Friday, January 05, 2018

Dead Seas

The oceans dead zones with zero oxygen have quadrupled in size since 1950, scientists have warned, while the number of very low oxygen sites near coasts have multiplied tenfold. The oceans feed more than 500 million people, especially in poorer nations, and provide jobs for 350 million people. But at least 500 dead zones have now been reported near coasts, up from fewer than 50 in 1950. Lack of monitoring in many regions means the true number may be much higher.

Climate change caused by fossil fuel burning is the cause of the large-scale deoxygenation, as warmer waters hold less oxygen. The coastal dead zones result from fertiliser and sewage running off the land and into the seas. The open ocean has natural low oxygen areas, usually off the west coast of continents due to the way the rotation of the Earth affects ocean currents. But these dead zones have expanded dramatically, increasing by millions of square kilometres since 1950, roughly equivalent to the area of the European Union.

Most sea creatures cannot survive in these zones and current trends would lead to mass extinction in the long run, risking dire consequences for the hundreds of millions of people who depend on the sea.

“This is a problem we can solve,”   Denise Breitburg, at the Smithsonian Environmental Research Center in the US and who led the analysis said. “Halting climate change requires a global effort, but even local actions can help with nutrient-driven oxygen decline.” She pointed to recoveries in Chesapeake Bay in the US and the Thames river in the UK, where better farm and sewage practices led to dead zones disappearing.

The new analysis was produced by an international working group created in 2016 by Unesco’s Intergovernmental Oceanographic Commission. The commission’s Kirsten Isensee said: “Ocean deoxygenation is taking place all over the world as a result of the human footprint, therefore we also need to address it globally.”

However, Prof Robert Diaz at the Virginia Institute of Marine Science, said: “Right now, the increasing expansion of coastal dead zones and decline in open ocean oxygen are not priority problems for governments around the world. Unfortunately, it will take severe and persistent mortality of fisheries for the seriousness of low oxygen to be realised.” Diaz said the speed of ocean suffocation already seen was breathtaking: “No other variable of such ecological importance to coastal ecosystems has changed so drastically in such a short period of time from human activities as dissolved oxygen.” He said the need for urgent action is best summarised by the motto of the American Lung Association: “If you can’t breathe, nothing else matters.”

Lucia von Reusner, campaign director the campaign group, Mighty Earth, which recently exposed a link between the dead zone in the Gulf of Mexico and large-scale meat production, said: “These dead zones will continue to expand unless the major meat companies that dominate our global agricultural system start cleaning up their supply chains to keep pollution out of our waters.” 

The situation isn't likely to improve with Trump's decision to open almost all US offshore territory to oil and gas drilling, including previously protected areas of the Atlantic, Arctic and Pacific oceans. The plan reverses protections put in place by the Obama administration and would introduce drilling for the first time to the Atlantic seaboard – a prospect fiercely opposed by communities along the east coast.

“Trump’s trying to turn our oceans into oilfields,” said Kristen Monsell, ocean program legal director at the Center for Biological Diversity. “His reckless plan would expose more wildlife and coastal communities to devastating oil spills. Offshore drilling is dirty and dangerous and many coastal communities want no part of it. Letting the oil industry loose in our oceans will mean more deadly disasters like the Deepwater Horizon. And when those big oil spills happen in the Arctic, they’ll be impossible to clean up."

The governors of New Jersey, Virginia, North Carolina and South Carolina all expressing concerns about the potential impact upon marine ecosystems.  The Republican governor of Florida, said he opposed drilling off the state’s coast due to environmental concerns. The governors of west coast states – California, Washington and Oregon – have also condemned the prospect of drilling in the Pacific for the first time since 1984.




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