80 Guadalupe fur seals have been left stranded and dying along the central California coast, raising concerns among environmentalists.
According to the National Oceanic and Atmospheric Administration (NOAA), this is an “unusual mortality event” for the marine mammals. The average number of such strandings has normally been at around 12 per year between 1984 and 2014, as NOAA has reported.
42 of the animals that had been washed up on the shore had already been dead. In addition, the majority of the surviving Guadalupe fur seals were severely malnourished and sick. As a result, only 16 of them were well enough to be released back into the ocean, after receiving veterinary treatment.
It appears that a large number of the animals that were beached on the coast are actually pups born last year, which were probably “prematurely weaned or abandoned”.
“They’re young animals, and they’re coming in starving to death”, explained Justin Viezbicke, NOAA Fisheries stranding coordinator.
The mysterious strandings may be caused by unusually warm waters in the eastern Pacific Ocean, a phenomenon which has been nicknamed “The blob”. This ocean anomaly off the coast of North America depletes nutrients from the water and has been greatly damaging to marine life, because of disruptions in phytoplankton and zooplankton.
Fish like salmon and skipjack tuna have had to migrate up north, and thousands of starving sea lion pups have been left stranded on southern California beaches.
It appears that now Guadalupe fur seals are facing a similar fate. Normally, the most important breeding ground for this species is Guadalupe island, Mexico, although there are smaller populations off Baja California and Southern California.
Experts speculate that while foraging for food the seals have had to migrate more than 600 miles away from their regular territories, in search of increasingly elusive prey.
Even more worryingly, this trend is set to continue in the next months, given that unusually-high water temperatures related to “the blob” have been forecast to persist. In addition, El Nino, which will peak this winter, will also have a warming effect on the ocean, perturbing the marine ecosystem even further.
Guadalupe fur seals are currently considered threatened under the Endangered Species Act, although their population has been gradually recovering after being on the verge of extinction. They had been hunted extensively by commercial sealers in the 18th and 19th century, to the point of being almost wiped out by the 1900’s.
Now, there are about 15,000 animals left of this species, and their limited habitats make it difficult for researchers to study them more carefully. Another unusual mortality event concerning Guadalupe fur seal strandings was reported by NOAA back in June 2006, in Washington and Oregon.
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