Humpback whales swim near Golden Gate Bridge

SAN FRANCISCO -- Humpback whales were spotted swimming in San Francisco Bay on Thursday.

Sky7 HD was over the huge marine mammals as they swam just inside the Golden Gate Bridge.

We saw as many as four whales so far, but there may be more.

Marine biologists believe the humpbacks are being attracted by large numbers of anchovies swimming along the bay's shoreline.