Extinction of Species .ORG

Researchers in Australia and Sweden have found that coral bleaching and death can have a direct effect on how reef-dwelling fish learn about their environment - particularly how to avoid predators.

The exact causes behind the Permian-Triassic mass extinction have been much debated. Two separate pulses of CO2 into the atmosphere - a "one-two punch" - may have helped fuel the die-off, new research suggests. Changes to ocean acidity would have been one of the consequences, according to the study in Science journal. Computer models suggested that this CO2 may have been released by massive bouts of volcanism from the Siberian Traps, now represented as a large region of volcanic rock in northern Eurasia. The Permian-Triassic mass extinction, which took place 252 million years ago, wiped out more than 90% of marine species and more than two-thirds of the animals living on land. The event is thought to have played out over a 60,000-year period and acidification of the oceans lasted for about 10,000 years. The team led by Dr Matthew Clarkson from the University of Edinburgh analysed rocks unearthed in the United Arab Emirates - which were on the ocean floor at the time. The rocks preserve a detailed record of changing oceanic conditions at the time. They then developed a climate model to work out what drove the extinction. The researchers think the rapid rate of release of carbon was a crucial factor in driving the ocean acidification. The carbon was released at a similar rate to modern emissions. Dr Clarkson commented: "Scientists have long suspected that an ocean acidification event occurred during the greatest mass extinction of all time, but direct evidence has been lacking until now.

Two Vietnamese nationals in South Africa have been charged with the illegal possession of 41kg (90lbs) of rhino horn, police have told the BBC. Officials say it is the largest amount of black market rhino horn to be seized in South Africa. The men, believed to be linked to an international poaching ring, had been under surveillance before their arrest at a Johannesburg airport, police say. Nearly 900 rhino have been killed in South Africa since January. Rhino horn can sell for up to $65,000 (£47,500) per kg - which is nearly double the price of gold - with China and Vietnam being the largest markets. Police say the illegal haul was found by a dog that specialises in sniffing out rhino horn at OR Tambo International Airport in Johannesburg on Sunday. 'National crisis' Paul Ramaloko, spokesperson for South Africa's organised crime fighting unit, told the BBC it was equivalent of 20 rhino horns with an estimated value of $358,000. Some South Africans have staged protests calling for more action against poaching. "Rhino poaching is regarded as a national crisis - for this reason those found guilty of the crime are dealt with harshly," he said. It is believed that the horns were most likely to have been removed from animals in South Africa's Kruger National Park, but tests need to be done to determine their origin, officials say.

Ancient sturgeon in China's Yangtze 'nearly extinct' This picture taken on 13 April 2014 shows artificially bred Chinese sturgeons released into the Yangtze river in Yichang, central China's Hubei province The Chinese sturgeon, thought to have existed for more than 140 million years, is now on the brink of extinction, according to local media. Xinhua reported that no wild sturgeon reproduced naturally last year in the Yangtze river. It was the first time since researchers began recording levels 32 years ago. Chinese researches say the fall is due to rising levels of pollution in the Yangtze river and the construction of dozens of dams. Researchers from the Chinese Academy of Fishery Sciences also found that no young sturgeons were found swimming along the Yangtze toward the sea during the period they usually do so. A researcher told Xinhua that in the 1980s, at least several thousand sturgeon could be found in the river. It is estimated only around 100 fish remain. "Without natural reproduction, the fish population cannot replenish itself. If there are no further steps taken to strengthen conservation, the wild sturgeon faces the danger of extinction," he said. The finless porpoise, another native species to the Yangtze river, is said to be at risk as well. In recent decades the Chinese authorities have built numerous dams along the 6,300km-long Yangtze river to boost the country's electricity supply. Such moves have drawn criticism of environmental degradation and displacement of villagers.

This photo taken on 13 November 2013 shows a timber company's vehicle driving down a dirt road in the forests of in Berau, East Kalimantan. Researcher say deforestation has led to an increase in greenhouse gas emissions and a loss of Indonesia's biodiversity. A new study has shown that Indonesia lost about 60,000 sq km of virgin forest - an area close to the size of Ireland - over a period of 12 years. The rate of deforestation has increased so much that Indonesia has for the first time surpassed Brazil in the rate of its clearance of tropical forests. The study was published in the journal Nature Climate Change. Scientists monitored the growth of deforested land in Indonesia between 2000 and 2012 using satellites. Picture of Riau province's rate of deforestation. Satellite imagery of Indonesia's Riau province showed wetland forest loss (in red) and forest degradation (in blue) over the study period They say the land was cleared to make way for palm oil plantations and other farms. By 2012, the loss of primary forest every year in Indonesia was estimated to be higher than that in Brazil, said scientists. In that year, Indonesia lost 8,400 sq km of forest compared to Brazil which lost 4,600 sq km.

Ivory destruction Despite efforts to destroy ivory, criminals are becoming more organised, ingenious and dangerous. "We have seen more and more organised crime networks moving into the wildlife trade," says Davyth Stewart from Interpol, the international intelligence agency. "Groups who have been traditionally involved in drug trafficking, fire arms and human trafficking are now moving onto wildlife." It's clearly not a fair match: conservationists pitted against criminal gangs. But the wildlife experts say it's a fight they have to take on. They have gathered at the Zoological Society of London to tackle how to halt the rapidly growing trade in animals. The backdrop to these crisis talks is bleak. Thousands of rhinos, elephants, tigers and others have been slaughtered, becoming part of an illegal market that's worth an estimated $19bn a year. Many criminals see it as low risk, high profit, says Mr Stewart. "There is a lower risk of apprehension, it's unfortunate but law enforcement has not invested the resources in attacking wildlife crime as it has in other crimes," he explains. "Even in courts the penalties are much lower. Just last year in Ireland, we saw two people arrested for smuggling rhino horns worth half a million euros. They received a 500-euro fine." Demand and supply John Sellar, the former chief of enforcement at Cites (the Convention on International Trade in Endangered Species), says the focus of the battle should be shifted away from conservation towards the issue of criminality. "It's about locking up the bad guys," he tells the conference.