A popular question around San Francisco is “Are there sharks in the bay?”  A quick visit to any pier will often reveal fishermen pulling in bottom-feeding sharks such as the beautiful Leopard Shark and other harmless species.
However, while standing at Pier 39 watching 800 pound sea lions play, the question becomes much more specific; “Are there Great Whites in the bay?”
In 2009, the results from an ongoing satellite tag study between the years 2000 and 2008 settled this question.  Between 2007 and 2008 satellite receivers detected that great whites poked their heads past the Golden Gate at least 5 times, although it doesn't seem they stayed long and probably didn't go in far since they prefer the saltier water of the open ocean.

On the other hand, the chances that Great Whites have entered the bay frequently in the past are fairly good, especially considering that whaling stations existed as far north into the bay as Richmond.  Dragging the bloody carcasses of blubber-rich behemoths through the bay almost certainly brought Great Whites and a multitude of other predators and scavengers in hot pursuit.  After all, to the Great White, the more blubber, the more irresistible.

More disturbing is a report that discarded whale carcasses were buried under the bay, leaving an unmistakable scent to be followed for years to come.  Nevertheless, the chance of encountering a Great White in the bay is slim to none and no one has ever been attacked inside the boundary of the Golden Gate Bridge.