Native Oyster and Reef Balls at the San Fransisco Bay

When you stroll down Point Pinole Pier you get a great view over the San Fransisco Bay. Looking not too far you can also find some interesting strctures. If you read all the signs along the way you know what these are. We did not at first.

After speculating for a while we walked along the path and found that sign that gave away the explanation. These obscure concrete structures are Native Oyster and Reef Balls.

To provide the habitat for the Olympia Oyster, also known as the Ostrea lurida these Oyster and Reef Balls have been placed along the shores of the San Fransisco bay.

In order not to fall apart so fast these balls are made of marine-grade concrete with special additives for proper Ph balance. This technique has proven great for the growth of oysters.
See also the page of reef innovation