Rare Guadalupe fur seals stranding in record numbers – ‘These stranded animals are just the tip of the iceberg in terms of animals affected by the unusually warm water temperatures we’ve been seeing off the coast’

Desdemona Despair

10 June 2015 (The Marine Mammal Center) – California sea lions aren’t the only pinnipeds in crisis this year. Guadalupe fur seals, a threatened species, seem to be struggling with the same food availability issues and have stranded along our coast at five times the record yearly rate.

With their diminutive snouts, extra-long front flippers and outstretched ear flaps, Guadalupe fur seal pups can appear almost alien-like, especially when wet. But this year, the appearance of these furry “Yodas” is more than just a little unusual—it’s downright alarming.

So far in 2015, The Marine Mammal Center has rescued 27 Guadalupe fur seals—more than five times the record high we’ve seen in our 40 years.

These numbers pale in comparison to the more than 1,100 California sea lions we’ve rescued during this same time period, but relatively speaking, the influx of Guadalupe fur seals is just as distressing, if not more so.

Unlike California sea lions, which are thriving with a population estimated at 300,000 individuals, Guadalupe fur seals are currently listed as Threatened under the U.S. Endangered Species Act with as few as 10,000 individuals remaining. Little is known about this elusive species, which spends most of its time offshore, fishing for food in deeper waters.

What we do know about Guadalupe fur seals is that their primary breeding ground is Guadalupe Island, 150 miles off the coast of Baja California. Their life cycle is similar to their more abundant sea lion cousins. Mothers give birth on the island in June and July, and temporarily leave their pups on the beach for several days as they forage for food nearby. They return frequently to nurse their pups over the course of about nine months.

Scientists say that the unusually warm waters that have been affecting food availability for mother sea lions near the Channel Islands have also been affecting the waters near Guadalupe Island. As fish populations change in response to these warmer waters, mother fur seals may have a harder time finding the food they need to nourish themselves and their pups. Once the pups are weaned, they too seem to be having trouble finding the food they need.

“These stranded animals are just the tip of the iceberg in terms of animals affected by the unusually warm water temperatures we’ve been seeing off the coast,” says Tenaya Norris, the Center’s marine scientist.

Most of the Guadalupe fur seals we’ve seen this year have been young animals stranding in an emaciated condition not unlike the sea lion pups.

Guadalupe fur seal Silkster was admitted to the Center’s hospital on April 2 weighing just 17 pounds. Less than two weeks later, Rico was admitted at 14 pounds. Though both of these pups were about 10 months old at the time, they tipped the scales at barely over birth weight, which is estimated to be about 13 pounds for a healthy pup.

As our veterinary experts continue to care for emaciated patients like these, our researchers are using this unusual occurrence to learn as much as they can about this threatened species.

“We rarely, if ever, see Guadalupe fur seals near shore,” says Geno DeRango, a stranding coordinator at The Marine Mammal Center. “So the animals that strand on our beaches provide researchers with some of the only opportunities to learn more about their natural history and biology.” [more]

Rare Guadalupe Fur Seals Stranding in Record Numbers