Nov 1

Nov 1 Sea Lion Rebellion

Conditions were ripe for revolution. As property owners stood helplessly by, a mob of large, blubbery marine mammals armed with formidable teeth, attitude, and deafening barks carried out the takeover of San Francisco’s prime waterfront real estate: the Pier 39 Marina at Fisherman’s Wharf. It was January 1990, and the pier was a thriving tourist mecca known for its shops, seafood restaurants and maritime ambience. Unfazed by human presence, the intruders made their move, having abruptly abandoned the eponymous Seal Rocks just outside the Golden Gate, overcrowded, and pummeled by Pacific storms. No one knows what triggered the exodus, but herring was plentiful inside the bay that winter; perhaps some enterprising individuals followed a shoal of fish in, noted the marina’s invitingly accessible floating docks, and raised the Sea Lion Nation flag; others followed suit. Boat slip owners howled in outrage, but were out-shouted by merchants and restaurateurs hearing the ka-ching! of cash registers. Suddenly, these smelly squatters were a world-famous attraction. Indeed, the facility built them floating “condos” to restore harmony with the boating community. Win-win. Meet the California sea lion, Zalophus Californianus.

The California sea lion is one of the four species of “eared” pinnipeds (fur seals and sea lions) native to the West Coast of North America and the Gulf of California, numbering just over 257,000 in US waters, and increasing. However, periodic warm water events such as El Niños, can suppress ocean productivity, resulting in widespread starvation and fluctuating numbers. Sea lions are bellwethers, excellent indicators of ocean conditions for natural resource managers such as Greater Farallones National Marine Sanctuary.

SALTY DOGS: Sea lions are distinguished by large, leathery fore flippers that enable them to “fly” underwater. Their hind flippers are rotatable, allowing them to walk and climb on land. Their doglike faces are appealing, and they have a cheekiness and charm that makes them popular in zoos and aquaria worldwide as ambassadors for the ocean. Playful and intelligent, they have a sportive disposition, sometimes “porpoising” across the waves, racing to parts unknown—or from sheer exuberance. They’ve been known to play FrisbeeTM with round, flat ocean sunfish and rays: whether it’s to break them into bite-sized pieces, or simply for fun, we can only speculate.

Bulls are much larger then cows (sexual dimorphism): males can exceed eight feet and 800 pounds. Females are more diminutive, at just 240 pounds. Adult males develop a bump on their forehead, the sagittal crest.

PINNIPED PARENTING: In the U.S., California sea lions breed mainly in the Channel Islands, with smaller colonies at Año Nuevo; a few are born at the Farallon Islands. Each summer they form breeding groups, or “leks” of a male and a group of females. The males leave immediately after mating. Females are caring and attentive moms, nursing a pup from nine months to a year while teaching it swimming, foraging and other survival skills.

SEAFOODIES: California sea lions’ diet includes anchovy, squid, herring, salmon, dogfish sharks, clams, and lampreys: “Catch of the Day.” Clever and opportunistic, they’re the bane of fishermen, stealing precious salmon from lines, or jumping into nets to gorge on fish trapped inside. Sea lions are federally protected under the Marine Protection Act, though legal “takes” can occur under NOAA Fisheries permit, if they interfere substantially with fishery operations.

Credit: WikiCommons-Bramans File Californiasealions@pier39sign

SEA LION SURVIVAL: Their natural predators are mainly sharks and killer whales. But human-caused threats include entanglement in fishing gear, and shooting. Biotoxins resulting from harmful algal blooms, often caused by farm fertilizer runoff, and diseases such as leptospirosis, periodically take their toll.

The next time you visit the coast, look for dark forms on the rocks, or playing in the surf. Listen for the repetitive barking that marks a sea lion haulout. Know that, due to the Marine Mammal Protection Act, a once-hunted species can survive and thrive. Greater Farallones National Marine Sanctuary’s story map, at https://farallones.noaa.gov/visit/plan-your-visit.html, can lead you to some likely spots!