker said.
"We focused on the innate immunity of bats, in particular the role of interferons -- which are integral for innate immune responses in mammals -- to understand what's special about how bats respond to invading viruses.
"Interestingly we have shown that bats only have three interferons which is only a fraction -- about a quarter -- of the number of interferons we find in people.
"This is surprising given bats have this unique ability to control viral infections that are lethal in people and yet they can do this with a lower number of interferons."
The team also compared two type 1 interferons -- alpha and beta.
The research showed that bats express a heightened innate immune response even when they were not infected with any detectable virus.
"Unlike people and mice, who activate their immune systems only in response to infection, the bats interferon-alpha is constantly 'switched on' acting as a 24/7 front line defence against diseases," Dr Baker said.
"In other mammalian species, having the immune response constantly switched on is dangerous -- for example it's toxic to tissue and cells- whereas the bat immune system operates in harmony."
While we are familiar of the important role bats play in the eco-system as pollinators and insect controllers, they are also increasingly demonstrating their worth in potentially helping to protect people from infectious diseases.
"If we can redirect other species' immune responses to behave in a similar manner to that of bats, then the high death rate associated with diseases, such as Ebola, could be a thing of the past," Dr Baker said.
This work builds on previous research undertaken by CSIRO and its partners to better understand bat immunity to help protect Australia and its people from exotic and emerging infectious diseases.
Led by CSIRO, this international research effort included expertise from CSIRO, Duke-NUS Medical School and the Burnet Institute.
Peng Zhou, Mary Tachedjian, James W. Wynne, Victoria Boyd, Jie Cui, Ina Smith, Christopher Cowled, Justin H. J. Ng, Lawrence Mok, Wojtek P. Michalski, Ian H. Mendenhall, Gilda Tachedjian, Lin-Fa Wang, and Michelle L. Baker. Contraction of the type I IFN locus and unusual constitutive expression of IFN-α in bats.Proceedings of the National Academy of Sciences, 2016; DOI:10.1073/pnas.1518240113
Japanese earthenware time capsules contain 4,300-year-old cockroach egg case impressions
February 22, 2016
Scanning electron microscope (SEM) image of a cockroach egg case silicone replica. Credit: Prof. Hiroki Obata
Long ago, in a field far away...
Impressions of cockroach egg cases from 4,300 year old Japanese potsherds (broken pottery fragments) have been found in southern Japan. X-ray, computed tomography (CT) and scanning electron microscopy were used to image the impressions and reveal aspects about ancient Japanese life in this latest archeological survey from Kumamoto University.
These are impressions you are looking for
To archeologists, ancient earthenware is almost always packed full of treasure. This may seem logical since the pots may have held water, food or other historically valuable items. This time, however, the "treasure" was found not in the pot, but inside the pottery itself.
"Countless vacant holes on the surface of potsherds had been all but ignored until about 25 years ago," said Professor Hiroki Obata, researcher of archeology from Kumamoto University, Japan. "Since then, however, the meaning and importance of these holes has become well understood. They can be the impression of seeds, nuts, insects or shells."
From the cavities left by soybeans or adzuki beans which were mixed in the pottery during creation, it is possible to more correctly estimate the beginning of cultivation in the district. Impressions are an important key to understanding the lifestyle of those who lived in a particular area during a particular period. Furthermore, with a quantitative survey of the impressions, it is possible to extrapolate the range of the propagation and cultivation of the plants.
Professor Obata's group examined impressions on the surface and from the inside of the potsherds from the Odake shell mound site in Toyama Prefecture, which contains artifacts from the early Jomon Period of Japan (5,300 -- 3,500 BC). Using X-ray, CT and scanning electron microscopy they found more than 500 impressions, even though only 66 could be visually confirmed, of Egoma -- Perilla frutescens var. frutescens -- seed related imprints on the surface. The impressions within the potsherds were unique to the period making them easily distinguishable from potsherds that had been created at another time.
That's no seed. That's a cockroach impression
In their latest survey the research group employed an "impression replica" method of investigation, where a silicon replica cast is made of an item's surface and then scanned with a scanning electron microscope producing a detailed examination of the original surface. Cockroach egg case impressions found during the examinations were about 11 mm (0.43 in) long, and it was determined that the egg cases were from the smokybrown cockroach (Periplaneta fuliginosa) native to the southern area of China. In Japan, smokybrown cockroaches have been portrayed in 18 century (Edo Period) literature and art work, with literary and artistic appearances by cockroaches previous to that period considered to be a domestic species.
The two of the potsherds which contained the egg case impressions were unearthed from the Motonobaru archeological site which dates back to the late Jomon Period of Japan (2,500 -- 1,300 BC). The impressions were found from fragments that were about 4,000 and 4,300 years old respectively. This shows that smokybrown cockroaches have existed in Japan nearly 3,700 to 4,000 years longer than had ever been considered from literary and artistic works.
Maize weevils be with you
One year previously, Professor Obata and colleagues presented results of their research from the same site in which they found 173 impressions of an insect called the maize weevil. At that time, it was about half of all ancient maize weevils that had ever been discovered in Japan.
"The maize weevil is a type of harmful insect that eats stored starch food materials such as acorns or chestnuts, which are known to be typical stored food for that period in Japan. The existence of many maize weevils and cockroaches shows that these ancient humans lived settled lifestyles," said Professor Obata. "With this latest research, we have revealed that there were cockroaches in human living areas from a period older than was previously believed. More and more information about ancient human life is being found from potsherds. Soft and small items have some difficulty remaining in the soil for a significant amount of time, but they can be kept safe within these pottery fragments. Like little time capsules, potsherds are packed full of treasures which help to reveal the story about the living conditions of ancient humans."
Further investigations are currently being performed on ancient potsherds and more discoveries are expected in the future.
The above is reprinted from materials provided by Kumamoto University.
New species couldn't hop, but outlived its fanged kangaroo contemporaries
February 22, 2016
Fossil skull of the ancient kangaroo, Cookeroo hortusensis. Credit: Kaylene Butler
A University of Queensland (UQ)-led study has discovered a new genus and two new species of extinct kangaroos which couldn't hop, but may have been ancestral to all kangaroos and wallabies living today.
Lead author Kaylene Butler of UQ's School of Earth Sciences said the new kangaroo species were discovered in ancient fossil deposits at the Riversleigh World Heritage Area in north-western Queensland, Australia.
"They lived around 15-23 million years ago and were the size of very small wallabies or pademelons," she said.
"They moved on all fours, scurrying across a densely forested landscape quite different from the dry outback we see in western Queensland today.
"It also appears that our new species were direct competitors with a second group of kangaroos at Riversleigh, the even weirder 'balbarid' or fanged kangaroos.
"It seems likely that the fanged cousins were out-competed by our new species and their descendants."
The new species may have been better adapted than their fanged cousins to the environmental change from rainforest to more open forest and woodland environments. They are described in the Journal of Vertebrate Paleontology.
Ms Butler worked on fossil material as part of her PhD research supervised by study co-authors former UQ Robert Day Fellow, Dr Kenny Travouillon, now of Western Australian Museum, and Dr Gilbert Price of UQ.
Riversleigh research leaders Professors Michael Archer and Suzanne Hand, of the University of New South Wales, are also study authors.
She said that by taking measurements and comparing skulls and teeth with known species, it was discovered that they were looking at both a new genus (taxonomic rank) and two new species within the genus.
She said the new genus was named Cookeroo, in honour of Dr Bernard Cooke, a distinguished Queensland Museum researcher who led much of the research program focused on the evolution of Riversleigh's ancient kangaroos.
The two new species within the genus are Cookeroo bulwidarri, which lived about 23 million years ago, and Cookeroo hortusensis which lived 20 million to 18 million years ago.
Bulwidarri means "white" in the Aboriginal Waanyi language, and is named for White Hunter Site at the Riversleigh World Heritage Area where specimens of this species were obtained. Hortusensis is Latin for "belonging to the garden," in reference to Neville's Garden Site at Riversleigh where specimens of this species were found.
Kaylene Butler, Kenny J. Travouillon, Gilbert J. Price, Michael Archer, Suzanne J. Hand. Cookeroo, a new genus of fossil kangaroo (Marsupialia, Macropodidae) from the Oligo-Miocene of Riversleigh, northwestern Queensland, Australia. Journal of Vertebrate Paleontology, 2016; e1083029 DOI: 10.1080/02724634.2016.1083029
Solved! First distance to a ‘fast radio burst’
25 February 2016: CSIRO
For the first time a team of scientists has tracked down the location of a fast radio burst (FRB), confirming that these short but spectacular flashes of radio waves originate in the distant universe.
The breakthrough, published today in the journal Nature, was made using CSIRO radio telescopes in eastern Australia and the National Astronomical Observatory of Japan’s Subaru telescope in Hawaii.
“Our discovery opens the way to working out what makes these bursts,” Dr Simon Johnston, Head of Astrophysics at CSIRO and a member of the research team said.
FRBs emit as much energy in one millisecond as the sun emits in 10,000 years, but the physical phenomenon that causes them is unknown.
This, and their apparently huge distances, have tantalised scientists since their discovery in 2007. Only 16 bursts have ever been found but astronomers estimate that they might occur 10,000 times a day across the entire sky.
Today’s paper in Nature records a burst from a host galaxy around six billion light-years away.
Importantly, it also confirms that FRBs can be used to find matter in the universe that had ‘gone missing’.
Astronomers think the contents of the universe are 70 per cent dark energy, 25 per cent dark matter and 5 per cent ordinary matter.
But when they add up the matter they can see in stars, galaxies and hydrogen gas, they still only find half as much ordinary matter as should be there - the rest has not been seen directly and so has been described as ‘missing’.
Using the burst (FRB 150418) as a tool, the team were able to ‘weigh’ the universe, or at least the normal matter it contains.
"The good news is our observations and the model match — we have found the missing matter," explained Dr Evan Keane from the SKA Organisation, lead author on the Nature paper.
"It's the first time a fast radio burst has been used to conduct a cosmological measurement."
Most FRBs have been found by sifting through recorded data months or even years after it was taken, by which time it was too late for follow-up observations.
To remedy this, Dr Keane and his international team developed a system to detect FRBs within seconds, immediately alerting other telescopes with a view to pinpointing their location.
The Parkes telescope detected the new FRB on 18 April 2015 and two hours later, CSIRO’s Compact Array telescope (above), 400km north of Parkes, homed in on the patch of sky the flash had come from.
It saw a radio source that lasted for six days before fading — the FRB’s radio afterglow.
This let the researchers zoom in on the FRB about 1000 times more precisely than any of the 16 previously detected bursts.
Meanwhile, in Hawaii the 8.2m optical Subaru telescope was also at work. Looking at the FRB field, it found a galaxy that could be matched with the radio source seen by the Compact Array.
More sleuthing showed that this object was an elliptical galaxy — a huge football-shaped mass of stars. Its redshift (0.492) means that it is about six billion light-years away.
The galaxy is old, well past its prime period for star formation.
“This is not what we expected,” Dr Johnston said.
“It might mean that the FRB resulted from, say, two neutron stars colliding rather than anything to do with recent star birth.”
But there could be more than one road to an FRB, he added.
“In the near future, using CSIRO’s Australian SKA Pathfinder (ASKAP) should be ideal and ASKAP will be able to start looking for FRBs this year,” he said.
“We expect to find several a week, and really clean up.”
Top: CSIRO’s Compact Array telescope picked the FRB’s afterglow. © Alex Cherney
Reef sharks prefer bite-size meals
February 22, 2016
Reef sharks, like this black-tip shark, typically eat small fishes, mollusks and crustaceans. Black-tip sharks, in turn, are eaten by larger sharks such as tiger and hammerhead sharks. Credit: Simon Gingins
Sharks have a reputation for having voracious appetites, but a new study shows that most coral reef sharks eat prey that are smaller than a cheeseburger.
Researchers from James Cook University's ARC Centre of Excellence for Coral Reef Studies examined stomach contents of reef sharks and conducted chemical analyses of shark body tissue to find out what they had been eating.
Lead author, Dr Ashley Frisch said that after pumping a shark's stomach to identify the contents of its last meal, the most common thing to find was in fact, nothing.
"We were surprised to find a broad range of small prey items such as fish, molluscs, sea snakes, crabs and more often than not, nothing at all."
"These results suggest that reef sharks eat small meals infrequently and opportunistically," Dr Frisch said.
To understand what the sharks were eating over longer periods, the researchers analysed shark body tissue.
"Although black-tip, white-tip and grey reef sharks have long been thought of as top predators, we found that the chemical structure of the sharks' body tissue actually matched closely with that of large reef fishes such as groupers, snappers and emperors," Dr Frisch said.
"This result tells us that reef sharks and large fishes have a similar diet, but they don't eat each other. So rather than eating big fish, reef sharks are eating like big fish."
Understanding 'who eats who' on coral reefs is important in helping scientists better predict how changes in one population impact another.
Co-author of the study, Dr. Justin Rizzari, said the new research changes how scientists think about food webs on coral reefs and acts as a reminder that large, conspicuous predators are not always at the top of the food chain.
"We now know that reef sharks are an important link in the food chain, but they are not the last link in the food chain. In most cases, the top predators are tiger sharks, hammerhead sharks, or people," Dr Rizzari said.
"Coral reef ecosystems are very complex. The more we look, the more we realise that each and every species plays an important role. Sharks are no exception. They help to keep coral reefs healthy and should be managed wisely."
With coral reefs around the world in decline and humans killing an estimated 100 million sharks every year, understanding the exact role sharks play in coral reef ecosystems is more urgent now than ever.
The article entitled "Reassessing the trophic role of reef sharks as apex predators on coral reefs" was recently published by the journal Coral Reefs.
Ashley J. Frisch, Matthew Ireland, Justin R. Rizzari, Oona M. Lönnstedt, Katalin A. Magnenat, Christopher E. Mirbach, Jean-Paul A. Hobbs.Reassessing the trophic role of reef sharks as apex predators on coral reefs. Coral Reefs, 2016; DOI: 10.1007/s00338-016-1415-2
Gulf of Mexico historic shipwrecks help scientists unlock mysteries of deep-sea ecosystems
February 22, 2016
The ROV collects sediment cores for microbiological and geochemical analysis during the Gulf of Mexico Shipwreck Study expedition in July 2014. Credit: Credit: BOEM
The 2010 Deepwater Horizon oil spill significantly altered microbial communities thriving near shipwrecks in the Gulf of Mexico, potentially changing these diverse ecosystems and degrading the historically and culturally significant ships they live on, according to new research being presented here. The findings are also revealing how decades-old, or even centuries-old, shipwrecks could be used to monitor the health of deep-ocean ecosystems, and the effects of oil and gas activity in the Gulf, according to the researchers.
There are more than 2,000 known historic shipwrecks sitting on the ocean floor in the Gulf of Mexico, spanning some 500 years of maritime history: from the time of the 16th century Spanish explorers to the American Civil War and through the World War II era. In addition to their historical and cultural significance, historic shipwrecks also serve as artificial reefs, supporting a rich deep-sea ecosystem.
In 2014, a multidisciplinary team of scientists launched a project investigating the effects of the Deepwater Horizon oil spill on shipwrecks that lie hundreds to thousands of feet underwater and the microbial communities forming the base of these ecosystems. The project is the first of its kind to study deep-sea shipwreck microbiomes, and the long-term impacts of an oil spill on shipwrecks and their microbial inhabitants, according to the researchers.
"We are filling a huge void in our scientific understanding of the impacts of the spill," said Melanie Damour, a marine archaeologist at the Bureau of Ocean Energy Management in New Orleans, Louisiana, and a co-leader of the project.
Scientists found that the presence of a shipwreck influences which microbes are present on the seafloor, and the release of 4 million barrels of oil from the Macondo well for 87 days significantly altered nearby shipwreck microbial communities. Even four years after the event, the oil was still affecting the community structure and function of these microbes, potentially impacting other parts of the ecosystem. Laboratory studies found that the dispersant used to clean up the oil spill significantly alters the shipwreck microbial community that forms the foundation for other life, like coral, crabs and fish, which thrive there.
Not only did these studies show that the spill affected these ecosystems, but they also provide a new way to monitor the spill's effects, said Leila Hamdan, a microbial ecologist at George Mason University in Manassas, Virginia and co-leader of the project.
"The microorganisms in these deep-water habitats, where these artificial reefs are present, they make life habitable, make it luxurious, in a place that is cold and dark and permanently separated from light," she said. "If we are performing activities in the ocean that potentially change these extremely important communities, we should know about that."
The laboratory studies also found that oil exposure increases metal corrosion caused by microbes, showing that the oil spill could potentially speed up degradation of the steel-hulled shipwrecks, according to Jennifer Salerno, a microbial ecologist at George Mason University.
The team also used innovative 3-D laser and sonar technology to obtain high-resolution images of the vessels to document their current state of preservation. In one case, a World War II German U-boat that has been previously examined several times since its discovery in 2001 was found to be buried by more sediment than was observed prior to the spill, although the researchers are working to determine if it was a natural process or related to the oil spill. The team plans to repeatedly scan the shipwrecks to document how they change over time.
"These are pieces of our collective human history down there and they are worth protecting," said Damour, adding that in some cases these ships may still contain human remains. "We are concerned that the degradation of these sites a lot faster than normal will cause the permanent loss of information that we can never get back."
Members of the project team will be presenting their new research today at the 2016 Ocean Sciences Meeting co-sponsored by the Association for the Sciences of Limnology and Oceanography, The Oceanography Society and the American Geophysical Union.
The new findings show that deep-sea shipwrecks could be used for long-term monitoring of deep-sea ecosystems, according to the researchers. Understanding this unique ecosystem could aid in protecting and conserving it -- both the animals that live on the shipwrecks, and the ships themselves, they said. Information about these shipwrecks could also aid scientists who research the deep sea, and companies performing activities there, the researchers said.
For Hamdan, the experience of working on the shipwreck project has been transformative. "I will never forget the sensation I had when the ROV flew across the dark seafloor, an already beautifully muddy landscape, and suddenly there was a shipwreck, with all of its history and ecology before my eyes," she said recalling the project's first expedition in 2014. "It really changed me as a scientist ... In a single instant I knew that there was more to the seafloor than I ever really considered."
The above is reprinted from materials provided by American Geophysical Union.