A map of the west coast of North America show the
extreme mortality of murres, seabirds who died in mass from a giant heat blob
off New Zealand’s coast. Photograph: PLOSone
Huge ‘hot blob’ in Pacific Ocean killed nearly a
million seabirds
Thousands of bodies washed up on North America’s
Pacific coast
Study finds common murres probably died of starvation
Kenya
Evelyn in New York
@LiveFromKenya
Thu 16 Jan
2020 18.12 GMTLast modified on Thu 16 Jan 2020 22.35 GMT
A million
seabirds died in less than a year as a result of a giant “blob” of hot ocean,
according to new research.
A study
released by the University of Washington found the birds, called the common
murre, probably died of starvation between the summer of 2015 and the spring of
2016.
Most dead
seabirds never wash ashore, so while 62,000 dead or dying murres were found
along the coasts of Alaska, Washington, Oregon and California, researchers
estimate the total number is closer to 1 million.
Alaska saw
the most birds wash up. In Prince William Sound in southern Alaska, more than
4,500 bird carcasses were found every kilometer, or 0.62 miles.
A map of
the U.S. and Canadian west coasts show the extreme mortality of murres,
seabirds who died in mass from a giant heat blob off New Zealand’s coast.
The blob
stems from a years-long severe marine heatwave, believed to be caused by an
anticyclone weather system that first appeared in 2013. A weather phenomenon
known as El Niño accelerated the warming temperatures beginning in 2015 and, by
2016, the rising heat resulted in water temperatures nearly 11F (6C) above
average.
Anticyclones
form when a mass of air cools, contracts and becomes more dense, increasing the
weight of the atmosphere and the surface air pressure.
Heat maps
at the time showed a massive red blob growing, spanning more than 380,000 sq
miles (1 million sq km). That’s nearly 1.5 times the size of Texas or four
times larger than New Zealand.
The study
found that the murres mostly likely starved to death. The seabird must eat half
its body weight to survive, but food grew scarce amid intense competition from
other creatures. Warming ocean waters gave fish such as salmon and halibut a
metabolism boost, causing a fight for survival over the limited supply of
smaller fish.
Researchers
also uncovered other effects, including a massive bloom of harmful algae along
the US west coast that cost fisheries millions of dollars in revenue. Other
animals also died off, including sea lions, tufted puffins and baleen whales.
“Think of it as a run on the grocery stores at
the same time that the delivery trucks to the stores stopped coming so often,”
Julia Parrish, a co-author of the study and UW professor in the School of
Aquatic and Fishery Sciences, said in a press release.
The murres’
population also took a hit. According to the study, a limited food supply
resulted in reduced breeding colonies across the entire region. Between the
2015 and 2016 breeding seasons, more than 15 colonies did not produce a single
chick. Researchers say those estimates could be low since they only monitor a
quarter of all colonies.
“The
magnitude and scale of this failure has no precedent,” said John Piatt, the
lead researcher. “It was astonishing and alarming, and a red-flag warning about
the tremendous impact sustained ocean warming can have on the marine
ecosystem.”
Researchers
cannot determine how long it would take for the population to rebound – or if
it ever will.
“In light
of predicted global warming trends and the associated likelihood of more
frequent heatwaves”, the study concluded, this could be a stark warning about
the impending effects of the climate crisis.
Meanwhile,
another huge heat blob has formed off the Washington coast and up into the Gulf
of Alaska, and is growing.
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