US President Barack Obama has described a sprawling oil slick in the Gulf of Mexico as a "potentially unprecedented" environmental disaster.

Speaking in Louisiana, Mr Obama said his government would do whatever it takes to clean up the oil, adding that BP was responsible and must pay.

He said the focus was now on preventing any further damage to the Gulf coast.

BP says it will be at least a week before temporary measures to stem the leak are in place.

But it could take up to three months to drill relief wells that could fully contain the spillage, Interior Secretary Ken Salazar warned on Sunday.

BP is responsible for this leak, BP will be paying the bill  Barack Obama Strong winds drive slick onshore Your stories of the oil spill In pictures: Oil spill clean-up

The BP-operated Deepwater Horizon rig sank on 22 April, two days after a huge explosion that killed 11 workers.

Louisiana Governor Bobby Jindal has warned the spill threatens the way of life in his state.

Mr Obama flew to Louisiana on Sunday to see for himself the damage.

Speaking in the town of Venice, he said: "We're dealing with a massive and potentially unprecedented environmental disaster.

"The oil that is still leaking from the well could seriously damage the economy and the environment of our Gulf states.

"And it could extend for a long time. It could jeopardise the livelihoods of thousands of Americans who call this place home."

Following the explosion of a BP-operated rig, an oil slick has begun washing up on the Louisiana coast and is threatening three other states.

Up to 5,000 barrels of oil a day are gushing into the sea. The oil slick is moving towards the coast line and communities are waiting to find out how it will affect them.

BBC News website readers discuss their concerns as they wait for news.

Saturday 1 May:

I own and operate boat tours of the Pascagoula River swamp and marsh. This oil spill has given me the most sickening feeling. We are just waiting for the thing to hit and wondering how it will affect us.

My business already seems to have been affected. I usually have several phone calls a day but none so far. I have nothing booked for the weekend, which is unusual.

If it's the magnitude they're predicting, it could be the end of life as we know it here on the beautiful Mississippi Gulf Coast, at least until the spill is completely cleaned up. It breaks my heart to think of all the marine life and birds that will no doubt be affected by this disaster.

The mutation may have helped mammoths survive in the ice Age

Mammoths had a form of "anti-freeze" blood to keep their bodies supplied with oxygen at freezing temperatures.

Nature Genetics reports that scientists "resurrected" a woolly mammoth blood protein to come to their finding.

This protein, known as haemoglobin, is found in red blood cells, where it binds to and carries oxygen.

The team found that mammoths possessed a genetic adaptation allowing their haemoglobin to release oxygen into the body even at low temperatures.

The ability of haemoglobin to release oxygen to the body's tissues is generally inhibited by the cold.

The resulting haemoglobin molecules are no different than 'going back in time' and taking a blood sample from a real mammoth  Kevin Campbell University of Manitoba

The researchers sequenced haemoglobin genes from the DNA of three Siberian mammoths, tens of thousands of years old, which were preserved in the permafrost.

The mammoth DNA sequences were converted into RNA (a molecule similar to DNA which is central to the production of proteins) and inserted into E. coli bacteria.

The bacteria faithfully manufactured the mammoth protein.

"The resulting haemoglobin molecules are no different than 'going back in time' and taking a blood sample from a real mammoth," said co-author Kevin Campbell, from the University of Manitoba in Canada.

Scientists then tested the "revived" mammoth proteins and found three distinctive changes in the haemoglobin sequence allowed mammoth blood to deliver oxygen to cells even at very low temperatures.

More than 2m bees were stolen last year, says Japan's apiary association

Japanese bee-keepers have been warned to be on their guard, following a spate of hive thefts.

The price of honeybees has doubled in recent years after a ban on imports. Police suspect a gang of specialist thieves is stealing honeybees to order.

In central Shizuoka prefecture, eight hives of 60,000 bees were taken in a single night from five separate farms.

The area is well known for strawberry growing and farmers need honeybees to propagate their crops.

The insects have been in short supply in Japan after imports were banned for several years to try to prevent the spread of parasites.

The price of a swarm has doubled to more than $400 (£260).

The Japan Beekeepers and Honey Association says more than two million of the insects were stolen in 2009, and thefts are becoming more frequent.

The organisation has urged its members to be alert, but has admitted it is difficult to protect hives around the clock on remote farms.

Production at Gossainbarie tea estate has gone up since it started using organic manure

Visitors making their way along the muddy track leading to the Gossainbarie tea estate in India's north-eastern Assam state will be greeted by huge mounds of cow dung, rotting water hyacinth, as well as and fish and meat waste.

But this is no cause for alarm - the tea-estate has gone organic and is following the principles of India's ancient plant medicine Vriksh Ayurveda.

"This is our fertiliser because we don't use any chemical ones in our gardens," says Gossainbarie's owner Binod Saharia.

He has enlisted the help of a hermit-like bearded figure - former management consultant Swami Valmiki Iyengara.

Mr Iyengara says he has studied Vriksh Ayurveda, a system of traditional medicine, and evolved a concept of organic farming that is both sustainable and profitable.

"All pollutants are useful wastes and we can convert most of them into organic manure," he says.

"The ancient Indian plant medicine details processes for creating organic fertiliser from virtually anything.

The already threatened manatee could be a casualty of the oil leak

How bad will the Gulf of Mexico oil spill turn out to be - for wildlife and for people whose jobs depend on wildlife, such as fishermen?

At the moment, the only completely accurate answer would appear to be: we do not know.

For David Kennedy from the US National Ocean Service, it is "a very very significant event, and of great concern".

"I'm frightened," he adds.

But Clifford Jones, an oil and gas engineering specialist from the UK's Aberdeen University, suggests it should not be considered in the same category as the Exxon Valdez spill of 1989, with which it is regularly being compared.

It is a threat to the ecosystem, he allows, but says the Exxon Valdez leaked significantly more oil than is likely to flow from the stricken Deepwater Horizons drillsite before pressure in the well drops and stops forcing the oil out.

The western clawed frog joins an illustrious list of sequencees

Scientists have published the first genome sequence from an amphibian.

Xenopus tropicalis, the western clawed frog, joins the list of sequenced organisms that includes chicken, horse, rat, yeast, platypus, and human being.

It has about 20,000 genes - about the same as a human - and scientists say it sheds new light on genetic evolution.

Conservationists say analysing the genes could lead to new ways of combating threats such as the often fatal fungal disease chytridiomycosis.

Presenting their results in the journal Science, the researchers also suggest it may lead to better understanding of the threat posed by endocrine-disrupting ("gender-bending") chemicals, to which amphibians are especially sensitive.

We've known for a couple of years or so that one of the impressive-sounding environmental promises that governments are signed up to - the pledge to reduce the rate of biodiversity loss significantly by 2010 - isn't going to be met.

Now, an analysis just published in the journal Science is giving us detail on some important dimensions of the problem.

It's particularly timely, as we are now on the path towards October's UN biodiversity convention summit in Nagoya, Japan. There you can expect all of these bones to be picked over, and some new targets to be set.

If you've been following the issue, the basic pattern should be familiar.

Numbers of species, size of populations, diversity within ecosystems: all these are going down.

Habitat loss, the spread of harmful alien species, depletion of fish stocks: all these are going up.

Joining the dots and concluding that the second batch of things causes the first isn't a leap of deduction likely gain you a Nobel Prize.

The Science paper, compiled by an impressive array of scientists across disciplines led by Stuart Butchart from the UN's World Conservation Monitoring Centre and BirdLife International, does three things that may prove useful.

• It sorts out what we know and what we don't know, and in which regions
• It refines measurements of how the various threats are changing
• It puts all of this together in a global whole

As usual, the global picture that scientists would like to have is in reality a patchwork of local and regional pixels, with the added constraint that the time-line for measurements in many parts of the world starts only a few decades ago.

Continue reading the main story

The ash cloud spread across much of northern Europe

In graphics: Volcano chaos

Scientists are looking at what impact volcanic ash from the recent eruption in Iceland has had on marine biology.

A team of researchers will spend a month at sea, studying a region of water in the North Atlantic.

They say the information will provide "unique data" on how the dust affects the chemistry and biology of seawater.

The eruption under a glacier in south-west Iceland created a vast ash cloud that spread across northern Europe.

"It is a very interesting and unique situation that we find ourselves in," said Eric Achterberg from the UK's National Oceanography Centre, which is leading the study.

"It will provide an angle that we did not expect."

Professor Achterberg said that the research cruise was originally planned about three or four years ago, and it was by chance that the study coincided with the eruption.

"We are interested in the sub-polar region of the North Atlantic, which is the area just south of Iceland and Greenland.

"We will be sampling the particles in the atmosphere and chemicals in the rainwater," he told BBC News.

Threats to biodiversity, such as habitat loss, are still on the increase

The world's governments will not meet their internationally-agreed target of curbing the loss of species and nature by 2010, a major study has confirmed.

Virtually all species and ecosystems show continued decline, while pressures on nature are increasing, it concludes.

Published in the journal Science, the study confirms what conservationists have known for several years.

The 2010 target was adopted in 2002, but the scientists behind this study say implementation has been "woeful".

"Our analysis shows that governments have failed to deliver on the commitments they made in 2002," said research leader Stuart Butchart, from the UN Environment Programme's World Conservation Monitoring Centre (Unep-WCMC) and BirdLife International.

"Biodiversity is still being lost as fast as ever, and we have made little headway in reducing the pressures on species, habitats and ecosystems."

Unep chief scientist Joseph Alcamo added: "Since 1970, we have reduced animal populations by 30%, the area of mangroves and seagrasses by 20% and the coverage of living corals by 40%.

"These losses are clearly unsustainable."