Warming oceans killing coral reefs
Warming oceans killing coral reefs
Coral reefs around the world are experiencing a massive die-off that could be the worst in recorded history, a new study warns. Stoked by climate change and a powerful El Ni?o, record-high ocean temperatures have triggered the global event, which began last year and is expected to destroy 5% of the world’s coral reefs by 2016. The temperature changes brought about a phenomenon known as bleaching, in which corals expel symbiotic algae that provide essential nutrients, causing the brilliantly coloured reefs to turn ghostly white. A resilient reef can recover if water temperatures return to normal quickly, but if algae loss is prolonged, the coral eventually dies. Two similar global events took place in 1998 and 2010, but researchers predict the current one is likely to be more persistent – and deadly. This year as many as 95%of all US coral reefs are expected to see ocean
temperatures that can lead to bleaching. Of those areas, 60% are likely to be “hit with severe thermal stress, and we’re going to see a lot of corals dying”, Mark Eakin of the National Oceanic and Atmospheric Administration (NOAA) told The Washington Post. Oceanographers caution that the long-term consequences of coral bleaching could be severe. “One in every four species of fish lives on a coral reef,” says Ove Hoegh Guldberg, of Australia’s University of Queensland. “Coral reefs provide food and livelihood to 500 million people.”
HRT debate reignited
Is hormone replacement therapy safe after all? In the past 15 years or so, the number of women taking HRT to stave off hot flushes, mood swings and other symptoms of menopause has dropped,
after research found links between the drugs and conditions including diabetes, heart disease and breast cancer. But a newly published study, in which women who took HRT were tracked for a decade, found no significant link between serious illnesses and the treatment – which boosts levels
of the female hormones oestrogen and progesterone. The researchers, from New York University, said the women didn’t even put on any more body fat – another common concern – than a comparison group of women who didn’t take HRT during menopause. They conclude the risks
of the drugs have been overstated and are clearly outweighted by the benefits. However, critics of the study – which involved only 80 women on HRT – say it is too limited, and further research is needed.
New species in the Himalayas
A bright blue dwarf snakehead fish that can wriggle around on land for up to four days at a time and a snub-nosed monkey that sneezes when it rains: These are just two of 211 new species found over the
past five years in the Eastern Himalayas, the World Wildlife Federation reports. The region, which spans central Nepal, Myanmar and Bhutan, as well as northeastern India and southern Tibet, has seen
the discovery of 26 fish, 133 plants, 39 invertebrates, 10 amphibians, one reptile, a bird and a mammal. The question is, how long will they survive? Researchers say many of these newly found species are under mortal threat – climate change, deforestation, poaching and pollution have left only 25% of the Eastern Himalayas’ original habitats intact. “These discoveries show that there is still a huge amount to learn about the species that share our world,” the WWF-UK’s chief adviser of species, Heather Sohl, tells The Guardian. “It is a stark reminder that if we don’t act now to protect these fragile ecosystems, untold natural riches could be lost forever.”
IVF link to ovarian cancer
Women who go through IVF are a third more likely to develop ovarian cancer, a new study has suggested. Scientists analysed the records of quarter of a million British women who’d had the fertility treatment, and – in initial findings, revealed last week – concluded they had a 37% greater risk of developing the cancer than other women. It’s possible the treatment itself somehow increases patients’ vulnerability to the disease – women were found to be most at risk in the three years after starting IVF – but researchers say it’s more likely the cancer was linked to the underlying problems that caused their infertility. In any case, though the variation in risk was significant, the absolute risk remained very small: 15 women out of every 10,000 who had IVF developed ovarian cancer in the
period of the study; the standard rate was 11 in 10,000.
The raisin intelligence test
To get a sense of how clever a two-year-old will be at the age of eight, put a raisin or a piece of chocolate under a cup, instruct the infant not to eat it until they’re told to and see what happens. If they’re able to muster the self-control to resist the sweet treat for a full minute, chances are, they’ll end up doing better at school than their peers. The test – a variation on the famous marshmallow test – was applied to more than 500 children involved in a longitudinal study in Germany when they were 20 months old. The raisin was put under a cup that was opaque, but within easy reach, and they were told not to touch it until they were told they could – which was after 60 seconds. Of the children
tested, 37% either didn’t wait, or only lasted 10 seconds before touching the raisin, 39% waited between 11-59 seconds and only 24% waited for 60 seconds. Immediate results showed that children who’d been born prematurely had less self-control than those born at full term. Follow-up research
found that by the age of eight, the children who’d demonstrated good self-control performed, on average, 19% better in standardised aptitude tests. The team, led by Professor Dieter Wolke of Warwick University, believe it could be used to help identify children who are likely to suffer cognitive problems, so that they can be given extra help early on.
Curbing nearsightedness
Myopia, or nearsightedness, affects more than 40% of Americans and a growing number of children around the world. But new research suggests this modernday epidemic could be curbed by
simple eye drops. While the effects of nearsightedness are easily corrected with glasses or contact lenses, the condition can sometimes lead to more serious eye disorders, such as glaucoma, macular
degeneration, and premature cataracts. In a five-year trial on 400 children ages 6 to 12, scientists in Singapore examined whether daily doses of atropine, a powerful medication used to treat lazy eye, could help prevent myopia from worsening. They found it could – and, to their surprise, that the lowest dose was the most effective. That’s significant, because in high doses, atropine can cause
side effects including light sensitivity and blurry vision. “We slowed the progression of myopia by 50%,” the study’s lead author, Donald Tan, tells The Washington Post. “For the first time, we
might have a treatment for myopia in children that looks to be effective.”
Man’s mysterious ancient cousin
Five years after identifying a previously unknown, long-extinct human species called the Denisovans, scientists have used genetic analysis to shed new light on our mysterious relatives. The Denisovans are named after the cave in Siberia’s Altai Mountains where their remains were found. A lack of intact bones has prevented scientists from reconstructing how the species looked or lived, but DNA analysis on a 110,000-year-old Denisovan molar has established that they were close cousins of Neanderthals, and distant ones of early Homo sapiens. They likely lived alongside and interbred with both of those species – and possibly another unidentified relative of modern humans – for about 60,000 years. The analysis also suggests that Denisovans were more widespread and genetically more diverse than Neanderthals, who became inbred after ice age glaciers trapped them in southern Europe. That theory is supported by the fact that Australian aborigines, New Guineans and Polynesians all have elements of Denisovan DNA. “The world at that time must have been far more
complex than previously thought,” the study’s author, Susanna Sawyer, tells National Geographic. “Who knows what other hominids lived and what effects they had on us?”
Earth’s vast, tainted groundwater reservoir
The amount of groundwater lying just beneath the Earth’s surface is vastly larger than previously thought – but almost none of it is of any use. Until recently, scientists based their estimates for the earth’s total groundwater – water that seeped underground and became trapped in tiny spaces between rock, sand and soil – on crude calculations made in the 1970s. But now, using data from more than 1 million watersheds and 40,000 groundwater models, hydrologists have estimated that there is as much as 6 quintillion (6,000,000,000,000,000,000) gallons of water in the upper 1.2 miles of the Earth’s crust. If that water were pumped out and spread across the continents, it would form a layer 600 feet deep. Unfortunately, almost all of this groundwater is old, salty, and contaminated with arsenic and uranium – making it useless to the 2 billion people living in arid regions who rely on wells and springs for fresh water. Just 6% of groundwater stores are younger than 50 years old, drinkable and renewable within a human lifetime – a smaller, more finite supply than previously estimated. The researchers say their findings could help governments better manage their groundwater reservoirs amid rising global demand. “We’re using our groundwater resources too fast – faster than they’re being renewed,” the study’s lead author, Tom Gleeson, tells CSMonitor.com. “We want to find out how long before we run out of this critical resource.”
