Sea lions depart Fisherman's Wharf

SAN FRANCISCO, Dec. 30 (UPI) -- Nearly 1,700 sea lions have disappeared within weeks after living for nearly two decades at San Francisco's Fisherman's Wharf, authorities said.

"It's hard to say why they've departed," said Joe Cordero, a biologist with the U.S. Marine Fisheries Service. "As to when and if they come back, no one can say. It's puzzling."

On Oct. 23, about 1,700 of the federally protected sea lions were counted on the docks of Pier 39, barking and shoving each other to the amusement of tourists. On Nov. 21, volunteers counted 927 sea lions at Pier 39 and a week later there were just 20, The San Francisco Chronicle reported Wednesday.

Scientists have found no fluctuation in food supply or water temperature -- two factors that would make the sea lions relocate, said Jeff Boehm, executive director of the California Marine Mammal Center.

While tourists are unhappy about the departure, many others are not. The big beasts had been known to bite swimmers, bump kayakers and climb on to docks and harass fishermen and dock workers.