The bay, as it is know locally, is not a hotspot for marine life, nor conducive to small craft. It has a large seasonal population of sea lions, decent populations of harbor seals, and birds.
Recently harbor porpoises have returned to the bay, they stopped coming in during WWII, due to nets, then pollution kept them out. They can often be seen from the Golden Gate Bridge, there is now a group of researchers studying them, their website is here. Whales sometimes wander in, prior to European settlers the bay was teeming with wildlife.
Early visitors described rafts of hundreds of sea otters carpeting the bay for miles. Otters have not yet moved back into the bay, but may do so in the future. They are now spotted as far north as Half Moon Bay from time to time.