Category Archives: Ecosystem Stress

PLEA Network

22 October 2015, Science Daily, Plastic litter taints the sea surface, even in the Arctic. For the first time, researchers survey litter on sea surface at such high latitudes. In a new study, researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) show for the first time that marine litter can even be found at the sea surface of Arctic waters. Though it remains unclear how the litter made it so far north, it is likely to pose new problems for local marine life, the authors report on the online portal of the scientific journal Polar Biology. Plastic has already been reported from stomachs of resident seabirds and Greenland sharks. Plastic waste finds its way into the ocean, and from there to the farthest reaches of the planet — even as far as the Arctic. This was confirmed in one of the first litter surveys conducted north of the Arctic Circle, carried out by an international research team from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) and Belgium’s Laboratory for Polar Ecology. The researchers presented their results in an article released on the online portal of the journal Polar Biology. Read More here

PLEA Network

22 October 2015, The Guardian. Perth’s double whammy: as sea levels rise the city itself is sinking. The city’s growing population means a growing demand for water, but as more and more water is drawn out of Perth’s acquifers, the land is slowly subsiding. Growing demand for water in Perth has caused the city to sink at up to 6mm a year and could be responsible for an apparent acceleration in the rate of sea level rise, according to new research released by Curtin University. The study, published in the Journal of Geophysical Research in October, found that the rate of subsidence in Perth increased between 2000 and 2005, at the same time as the Water Corporation of WA increased the amount of water it was drawing from the city’s two main aquifers to meet the demands of a growing population. Will Featherstone, professor of geodesy at Curtin and the lead author of the study, described the effect as “like slowly letting the air out of a balloon”. “If you take the water out of the ground, the overburden of all the rocks above pushes down,” he told Guardian Australia. The city appears to be sinking at a rate of between 2mm and 6mm a year, variable throughout the Perth basin. The greatest change was measured at the seaside suburb of Hillarys, which has a GPS sensor to measure the rate of subsidence and a tidal marker operating side by side. Data for much of the Perth basin is patchy. A sinking city also has ramifications for the measurement of sea levels. A few years ago the rate of sea level rise in Western Australia was reported – not entirely accurately, it turned out – to be three times greater than the global average. Read More here

 

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19 October 2015, The Conversation, The race to fish: how fishing subsidies are emptying our oceans. Fish numbers are rapidly dwindling globally, and fishery subsidies are one of the key drivers behind this decline. In 2009, these subsidies totalled about US$35 billion, creating incentives for fishers around the world to increase their catch. But this short-term “race to fish” is jeopardising the long-term environmental, social, and economic security that fisheries offer us all. My group at the University of British Columbia recently cast our net into the troubling waters of fishery subsidies, to see how this ship might be turned around. Overfishing: a major issue facing our oceans Fish numbers are rapidly dwindling globally, and fishery subsidies are one of the key drivers behind this decline. In 2009, these subsidies totalled about US$35 billion, creating incentives for fishers around the world to increase their catch. But this short-term “race to fish” is jeopardising the long-term environmental, social, and economic security that fisheries offer us all. My group at the University of British Columbia recently cast our net into the troubling waters of fishery subsidies, to see how this ship might be turned around. Overfishing: a major issue facing our oceans According to the recently released World Wildlife Fund Living Blue Planet Report, our oceans are in a bad state. Climate change, habitat destruction, and deep-sea mining are wreaking havoc on marine biodiversity. But overfishing is in a league of its own. The WWF report found that population numbers of utilised fish (those species used by humans for subsistence or commercial purposes) have fallen by half in the four decades from 1970 to 2010. A full 90% of fish stocks globally are now classified as either overexploited or fully exploited. Common seafood choices such as tuna, shrimp, whiting, and salmon are among the worst affected. According to the recently released World Wildlife Fund Living Blue Planet Report, our oceans are in a bad state. Climate change, habitat destruction, and deep-sea mining are wreaking havoc on marine biodiversity. But overfishing is in a league of its own. The WWF report found that population numbers of utilised fish (those species used by humans for subsistence or commercial purposes) have fallen by half in the four decades from 1970 to 2010. A full 90% of fish stocks globally are now classified as either overexploited or fully exploited. Common seafood choices such as tuna, shrimp, whiting, and salmon are among the worst affected. Read More here

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18 October 2015, Climate News Network, Climate changes can kick in below 2°C limit. Sudden shifts in settled climates can occur long before global warming reaches the internationally-agreed safety level, European scientists say. Climate change could arrive with startling speed. New research has identified at least 37 “tipping points” that would serve as evidence that climate change has happened – and happened abruptly in one particular region. And 18 of them could happen even before the world warms by an average of 2°C,  the proposed “safe limit” for global warming. Weather is what happens, climate is what people grow to expect from the weather. So climate change, driven by global warming as a consequence of rising carbon dioxide levels, in response to more than a century of fossil fuel combustion, could be – for many people – gradual, imperceptible and difficult to identify immediately. But Sybren Drijfhout, of the University of Southampton in the UK and his collaborators in France, the Netherlands and Germany, are not so sure. They report in the Proceedings of the National Academy of Sciences that they “screened” the massive ensemble of climate models that inform the most recent reports from the Intergovernmental Panel on Climate Change, and found evidence of abrupt regional changes in the ocean, the sea ice, the snow cover, the permafrost and in the terrestrial biosphere that could happen as average global temperatures reached a certain level. The models did not all simulate the same outcomes, but most of them did predict one or more abrupt regional shifts. No safe limit. But the future is not an exact science. “Our results show that the different state-of-the-art models agree that abrupt changes are likely, but that predicting when and where they will occur remains very difficult,” said Professor Drijfhout. “Also, our results show that no safe limit exists and that many abrupt shifts already occur for global warming levels much lower than two degrees.” The idea of a “tipping point” for climate change has been around for decades: the hypothesis is that a climate regime endures – perhaps with an increasing frequency of heat waves or windstorms or floods – as the average temperatures rise. However, at some point, there must be a dramatic shift to a new set of norms.Read More here