Humpback whale sightings in bay thrill boaters, alarm biologists

Humpback whale sightings in bay thrill boaters, alarm biologists

Humpback whales have been swimming into San Francisco Bay in unprecedented numbers over the past two weeks — even leaping out of the water near Alcatraz — in a sight that has thrilled boaters, alarmed marine biologists and harked back to a famous wayward whale three decades ago.

“I had never seen humpback whales before, and it was awesome,” said Lauri Duke, 54, of Rocklin (Placer County), who volunteers at the Marine Mammal Center and Golden Gate Cetacean Research and happened to spot the leviathans during visits over the past two weekends.

“If they head any direction except west they could get into big trouble,” said Schramm, adding that the potential for disease and skin problems is greater in fresh and brackish water.

Schramm’s biggest fear is that the giant bay intruders will go the way of Humphrey, the famous 40-ton humpback who caused pandemonium in 1985 when he swam through the Carquinez Strait, up the Sacramento River and into a creek near Rio Vista.

The Solano County city became the focal point of a whale craze, attracting 10,000 people a day as experts tried desperately to turn the lost animal around.

The recent influx, experts said, may be the result of an unusual concentration of anchovies near shore — a phenomenon that also occurred last year, when fishermen and whaling boats reported large numbers of the cetaceans near the Golden Gate.

Unlike gray whales, which generally make a beeline to Alaska, humpbacks slowly move north after giving birth in Mexico and Central America, feeding all along their migration route, Schramm said.

Humpbacks are unique among whales, known for their complex vocalizations that sound like singing and for their acrobatic breaching, an apparently playful activity in which they lift nearly their entire bodies out of the water before splashing down.

Marine scientists are looking at a variety of factors, including environmental changes, food distribution, predator behavior and the practices of the shipping industry.