Shark attacks are most likely to occur on Sunday, in less than 6 feet of water, during a new moon and involve surfers wearing black and white bathing suits, a first of its kind study from the University of Florida suggests.

Researchers analyzed statistics from shark attacks that occurred in Florida’s Volusia County, dubbed the “Shark Attack Capital of the World,” between 1956 and 2008. They also spent a year observing people between Daytona Beach and New Smyrna Beach, said George Burgess, director of the International Shark Attack File at UF.

“It’s basically an analysis of why, where and when in an area that traditionally has had more shark-human interactions than any other stretch of coastline in the world,” he said. “One of our students, Brittany Garner, essentially camped out there, counted the number of heads on the beach and took photographs.”

While this 47-mile-long section of Central Florida’s Atlantic coast leads in human-shark skirmishes, making up 21 percent of all global attacks between 1999 and 2008, most are “hit and run” incidents that seldom cause serious injury and no fatalities occurred, he said.

“Calling them attacks is probably a misnomer because the consequences are usually no more severe than a dog bite,” he said. “They’re not the same kind of bites made by 10- to 20-foot-long white sharks that you have off the coast of California. Here we see a different style of attack, primarily perpetrated by smaller fish-eating sharks such as spinners and blacktips that are less than 6 to 7 feet long, which because of their size normally seek smaller prey.”

There have been 231 shark attacks between the first one reported in 1956 in Volusia County and 2008, said Burgess, who works at UF’s Florida Museum of Natural History. The study, part of which was published recently in the edited volume “Sharks and Their Relatives II,” uses statistics from 220 of those cases for which detailed information is available.

Human, shark and environmental factors combine to create a perfect storm of favorable conditions in Volusia County for attacks, particularly near Ponce Inlet between Daytona Beach and New Smyrna Beach, he said.

The more people in the water the greater the chances they will encounter a shark, and New Smyrna Beach south of the inlet is a “hot spot” for surfers with its well developed sand bars and good waves, Burgess said. Hand splashing and feet kicking provoke sharks, which bite and release what they mistake for normal prey items in the turbid waters, he said.

Also, the strong tidal flow in the inlet makes it “an aquatic smorgasbord of food items for sharks, barracudas, mackerel and other large predators,” boosting shark numbers, he said.

Young white males were attacked most because they spend the most time in the water, Burgess said. Ninety percent of victims were male, 77 percent of 196 victims were between 11 and 30 years old and in the 171 cases where race was known, 98 percent were white, he said.

Well over half of the 220 victims were bit on the leg — 158 — more than five times the number bit on the arms — 34 — the second highest body part to be injured, he said.

Surfers were the most frequent victims, making up 61 percent of the total, Burgess said. They tended to be bitten more in the early morning and late afternoon when waves were highest and they spend more time surfing, he said.

“At the time of the attack, most of the surfers were sitting or holding onto the board waiting for a wave, which explains why most surf victims were bitten on the legs,” he said.

Sharks are not weekend warriors. Rather it is human leisure that leads to the fewest number of human encounters on Wednesdays and the highest on Sundays, followed by Saturdays, Burgess said. “There are a fair number of attacks on Fridays as well, reflective of people skipping work and taking three-day weekends,” he said.

The greatest number of attacks occurred during new moons, followed by full moons, the edges of the lunar extreme when the moon has its biggest pull on the tidal phase, Burgess said. Probably the moon’s phases influence the movements and reproductive patterns of fish, the shark’s food source, just as they affect human behavior, he said.

Not surprisingly, attacks were highest during the swimming season, from May through October, peaking in August, Burgess said. They spiked in April as sharks began their seasonal northern migration up the eastern coast of the United States, he said.

Most incidents involved one bite, occurred in turbid, murky or muddy waters and were at the water’s surface, Burgess said. Only one attack was on a diver, he said.

More victims wore swimsuits that were black and white than any other color combination, followed by black and yellow, attesting to sharks’ abilities to see contrast, he said.

Between 1999 and 2008, shark attacks worldwide numbered 639, of which there were 428 reports in the United States, 275 in Florida and 135 in Volusia County. Burgess said.

Scientists have discovered a link between low solar activity and cold winters that could explain why despite global warming trends, the UK and other regions North East of the Atlantic Ocean are experiencing and heading for more frequent cold winters.

Mike Lockwood from STFC’s Rutherford Appleton Laboratory and the University of Reading who led the work said of this year’s winter; “It’s been the 14th coldest in the last 160 years, yet global average temperature for the same period has been the 5th highest. We have discovered this kind of anomaly is significantly more common when solar activity is low”.

The results published in Environmental Research Letters describe how we are now moving into a period of low solar activity which is likely to result in UK winter temperatures more like those seen at the end of the seventeenth century.

The findings are different to previous efforts to explain the UK’s recent cold winters as they compare the most comprehensive, but regionally specific temperature data to the long-term behaviour of the Sun’s magnetic field to study the differences to the average trends for the entire Northern Hemisphere. More details can be found in the Institute of Physics press release on this.

Image Credit: NASA
You can see a high-res image of the covered UK here and more information on the NASA website.

For the first time elephants have been found to produce an alarm call associated with the threat of bees, and have been shown to retreat when a recording of the call is played even when there are no bees around.

A team of scientists from Oxford University, Save the Elephants, and Disney’s Animal Kingdom, made the discovery as part of an ongoing study of elephants in Kenya. They report their results in the journal PLoS One.

‘In our experiments we played the sound of angry bees to elephant families and studied their reaction,’ said Lucy King of Oxford University’s Department of Zoology and charity Save the Elephants, who led the research. ‘Importantly we discovered elephants not only flee from the buzzing sound but make a unique ‘rumbling’ call as well as shaking their heads.’

The team then looked to isolate the specific acoustic qualities associated with this rumbling call and played the sounds back to the elephants to confirm that the recorded call triggered the elephants’ decision to flee even when there was no buzzing and no sign of any bees.

‘We tested this hypothesis using both an original recording of the call, a recording identical to this but with the frequency shifted so it resembled a typical response to white noise, and another elephant rumble as a control,’ said King. ‘The results were dramatic: six out of ten elephant families fled from the loud speaker when we played the ‘bee rumble’ compared to just two when we played a control rumble and one with the frequency-shifted call. Moreover, we also found that the elephants moved away much further when they heard the ‘bee’ alarm call than the other rumbles.’

The researchers believe such calls may be an emotional response to a threat, a way to coordinate group movements and warn nearby elephants – or even a way of teaching inexperienced and vulnerable young elephants to beware. Further work is needed to confirm whether the rumble call is used for other kinds of threats, not just bees.

‘The calls also give tantalising clues that elephants may produce different sounds in the same way that humans produce different vowels, by altering the position of their tongues and lips,’ said Dr Joseph Soltis of Disney’s Animal Kingdom. ‘It’s even possible that, rather like with human language, this enables them to give superficially similar-sounding calls very different meanings.’

Earlier Oxford University research found that elephants avoid bee hives in the wild and will also flee from the recorded sound of angry bees. In 2009 a pilot study led by King showed that a fence made out of beehives wired together significantly reduced crop raids by elephants. The team hopes that the new findings could help develop new ways to defuse potential conflicts between humans and elephants.

Despite their thick hides adult elephants can be stung around their eyes or up their trunks, whilst calves could potentially be killed by a swarm of stinging bees as they have yet to develop this thick protective skin.

Further Information

Dr Susan Cheyne and Klara Wanelik are involved with the Orangutan Tropical Peatland Research Project.

The Orangutan Tropical Peatland Research Project works to protect one of the most important areas of tropical rainforest in Borneo – the Sabangau Forest in Central Kalimantan, Indonesia. We monitor the distribution, population status, behaviour and ecology of the forest’s flagship ape species – the orangutan and agile gibbon – carry out biodiversity and forestry research, provide scientific feedback to conservation managers, and work with our local partners to implement successful conservation programmes. Our research and volunteer program has been running since 2001 and is a focus for local conservation efforts, providing much-needed employment and financial benefits for the local community and replacing illegal logging as the main activity and source of income in the northern Sabangau Forest.
www.orangutantrop.com

Lake Tanganyika, the second oldest and the second-deepest lake in the world, could be in for some rough waters.

Geologists led by Brown University have determined the east African rift lake has experienced unprecedented warming during the last century, and its surface waters are the warmest on record. That finding is important, the scientists write in the journal Nature Geoscience, because the warm surface waters likely will affect fish stocks upon which millions of people in the region depend.

The team took core samples from the lakebed that laid out a 1,500-year history of the lake’s surface temperature. The data showed the lake’s surface temperature, 26 degrees Celsius (78.8°F), last measured in 2003, is the warmest the lake has been for a millennium and a half. The team also documented that Lake Tanganyika experienced its biggest temperature change in the 20th century, which has affected its unique ecosystem that relies upon the natural conveyance of nutrients from the depths to jumpstart the food chain upon which the fish survive.

“Our data show a consistent relationship between lake surface temperature and productivity (such as fish stocks),” said Jessica Tierney, a Brown graduate student who this spring earned her Ph.D. and is the paper’s lead author. “As the lake gets warmer, we expect productivity to decline, and we expect that it will affect the [fishing] industry.”

The research grew out of two coring expeditions sponsored by the Nyanza Project in 2001 and 2004. Cores were taken by Andrew Cohen, professor of geological sciences at the University of Arizona and director of the Nyanza project, and James Russell, professor of geological sciences at Brown, who is also Tierney’s adviser.

Lake Tanganyika is bordered by Burundi, the Democratic Republic of Congo, Tanzania, and Zambia — four of the poorest countries in the world, according to the United Nations Human Development Index. An estimated 10 million people live near the lake, and they depend upon it for drinking water and for food. Fishing is a crucial component for the region’s diet and livelihood: Up to 200,000 tons of sardines and four other fish species are harvested annually from Lake Tanganyika, a haul that makes up a significant portion of local residents’ diets, according to a 2001 report by the Lake Tanganyika Biodiversity Project.

Lake Tanganyika, one of the richest freshwater ecosystems in the world, is divided into two general levels. Most of the animal species live in the upper 100 meters, including the valuable sardines. Below that, the lake holds less and less oxygen, and at certain depths, it is anoxic, meaning it has no oxygen at all. What this all means is the lake is highly stratified and depends on wind to churn the waters and send nutrients from the depths toward the surface as food for algae, which supports the entire food web of the lake. But as Lake Tanganyika warms, the mixing of waters is lessened, the scientists find, meaning less nutrients are funneled from the depths toward the surface. Worse, more warming at the surface magnifies the difference in density between the two levels; even more wind is needed to churn the waters enough to ferry the nutrients toward the fish-dwelling upper layer.

The researchers’ data show that during the last 1,500 years, intervals of prolonged warming and cooling are linked with low and high algal productivity, respectively, indicating a clear link between past temperature changes and biological productivity in the lake.

“The people throughout southcentral Africa depend on the fish from Lake Tanganyika as a crucial source of protein,” noted Cohen, an author on the paper. “This resource is likely threatened by the lake’s unprecedented warming since the late 19th century and the associated loss of lake productivity.”

Climate change models show a general warming in the region, which, if accurate, would cause even greater warming of the Lake Tanganyika’s surface waters and more stratification in the lake as a whole. “So, as you move forward, you can imagine that density gradient increasing,” said Russell, an author on the paper.

Some researchers have posited that the declining fish stocks in Lake Tanganyika can be attributed mainly to overfishing, and Tierney and Russell say that may be a reason. But they note that the warming in the lake, and the lessened mixing of critical nutrients is exacerbating the stocks’ decline, if not causing it in the first place. “It’s almost impossible for it not to,” Russell said.

Other authors on the paper are Brown graduates Marc Mayes and Natacha Meyer; Christopher Johnson at the University of California, Los Angeles; and Peter Swarzenski, with the United States Geological Survey. The National Science Foundation and the Nyanza Project funded the research.

Two new stud­ies of­fer rare glimpses in­to how chim­panzees deal with the deaths of those clos­est to them, sci­en­tists say.

Chimps’ “aware­ness of death is prob­ably more highly de­vel­oped than is of­ten sug­gested. It may be re­lat­ed to their sense of self-awareness, shown through phe­nom­e­na such as self-recognition and em­pa­thy,” said said James An­der­son of the Uni­vers­ity of Stir­ling in the U.K., who col­la­bo­rat­ed in one of the stud­ies.

In that re­search, An­der­son and col­leagues de­scribed the fi­nal hours and death of an old­er fe­male chimp liv­ing in a small group at a U.K. sa­fa­ri park as cap­tured on vid­e­o. In the oth­er stu­dy, sci­en­tists watched as two chimp moth­ers in the wild car­ried their in­fants’ mum­mi­fied re­mains for weeks af­ter they were lost to an ill­ness.

Re­search­ers have posted vid­e­os from both stud­ies on­line. Both stud­ies are pub­lished in the April 27 is­sue of the jour­nal Cur­rent Bi­ol­o­gy.

Few have wit­nessed chimps’ re­sponse at the mo­ment a mem­ber of their group dies, An­der­son said. Moth­er chimps have been known to car­ry their dead in­fants, he noted, and some ob­servers have seen the com­mo­tion that fol­lows when an adult chimp is lost to some sort of sud­den trau­ma.

“In con­trast to the fren­zied, noisy re­sponses to trau­matic adult deaths, the chim­panzees wit­ness­ing the fe­male’s death in our case were mostly calm,” An­der­son said.

In the days lead­ing up to the old­er chim­p’s death, the group was very qui­et and paid close at­ten­tion to her, the re­search­ers re­port. Right be­fore she died, she re­ceived much groom­ing and ca­ress­ing from the oth­ers, who seemed to test her for signs of life as she died. They left her soon af­ter, but her adult daugh­ter re­turned and re­mained by her moth­er all night, sci­en­tists said. When keep­ers re­moved the moth­er’s body the next day, the chim­panzees re­mained sub­dued and stayed that way for some time. For sev­er­al days they avoided sleep­ing on the plat­form where the fe­male had died, though it was nor­mally a fa­vored sleep­ing spot.

“In gen­er­al, we found sev­er­al si­m­i­lar­i­ties be­tween the chim­panzees’ be­hav­ior to­ward the dy­ing fe­male, and their be­hav­ior af­ter her death, and some re­ac­tions of hu­mans when faced with the de­mise of an eld­erly group mem­ber or rel­a­tive,” An­der­son said.

In the sec­ond stu­dy, Do­ra Bi­ro of the Uni­vers­ity of Ox­ford and her col­leagues wit­nessed the deaths of five mem­bers, in­clud­ing two in­fants, of a sem­i-i­so­lat­ed chimp com­mun­ity that re­search­ers have been stu­dying for over three dec­ades in forests around Bossou, Guin­ea.

“We ob­served the deaths of two young in­fants—both from a flu-like res­pi­ra­to­ry ail­ment,” Bi­ro said. “In each case, our ob­serva­t­ions showed a re­mark­a­ble re­sponse by chim­pan­zee moth­ers to the death of their in­fants: they con­tin­ued to car­ry the corpses for weeks, even months, fol­low­ing death.”

In that time, the corpses mum­mi­fied com­plete­ly, and the moth­ers showed care of the bod­ies rem­i­nis­cent of their treat­ment of live in­fants: they car­ried them ever­ywhere dur­ing their daily ac­ti­vi­ties, groomed them, and took them in­to their day and night nests dur­ing rest times, Bi­ro said. Over this ex­tend­ed pe­ri­od, they al­so be­gan to “let go” of the in­fants grad­u­al­ly, Bi­ro added. They al­lowed oth­er group mem­bers to han­dle them more and more often and tolerat­ed long­er pe­ri­ods of separa­t­ion from them, in­clud­ing in­stances where oth­er in­fants and ju­ve­niles were al­lowed to car­ry off and play with the corpses.

Oth­er group mem­bers showed some in­ter­est in the bod­ies, and al­most none showed any aver­sion to­ward the corpses, ac­cord­ing to Bi­ro and col­leagues. She not­ed that a mem­ber of her team made very si­m­i­lar ob­serva­t­ions fol­low­ing the death of one chim­pan­zee in­fant in Bossou back in 1992.

“Chim­panzees are hu­mans’ clos­est ev­o­lu­tion­ary rel­a­tives, and they have al­ready been shown to re­sem­ble us in many of their cog­ni­tive func­tions: they em­pa­thize with oth­ers, have a sense of fair­ness, and can co­op­er­ate to achieve goals,” Bi­ro said. “How they per­ceive death is a fas­ci­nat­ing ques­tion, and lit­tle da­ta ex­ist so far” con­cern­ing it.

“Our ob­serva­t­ions con­firm the ex­istence of an ex­tremely pow­er­ful bond be­tween moth­ers and their off­spring which can per­sist, re­mark­ably, even af­ter the death of the in­fant, and they fur­ther call for ef­forts to elu­ci­date the ex­tent to which chim­panzees un­der­stand and are af­fect­ed by the death of a close rel­a­tive or group-mate. This would both have im­plica­t­ions for our un­der­standing of the ev­o­lu­tion­ary ori­gins of hu­man per­cep­tions of death and pro­vide in­sights in­to the way chim­panzees in­ter­pret the world around them.”

A 95-million-year-old am­ber de­pos­it is adding new­found fun­gus, in­sects, spi­ders, nem­a­tode worms, and bac­te­ria to the por­trait of an an­cient ec­o­sys­tem al­so shared by di­no­saurs, sci­en­tists say.

Am­ber is hard­ened, fos­sil­ized tree sap whose glassy, jewel-like and yel­low­ish form of­ten con­tains small crea­tures trapped from the time of its or­i­gin and pre­served nearly per­fect­ly.

The new­found de­pos­it, dat­ed to the Cre­ta­ceous era that was the last ma­jor pe­ri­od of the di­no­saurs, is re­ported to be the first ma­jor dis­cov­ery of its kind from Af­ri­ca.

The find­ing may al­so pro­vide in­sights in­to the rise and di­ver­sifica­t­ion of flow­er­ing plants dur­ing the Cre­ta­ceous, re­search­ers say. A re­port by 20 sci­en­tists on the dis­cov­ery, in the cur­rent is­sue of the re­search jour­nal Pro­ceed­ings of the Na­tional Acad­e­my of Sci­ences, re­con­structs an an­cient trop­i­cal for­est un­cov­ered in pre­s­ent-day Ethi­o­pia.

“Un­til now, we had discov­ered vir­tu­ally no Cre­ta­ceous am­ber sites from the south­ern hemi­sphere’s Gond­wanan su­per­con­ti­nent, a land mass that in­clud­ed mod­ern Af­ri­ca, said re­search group mem­ber Paul Nascim­bene of the Amer­i­can Mu­se­um of Nat­u­ral His­to­ry in New York. “Sig­nif­i­cant Cre­ta­ceous am­ber de­pos­its had been found pri­marily in North Amer­i­ca and Eura­sia.”

“The first an­giosperms, or flow­er­ing plants, ap­peared and di­ver­si­fied in the Cre­ta­ceous,” added Al­ex­an­der Schmidt of the Uni­vers­ity of Göt­tin­gen in Ger­ma­ny, an­oth­er of the in­ves­ti­ga­tors. “Their rise to dom­i­nance dras­tic­ally changed ter­res­tri­al ec­o­sys­tems, and the Ethi­o­pi­an am­ber de­pos­it sheds light on this time of change.”

While some of the au­thors worked on the ge­o­log­i­cal set­ting and the fos­sils en­tombed with­in the am­ber, Nascim­bene, with Ken­neth An­der­son of South­ern Il­li­nois Uni­vers­ity, stud­ied the am­ber it­self. They found that the res­in that seeped from these Cre­ta­ceous Gond­wanan trees is si­m­i­lar chem­ic­ally to more re­cent am­bers from flow­er­ing plants in Mi­o­cene de­pos­its found in Mex­i­co and the Do­min­i­can Re­pub­lic. The am­ber’s chem­ical de­signa­t­ion is Class Ic, and it is the only Ic fos­sil res­in discov­ered thus far from the Cre­ta­ceous. All oth­er doc­u­mented Cre­ta­ceous am­bers are from non-flow­er­ing plants, or gym­nosperms.

“The tree that pro­duced the sap is still un­known, but the am­ber’s chem­is­try is sur­pris­ingly very much like that of a group of more re­cent New World an­giosperms [flow­er­ing plants] called Hy­menaea,” says Nascim­bene. “This am­ber could be from an early an­gi­o­sperm or a previously-unknown co­ni­fer that is quite dis­tinct from the oth­er known Cre­ta­ceous am­ber-producing gym­nosperms.”

Oth­er team mem­bers discov­ered 30 in­sects and spi­ders trapped in the am­ber from thir­teen fam­i­lies of or­gan­isms. These fos­sils rep­re­sent some of the ear­li­est Af­ri­can fos­sil records for a va­ri­e­ty of types, in­clud­ing wasps, bark­lice, moths, bee­tles, a prim­i­tive ant, a rare in­sect called a zorapte­ran, and a sheet-web weav­ing spi­der. Par­a­sit­ic fun­gi that lived on the trees were al­so found, as well as fil­a­ments of bac­te­ria and the re­mains of flow­er­ing plants and ferns.

Queen ants who have to compete for dominance of a colony may act selfishly to promote their survival, but scientists have discovered that they are rigorously honest when declaring their status to potentially murderous workers. The research, published today in Proceedings of the Royal Society B, may have interesting wider implications in terms of the evolution of cooperative behaviour.

In some ant species, several queen ants work together to begin a new colony, each raising broods of workers until there are enough ants to form a viable colony. However, the worker ants cannot tolerate joint sovereignty and ultimately kill the queens until only one remains. Luke Holman and his team based at the University of Copenhagen aimed to discover whether queen ants prepare for this attack in any way and if so, what the best strategy might be.

Workers tend to prefer to spare the lives of queens who produce larger broods, identifying the more productive queens via chemical signals. However, productivity comes at a cost: producing a larger brood makes a queen weaker and less able to survive the onslaught of murderous workers when the time comes. The researchers discovered that when placed in direct competition against each other, queens would always produce smaller broods and save their strength for the final battle against the observers.

This is a “selfish” strategy on the part of the queens because producing smaller broods will ultimately mean that the colony as a whole is weaker, although their individual chance for survival might be increased. However, it also seems to be an inherently paradoxical behaviour: given that worker ants can readily identify unproductive individuals, it would seem that the additional strength gained by producing a smaller brood is likely to lose any selective advantage.

One way of getting round this would be for queen ants to produce smaller broods and then cheat the worker ants by producing a false chemical signal to fool them into thinking that they had been more productive than they appear. However, the scientists found no sign of cheaters, suggesting that even in a potentially life-threatening situation, honesty is the best policy. The research may even have significance beyond ant colonies – the question of how cooperation evolved is a hot topic and the authors suggest that “punishment and honest signalling may be universally important”.

Will 2010 be the warmest year on record? How do the recent U.S. “Snowmageddon” winter storms and record low temperatures in Europe fit into the bigger picture of long-term global warming?

NASA has launched a new web page to help people better understand the causes and effects of Earth’s changing climate.

The new “A Warming World” page hosts a series of new articles, videos, data visualizations, space-based imagery and interactive visuals that provide unique NASA perspectives on this topic of global importance.

The page includes feature articles that explore the recent Arctic winter weather that has gripped the United States, Europe and Asia, and how El Nino and other longer-term ocean-atmosphere phenomena may affect global temperatures this year and in the future. A new video, “Piecing Together the Temperature Puzzle,” illustrates how NASA satellites monitor climate change and help scientists better understand how our complex planet works.

The new web page is available on NASA’s Global Climate Change Web site
at:
http://climate.nasa.gov/warmingworld

For more information about NASA and agency programs, visit:
http://www.nasa.gov

Giant plankton-eating fishes roamed the prehistoric seas for over 100 million years before they were wiped out in the same event that killed off the dinosaurs, new fossil evidence has shown.

An international team describe how new fossils from Asia, Europe and the US reveal a previously unknown dynasty of giant plankton-eating bony fishes that filled the seas of the Jurassic and Cretaceous periods, between 66-172 million years ago.

The team report their findings in this week’s Science.

‘Today’s giant plankton-feeders – such as baleen whales, basking sharks and manta rays – include the largest living vertebrate animals, so the fact that creatures of this kind were missing from the fossil record for hundreds of millions of years was always a mystery,’ said Dr Matt Friedman of Oxford University’s Department of Earth Sciences, an author of the report. ‘We used to think that the seas were free of big filter feeders during the age of dinosaurs, but our discoveries reveal that a dynasty of giant fishes filled this ecological role in the ancient oceans for more than 100 million years.’

Several of the most important new fossils came from deposits in Kansas in the USA, with other remains from as far afield as Dorset and Kent in the UK, and Japan. Some members of this filter-feeding fish group are estimated to have been up to 9 metres long, a similar size to modern plankton-eating giants such as the basking shark.

‘One of the reasons these big fishes were overlooked or misidentified lies in their anatomy,’ said Dr Friedman. ‘Over their evolutionary history, these fishes reduced the amount of bone in their skeletons, probably to save weight, with the consequence that most of their hard parts were easily scattered after death. As it turns out, the only parts you routinely find in the fossil record are their well-developed forefins.’

With few clues to go on, palaeontologists had argued that the owner of these isolated fins looked something like the modern-day swordfish. This changed when some of Dr Friedman’s colleagues began cleaning a fossil that preserved skull bones along with the fins.

Dr Friedman said: ‘Instead of finding a head with a long sword-like snout and jaws lined with predatory fangs, they found something completely different: long, toothless jaws supporting a gaping mouth, and long, rod-like bones that contributed to the huge gill arches needed to filter out enormous quantities of tiny plankton.’ The team named this fish Bonnerichthys, honouring the Kansas family who discovered the fossil.

Remains of similar giant plankton-eating fishes had been known from much older rocks, but they were thought to be a short-lived and unsuccessful evolutionary experiment. ‘As soon as we recognised that these animals had a longer history than anyone thought, I started examining museum collections and found more examples that had been overlooked or misidentified,’ explained Dr Friedman. Revisiting previously collected fossils netted the team evidence that these fishes thrived for millions of years and colonised many parts of the globe.

Intriguingly the ancestors of large modern filter-feeders such as baleen whales and whale sharks only appeared after the extinction of Bonnerichthys and its relatives, suggesting that today’s filter-feeders evolved to fill the ecological niche left behind by these plankton-eating contemporaries of the dinosaurs.

The research team consisted of scientists from Oxford University (UK), DePaul University, Chicago (US), Fort Hays State University, Kansas (US), University of Kansas (US), University of Glasgow (UK), and Triebold Paleontology Inc & Rocky Mountain Dinosaur Resource Centre, Colorado (US).

For more information contact Dr Matt Friedman on +44 (0)1865 272035 or email matt.friedman@earth.ox.ac.uk

Re­li­gion evolved as a byprod­uct of pre-existing men­tal ca­pa­ci­ties, and not be­cause it ful­filled a spe­cif­ic func­tion of its own—though it can fa­cil­i­tate coop­era­t­ion in so­ci­e­ty, a study con­cludes.

Why re­li­gion emerged among early hu­mans re­mains a source of con­ten­tion among schol­ars. Many sci­en­tists be­lieve re­li­gion is ul­ti­mately based in the brain, but that still leaves un­clear how and why these be­hav­iors orig­i­nat­ed and how they may have been shaped dur­ing ev­o­lu­tion. Some arch­aeo­logists think re­li­gion came about partly as a stra­tegy by some peo­ple to grab pow­er, sim­ply by claim­ing some sort of se­cret know­ledge.

The new stu­dy, pub­lished Feb. 8 in the re­search jour­nal Trends in Cog­ni­tive Sci­ences, takes a some­what diff­er­ent track, ex­plor­ing the link be­tween mor­al­ity and re­li­gion.

“Some schol­ars claim that re­li­gion evolved as an adapta­t­ion to solve the prob­lem of coop­era­t­ion among ge­net­ic­ally un­re­lat­ed in­di­vid­u­als, while oth­ers pro­pose that re­li­gion emerged as a by-prod­uct of pre-existing cog­ni­tive ca­pa­ci­ties,” said study co-author Ilkka Pyysi­ainen of the Hel­sin­ki Col­le­gi­um for Ad­vanced Stud­ies in Fin­land.

Pyysi­ainen and a co-author, ev­o­lu­tion­ary psy­chol­o­gist Marc Hauser Har­vard Uni­vers­ity, re­viewed the two com­pet­ing the­o­ries us­ing the prin­ci­ples of what they call ex­pe­ri­men­tal mor­al psy­chol­o­gy.

“Re­li­gion is linked to mor­al­ity in dif­fer­ent ways,” said Hauser. “For some, there is no mor­al­ity with­out re­li­gion, while oth­ers see re­li­gion as merely one way of ex­press­ing one’s mor­al in­tu­itions.” But past stud­ies, the au­thors said, show that peo­ple of dif­fer­ing re­li­gion or no re­li­gion show si­m­i­lar mor­al judg­ments when asked to com­ment on un­fa­mil­iar mor­al dilem­mas. That sug­gests in­tu­i­tive judg­ments of right and wrong work in­de­pend­ently of ex­plic­it re­li­gious com­mit­ments, the re­search­ers ar­gued.

“This sup­ports the the­o­ry that re­li­gion did not orig­i­nally emerge as a bi­o­log­i­cal adapta­t­ion for coop­era­t­ion, but evolved as a sep­a­rate by-prod­uct of pre-existing cog­ni­tive func­tions that evolved from non-re­li­gious func­tions,” said Pyysi­ainen. “How­ever, al­though it ap­pears as if coop­era­t­ion is made pos­si­ble by men­tal mech­a­nisms that are not spe­cif­ic to re­li­gion, re­li­gion can play a role in fa­cil­i­tating and sta­bi­liz­ing coop­era­t­ion be­tween groups.”

This might help to ex­plain the com­plex as­socia­t­ion be­tween mor­al­ity and re­li­gion, the sci­en­tists added. “It seems that in many cul­tures re­li­gious con­cepts and be­liefs have be­come the stand­ard way of con­cep­tu­al­ mor­al in­tu­itions. Al­though, as we dis­cuss in our pa­per, this link is not a nec­es­sary one, many peo­ple have be­come so ac­cus­tomed to us­ing it, that crit­i­cism tar­geted at re­li­gion is ex­perienced as a fun­da­men­tal threat to our mor­al ex­is­tence,” said Hauser.

Governments from across Asia’s tiger range countries (TRCs) sent a powerful message that new efforts to save wild tigers from extinction would begin immediately and called for total protection of critical tiger habitats as the 1st Asia Ministerial Conference on Tiger Conservation concluded today at the resort of Hua Hin, Thailand.

The Royal Government of Thailand hosted the meeting. Thailand’s Minister of Environment and Natural Resources Suwit Khunkitti pointed to commitments in the Hua Hin Declaration, and urged other TRCs to follow through with consolidated technical recommendations that resulted from an earlier meeting in Kathmandu on tiger conservation: “We shall reach up to the highest levels of our governments for support at the Year of the Tiger Heads of State Summit in Russia. Let us join together boldly to save the wild tiger.”

Thailand made a number of new commitments at the conference:

• Expansion of its SMART wildlife area patrolling program in its Western Forest Complex (WEFCOM) at Huai Kha Khaeng-Thung Yai
• Assistance to its neighbor countries to repatriate tigers when the population of tigers in WEFCOM and Kaeng Krachan/Kuiburi becomes large enough to act as a donor source
• Announcement that it would make funding for the ASEAN Wildlife Enforcement Network a permanent item in its budget

Seven ministers, along with senior delegations from 13 tiger range countries, gathered with top wildlife conservation experts and representatives from international organizations and donor institutions such as the World Bank, Global Tiger Initiative, WWF, Save the Tiger Fund, Wildlife Conservation Society, USAID, FREELAND, and TRAFFIC, to energize the wildlife conservation agenda, update national action plans, and announce specific proposals to reverse the continuing decline of tiger populations.

President of the World Bank Group Robert B. Zoellick, who launched the Global Tiger Initiative (GTI) in June 2008 together with the Smithsonian Institution, Global Environment Facility, and other partners, delivered a video message to the ministers and delegations, promising support for the range countries’ efforts and to spearhead sustainable development in Asia: “The World Bank stands ready to support regional projects in the tiger range countries and to mobilize the donor community and develop innovative financial instruments to support tiger conservation funds.”

Populations of wild tigers have declined to only 3,200 worldwide, according to latest estimates, from 100,000 a century ago. The GTI is one of the drivers of the World Bank’s commitment to new strategies that balance economic development with nature conservation, biodiversity and environmental protection.

Another significant development in Thailand came from Prime Minister Vladmir Putin and the Government of the Russian Federation, who officially announced plans to host the Heads of State Summit in September.

The Hua Hin Declaration reflected agreement among the TRCs to redouble efforts on the ground to halt the decline of tigers and assist in recovery of habitats. An international donor conference is also planned later this year to support the countries to bring increased resources for integrated game-changing policy to save the species from extinction.

Michael Baltzer, Leader of WWF’s Tiger Initiative, said: “We are delighted to see a ray of hope for the tiger as represented by the tiger range countries’ commitment to work together to double wild tiger numbers by 2022. We look forward to seeing their pledges turn into firm actions in Vladivostok.”

All 13 tiger range countries were represented in Hua Hin. They include Bangladesh, Bhutan, Cambodia, China, India, Indonesia, Lao PDR, Malaysia, Myanmar, Nepal, Russia, Thailand, and Vietnam.

New research suggests that animals living at high latitudes grow better than their counterparts closer to the equator because higher-latitude vegetation is more nutritious. The study, published in the February issue of The American Naturalist, presents a novel explanation for Bergmann’s Rule, the observation that animals tend to be bigger at higher latitudes.

Ever since Christian Bergmann made his observation about latitude and size in 1847, scientists have been trying to explain it. The traditional explanation is that body temperature is the driving force. Because larger animals have less surface area compared to overall body mass, they don’t lose heat as readily as smaller animals. That would give big animals an advantage at high latitudes where temperatures are generally colder.

But biologist Chuan-Kai Ho from Texas A&M University wondered if there might be another explanation. Might plants at higher latitudes be more nutritious, enabling the animals that eat those plants to grow bigger?

To answer that question, Ho along with colleagues Steven Pennings from the University of Houston and Thomas Carefoot from the University of British Columbia, devised a series of lab experiments. They raised several groups of juvenile planthoppers on a diet of cordgrass, which was collected from high to low latitudes. Ho and his team then measured the body sizes of the planthopppers when they reached maturity. They found that the planthoppers that fed the high-latitude grass grew larger than those fed low latitude grass.

The researchers performed similar experiments using two other plant-eating species—grasshoppers and sea snails. “All three species grew better when fed plants from high versus low latitudes,” Ho said. “These results showed part of the explanation for Bergmann’s rule could be that plants from high latitudes are better food than plants from low latitudes.” Although this explanation applies only to herbivores, Ho explained that predators might also grow larger as a consequence of eating larger herbivores.

“We don’t think that this is the only explanation for Bergmann’s rule,” Ho added. “But we do think that studies of Bergmann’s rule should consider ecological interactions in addition to mechanisms based on physiological responses to temperature.”

It’s not known why the higher-latitude plants might be more nutritious. But research in Pennings’s lab at the University of Houston offers a clue. Pennings has shown that plants at low latitudes suffer more damage from herbivores than those at higher latitudes. Ho and Pennings suggest that perhaps lower nutrition and increased chemical defenses are a response to higher pressure from herbivores.

Going about their day-to-day business, bees have no need to be able to recognise human faces. Yet in 2005, when Adrian Dyer from Monash University trained the fascinating insects to associate pictures of human faces with tasty sugar snacks, they seemed to be able to do just that. But Martin Giurfa from the Universite de Toulouse, France, suspected that that the bees weren’t learning to recognise people. ‘Because the insects were rewarded with a drop of sugar when they chose human photographs, what they really saw were strange flowers. The important question was what strategy do they use to discriminate between faces,’ explains Giurfa. Wondering whether the insects might be learning the relative arrangement (configuration) of features on a face, Giurfa contacted Dyer and suggested that they go about systematically testing which features a bee learned to recognise to keep them returning to Dyer’s face photos. The team publish their discovery that bees can learn to recognise the arrangement of human facial features on 29 January 2010 in the Journal of Experimental Biology at http://jeb.biologists.org.

Teaming up with Aurore Avargues-Weber, the team first tested whether the bees could learn to distinguish between simple face-like images. Using faces that were made up of two dots for eyes, a short vertical dash for a nose and a longer horizontal line for a mouth, Avargues-Weber trained individual bees to distinguish between a face where the features were cramped together and another where the features were set apart. Having trained the bee to visit one of the two faces by rewarding it with a weak sugar solution, she tested whether it recognised the pattern by taking away the sugar reward and waiting to see if the bee returned to the correct face. It did.

So the bees could learn to distinguish patterns that were organised like faces, but could they learn to ‘categorise’ faces? Could the insects be trained to classify patterns as face-like versus non-face like, and could they decide that an image that they had not seen before belonged to one class or the other? To answer these questions, Avargues-Weber trained the bees by showing them five pairs of different images, where one image was always a face and the other a pattern of dots and dashes. Bees were always rewarded with sugar when they visited the face while nothing was offered by the non-face pattern. Having trained the bees that ‘face-like’ images gave them a reward, she showed the bees a completely fresh pair of images that they had not seen before to see if the bees could pick out the face-like picture. Remarkably they did. The bees were able to learn the face images, not because they know what a face is but because they had learned the relative arrangement and order of the features.

But how robust was the bees’ ability to process the ‘face’s’ visual information? How would the bees cope with more complex faces? This time the team embedded the stick and dot faces in face-shaped photographs. Would the bees be able to learn the arrangements of the features against the backgrounds yet recognise the same stick and dot face when the face photo was removed? Amazingly the insects did, and when the team tried scrambling real faces by moving the relative positions of the eyes, nose and mouth, the bees no longer recognised the images as faces and treated them like unknown patterns.

So bees do seem to be able to recognise face-like patterns, but this does not mean that they can learn to recognise individual humans. They learn the relative arrangements of features that happen to make up a face-like pattern and they may use this strategy to learn about and recognise different objects in their environment.

What is really amazing is that an insect with a microdot-sized brain can handle this type of image analysis when we have entire regions of brain dedicated to the problem. Giurfa explains that if we want to design automatic facial recognition systems, we could learn a lot by using the bees’ approach to face recognition.

Article Credit: Science Centric

A team of researchers including scientists from the University of Florida has shown insect colonies follow some of the same biological “rules” as individuals, a finding that suggests insect societies operate like a single “superorganism” in terms of their physiology and life cycle.

For more than a century, biologists have marveled at the highly cooperative nature of ants, bees and other social insects that work together to determine the survival and growth of a colony.

The social interactions are much like cells working together in a single body, hence the term “superorganism” — an organism comprised of many organisms, according to James Gillooly, an assistant professor in the department of biology at UF’s College of Liberal Arts and Sciences.

Now, researchers from UF, the University of Oklahoma and the Albert Einstein College of Medicine have taken the same mathematical models that predict lifespan, growth and reproduction in individual organisms and used them to predict these features in whole colonies.

By analyzing data from 168 different social insect species including ants, termites, bees and wasps, the authors found that the lifespan, growth rates and rates of reproduction of whole colonies when considered as superorganisms were nearly indistinguishable from individual organisms.

The findings will be published online this week in the Proceedings of the National Academy of Sciences.

“This PNAS paper regarding the energetic basis of colonial living in social insects is notable for its originality and also for its importance,” said Edward O. Wilson, a professor of biology at Harvard University and co-author of the book “The Super-Organism,” who was not involved in the research. “The research certainly adds a new perspective to our study of how insect societies are organized and to what degree they are organized.”

The study may also help scientists understand how social systems have arisen through natural selection — the process by which evolution occurs. The evolution of social systems of insects in particular, where sterile workers live only to help the queen reproduce, has long been a mystery, Gillooly said.

“In life, two of the major evolutionary innovations have been how cells came together to function as a single organism, and how individuals joined together to function as a society,” said Gillooly, who is a member of the UF Genetics Institute. “Relatively speaking, we understand a considerable amount about how the size of multicellular organisms affects the life cycle of individuals based on metabolic theory, but now we are showing this same theoretical framework helps predict the life cycle of whole societies of organisms.”

Researchers note that insect societies make up a large fraction of the total biomass on Earth, and say the finding may have implications for human societies.

“Certainly one of the reasons folks have been interested in social insects and the consequences of living in groups is that it tells us about our own species,” said study co-author Michael Kaspari, a presidential professor of zoology, ecology and evolutionary biology at the University of Oklahoma and the Smithsonian Tropical Research Institute. “There is currently a vigorous debate on how sociality evolved. We suggest that any theory of sociality be consistent with the amazing convergence in the way nonsocial and social organisms use energy.”

In addition to Gillooly and Kaspari, Chen Hou from the Albert Einstein College of Medicine, and Hannah B. Vander Zanden of the University of Florida participated in the study.

The robust, efficient shell of a tiny deep-sea snail could pro­vide in­spira­t­ion for ad­vanc­es in hu­man body ar­mor de­sign, re­search­ers say.

Ma­te­ri­als sci­ent­ist Chris­tine Or­tiz of the Mas­sa­chu­setts In­sti­tute of Tech­nol­o­gy and col­leagues in­ves­t­i­gated the iron-rich shell of the snail Cryso­ma­l­lon squa­m­ife­rum, re­cently dis­cov­ered near deep-sea vents in the In­di­an Ocean.

The shell has an un­usu­al three-lay­ered de­sign and is un­ique among an­i­mal ar­mor for in­clud­ing a lay­er based on iron sul­fide, chem­i­cal com­pounds of iron and sul­fur, re­search­ers said.

They stud­ied the me­chan­i­cal prop­er­ties of the in­di­vid­ual lay­ers in cross-sections of the shell at the mo­lec­u­lar lev­el and used the da­ta to de­vel­op a com­put­er mod­el of the snail’s out­er skel­e­ton.

Sim­ula­t­ions of an­i­mals’ nat­u­ral pro­tec­tive sys­tems can al­low re­search­ers and en­gi­neers to ex­plore how an­i­mals de­fend them­selves while re­tain­ing free move­ment and body regula­t­ion, the sci­ent­ists not­ed. They ex­am­ined how the shell pro­tects the snail against a pred­a­tor at­tack and found that each of the shel­l’s three lay­ers seems to be re­spon­si­ble for dif­fer­ent as­pects of the ar­mor’s ef­fec­tive­ness.

The mid­dle lay­er is a “com­pli­ant” lay­er sand­wiched be­tween two stiffer “min­er­al­ized” lay­ers, they found. The in­ner, cal­cium-rich lay­er pro­vides struct­ural sup­port, while the more flex­ible mid­dle layer helps pre­vent cracks in other lay­ers from spread­ing. The outer lay­er prov­ides add­i­tional stiff­ness but also is sus­cep­tible to de­vel­op­ing “mi­cro­frac­tures” that pa­rad­ox­ic­ally head off more ser­ious cracks by dis­sip­a­ting en­ergy.

Ortiz’ at­ten­tion was drawn to the snail in 2003, when its discovery was first reported. The ani­mal lives in a harsh en­viron­ment on the sea floor, near vents that spew hot water. Thus it is exposed to fluc­tu­ations in temp­er­ature as well as high acidity, and also faces attack from pre­da­tors such as crabs and other snails.

When a crab attacks a snail, it grasps the shell and squeezes it until it breaks—for days if ne­ces­sary.

The three-layer ar­range­ment pro­tects against pen­etra­t­ion, im­proves en­er­gy dis­sipa­t­ion, and re­sists bend­ing, the in­vest­i­gators found. This could pro­vide a mod­el for de­vel­oping pro­tec­tive ma­te­ri­als for hu­mans, they noted. Their re­port ap­pears in this week’s early on­line is­sue of the re­search jour­nal Pro­ceed­ings of the Na­tio­n­al Aca­de­my of Sci­en­ces.

Lungs with one-way air flow may have helped dinosaurs’ ancestors become dominant when oxygen levels dropped after the Permian-Triassic extinction. It was a period around 250 million years ago when most land-based life died off.

Air follows a one-way loop in alligator lungs, scientists found, a pattern also found in birds, which allows them to fly at high-altitude where oxygen levels are low. This similarity between bird and alligator lungs shows that one-way airflow emerged before the two groups split over 246 million years ago, said University of Utah evolutionary biologist C. G. Farmer, who led the study published Thursday in Science.

In turn, this lung structure may have enabled the common ancestors of dinosaurs and modern-day birds and alligators, the archosaurs, to thrive when oxygen levels dropped and killed off most other animals.

Before the extinction, synapsids, the ancestors to modern mammals, were the dominant group. But after the extinction, the archosaurs dwarfed the synapsids, Farmer said. Prestosuchids, for example, could reach 23 feet in length, while mammals’ ancestors maxed out at just a few feet.

“We think mammals were unable to compete in niches that require some athleticism and a good set of lungs,” Farmer said. “If you can’t run you better hide, and you better be small enough to hide.”

In mammals, air flows into the lungs through progressively smaller airways, stops in little sacs where oxygen is absorbed into the blood and then reverses course and is exhaled by the same route. In birds, air goes one way through small tubes called parabronchi that loop around to send the air back out.

This system allows modern birds to function in a low-oxygen atmosphere. For instance, bar-headed geese can fly over the thin air above Mt. Everest, Farmer said. A similar ability to squeeze out ample oxygen from thin air probably gave bird’s’ archosaur ancestors an edge over the synapsids.

To see how alligator lungs worked, the group sedated six alligators, put flow-meters in their lungs and measured air flow once they awoke. They also cut out the lungs of alligators that had died on a Louisiana wildlife refuge and pumped air through the lungs. Finally, they pushed salt water filled with tiny fluorescent beads through a set of lungs from a dead alligator.

This showed that like birds, the air flows into the chambers of alligators’ lungs and follows a one-way path that loops back to the windpipe.

The findings on air-flow are convincing, said evolutionary biologist Elizabeth Brainerd of Brown University. “One of the strengths of the paper is the author used three different approaches to demonstrate the unidirectional air flow,” she said.

But the claim that this trait may have helped archosaurs edge out the synapsids is “highly speculative,” she said. To bolster thhe hypothesis, the group would need to show that this one-way flow is actually better at extracting oxygen.

Article Credit: Wired Science

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A new and previously unknown species of spider has been discovered in the dune of the Sands of Samar in the southern Arava region by a team of scientists from the Department of Biology in the University of Haifa-Oranim. Unfortunately, however, its habitat is endangered. “The discovery of this new spider illustrates our obligation to preserve the dune,” says Dr. Shanas, who headed the team of scientists. The Sands of Samar are the last remaining sand dune in Israeli territory in the southern Arava region. In the past, the sands stretched across some 7 square kilometers, but due to the rezoning of areas for agriculture and sand quarries, the sands have been reduced to fewer than 3 square kilometers.

During a course of studies that Dr. Shanas’s research team has carried out in the region, they discovered this new spider, a member of the Cerbalus genus. Since it has been found in the Arava, it has been given the name Cerbalus aravensis. The researchers say that this spider’s leg-span can reach up to 14 cm., which makes it the largest spider of its type in the Middle East. Even though details are still lacking to enable a full analysis of its biology and of its population in the sands, the scientists know that this is a nocturnal spider, mostly active in the hottest months of the year, and that it constructs an underground den which is closed with a “lifting door” made of sand particles that are glued together to camouflage the den.

The scientists’ excitement is indeed mixed with apprehension. According to Dr. Shanas, the Israel Land Administration intends to renew mining projects in the Sands of Samar in the near future, which will endanger the existence of the newly discovered spider. He adds that it is possible that there are additional unknown animal species living in the sands, and therefore efforts should be made to preserve this unique region in the Arava. “The new discovery shows how much we still have to investigate, and that there are likely to be many more species that are unknown to us. If we do not preserve the few habitats that remain for these species, they will become extinct before we can even discover them,” Dr. Shanas concludes.

Photo Credit: Photo 1 – by Yael Olek, courtesy of the University of Haifa. Photo 2 – by Roy Talbi, courtesy of the University of Haifa

A new study examines how ice sheets, such as the West Antarctic Ice Sheet, could become unstable as the world warms.

The team from Oxford University and Cambridge University developed a model to explore how changes in the ‘grounding line’ – where an ice sheet floats free from its base of rock or sediment – could lead to the disintegration of ice sheets and result in a significant rise in global sea level.

A report of their research is published in Proceedings of the Royal Society A.

‘The volume of ice locked up in the West Antarctic Ice Sheet is equivalent to a sea level rise of around 3.3 metres,’ said Dr Richard Katz of Oxford University’s Department of Earth Sciences, an author of the report. ‘Our model shows how instability in the grounding line, caused by gradual climatic changes, has the potential to reach a ‘tipping point’ where disintegration of the ice sheet could occur.’

At the moment the model – that uniquely takes into account the three dimensional shape of ice sheets – is still fairly simple, but the researchers hope to eventually include more detail on how ice sheets interact with their base slopes and show the behaviour of individual ice streams.

When the team applied their theoretical and mathematical model to the West Antarctic Ice Sheet they found that, contrary to earlier assessments, a scenario which would see instability grow as the grounding line recedes was likely. In the case of the Pine Island Glacier it may already be occurring.

‘Global climate models often assume that, as the world warms, ice sheets will melt at a steady rate, leading to gradual rises in sea level – but ice sheets are much more complex structures than this,’ said Dr Katz. ‘We need to do a lot more work to build better models of how ice sheets behave in the real world. Only then can we start to predict how this behaviour might change in the future as the climate changes.’

A report of the research, ‘Stability of ice sheet grounding lines’, is published in Proceedings of the Royal Society A. The research was conducted by Dr Richard Katz of Oxford University’s Department of Earth Sciences and Professor M Grae Worster of Cambridge University’s Institute of Theoretical Geophysics.

Warmed, overfished and polluted, the small Mediterranean Sea is giving scientists a look at what the future may hold for the rest of Earth’s oceans — and it’s not pretty.

Beneath its surface, a transformation is taking place. Food webs are shrinking, with rich ecosystems that supported valuable commercial fisheries giving way to barrens dominated by jellyfish and tiny invertebrates. Mass die-offs and disease are now common.

“The predicted effects of climate change are being met in the Mediterranean. The results are more obvious and dramatic, but the drivers are the same all over the world,” said Pierre Chevaldonné, a University of the Mediterranean biologist.

Chevaldonné is a co-author of a review of more than 100 studies on the Mediterranean’s changing ecological dynamics. Published last Monday in Trends in Ecology and Evolution, it describes the convergence of climate change and human impacts in waters that had been stable since the time of Aristotle.

During the latter half of the 20th century, the Mediterranean’s deep northern regions, a traditional source of cold waters that flowed south into warmer basin currents, warmed by one-fifth of a degree Fahrenheit. Shallow northwest waters — an intermediate zone more productive than any other region of the Mediterranean — warmed by 1.8 degrees Fahrenheit. Some of the warming was expected, but it appears to have accelerated in the last 20 years, as the unusually hot 1990s coincided with natural cycles.

With that overheated decade came anomalies in surface temperature and rainfall. These appear to have disrupted deep-water hydrology, changing its composition and currents. That disruption has now rippled to the western shallows. Compounding the problem, runaway population growth has packed 132 million people around the sea’s rim, with habitat destruction, pollution and fishing pressure increasing apace.

The effects of these interacting stresses make the Mediterranean a model system for the rest of Earth’s oceans, which are also overfished and, in many regions, warming at comparable or greater rates. Scientists say warming will continue for decades even if greenhouse gas emissions soon fall to a fraction of current levels. And though it will take longer for disruption to become visible in those larger waters, the lessons are the same.

“It’s difficult to know exactly what’s going to happen elsewhere, but the principles can be extrapolated,” said Marta Call, a Dalhousie University marine biologist who has modeled the interactions of Mediterranean species. In a paper published last year in Ecosystems, she and her colleagues described Mediterranean food webs as “in an advanced state of degradation.”

Degradation in the Mediterranean has taken place on multiple levels. Many large fish species, including top-level predators like sharks and tuna, have been fished to functional extinction. A few still swim, but they no longer have the same ecological role. Coll’s models and other research on predator interactions suggest that they helped stabilize food webs, and their absence now leaves other species prone to wild fluctuations.

Mass die-offs of dozens of invertebrate species are now common in the northeast. They’re stressed by rising temperatures and vulnerable to disease, and the most common invasive species are not new predators, but microbes. Most strikingly, soft corals that once carpeted the northwest seafloor, forming a literal underwater forest, have in many areas been wiped out altogether. Replacing them is what Chevaldonné calls “lawns” of algae and short-lived invertebrates.

The prevailing dynamic is what scientists call “brittleness,” or a decline in “robustness.” Historically complex food webs cannot find balance. In their place have emerged simpler food webs dominated by species that Coll and her colleagues characterize as “unpalatables” and “detritus” — algae, invertebrates and jellyfish. There are still some fish, but they’re relatively few in number, and small. Much of the Mediterranean catch is now processed and sold as animal feed.

“In terms of biomass and production, the Mediterranean is basically impoverished,” said Coll.

These conditions probably represent a transitional period for the Mediterranean, though it’s likely a one-way transition. Neither Chevaldonné nor Coll claims to know exactly what the sea’s next stable ecological configuration will look like, but this may be a preview, just as the Mediterranean may be a preview of the profound shifts likely elsewhere.

“In the future, we may get only jellyfish. Then we’ll find a way of consuming jellyfish,” Coll said. “The problem is, do we want that?”

Article Credit: Wired Science