Earth ChangesS


Fish

Shellfish reefs are 'most imperilled sea habitat'

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© Getty Images / GlowimagesAn American costal shellfish reef. These are at risk, because their importance as ecosystem engineers has been overlooked until now
Globally, 85 per cent of reefs have been lost. Destructive fishing practices, disease and coastal development threaten many of the survivors. What sounds like an apocalyptic vision of the future for the world's tropical corals is in fact a chilling assessment of the current state of reefs built in cooler waters by oysters and other bivalve shellfish.

According to a report from The Nature Conservancy (TNC), released this week at the International Marine Conservation Congress in Washington DC, shellfish reefs are the world's most imperilled marine habitats - faring worse than coral reefs and mangrove forests.

"Shellfish like oysters, cockles and mussels have been feeding people for millennia," says co-author Robert Brumbaugh, a member of TNC's global marine team based in Summerland Key, Florida. "But there is very little appreciation for their plight." Shellfish biologists hope that TNC's global survey will galvanise conservation efforts in a similar way to the 1998 report of the Global Coral Reef Monitoring Network, which raised the alarm on tropical reefs.

Bandaid

Rubber plantations may be 'devastating'

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© UnknownRubber plantations may have a "devastating" environmental impact in southeast Asia, scientists say.
The expansion of rubber plantations in southeast Asia could have a "devastating" environmental impact, scientists warned as they pressed for a substantial increase in forest preserves.

More than 500,000 hectares may have already been converted to rubber plantations in the uplands of China, Thailand, Vietnam, Laos, Cambodia and Burma.

And researchers predict the area of land dedicated to rubber and other farming systems could more than double or triple by 2050, replacing lands currently occupied by evergreen broadleaf trees and secondary vegetation growing in areas subjected to slash-and-burn farming.

Fish

Scientists find evidence of whale travel

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© UnknownHumpback whales tagged off Australia's east coast also spend time feeding in Bass Strait and off NZ.
Australian scientists have found humpback whales tagged off the east coast travel more widely than previously thought.

The discovery is also at odds with the traditional understanding of the humpback whale's travel routes identified by the International Whaling Commission (IWC).

The federal government hopes the research will help protect Southern Ocean whales.

Last October, scientists tagged 16 whales near Eden in NSW.

Their movements were tracked for six months over an area covering about 4,000 kilometres.

Eagle

Tough birds make better singers

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© FotosearchA Northern Mockingbird
A hostile environment and inconsistent weather may explain why some birds become better singers than others, and are also likely to have superior learning and mating skills, according to a new study.

The research is based on a large-scale study of mockingbirds in different habitats carried out by researchers at the National Evolutionary Synthesis Centre (NESCent) in Durham, North Carolina, the Cornell University Lab of Ornithology, and McGill University.

"As environments become more variable or unpredictable, song displays become more elaborate," said Carlos Botero, a postdoctoral researcher at NESCent.

Ambulance

Afghan mudslide kills five children

A mudslide has killed five children in northern Afghanistan, where weeks of heavy rain has killed about 150 people and destroyed hundreds of houses, officials said on Saturday.

The children, aged between seven and 10, died in the northern province of Balkh late on Friday when they were buried by earth and stones as they were playing and watching animals graze, deputy provincial governor Abdul Satar Barez said.

The earth had been loosened by construction and days of downpour, he said.

Arrow Up

Australia: Massive dust storm envelops Southwestern New South Wales

NSW Dust Storms
© BOMLatest colour mean sea level pressure analysis for Australia and New Zealand
There have been reports of huge dust storms in the south-west of New South Wales as winds whip up dirt from dry paddocks.

The Bureau of Meteorology says there are strong easterly winds in excess of 35 kilometres per hour going right through the ranges, northern tablelands and central tablelands, with the strongest winds in Wagga.

Fish

Corals upgrade algae to beat the heat

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© Jurgen Freund / Nature Picture Library / Rex FeaturesThis fan coral is in good health, and many of its relatives may stay healthy if they can upgrade their in-house algae.
In oceans around the world, heat-resistant algae are offering the prospect of a colourful future for corals. The reef-forming animals are upgrading their symbiotic algae so that they can survive the bleaching that occurs in waters warming under climate change.

"The most exciting thing was discovering live, healthy corals on reefs already as hot as the ocean is likely to get 100 years from now," says Stephen Palumbi of Stanford University.

Corals have a symbiotic relationship with tiny algae called zooxanthellae. The corals give the algae a home and, in exchange, the algae provide the corals with food. When water temperatures get too hot, the corals expel the algae. This is what is known as coral bleaching and it is expected to kill coral reefs around the world as global temperatures rise.

Magnify

Flashback Ancient Colony of Microbes Found Thriving Without Oxygen, Warmth or Light

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© AP Iron oxides stain the snout of the Taylor Glacier in Antarctica
An ancient colony of microbes thriving without oxygen, warmth or light beneath a rusty glacier has led scientists to re-evaluate what it takes for life to survive.

The bugs, believed to be descended from ocean-dwelling organisms, have evolved a unique ecosystem in a briny pool under 400 meters of ice.

There they have flourished for at least 1.5 million years, transforming sulfur and iron compounds to fuel their growth.

Bizarro Earth

Earthquake Magnitude 5.7 - Puebla, Mexico

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© US Geological Survey
Date-Time Friday, May 22, 2009 at 19:24:18 UTC

Friday, May 22, 2009 at 02:24:18 PM at epicenter

Location 18.347°N, 98.267°W

Depth 56 km (34.8 miles) set by location program

Region PUEBLA, MEXICO

Distances 75 km (45 miles) NW of Huajuapan de Leon, Oaxaca, Mexico
80 km (50 miles) S of Puebla, Puebla, Mexico

90 km (55 miles) W of Tehuacan, Puebla, Mexico

150 km (95 miles) SE of MEXICO CITY, D.F., Mexico

Arrow Down

Australia's Tasmanian devil declared endangered

Tasmanian devil
© Agence France-Presse/Torsten BlackwoodAustralia's Tasmanian devil, the world's largest surviving marsupial carnivore, will be listed as endangered because of a contagious and deadly cancer, the government said
Australia's Tasmanian devil, the world's largest surviving marsupial carnivore, will be listed as endangered because of a contagious and deadly cancer, the government said.

"This disease has led to the decline of about 70 percent of the Tasmanian devil population since the disease was first reported in 1996," Environment Minister Peter Garrett said in a statement.

Devil facial tumour disease, which is spread through biting, kills the animals usually within three months by growing over their faces and mouths, preventing them from eating.