“There are sharks in San Francisco Bay?”
Off the coast there is a sizable seal and sea lion population. Over the years with the prohibition of hunting seals the Great White Shark population has flourished as well.
Where there are seals and sea lions there are sharks. There are seals and sea lions inside San Francisco Bay.
Sea Otters are relatively safe as sharks spit them out wounded. Apparently, science is settled on the notion that sharks do not like the taste.
Here is a good read on the subject:
https://en.m.wikipedia.org/wiki/The_Devil%27s_Teeth