The massive bleaching hitting the Great Barrier Reef off the coast of Australia is likely that country's "biggest ever environmental disaster," says Dr. Justin Marshall, who has studied the reef for three decades.

Only 7 percent of the reef has escaped bleaching, according to researchers at the ARC Center of Excellence. Marshall, a professor at the University of Queensland, says the destructive phenomenon is happening in an area the size of Scotland.

"Before this mass bleaching started, we already were at the point of losing 50% of the coral cover on the Great Barrier Reef. This, I think, will probably take another 50% off what was left," Marshall says.

Over the course of the last six months, Marshall and his colleagues with the citizen science project Coral Watch have documented the degradation of reef structures near Lizard Island, one of the worst-hit areas.

They photographed the same formations of coral multiple times, showing clearly the pace of the destruction.

New species of dolphin identified.
A team of researchers says it has identified a new species of humpback dolphin.

Physical and genetic evidence suggests that cetaceans found in waters off northern Australia are distinct within the humpback family.

This general group grows up to 2.4m in length and inhabits coastal waters from the Atlantic to the Pacific.

The evidence for the distinct species in northern Australia is outlined in the academic journal Molecular Ecology.

"Based on the findings of our combined morphological and genetic analyses, we can suggest that the humpback dolphin genus includes at least four member species," said co-author Martin Mendez, from the Wildlife Conservation Society's Latin America and the Caribbean programme.

Dr Mendez added: "This discovery helps our understanding of the evolutionary history of this group and informs conservation policies to help safeguard each of the species."

New species scheme for humpback dolphins:
Atlantic humpback dolphin (Sousa teuszii), which occurs in the eastern Atlantic off West Africa
An Indo-Pacific humpback dolphin (Sousa plumbea), which ranges from the central to the western Indian Ocean
Another species of Indo-Pacific humpback dolphin (Sousa chinensis), inhabiting the eastern Indian and western Pacific Oceans
Fourth Sousa species found off northern Australia yet to be named

Humans hunted Australia's giant

vertebrates to extinction about 40,000 years ago, the latest research published

in Science has concluded.

The cause of the widespread extinction has provoked much debate, with climate

change being one theory.

However, scientists studied dung samples from 130,000 and 41,000 years ago,

when humans arrived, and concluded hunting and fire were the cause.

The extinction in turn caused major ecological changes to the landscape.

The scientists looked at pollen and charcoal from Lynch's Crater, a

sediment-filled volcanic crater in Queensland that was surrounded by tropical

rainforest until European settlement.

They found Sporormiella spores, which grow in herbivore dung, virtually

disappeared around 41,000 years ago, a time when no known climate transformation

was taking place.

    

The Great Barrier Reef off the Queensland coast is home to a wealth of marine life

A UN team has arrived in Australia to investigate possible damage to the Great Barrier Reef by the mining industry.

Fears that coal exports and oil and gas exploration would jeopardise the reef prompted the Unesco delegation's visit.

Environmentalists have urged the government to suspend mining development until a government review is completed.

The reef is home to 400 types of coral and 1,500 species of fish.

The Great Barrier Reef, which holds Unesco World Heritage

status, lies off the coast of the state of Queensland, which is the

largest producer of coal in the country.

The Unesco team is scheduled to visit the reef for a week

before making recommendations to the World Heritage committee. They will

also meet members of the government.

Environmentalists are concerned that an increase in coal

production and the shipping traffic that would follow could affect the

Great Barrier Reef's World Heritage status.

They want the government to suspend all new developments

while a state and federal review of the health of the reef is carried

out.