Elephant seals, once nearly extinct, are finding new homes
SAN JOSE — Wildlife is vanishing around the world, plummeting at rates unprecedented in human history.
Then there are elephant seals.
Once on the brink of extinction, elephant seals are expanding north into new breeding grounds along the California coast, turning long-empty beaches into a ruckus of roars, grunts, chirps and moans.
“It’s a conservation success story,” said zoology Professor Dawn Goley of Cal Poly Humboldt. “They were in dire trouble.”
Last Thursday, Goley’s team hiked 10 miles and crossed a raging river to count and tag pups at the state’s newest and northernmost colony on Humboldt County’s Lost Coast, near Punta Gorda. They tallied 265 pups, up from only nine seven years ago.
Scientists attach tiny colored tags on flippers to identify a seal’s birthplace: yellow for Santa Barbara’s Channel Islands, white for San Luis Obispo’s San Simeon, green for San Mateo’s Año Nuevo State Park, pink for Marin’s Point Reyes National Seashore — and green for members of Humboldt’s young colony, in the King Range Conservation Area.
The tags make it possible to trace the origins of a group as they pick a breeding ground. For instance, it’s known that newborns on the Humboldt beach descend from animals who ventured north from Point Reyes, but also Año Nuevo and San Simeon.
“As they expand at sites, they fill up the space,” said marine ecologist Sarah Allen, former science adviser at Point Reyes. “Then females and juveniles start looking for some other place to get established.”
While this year’s storms have claimed some young lives, an estimated 200,000 animals are breeding and giving birth this season in the five National Marine Sanctuaries along the Pacific coast, covering nearly 15,000 square miles.
They’re all related, descendants of a tiny colony in Mexico — which once numbered fewer than 100 animals — that escaped the violence of 19th century hunters.
Massive and magnificent, elephant seals are famed for their extraordinary physiological abilities, which allow them to endure environmental
extremes. They spend most of their lives at sea, migrating twice a year as far north as Alaska before returning to California beaches to molt and reproduce.
Their distant ancestors were wanderers, venturing from warm Caribbean waters through an ancient sea that once separated North and South America.
Hunted for oil-rich blubber in the 1800s, “few or none can be found north of San Diego” by 1868, natural historian Titus Cronise wrote. The species was presumed extinct by the late 1870s.
Remarkably, a small cluster of animals survived in Baja California.
With legal protection from further hunting, six pups were reported in 1911. As the colony grew in the 1920s, animals began to depart for nearby islands.
Experts now estimate more than 40,000 births annually.
Populations of California’s other pinniped species, such as harbor seals and sea lions, also have rebounded to healthy levels since passage of the Marine Mammal Protection Act, said Allen. But elephant seals are the most successful because they are not dependent on the California Current, which is influenced by El Niño conditions, for their food. Instead, they dive deep off the continental shelf into a different ecosystem.