Climate change, sewage and fertilisers could trigger mass extinction of life in oceans, scientists warn

Climate change, sewage and fertilisers could trigger mass extinction of life in oceans, scientists warn

SOURCE: Independent DATE: Aug 9, 2017 SNIP: The ocean is slowly being suffocated with levels of oxygen falling at a similar rate to 94 million years ago when there was a mass extinction of marine life, scientists have warned. While that event was caused naturally, humans are responsible for several different factors driving the increase in “dead zones” in our seas. Writing in the journal Science Advances, the researchers said that current rates of deoxygenation were similar to those 94 million years ago during what is known as Oceanic Anoxic Event-2 (OAE-2). OAE-2, which developed over about 50,000 years, is believed to have caused the extinction of about 27 per cent of marine invertebrates. One of the researchers, Dr Sune Nielsen, of Woods Hole Oceanographic Institution in the US, said: “Our results show that marine deoxygenation rates prior to the ancient event were likely occurring over tens of thousands of years, and surprisingly similar to the two per cent oxygen depletion trend we’re seeing induced by anthropogenic activity over the last 50 years. “We don’t know if the ocean is headed toward another global anoxic event, but the trend is, of course,...
Sixth mass extinction: The era of ‘biological annihilation’

Sixth mass extinction: The era of ‘biological annihilation’

SOURCE: CNN and PNAS DATE: July 11, 2017 SNIP: Many scientists say it’s abundantly clear that Earth is entering its sixth mass-extinction event, meaning three-quarters of all species could disappear in the coming centuries. That’s terrifying, especially since humans are contributing to this shift.But that’s not even the full picture of the “biological annihilation” people are inflicting on the natural world, according to a study published Monday in the Proceedings of the National Academy of Sciences. Their key findings: Nearly one-third of the 27,600 land-based mammal, bird, amphibian and reptile species studied are shrinking in terms of their numbers and territorial range. The researchers called that an “extremely high degree of population decay.” Looking at the extinction crisis not only in terms of species that are on the brink but also those whose populations and ranges are shrinking helps show that “Earth’s sixth mass extinction is more severe” than previously thought, the authors write. They say a major extinction event is...
Extinction risk for many species vastly underestimated, study suggests

Extinction risk for many species vastly underestimated, study suggests

SOURCE: Columbia University News and Phys.org DATE: April 24, 2017 SNIP: A new study indicates that the number of plant and animal species at risk of extinction may be considerably higher than previously thought. A team of researchers, however, believe they’ve come up with a formula that will help paint a more accurate picture. The study appears in the journal Biological Conservation. Currently, IUCN makes use of species sightings reported by experts to draw boundaries reflecting the geographic range of a given species. From these maps, the IUCN develops its Red List, which assigns a threat status to wild species: Vulnerable, Endangered, or Critically Endangered. Though the accuracy of threat risk assigned to a species relies heavily on these maps, Melnick and his colleagues believe they almost always overestimate the actual distribution of a species by incorporating areas of unsuitable habitat. This overestimation of range size, in turn, leads to a significant overestimation of population size and therefore an underestimation of extinction...
Climate Change Has Likely Harmed Nearly Half of Threatened Mammals, Study Says

Climate Change Has Likely Harmed Nearly Half of Threatened Mammals, Study Says

SOURCE: Inside Climate News DATE: February 14, 2017 SNIP: Climate change may be harming far more of the world’s threatened species than previously thought. A new study suggests that nearly half of the mammals and a quarter of the birds on the International Union for the Conservation of Nature’s “red list” have already become victims of a shifting climate. The research, published this week in the journal Nature Climate Change, concludes that scientists and wildlife conservationists have failed to account for the damage inflicted by global warming. “Our results clearly show that the impact of climate change on mammals and birds to date is currently greatly under-estimated and reported upon,” co-author James Watson, of the Wildlife Conservation Society and the University of Queensland in Australia, said in a statement. “We need to greatly improve assessments of the impacts of climate change on species right now, we need to communicate this to the wider public and we need to ensure key decision-makers know that something significant needs to happen now to stop species going extinct. “Climate change is not a future threat...