SAN FRANCISCO (AP) — Migrating humpback whales have been swimming into San Francisco Bay in unprecedented numbers during the past two weeks — an onslaught that experts say could be caused by an unusual concentration of anchovies near shore.
As many as four humpbacks at a time have been spotted flapping their tails and breaching in bay waters, apparently feeding on the anchovies and other schooling fish during incoming tides, the San Francisco Chronicle reported (http://bit.ly/1TB4C8p) Thursday.
It's normal for gray whales to wander into the bay, but humpbacks generally feed farther offshore and are not accustomed to navigating shallow water and narrow straits such as those in San Francisco Bay, the newspaper reported.
Mary Jane Schramm, a spokeswoman for the Greater Farallones National Marine Sanctuary, said she and other marine experts worry that the whales could swamp boats while breaching, get hit by a ship or spooked by people who paddle or sail out to see them.
KSBW-TV reports a humpback whale was rescued in Monterey Bay this week after it became tangled in crab gear. On Thursday afternoon, a pair of whales surfaced near Golden Gate Bridge as two kite surfers came dangerously close to them.
Some have expressed excitement at seeing the whales.
"I had never seen humpback whales before, and it was awesome," said Laurie Duke, 54, who volunteers at the Marine Mammal Center and Golden Gate Cetacean Research. "They were mostly coming partially out of the water, showing their tails.'
Schramm said the animals could get into trouble if they head any direction except west because the potential for disease and skin problems is greater in fresh and brackish water.
"The deeper they get into the bay, the more acoustically confusing it becomes," she said of the whale's sense of direction.
The whales are migrating north after likely giving birth in the waters off Mexico and Central America, Schramm said.
Schramm's biggest fear is that the giant visitors will go the way of Humphrey, a famous 40-ton humpback who caused pandemonium in 1985 when he swam through the Carquinez Strait, up the Sacramento River and into a creek.
Large numbers of whales were reported last year near the Golden Gate Bridge due to a concentration of anchovies.
Information from: San Francisco Chronicle, http://www.sfgate.com