Earth ChangesS


Frog

Nutrient Pollution Chokes Marine And Freshwater Ecosystems

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© Michael MillIn freshwater ecosystems, like lakes, phosphorus pollution causes algal blooms.

Protecting drinking water and preventing harmful coastal "dead zones", as well as eutrophication in many lakes, will require reducing both nitrogen and phosphorus pollution. Because streams and rivers are conduits to the sea, management strategies should be implemented along the land-to-ocean continuum. In most cases, strategies that focus only on one nutrient will fail.

These policy recommendations were put forth by a team of distinguished scientists in the recent issue of Science. Led by Dr. Daniel J. Conley, a marine ecologist at the GeoBiosphere Science Centre in Sweden and a Visiting Scientist at the Cary Institute of Ecosystem Studies, the paper reviews weaknesses in single-nutrient management strategies.

In most cases, improving water quality and preserving coastal oceans will require a two-pronged approach.

Plant growth is tied to nitrogen and phosphorus availability. Human activities have greatly increased the abundance of these nutrients, causing the overproduction of aquatic plants and algae.

Bizarro Earth

Study: Antarctic Glaciers Slipping Swiftly Seaward

Antarctic
© AP Photo/Charles J. Hanley
Antarctic glaciers are melting faster across a much wider area than previously thought, scientists said Wednesday - a development that could lead to an unprecedented rise in sea levels.

A report by thousands of scientists for the 2007-2008 International Polar Year concluded that the western part of the continent is warming up, not just the Antarctic Peninsula.

Previously most of the warming was thought to occur on the narrow stretch pointing toward South America, said Colin Summerhayes, executive director of the Britain-based Scientific Committee on Antarctic Research and a member of International Polar Year's steering committee.

Bizarro Earth

South African fires threaten historic wine estates

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© Unknown

Fires raging for days in the mountains around Cape Town are threatening historic South African wine estates, local media reported Tuesday.

The Cape Times reported firefighters suspect arson is to blame for fires burning in the Helderberg mountains, the latest in a string of blazes in the province spurred on by extreme heat and windy weather conditions.

A fire which broke out on the Lourensford Wine Estate is believed to have been started deliberately, and has spread to several other wine estates in Somerset West including the 300-year-old Vergelegen Wine Estate.

Some 300 firefighters are battling the blaze, expected to burn on for several days before it is brought under control.

Better Earth

King of the swingers has no use for mirrors

gibbon
© Emma Collier-BakerA gibbon seems to be interested in itself, but none tried to get at icing on their own faces.

Never accuse a gibbon of vanity. The apes do not recognise their own face in a mirror, a study claims.

This stands in contrast to chimpanzees, orang-utans and perhaps gorillas, which all show a glimmer of recognition when confronted with their visage.

While primatologists may bicker over the significance of such observations, the lack of self-recognition in gibbons and other lesser apes indicates that this mental capacity emerged 14 to 18 million years ago when their evolutionary lineage split from great apes.

"We can reason about the mind of an ancestor without even laying eyes on the fossil," says Thomas Suddendorf, a psychologist at the University of Queensland, Australia, who led the study.

Bizarro Earth

Bizarre Bird Behavior Predicted by Game Theory

Raven
© UnknownRaven

A team of scientists, led by the University of Exeter, has used game theory to explain the bizarre behaviour of a group of ravens. Juvenile birds from a roost in North Wales have been observed adopting the unusual strategy of foraging for food in 'gangs'. New research, published in the journal PLoS One (on Wednesday 25 February 2009), explains how this curious behaviour can be predicted by adapting models more commonly used by economists to analyse financial trends.

This is the first time game theory has been used to successfully predict novel animal behaviour in the real world. The researchers believe this analysis could also shed light on the variation in feeding strategies in different populations in other species.

Butterfly

British Butterfly Reveals Role of Habitat for Species Responding to Climate Change

Most wild species are expected to colonise northwards as the climate warms, but how are they going to get there when so many landscapes are covered in wheat fields and other crops? A study published today (Wednesday 25 February 2009) shows it is possible to predict how fast a population will spread and reveals the importance of habitat conservation in helping threatened species survive environmental change.

Published in the journal Proceedings of the Royal Society B, the research tracks the recovery of a rare British butterfly over 18 years and offers hope for the preservation of other species.

Conducted by the Universities of Exeter, York and Sheffield and funded by the Natural Environment Research Council, the study could inform future conservation policy to help safeguard vulnerable species against the effects of climate change and habitat destruction.

Magnet

Florida tests using magnets to repel crocodiles

Florida wildlife managers have launched an experiment to see if they can keep crocodiles from returning to residential neighborhoods by temporarily taping magnets to their heads to disrupt their "homing" ability.

Researchers at Mexico's Crocodile Museum in Chiapas reported in a biology newsletter they had some success with the method, using it to permanently relocate 20 of the reptiles since 2004.

"We said, 'Hey, we might as well give this a try," Lindsey Hord, the Florida Fish and Wildlife Conservation Commission's crocodile response coordinator, said on Tuesday.

Crocodiles are notoriously territorial and when biologists move them from urban areas to new homes in the wild, they often go right back to the place where they were captured, traveling up to 10 miles a week to get there.

Scientists believe they rely in part on the Earth's magnetic fields to navigate, and that taping magnets to both sides of their heads disorients them.

"They're just taped on temporarily," Hord said. "We just put the magnets on when they're captured and since they don't know where we take them, they're lost. The hope would be that they stay where we take them to."

Fish

Fish has transparent head

Scientists in California have filmed a fish with a transparent head.

And the encounter has helped researchers solve the 50-year-old mystery of how the fish uses its extraordinary eyes to see in the gloomy ocean depths.


Better Earth

First evidence of a supernova in an ice core

supernova
click to enlarge

There hasn't been a decent supernova in our part of the universe in living memory but astronomers in the 11th century were a little more fortunate. In 1006 AD, they witnessed what is still thought to be the brightest supernova ever seen on Earth (SN 1006) and just 48 years later saw the birth of the Crab Nebula (SN 1054).

Our knowledge of these events come from numerous written accounts, mainly by Chinese and Arabic astronomers (and of course from the observations we can make today of the resultant nebulae).

Now we can go one better. A team of Japanese scientists has found the first evidence of supernovae in an ice core.

The gamma rays from nearby supernova ought to have a significant impact on our atmosphere, in particular by producing an excess of nitrogen oxide. This ought to have left its mark in the Earth's ice history, so the team went looking for it in Antarctica.

The researchers took an ice core measuring 122 metres from Dome Fuji station, an inland site in Antarctica. At a depth of about 50 metres, corresponding to the 11th century, they found three nitrogen oxide spikes, two of which were 48 years apart and easily identifiable as belonging to SN 1006 and SN 1054. The cause of the third spike is not yet known.

Evil Rays

US: Thousands still lack power

Snowstorm Maine
© Jose Leiva/Sun JournalElaine Asselin of Lewiston walks her dog Zoe down Novella St. early Monday morning after the storm among the snow laden trees and power lines.

National Weather Service meteorologist Eric Schwibs says Sunday's snowstorm was the season's "highest impact event in terms of damage" because the snow was wet and heavy.

"It caused quite a bit of damage to the power grid as far as outages," Schwibs said. "I was driving home last night watching the transformers blow."

There were some impressive snowfall totals, with Livermore Falls topping out at 21 inches, Turner at 19 and Lewiston-Auburn saw 15½. Winds blowing at 35 to 40 miles per hour made the storm feel and look worse.

"This was a classic track for a snowstorm like this for us. The only real difference was the wetness and the heaviness of the snow," NWS meteorologist Jim Hayes said. "This one was more like what we'd normally see in mid to late March."

Power outages added to people's sense of frustration. Gail Rice, spokeswoman for Central Maine Power Co., said the total number of customers without power was just over 130,000 at 11 a.m. Monday; 11,000 of those customers were in the Twin Cities and surrounding area.

"The highest concentration of outages were for customers out of our Brunswick service station," Rice said.

Crystal St. Hilaire of Minot was without power from Sunday night until 2:30 p.m. Monday. She said she was equally frustrated by having no power as she was by having to clear the snow.