When I happen to jog at very low tide, I can walk out and see them clinging to the rocks.
They're under assault from a number of directions.
Sometimes people visiting the beach peel them off and take one home for a souvenir.
Pollution from the sewers that empty directly into the ocean also threatens them.
Then there are the sea gulls and other natural predators.
These living things were at this beach three hundred years ago when only native people lived here.
They were moving slowly from rock to rock on many seashores long before humans existed, and they may be here long after Los Angeles and the human race are gone.