‘Irreversible change’ to sea life from CO2

A major report warns that life in the seas will be irreversibly changed unless CO2 emissions from industrial society are drastically cut

Twenty-two experts in the journal Science say the oceans are heating, losing oxygen and becoming more acidic - all in response to our carbon dioxide.

The scientists in Germany have been studying an event five million years ago that could throw light on today's challenges.

From BBC Science

The lion: A victim of its own power?

Lions have padded their way through history, their beauty and physical prowess inspiring fear and respect. But despite a fascination with the creatures, humans have managed to wipe out one type of lion completely, writes Mary Colwell.

The lion motif appears on the insignia of kings, cars, chocolate bars and rugby shirts - the giant media company MGM has famously used the roaring creature as its logo since 1924.

Lions are among the most popular subjects for natural history films, where every nuance of their lives is explored in detail. We never tire of the thrill of a hunt or seeing cubs playing around a dozing adult.

Leo the lion, the star constellation of the outgoing and showy, prowls the night sky. The embodiment of power and wealth, lions symbolise physical beauty, muscular prowess and majesty.

Find out more

• Eleven facts about lions

• Natural Histories  is a series about our relationships with the natural world

From BBC news magazine

Call for more protection for seagrass meadows

Seagrasses - the underwater plants that act as nursery grounds for young fish - need more protection, say scientists.

Seagrass is found in shallow water around the coast of the UK

Monitoring of seagrass meadows off the North Wales coast found areas damaged by the likes of boat moorings, anchors and vehicles crossing at low tide had reduced value to the ecosystem.

Fewer species of fish were found where seagrass was degraded, according to research published in PeerJ journal.

The seagrass studied was near the village of Porthdinllaen, in Gwynedd.

Researchers at Swansea University studied areas with both high and low cover over a 28-hectare stretch of sea bed.

They also sampled fish living in the underwater meadows of flowering plants.

Plaice in seagrass

There was a three-fold reduction in the diversity of fish species and invertebrates, such as prawns, shrimp, juvenile cod and juvenile plaice, in areas of low cover, said lead researcher Dr Richard Unsworth.

He said that in the areas that had become damaged, there was "a reduction in diversity of the species and in the value of the habitat for juvenile fish".

The seagrass is in a special area of conservation, which is a strictly protected site under the European Habitats Directive.

However, despite this protection it was still being degraded, he said.

"We have a lot of legislation in the UK already to conserve a lot of marine habitats but these mechanisms do not have enough financial clout," said Dr Unsworth.

Impacts

Dr Jean-Luc Solandt of the Marine Conservation Society said the study reaffirmed that seagrass meadows are important habitats that should be protected.

"This research shows that disturbance to seagrass beds negatively impacts on ecosystems, and the capacity for these habitats to support a wealth of species.

"It is further evidence that protection measures are needed to preserve these diverse but fragile places."

Seagrasses are also found in several marine conservation zones off England.

Some marine conservation zones have already designated, with others due for consideration next year.

Conservation groups, backed by MPs, have been calling for a full network of protected zones to be created around the coastline of the UK.
From BBC -Science

Seagrasses are the only flowering plants that are able to live in seawater and able to pollinate while submerged. Seagrass often grow in large groups giving the appearance of terrestrial grassland – a kind of underwater meadow. There are four species of seagrass in the UK, two species of tasselweeds and two zostera species commonly known as eelgrass.

What is it?

The plants’ roots are anchored in mud, sand or fine gravel acting to stabilize the seabed and prevent erosion, which has the further effect of helping to stabilise and defend the wider coastline. The leaves are narrow and long, forming a three-dimensional habitat allowing a wide range of species to inhabit the area. The density of the grasses causes the water currents to slow down and allows nutrients to settle, in turn attracting wildlife.
Where is it found?

Seagrass is dependent on high levels of light for photosynthesis to grow and can therefore only be found in shallow water to a depth of around 4 metres. They are found around the coast of the UK in sheltered areas such as harbours, estuaries, lagoons and bays. ( From The Wildlife Trust)

http://www.wildlifetrusts.org/wildlife/habitats/seagrass

Madagascar's lemurs cling to survival

The famous lemurs of Madagascar face such severe threats to their survival that none of them may be left in the wild within 25 years.

Deforestation and hunting in Madagascar are taking a devastating toll on lemurs

That stark warning comes from one of the world's leading specialists in the iconic animals.

Deforestation and hunting are taking an increasing toll, according to Professor Jonah Ratsimbazafy, director of GERP, a centre for primate research in Madagascar.

"My heart is broken," he told the BBC, "because the situation is getting worse as more forests disappear every year. That means the lemurs are in more and more trouble."

So far 106 species of lemur have been identified and nearly all of them are judged to be at risk of extinction, many of them critically endangered.

The habitats they depend on - mostly a variety of different kinds of forest - only exist in Madagascar.

"Just as fish cannot survive without water, lemurs cannot survive without forest, but less than 10% of the original Madagascar forest is left," said Prof Ratsimbazafy, who is also a co-vice chair of the Madagascar primates section of the International Union for the Conservation of Nature (IUCN).

"I would believe that within the next 25 years, if the speed of the deforestation is still the same, there would be no forest left, and that means no lemurs left in this island."

A form of slash-and-burn agriculture known as 'tavi' sees trees felled and undergrowth scorched

The pressure to clear the forests comes from a rapidly growing but extremely poor population seeking to open up new farmland. At least 92% of people in Madagascar live on less than the equivalent of $2 a day.

A form of slash-and-burn agriculture known as "tavi" sees trees felled and undergrowth scorched to make way for fields of rice and other crops.

Video of one recent forest clearance shows an apocalyptic scene of an entire hillside of charred stumps and smouldering vegetation.

In one supposedly protected area I visited in eastern Madagascar, a sign announcing a prohibition on tree felling stood ignored amid new plantations of banana palms and maize.

Conservationists have long argued that slash-and-burn farming is needlessly damaging, leaving the soil unproductive after a few years, and that more intensive forms of cultivation would allow more forests to be left standing.

The government of Madagascar has recently confirmed that as much as 10% of the country is now earmarked in some way for wildlife - from national parks to what are called protected areas - but the rules are often not enforced at a local level.

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Earth 'entering new extinction phase' - US study

The Earth has entered a new period of extinction, a study by three US universities has concluded, and humans could be among the first casualties.

Climate change and deforestation are among the reasons we may be facing an extinction event

The report, led by the universities of Stanford, Princeton and Berkeley, said vertebrates were disappearing at a rate 114 times faster than normal.

The findings echo those in a report published by Duke University last year.

One of the new study's authors said: "We are now entering the sixth great mass extinction event."

The last such event was 65 million years ago, when dinosaurs were wiped out, in all likelihood by a large meteor hitting Earth.

"If it is allowed to continue, life would take many millions of years to recover and our species itself would likely disappear early on," said the lead author, Gerardo Ceballos.

Pollination by bees could disappear within three generations, the report warns

The scientists looked at historic rates of extinction for vertebrates - animals with backbones - by assessing fossil records.

They found that the current extinction rate was more than 100 times higher than in periods when Earth was not going through a mass extinction event.

Since 1900, the report says, more than 400 more vertebrates had disappeared.

Such a loss would normally be seen over a period of up to 10,000 years, the scientists say.

The study - published in the Science Advances journal - cites causes such as climate change, pollution and deforestation.

Given the knock-on effect of ecosystems being destroyed, the report says benefits such as pollination by bees could be lost within three human generations.

Extinction may be more gradual than when the dinosaurs died, the report says

Stanford University professor Paul Ehrlich said: "There are examples of species all over the world that are essentially the walking dead.

"We are sawing off the limb that we are sitting on."

The International Union for Conservation of Nature (IUCN) says at least 50 animals move closer to extinction every year.

Around 41% of all amphibians and 25% of mammals are threatened with extinction, it says.

Most at risk: the lemur

According to the IUCN, the lemur faces a real struggle to avoid extinction in the wild in the coming years.

The group says that 94% of all lemurs are under threat, with more than a fifth of all lemur species classed as "critically endangered".

As well as seeing their habitat in Madagascar destroyed by illegal logging, lemurs are also regularly hunted for their meat, the IUCN says.

What were the five mass extinction events?

Last year, a report by Stuart Pimm, a biologist and extinction expert at Duke University in North Carolina, also warned mankind was entering a sixth mass extinction event.

But Mr Pimm's report said the current rate of extinction was more than 1,000 times faster than in the past, not 114, as the new report claims.

The new report's authors said it was still possible to avoid a "dramatic decay of biodiversity" through intensive conservation, but that rapid action was needed.

From BBC News