More than 30 different kinds of fish occur in the calm waters of the harbor of Marina Del Rey and estuary of Ballona Creek where the water is warmer than the ocean, as well as less saline, with no wave action. The tides rise and fall in the harbor and river estuary but do so gently in a twice daily rhythm influenced by the moon.
The diverse fish species richness in this harbor and river estuary that is adjacent to the fully marine oceanic waters (i.e. non-estuarine waters) of Santa Monica Bay on the southern California coast also includes the daily arrival and departure of several very special marine mammals.
Marine mammals that are attracted to these waters that are warmer, calmer, and less-saline than the ocean include: Various kinds of seals and Bottlenose Dolphin. Even a California Gray Whale spent weeks at the entrance of this river estuary and harbor a few years ago. Alongside these marine mammals, the Sea Otter will be arriving very soon, as the central California population expands southward into Los Angeles County. Just as in other harbors of California, the Sea Otters will establish a resident population at Marina Del Rey in order to take advantage of the vast clam beds and diverse fish that are found in the harbor of Marina Del Rey and the Ballona Creek Estuary.
The many crabs and the octopus of Marina Del Rey will also provide nourishment for the Sea Otter.
