Fur seal strandings on California coast raise alarm on ocean conditions
In what’s already a grim year along California’s shores for marine wildlife, concern is growing about rare fur seals that are turning up, weak and emaciated along the coastline, including the Sonoma Coast.
Guadalupe fur seals, an imperiled species few in number and rarely seen anywhere close to land, have been coming ashore along the Central Coast and the Bay Area and as far north as Crescent City, well outside their normal range, marine mammal experts said. Most of the affected animals appear to have been weaned just weeks ago, experts said.
About 50 or 60 strandings have been reported so far, with exact numbers unavailable this week as wildlife rescue and rehabilitation crews have scrambled to deal with the new crisis.
At least three Guadalupe fur seals have been rescued from the Sonoma Coast, including two on Salmon Creek Beach and one at Doran Beach, according to records kept by the nonprofit Marine Mammal Center near Sausalito.
Two or three also have been found dead on local shores, said Bodega Bay resident Phil Warren, a Marine Mammal Center board member and volunteer.
Though arriving on land at a far lower rate than California sea lions — several thousand of which have been rescued or recovered along the Pacific Ocean shoreline since January — Guadalupe fur seals exist in limited numbers and are listed as threatened on the federal Endangered Species List.
There are believed to be fewer than 10,000 remaining, so the impact of large-scale losses could be significant, said Moe Flannery, collection manager for the department of ornithology and mammology at the California Academy of Sciences.
“They’re just starving to death,” said Sue Pemberton, a Cal Academy curatorial assistant. “They’re all really young. We’ve found a couple that are probably between one and two years old, though really, for the most part, we’re seeing little guys that are just about to turn 1 this summer.”
The stranding surge comes amid a scramble to address a variety of issues among marine mammals on the California coast, including the “unusual mortality event” that has resulted in thousands of sea lion deaths, a recent spike in beached whales on the North Coast, the oil spill off Refugio State Beach near Santa Barbara, and a toxic algal bloom affecting Monterey Bay that has led to skyrocketing levels of a deadly neurotoxin called domoic acid. The substance becomes concentrated as it moves up the food chain and already has killed numerous seal species.
“We’re kind of all hands on deck for the stranding community right now,” said Justin Viezbicke, west coast stranding network coordinator for the National Marine Fisheries Service.
Marine scientists say most of the current challenges are related to an unusually warm band of water along the coast that is causing shifts in the ocean environment and availability of food. (The whale strandings are the anomaly as experts say they may be linked to winds and currents that are pushing ashore migrating whales that would otherwise decompose at sea.)
Guadalupe fur seals were once hunted extensively because of thick, dense pelts similar to an otter’s. They were plentiful off the California coast, but by 1928 were believed to be extinct, according to the National Marine Fisheries Service and other sources. In 1954, a small number were discovered in breedings grounds on Guadalupe Island off Baja California. They have been recovering slowly since then.