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Sorry - this page has been removed. Record number of sea lion pup strandings blamed on warmer ocean
(4 months later)
This could be because it launched early, our rights have expired, there was a legal issue, or for another reason. The strandings of a record number of sea lion pups along the California coast this year are linked to a weather pattern that has warmed their Pacific Ocean habitat and likely impacted fish populations they rely on for food, US scientists have said.
More than 900 stranded sea lions, mostly pups, have been treated by marine mammal centres in California so far this year, according to Justin Viezbicke of the National Oceanic and Atmospheric Administration.
For further information, please contact: That is well above the 240 strandings typically seen through April, and scientists suspect the emaciated pups are prematurely leaving southern California sea lion rookeries to seek food on their own after their mothers fail to return swiftly from hunting trips to suckle them.
“These little pups, so desperate and so thin, are leaving the rookeries long before they’re capable of hunting effectively,” said Shawn Johnson, director of veterinary science at the Marine Mammal Centre in Sausalito, which has treated 220 stranded animals. “It’s alarming because we haven’t seen this number of stranded pups this early in 40 years.”
The strandings are unusual because the pups, born last June, are not supposed to be completely weaned until May.
Satellite data showed sea lion mothers are foraging in traditional hunting grounds but likely spending longer periods away, said Sharon Melin, a NOAA marine biologist in Seattle.
Fish populations were likely being disrupted by a layer of ocean water 100 metres (330ft) deep that is 2 to 5 degrees warmer than usual along the Pacific coast from Baja to Alaska’s Aleutian Islands, said NOAA climatologist Nate Mantua.
The change was caused by a weather pattern involving weak northern and strong southern winds creating warmer-than-normal conditions.
It is unclear how many stranded animals will die from the population of 300,000 sea lions. In 2013 about 70% of nursing pups perished in what NOAA declared an “unusual mortality event” linked to strandings.
Melin said pups checked on San Miquel Island this month were 44% below average weight at seven months old, marking the lowest growth rate since scientists began recording such measurements in the 1990s.
Most of the stranded pups have been recovered in southern California, but the pups also swim or are carried further north and may eventually turn up in Washington state and Oregon, according to Johnson.
“We’re braced for more,” Johnson said.