From  The Economist  -  Feb. 2016



United States


Ecology



Murre mystery


HOMER, ALASKA


Thousands of seabirds are washing up dead on Alaska's shores



AT THE end of the highway, 200 miles from Anchorage, sits a small fishing and tourism town where, in early January, thousands of dead common murres, or guillemots, were washed ashore. These penguin-like seabirds littered the tidal wracks so densely that beach walkers had to be careful where they stepped. And beyond Homer, tens-probably hundreds-of thousands of these birds have drifted in dead along Alaska's vast coastline or have been found far inland half-dead in the snow.


Alaska is home to about 3m common murres, which spend most of their lives on the open ocean but come to shore to nest in dense colonies on coastal cliffs. The female lays a pear-shaped egg so pointed at one end that it will roll in a circle, helping to keep the egg from plummeting off the bird's narrow nest. Murres are renowned divers, using their wings to "fly" down 600 feet (183 metres) under water in search of a meal.


Around Homer, they are a daily sight all summer. They nest in a raucous crowd on a rocky island a few miles offshore, which becomes a magnet for tour boats during the warm months. But last summer they failed to raise chicks. And they have been dying in large numbers along the Pacific coast, from California to Alaska. The birds appear to have starved.


The likely cause is warmer ocean waters. Temperatures in the North Pacific have been three to seven degrees Fahrenheit higher than average for the last two years. The "warm blob", as it has been called, is rattling the marine food chain from bottom to top. "Whole systems are out of whack," says Heather Renner of the Alaska Maritime National Wildlife Refuge, a federal agency which manages a collection of far-flung islands and remote coastline in Alaska which, if laid over a map of the continental United States, would stretch right across it. The refuge contains nesting colonies for most of the state's murres, which are a sizeable chunk of the worldwide population.


In a town that grew up as a collection of homesteads, where people still build their own houses, split wood, tend gardens and put up a winter's-worth offish and game, local knowledge is valuable currency. But know-how is not enough to explain what is happening to these birds.


"I think we're going to start seeing more events like this that we don't have the right data to explain," says Ms Renner. Scientists are starting to understand certain links between climate change, ocean warming and their impact on polar regions. These areas warm at twice the rate of the rest of the world on average; what's happening now may hint at what more ocean warming would bring.


Old-timers in Homer have never experienced-anything like this. And they are perplexed by a host of other freakish phenomena: humpback whales lingering in local waters months after they typically head south for the winter, toxic algae populations surging, sea otters dying in large numbers, and out-of-this-world king-salmon-fishing. "Global weirding," the complex impacts of climate change, can be a mixed bag.


While the sea has taken back many of the dead birds, a robust population of bald eagles has carried other carcasses off the beach, scattering bits and pieces into back yards and parking lots. Ms Renner expects murres to continue to wash ashore for the rest of the winter. They will serve as a constant reminder, as the days slowly lengthen into spring, of mysteries still to be solved.

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THIS  IS  A  FORETASTE  OF  ECOLOGICAL  DISASTERS  THAT  BLOW  YOUR  MIND,  AS  FORETOLD  IN  THE  BOOK  OF  REVELATION  -  Keith Hunt