Monthly Archives: September 2008

One-third of coral reefs worldwide face extinction

Source: European Commission, Environment DG
Published Sep. 12, 2008

Coral reefs harbour the highest concentration of marine biodiversity in the world, form the basis of ecosystems and food webs that sustain communities and provide coastal protection. However, according to recent research, climate change and human impacts are placing one-third of reefs at serious risk of extinction. Areas at risk include the Caribbean and the Coral Triangle in the western Pacific. Humans can have negative impacts on coral reefs through a number of means, including increased coastal development, sedimentation due to poor land-use and watershed management, sewage discharge, pollution from agrochemicals, coral mining and over-fishing.

These impacts reduce the resilience of corals to withstand global threats from a rise in sea surface temperatures and increased ocean acidification arising from climate change. Higher temperatures lead to heat stress, which causes the coral to expel the zooxanthellate algae that live in their tissues in a protective, symbiotic relationship. This increases the risk of mass coral bleaching and mortality from diseases, some of which can kill 500 year old colonies within months. Additionally, ocean acidification is reducing ocean carbonate ion concentrations which in turn limits the ability of corals to build skeletons and reef structures.

Categories and criteria from the International Union for Conservation of Nature (IUCN) Red List were used to identify corals that are ‘Vulnerable’, ‘Endangered’ or ‘Critically Endangered’. The results emphasise the widespread plight of coral reefs and the urgent need for conservation measures. The majority of the species were found to be vulnerable. Of 704 species studied that could be assigned conservation status, 32.8 per cent were in categories with an elevated risk of extinction.

Among the researchers’ other findings were:

  • The proportion of corals threatened with extinction has increased dramatically over the last 2 decades
  • Corals are at greater risk of extinction than any group of land-based animals apart from amphibians
  • 40 per cent of coral species only inhabit shallow-waters and are therefore more vulnerable to human impacts
  • 303 species are highly susceptible to bleaching, and of these, only 102 species can easily recover within a few
  • Each year, 1-2 per cent of coral is lost in the Indo-Malay-Philippine Archipelago

The Caribbean has been devastated by population declines of two key species, the staghorn and elkhorn corals, which were recently listed under the US Endangered Species Act. This area has the largest number of corals that are listed as Critically Endangered or Endangered categories, while the Coral Triangle of the western Pacific has the highest proportion of threatened species overall.

The authors draw attention to the high aesthetic, resource and recreational value of coral reefs. By identifying the areas and species most at risk, it is hoped that the research can help policy makers set priorities for biodiversity conservation.

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Drought threat to rare emu-wren


The Environment Department says ongoing drought is significantly affecting the almost-extinct mallee emu-wren.

The tiny bird is found in South Australia in Ngarkat Conservation Park, south of Pinnaroo.

The department is keen to draw attention to the bird as World Threatened Species Day in marked on Sunday.

Ecologist Peter Cale says dried-out vegetation and bushfires have reduced available habitats for mallee emu-wrens.

“A single extensive fire in the reserve that burns out the area where they occur would cause their local extinction from this state,” he said.

“However in Victoria there’s still numbers extending across Murray Sunset and Hattah [Kulkyne] conservation reserves so they’re not likely to go extinct in total but certainly in South Australia [they could].”

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Thousands of Australia’s koalas felled by land-clearing: WWF


SYDNEY (AFP) — Australian koalas are dying by the thousands as a result of land clearing in the country’s northeast, while millions of birds and reptiles are also perishing, conservation group WWF said Sunday.

The environmental body warned that unless urgent action was taken to stop trees being felled, some species would be pushed to the brink of extinction.

In an annual statement, Queensland state last week revealed that 375,000 hectares of bush were cleared in 2005-06 — a figure WWF said would have resulted in the deaths of two million mammals.

Among those that perished as a result of loss of habitat would have been 9,000 tree-hugging koalas, WWF Australia spokesman Nick Heath said.

“It’s a horrifying figure,” Heath told AFP. “Two million mammals and that’s all sorts of kangaroos, wallabies. We couldn’t come to an exact figure on the birds, but I would say it would be over five million.”

Heath said WWF’s figures were based on earlier scientific assessments of animal density in each area of the state combined with the amount of land cleared over the 2005-2006 period.

He said the animals that died in the largest numbers were reptiles, including lizards and turtles.

Of particular concern was the impact on the koala, an iconic marsupial found only in Australia and which is most populous in Queensland state.

“There is scientific debate about whether koalas are on the verge of extinction or not… I don’t want to enter into that debate,” Heath said.

“All I say is, whether they are endangered or not, killing 9,000 koalas is unacceptable.

“People want koalas to exist, they don’t want them to be on the endangered list. And if we kill 9,000 a year, even if they are not on the endangered list now, they will be if we don’t stop.”

Heath said that turning native bush into grazing paddocks meant that many of the animals killed died in fires set by farmers to clear debris after bulldozers cut down the trees.

“So these animals die horrific deaths,” he said. “They are either dead from being run over or falling from a tree, or if they survive that, they are burnt alive.”

The Queensland government has set up a task force to help conserve koala populations amid greater urban development in the state’s southeast.

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Endangered species may not survive low flows


Two rare native fish facing extinction may not survive in the lower Waitaki and Hakataramea catchments with low river flows, the Department of Conservation warned yesterday.

The lowland longjaw galaxias is New Zealand’s most threatened fish, ranked as “nationally critical”.

It and the “nationally endangered” Canterbury mudfish have populations in both catchments.

But the department is worried by applicants wanting to take water within the two catchments and have a minimum flow of 100 cumecs in the lower Waitaki River, instead of the 150 cumecs environmental minimum low set in the Waitaki catchment water allocation regional plan.

It is also concerned about minimum flows suggested for the Hakataramea catchment and tributaries of the lower Waitaki River.

Yesterday, it made those concerns known, not just for fish but also for birds, to an Environment Canterbury hearings panel.

Freshwater ranger Peter Ravenscroft said dropping the minimum flow would affect shallow areas, groundwater and wetlands, upon which the lowland longjaw and mudfish depended for survival.

“Given their high risk of extinction, any loss in their respective habitats will be significant and pose a serious risk to the ongoing survival of these species,” he said.

The mudfish were on the south bank of the Waitaki River at four distinct locations, occupying wetlands and springs linked to the Waitaki River.

Reducing the river’s minimum flow would shrink or remove wetlands, threatening their long-term survival.

Other indigenous fish, including longfin eel, lamprey and torrentfish, were migratory and were at risk from reduced flows in the lower Waitaki, Hakataramea and Maerewhenua Rivers.

There were seven known populations of the lowland longjaw in the Waitaki catchment and two in the Hakataramea catchment.

The Hakataramea population made up half of the known numbers.

Water takes in the Hakataramea had the potential to have an adverse effect on their survival, he said.

Legal counsel Philippa Rutledge said the department wanted to ensure Waitaki and Hakataramea catchment flows and levels continued to support the habitats of braided river birds and indigenous fish, particularly threatened species.

It was also concerned about the implications for the integrity of the water allocation regional plan and its environmental minimum flow of 150 cumecs, which the department supported.

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Another creature edging towards extinction!


OUT OF the nine species of storks found throughout North-east Asia, the adjutant stork is the largest. The population of this species is dwindling fast. At the beginning of the 19th century, Assam was the habitat for lakhs of greater adjutant storks. After India’s Uttaranchal, Nepal, Bangladesh, Myanmar, Cambodia and Vietnam, the Brahmaputra valley has been the main habitat for this fast-dwindling species of stork. But now, ironically, they can be easily counted in this once highly-populated habitat.

Deepor Beel and Silsaku Beel were some of the famous wetlands of Guwahati known as the resting grounds of these species of storks.

Apart from these, a flock of greater adjutant storks was also sighted near Guwahati Commerce College, Hajimusaphirkhana and Maligaon’s Aruna Cinema Hall. But now only a few of them can be seen in parts of Deepor Beel, Charusala Beel and Hajimusaphirkhana. But quite noticeably, a few years back, a number of birds belonging to this species died because of some unknown reason in Deepor Beel.

It is to be noted here that this particular species of stork plays an important role in maintaining the ecological balance. Lack of proper habitat and food are the major causes behind the declining number of this species. And since food is a major requirement for reproduction, a planned conservation measure is the only means to ensure their continuation.

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Development threatening endangered cockatoo


The World Wildlife Fund (WWF) says better town planning is needed to maintain the habitat of the carnaby’s black cockatoo so that it does not become extinct.

The birds are found in the south-west of Western Australia, and the fund says numbers have fallen by more than 50 per cent in the past 45 years.

It blames the rising development in the area which is destroying the birds’ habitat.

The carnaby’s black cockatoo is listed as endangered by the Federal Government

Michael Roache from WWF says plants in the birds’ habitat need to be replanted.

“We don’t necessarily place the true value on environmental services or indeed habitat for biodiversity. In south-west WA we have so many threatened species because of those threats of development,” he said.

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Endangered vulture closer to extinction


ANN ARBOR, Mich., Sept. 9 (UPI) — U.S. scientists say captive breeding colonies of a critically endangered vulture are too small to protect the bird species from extinction.With a seven-foot wingspan, the oriental white-backed vulture (Gyps bengalensis) was an awesome presence in south Asia until the mid-1990s, when populations in the tens of millions began to collapse. A University of Michigan study led by Jeff Johnson determined the decline was caused by an anti-inflammatory drug, diclofenac, used to alleviate arthritis-like symptoms in livestock. The drug is fatally toxic to vultures.

Although India, Nepal and Pakistan outlawed its manufacture in 2006, diclofenac is still available and birds are still dying.

The scientists said the absence of vultures poses a threat to public health, since uneaten livestock carcasses provide breeding grounds for bacteria.

“We know the problem, and we know the solution,” said Johnson, now an assistant professor at the University of North Texas-Denton. “We just need to get diclofenac out of the environment and more birds into protection before it is too late.”

The research that included Martin Gilbert, Munir Virani, Muhammad Asim and former University of Michigan professor David Mindell appeared in the Aug. 15 online edition of the journal Biological Conservation.

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